[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/mm/Kconfig b/ap/os/linux/linux-3.4.x/mm/Kconfig
new file mode 100644
index 0000000..4bc8b2b
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/Kconfig
@@ -0,0 +1,468 @@
+config SELECT_MEMORY_MODEL
+ def_bool y
+ depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL
+
+choice
+ prompt "Memory model"
+ depends on SELECT_MEMORY_MODEL
+ default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT
+ default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT
+ default FLATMEM_MANUAL
+
+config FLATMEM_MANUAL
+ bool "Flat Memory"
+ depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) || ARCH_FLATMEM_ENABLE
+ help
+ This option allows you to change some of the ways that
+ Linux manages its memory internally. Most users will
+ only have one option here: FLATMEM. This is normal
+ and a correct option.
+
+ Some users of more advanced features like NUMA and
+ memory hotplug may have different options here.
+ DISCONTIGMEM is an more mature, better tested system,
+ but is incompatible with memory hotplug and may suffer
+ decreased performance over SPARSEMEM. If unsure between
+ "Sparse Memory" and "Discontiguous Memory", choose
+ "Discontiguous Memory".
+
+ If unsure, choose this option (Flat Memory) over any other.
+
+config DISCONTIGMEM_MANUAL
+ bool "Discontiguous Memory"
+ depends on ARCH_DISCONTIGMEM_ENABLE
+ help
+ This option provides enhanced support for discontiguous
+ memory systems, over FLATMEM. These systems have holes
+ in their physical address spaces, and this option provides
+ more efficient handling of these holes. However, the vast
+ majority of hardware has quite flat address spaces, and
+ can have degraded performance from the extra overhead that
+ this option imposes.
+
+ Many NUMA configurations will have this as the only option.
+
+ If unsure, choose "Flat Memory" over this option.
+
+config SPARSEMEM_MANUAL
+ bool "Sparse Memory"
+ depends on ARCH_SPARSEMEM_ENABLE
+ help
+ This will be the only option for some systems, including
+ memory hotplug systems. This is normal.
+
+ For many other systems, this will be an alternative to
+ "Discontiguous Memory". This option provides some potential
+ performance benefits, along with decreased code complexity,
+ but it is newer, and more experimental.
+
+ If unsure, choose "Discontiguous Memory" or "Flat Memory"
+ over this option.
+
+endchoice
+
+config DISCONTIGMEM
+ def_bool y
+ depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL
+
+config SPARSEMEM
+ def_bool y
+ depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) || SPARSEMEM_MANUAL
+
+config FLATMEM
+ def_bool y
+ depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL
+
+config FLAT_NODE_MEM_MAP
+ def_bool y
+ depends on !SPARSEMEM
+
+#
+# Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's
+# to represent different areas of memory. This variable allows
+# those dependencies to exist individually.
+#
+config NEED_MULTIPLE_NODES
+ def_bool y
+ depends on DISCONTIGMEM || NUMA
+
+config HAVE_MEMORY_PRESENT
+ def_bool y
+ depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM
+
+#
+# SPARSEMEM_EXTREME (which is the default) does some bootmem
+# allocations when memory_present() is called. If this cannot
+# be done on your architecture, select this option. However,
+# statically allocating the mem_section[] array can potentially
+# consume vast quantities of .bss, so be careful.
+#
+# This option will also potentially produce smaller runtime code
+# with gcc 3.4 and later.
+#
+config SPARSEMEM_STATIC
+ bool
+
+#
+# Architecture platforms which require a two level mem_section in SPARSEMEM
+# must select this option. This is usually for architecture platforms with
+# an extremely sparse physical address space.
+#
+config SPARSEMEM_EXTREME
+ def_bool y
+ depends on SPARSEMEM && !SPARSEMEM_STATIC
+
+config SPARSEMEM_VMEMMAP_ENABLE
+ bool
+
+config SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
+ def_bool y
+ depends on SPARSEMEM && X86_64
+
+config SPARSEMEM_VMEMMAP
+ bool "Sparse Memory virtual memmap"
+ depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE
+ default y
+ help
+ SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise
+ pfn_to_page and page_to_pfn operations. This is the most
+ efficient option when sufficient kernel resources are available.
+
+config HAVE_MEMBLOCK
+ boolean
+
+config HAVE_MEMBLOCK_NODE_MAP
+ boolean
+
+config ARCH_DISCARD_MEMBLOCK
+ boolean
+
+config NO_BOOTMEM
+ boolean
+
+# eventually, we can have this option just 'select SPARSEMEM'
+config MEMORY_HOTPLUG
+ bool "Allow for memory hot-add"
+ depends on SPARSEMEM || X86_64_ACPI_NUMA
+ depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG
+ depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390)
+
+config MEMORY_HOTPLUG_SPARSE
+ def_bool y
+ depends on SPARSEMEM && MEMORY_HOTPLUG
+
+config MEMORY_HOTREMOVE
+ bool "Allow for memory hot remove"
+ depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE
+ depends on MIGRATION
+
+#
+# If we have space for more page flags then we can enable additional
+# optimizations and functionality.
+#
+# Regular Sparsemem takes page flag bits for the sectionid if it does not
+# use a virtual memmap. Disable extended page flags for 32 bit platforms
+# that require the use of a sectionid in the page flags.
+#
+config PAGEFLAGS_EXTENDED
+ def_bool y
+ depends on 64BIT || SPARSEMEM_VMEMMAP || !SPARSEMEM
+
+# Heavily threaded applications may benefit from splitting the mm-wide
+# page_table_lock, so that faults on different parts of the user address
+# space can be handled with less contention: split it at this NR_CPUS.
+# Default to 4 for wider testing, though 8 might be more appropriate.
+# ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock.
+# PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes.
+# DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC spinlock_t also enlarge struct page.
+#
+config SPLIT_PTLOCK_CPUS
+ int
+ default "999999" if ARM && !CPU_CACHE_VIPT
+ default "999999" if PARISC && !PA20
+ default "999999" if DEBUG_SPINLOCK || DEBUG_LOCK_ALLOC
+ default "4"
+
+#
+# support for memory compaction
+config COMPACTION
+ bool "Allow for memory compaction"
+ select MIGRATION
+ depends on MMU
+ help
+ Allows the compaction of memory for the allocation of huge pages.
+
+#
+# support for page migration
+#
+config MIGRATION
+ bool "Page migration"
+ def_bool y
+ depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION
+ help
+ Allows the migration of the physical location of pages of processes
+ while the virtual addresses are not changed. This is useful in
+ two situations. The first is on NUMA systems to put pages nearer
+ to the processors accessing. The second is when allocating huge
+ pages as migration can relocate pages to satisfy a huge page
+ allocation instead of reclaiming.
+
+config PHYS_ADDR_T_64BIT
+ def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
+
+config ZONE_DMA_FLAG
+ int
+ default "0" if !ZONE_DMA
+ default "1"
+
+config BOUNCE
+ def_bool y
+ depends on BLOCK && MMU && (ZONE_DMA || HIGHMEM)
+
+config NR_QUICK
+ int
+ depends on QUICKLIST
+ default "2" if AVR32
+ default "1"
+
+config VIRT_TO_BUS
+ def_bool y
+ depends on !ARCH_NO_VIRT_TO_BUS
+
+config MMU_NOTIFIER
+ bool
+
+config KSM
+ bool "Enable KSM for page merging"
+ depends on MMU
+ help
+ Enable Kernel Samepage Merging: KSM periodically scans those areas
+ of an application's address space that an app has advised may be
+ mergeable. When it finds pages of identical content, it replaces
+ the many instances by a single page with that content, so
+ saving memory until one or another app needs to modify the content.
+ Recommended for use with KVM, or with other duplicative applications.
+ See Documentation/vm/ksm.txt for more information: KSM is inactive
+ until a program has madvised that an area is MADV_MERGEABLE, and
+ root has set /sys/kernel/mm/ksm/run to 1 (if CONFIG_SYSFS is set).
+
+config DEFAULT_MMAP_MIN_ADDR
+ int "Low address space to protect from user allocation"
+ depends on MMU
+ default 4096
+ help
+ This is the portion of low virtual memory which should be protected
+ from userspace allocation. Keeping a user from writing to low pages
+ can help reduce the impact of kernel NULL pointer bugs.
+
+ For most ia64, ppc64 and x86 users with lots of address space
+ a value of 65536 is reasonable and should cause no problems.
+ On arm and other archs it should not be higher than 32768.
+ Programs which use vm86 functionality or have some need to map
+ this low address space will need CAP_SYS_RAWIO or disable this
+ protection by setting the value to 0.
+
+ This value can be changed after boot using the
+ /proc/sys/vm/mmap_min_addr tunable.
+
+config ARCH_SUPPORTS_MEMORY_FAILURE
+ bool
+
+config MEMORY_FAILURE
+ depends on MMU
+ depends on ARCH_SUPPORTS_MEMORY_FAILURE
+ bool "Enable recovery from hardware memory errors"
+ help
+ Enables code to recover from some memory failures on systems
+ with MCA recovery. This allows a system to continue running
+ even when some of its memory has uncorrected errors. This requires
+ special hardware support and typically ECC memory.
+
+config HWPOISON_INJECT
+ tristate "HWPoison pages injector"
+ depends on MEMORY_FAILURE && DEBUG_KERNEL && PROC_FS
+ select PROC_PAGE_MONITOR
+
+config NOMMU_INITIAL_TRIM_EXCESS
+ int "Turn on mmap() excess space trimming before booting"
+ depends on !MMU
+ default 1
+ help
+ The NOMMU mmap() frequently needs to allocate large contiguous chunks
+ of memory on which to store mappings, but it can only ask the system
+ allocator for chunks in 2^N*PAGE_SIZE amounts - which is frequently
+ more than it requires. To deal with this, mmap() is able to trim off
+ the excess and return it to the allocator.
+
+ If trimming is enabled, the excess is trimmed off and returned to the
+ system allocator, which can cause extra fragmentation, particularly
+ if there are a lot of transient processes.
+
+ If trimming is disabled, the excess is kept, but not used, which for
+ long-term mappings means that the space is wasted.
+
+ Trimming can be dynamically controlled through a sysctl option
+ (/proc/sys/vm/nr_trim_pages) which specifies the minimum number of
+ excess pages there must be before trimming should occur, or zero if
+ no trimming is to occur.
+
+ This option specifies the initial value of this option. The default
+ of 1 says that all excess pages should be trimmed.
+
+ See Documentation/nommu-mmap.txt for more information.
+
+config TRANSPARENT_HUGEPAGE
+ bool "Transparent Hugepage Support"
+ depends on X86 && MMU && !PREEMPT_RT_FULL
+ select COMPACTION
+ help
+ Transparent Hugepages allows the kernel to use huge pages and
+ huge tlb transparently to the applications whenever possible.
+ This feature can improve computing performance to certain
+ applications by speeding up page faults during memory
+ allocation, by reducing the number of tlb misses and by speeding
+ up the pagetable walking.
+
+ If memory constrained on embedded, you may want to say N.
+
+choice
+ prompt "Transparent Hugepage Support sysfs defaults"
+ depends on TRANSPARENT_HUGEPAGE
+ default TRANSPARENT_HUGEPAGE_ALWAYS
+ help
+ Selects the sysfs defaults for Transparent Hugepage Support.
+
+ config TRANSPARENT_HUGEPAGE_ALWAYS
+ bool "always"
+ help
+ Enabling Transparent Hugepage always, can increase the
+ memory footprint of applications without a guaranteed
+ benefit but it will work automatically for all applications.
+
+ config TRANSPARENT_HUGEPAGE_MADVISE
+ bool "madvise"
+ help
+ Enabling Transparent Hugepage madvise, will only provide a
+ performance improvement benefit to the applications using
+ madvise(MADV_HUGEPAGE) but it won't risk to increase the
+ memory footprint of applications without a guaranteed
+ benefit.
+endchoice
+
+#
+# UP and nommu archs use km based percpu allocator
+#
+config NEED_PER_CPU_KM
+ depends on !SMP
+ bool
+ default y
+
+config CLEANCACHE
+ bool "Enable cleancache driver to cache clean pages if tmem is present"
+ default n
+ help
+ Cleancache can be thought of as a page-granularity victim cache
+ for clean pages that the kernel's pageframe replacement algorithm
+ (PFRA) would like to keep around, but can't since there isn't enough
+ memory. So when the PFRA "evicts" a page, it first attempts to use
+ cleancache code to put the data contained in that page into
+ "transcendent memory", memory that is not directly accessible or
+ addressable by the kernel and is of unknown and possibly
+ time-varying size. And when a cleancache-enabled
+ filesystem wishes to access a page in a file on disk, it first
+ checks cleancache to see if it already contains it; if it does,
+ the page is copied into the kernel and a disk access is avoided.
+ When a transcendent memory driver is available (such as zcache or
+ Xen transcendent memory), a significant I/O reduction
+ may be achieved. When none is available, all cleancache calls
+ are reduced to a single pointer-compare-against-NULL resulting
+ in a negligible performance hit.
+
+ If unsure, say Y to enable cleancache
+
+config RAMDUMP
+ bool "Enable ramdump support"
+ default y
+ help
+ This option enables support for performing ramdump. You almost
+ certainly want to say Y here. Not necessary on systems that never
+ need debugging or only ever run flawless code.
+
+config RAMDUMP_TRANS_SERVER
+ bool "Enable ramdump support for server"
+ default n
+ help
+ This option enables support for server ramdump when core dump is enabled.
+ Ramdump is a extension of core dump, it enables full context restore
+ for Linux kernel space and current user application, but it will consumes
+ more memory for context save and restore.
+
+config RAMDUMP_CLIENT
+ bool "Enable ramdump support for client"
+ default n
+ depends on RAMDUMP && !RAMDUMP_TRANS_SERVER
+ help
+ This option enables support for client ramdump when core dump is enabled.
+ Ramdump is a extension of core dump, it enables full context restore
+ for Linux kernel space and current user application, but it will consumes
+ more memory for context save and restore.
+
+config TRANS_WITH_COLLECT
+ bool "config ramdump trans with collect"
+ default n
+ depends on RAMDUMP
+ help
+ This option config ramdump trans server with collect server or not.
+ Ramdump is a extension of core dump, it enables full context restore
+ for Linux kernel space and current user application, but it will consumes
+ more memory for context save and restore.
+
+config RAMDUMP_ABNORMAL_EXIT_TASK
+ bool "config task abnormal exit will ramdump"
+ default n
+ depends on RAMDUMP
+ help
+
+config HW_BREAKPOINT_MANAGE
+ bool "config manage the breakpoint"
+ default n
+ depends on PERF_EVENTS && HAVE_HW_BREAKPOINT
+ help
+
+config KERNEL_GLOBAL_DEBUG
+ bool "Global debug flag in kernel"
+ default n
+ help
+
+config MEM_TRACKER
+ bool "config memory alloc and free tracker"
+ default n
+ help
+
+config KMALLOC_TRACKER
+ bool "config kmalloc alloc and free tracker"
+ default n
+ depends on MEM_TRACKER
+ help
+
+config LIMIT_PAGE_CACHE
+ bool "Limit size of pagecache(from linux)"
+ default n
+ help
+ Limit size of pagecache
+config DEBUG_SLAB_MARK
+ bool "add mark of slab to end(from linux)"
+ default y
+ help
+ Add Slab Debug Mark
+config DEBUG_SLAB_MARK_HEAD
+ bool "add mark of slab at the beginning of memory(from linux)"
+ default n
+ help
+ Add Mark of slab at the beginning of memory
+
+config DEBUG_SLOB_MARK_HEAD
+ bool "add mark of slob at the beginning of memory(from linux)"
+ depends on SLOB
+ default n
+
diff --git a/ap/os/linux/linux-3.4.x/mm/Kconfig.debug b/ap/os/linux/linux-3.4.x/mm/Kconfig.debug
new file mode 100644
index 0000000..4b24432
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/Kconfig.debug
@@ -0,0 +1,29 @@
+config DEBUG_PAGEALLOC
+ bool "Debug page memory allocations"
+ depends on DEBUG_KERNEL
+ depends on !HIBERNATION || ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC
+ depends on !KMEMCHECK
+ select PAGE_POISONING if !ARCH_SUPPORTS_DEBUG_PAGEALLOC
+ select PAGE_GUARD if ARCH_SUPPORTS_DEBUG_PAGEALLOC
+ ---help---
+ Unmap pages from the kernel linear mapping after free_pages().
+ This results in a large slowdown, but helps to find certain types
+ of memory corruption.
+
+ For architectures which don't enable ARCH_SUPPORTS_DEBUG_PAGEALLOC,
+ fill the pages with poison patterns after free_pages() and verify
+ the patterns before alloc_pages(). Additionally,
+ this option cannot be enabled in combination with hibernation as
+ that would result in incorrect warnings of memory corruption after
+ a resume because free pages are not saved to the suspend image.
+
+config WANT_PAGE_DEBUG_FLAGS
+ bool
+
+config PAGE_POISONING
+ bool
+ select WANT_PAGE_DEBUG_FLAGS
+
+config PAGE_GUARD
+ bool
+ select WANT_PAGE_DEBUG_FLAGS
diff --git a/ap/os/linux/linux-3.4.x/mm/Makefile b/ap/os/linux/linux-3.4.x/mm/Makefile
new file mode 100644
index 0000000..ad0bbab
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/Makefile
@@ -0,0 +1,56 @@
+#
+# Makefile for the linux memory manager.
+#
+
+mmu-y := nommu.o
+mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \
+ mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \
+ vmalloc.o pagewalk.o pgtable-generic.o \
+ process_vm_access.o
+
+obj-y := filemap.o mempool.o oom_kill.o fadvise.o \
+ maccess.o page_alloc.o page-writeback.o \
+ readahead.o swap.o truncate.o vmscan.o shmem.o \
+ prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \
+ page_isolation.o mm_init.o mmu_context.o percpu.o \
+ $(mmu-y)
+obj-y += init-mm.o
+
+ifdef CONFIG_NO_BOOTMEM
+ obj-y += nobootmem.o
+else
+ obj-y += bootmem.o
+endif
+
+obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o
+
+obj-$(CONFIG_BOUNCE) += bounce.o
+obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o thrash.o
+obj-$(CONFIG_HAS_DMA) += dmapool.o
+obj-$(CONFIG_HUGETLBFS) += hugetlb.o
+obj-$(CONFIG_NUMA) += mempolicy.o
+obj-$(CONFIG_SPARSEMEM) += sparse.o
+obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o
+obj-$(CONFIG_SLOB) += slob.o
+obj-$(CONFIG_COMPACTION) += compaction.o
+obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o
+obj-$(CONFIG_KSM) += ksm.o
+obj-$(CONFIG_PAGE_POISONING) += debug-pagealloc.o
+obj-$(CONFIG_SLAB) += slab.o
+obj-$(CONFIG_SLUB) += slub.o
+obj-$(CONFIG_KMEMCHECK) += kmemcheck.o
+obj-$(CONFIG_FAILSLAB) += failslab.o
+obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
+obj-$(CONFIG_FS_XIP) += filemap_xip.o
+obj-$(CONFIG_MIGRATION) += migrate.o
+obj-$(CONFIG_QUICKLIST) += quicklist.o
+obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o
+obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o
+obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o
+obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o
+obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
+obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
+obj-$(CONFIG_CLEANCACHE) += cleancache.o
+
+obj-$(CONFIG_RAMDUMP) += ramdump/
+obj-$(CONFIG_MEM_TRACKER) += mem_tracker.o
diff --git a/ap/os/linux/linux-3.4.x/mm/backing-dev.c b/ap/os/linux/linux-3.4.x/mm/backing-dev.c
new file mode 100644
index 0000000..dd8e2aa
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/backing-dev.c
@@ -0,0 +1,888 @@
+
+#include <linux/wait.h>
+#include <linux/backing-dev.h>
+#include <linux/kthread.h>
+#include <linux/freezer.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/writeback.h>
+#include <linux/device.h>
+#include <trace/events/writeback.h>
+
+static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
+
+struct backing_dev_info default_backing_dev_info = {
+ .name = "default",
+ .ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE,
+ .state = 0,
+ .capabilities = BDI_CAP_MAP_COPY,
+};
+EXPORT_SYMBOL_GPL(default_backing_dev_info);
+
+struct backing_dev_info noop_backing_dev_info = {
+ .name = "noop",
+ .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
+};
+EXPORT_SYMBOL_GPL(noop_backing_dev_info);
+
+static struct class *bdi_class;
+
+/*
+ * bdi_lock protects updates to bdi_list and bdi_pending_list, as well as
+ * reader side protection for bdi_pending_list. bdi_list has RCU reader side
+ * locking.
+ */
+DEFINE_SPINLOCK(bdi_lock);
+LIST_HEAD(bdi_list);
+LIST_HEAD(bdi_pending_list);
+
+static struct task_struct *sync_supers_tsk;
+static struct timer_list sync_supers_timer;
+
+static int bdi_sync_supers(void *);
+static void sync_supers_timer_fn(unsigned long);
+
+void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2)
+{
+ if (wb1 < wb2) {
+ spin_lock(&wb1->list_lock);
+ spin_lock_nested(&wb2->list_lock, 1);
+ } else {
+ spin_lock(&wb2->list_lock);
+ spin_lock_nested(&wb1->list_lock, 1);
+ }
+}
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+static struct dentry *bdi_debug_root;
+
+static void bdi_debug_init(void)
+{
+ bdi_debug_root = debugfs_create_dir("bdi", NULL);
+}
+
+static int bdi_debug_stats_show(struct seq_file *m, void *v)
+{
+ struct backing_dev_info *bdi = m->private;
+ struct bdi_writeback *wb = &bdi->wb;
+ unsigned long background_thresh;
+ unsigned long dirty_thresh;
+ unsigned long bdi_thresh;
+ unsigned long nr_dirty, nr_io, nr_more_io;
+ struct inode *inode;
+
+ nr_dirty = nr_io = nr_more_io = 0;
+ spin_lock(&wb->list_lock);
+ list_for_each_entry(inode, &wb->b_dirty, i_wb_list)
+ nr_dirty++;
+ list_for_each_entry(inode, &wb->b_io, i_wb_list)
+ nr_io++;
+ list_for_each_entry(inode, &wb->b_more_io, i_wb_list)
+ nr_more_io++;
+ spin_unlock(&wb->list_lock);
+
+ global_dirty_limits(&background_thresh, &dirty_thresh);
+ bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh);
+
+#define K(x) ((x) << (PAGE_SHIFT - 10))
+ seq_printf(m,
+ "BdiWriteback: %10lu kB\n"
+ "BdiReclaimable: %10lu kB\n"
+ "BdiDirtyThresh: %10lu kB\n"
+ "DirtyThresh: %10lu kB\n"
+ "BackgroundThresh: %10lu kB\n"
+ "BdiDirtied: %10lu kB\n"
+ "BdiWritten: %10lu kB\n"
+ "BdiWriteBandwidth: %10lu kBps\n"
+ "b_dirty: %10lu\n"
+ "b_io: %10lu\n"
+ "b_more_io: %10lu\n"
+ "bdi_list: %10u\n"
+ "state: %10lx\n",
+ (unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)),
+ (unsigned long) K(bdi_stat(bdi, BDI_RECLAIMABLE)),
+ K(bdi_thresh),
+ K(dirty_thresh),
+ K(background_thresh),
+ (unsigned long) K(bdi_stat(bdi, BDI_DIRTIED)),
+ (unsigned long) K(bdi_stat(bdi, BDI_WRITTEN)),
+ (unsigned long) K(bdi->write_bandwidth),
+ nr_dirty,
+ nr_io,
+ nr_more_io,
+ !list_empty(&bdi->bdi_list), bdi->state);
+#undef K
+
+ return 0;
+}
+
+static int bdi_debug_stats_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, bdi_debug_stats_show, inode->i_private);
+}
+
+static const struct file_operations bdi_debug_stats_fops = {
+ .open = bdi_debug_stats_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static void bdi_debug_register(struct backing_dev_info *bdi, const char *name)
+{
+ bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root);
+ bdi->debug_stats = debugfs_create_file("stats", 0444, bdi->debug_dir,
+ bdi, &bdi_debug_stats_fops);
+}
+
+static void bdi_debug_unregister(struct backing_dev_info *bdi)
+{
+ debugfs_remove(bdi->debug_stats);
+ debugfs_remove(bdi->debug_dir);
+}
+#else
+static inline void bdi_debug_init(void)
+{
+}
+static inline void bdi_debug_register(struct backing_dev_info *bdi,
+ const char *name)
+{
+}
+static inline void bdi_debug_unregister(struct backing_dev_info *bdi)
+{
+}
+#endif
+
+static ssize_t read_ahead_kb_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct backing_dev_info *bdi = dev_get_drvdata(dev);
+ char *end;
+ unsigned long read_ahead_kb;
+ ssize_t ret = -EINVAL;
+
+ read_ahead_kb = simple_strtoul(buf, &end, 10);
+ if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) {
+ bdi->ra_pages = read_ahead_kb >> (PAGE_SHIFT - 10);
+ ret = count;
+ }
+ return ret;
+}
+
+#define K(pages) ((pages) << (PAGE_SHIFT - 10))
+
+#define BDI_SHOW(name, expr) \
+static ssize_t name##_show(struct device *dev, \
+ struct device_attribute *attr, char *page) \
+{ \
+ struct backing_dev_info *bdi = dev_get_drvdata(dev); \
+ \
+ return snprintf(page, PAGE_SIZE-1, "%lld\n", (long long)expr); \
+}
+
+BDI_SHOW(read_ahead_kb, K(bdi->ra_pages))
+
+static ssize_t min_ratio_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct backing_dev_info *bdi = dev_get_drvdata(dev);
+ char *end;
+ unsigned int ratio;
+ ssize_t ret = -EINVAL;
+
+ ratio = simple_strtoul(buf, &end, 10);
+ if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) {
+ ret = bdi_set_min_ratio(bdi, ratio);
+ if (!ret)
+ ret = count;
+ }
+ return ret;
+}
+BDI_SHOW(min_ratio, bdi->min_ratio)
+
+static ssize_t max_ratio_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct backing_dev_info *bdi = dev_get_drvdata(dev);
+ char *end;
+ unsigned int ratio;
+ ssize_t ret = -EINVAL;
+
+ ratio = simple_strtoul(buf, &end, 10);
+ if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) {
+ ret = bdi_set_max_ratio(bdi, ratio);
+ if (!ret)
+ ret = count;
+ }
+ return ret;
+}
+BDI_SHOW(max_ratio, bdi->max_ratio)
+
+#define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store)
+
+static struct device_attribute bdi_dev_attrs[] = {
+ __ATTR_RW(read_ahead_kb),
+ __ATTR_RW(min_ratio),
+ __ATTR_RW(max_ratio),
+ __ATTR_NULL,
+};
+
+static __init int bdi_class_init(void)
+{
+ bdi_class = class_create(THIS_MODULE, "bdi");
+ if (IS_ERR(bdi_class))
+ return PTR_ERR(bdi_class);
+
+ bdi_class->dev_attrs = bdi_dev_attrs;
+ bdi_debug_init();
+ return 0;
+}
+postcore_initcall(bdi_class_init);
+
+static int __init default_bdi_init(void)
+{
+ int err;
+
+ sync_supers_tsk = kthread_run(bdi_sync_supers, NULL, "sync_supers");
+ BUG_ON(IS_ERR(sync_supers_tsk));
+
+ setup_timer(&sync_supers_timer, sync_supers_timer_fn, 0);
+ bdi_arm_supers_timer();
+
+ err = bdi_init(&default_backing_dev_info);
+ if (!err)
+ bdi_register(&default_backing_dev_info, NULL, "default");
+ err = bdi_init(&noop_backing_dev_info);
+
+ return err;
+}
+subsys_initcall(default_bdi_init);
+
+int bdi_has_dirty_io(struct backing_dev_info *bdi)
+{
+ return wb_has_dirty_io(&bdi->wb);
+}
+
+/*
+ * kupdated() used to do this. We cannot do it from the bdi_forker_thread()
+ * or we risk deadlocking on ->s_umount. The longer term solution would be
+ * to implement sync_supers_bdi() or similar and simply do it from the
+ * bdi writeback thread individually.
+ */
+static int bdi_sync_supers(void *unused)
+{
+ set_user_nice(current, 0);
+
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+
+ /*
+ * Do this periodically, like kupdated() did before.
+ */
+ sync_supers();
+ }
+
+ return 0;
+}
+
+void bdi_arm_supers_timer(void)
+{
+ unsigned long next;
+
+ if (!dirty_writeback_interval)
+ return;
+
+ next = msecs_to_jiffies(dirty_writeback_interval * 10) + jiffies;
+ mod_timer(&sync_supers_timer, round_jiffies_up(next));
+}
+
+static void sync_supers_timer_fn(unsigned long unused)
+{
+ wake_up_process(sync_supers_tsk);
+ bdi_arm_supers_timer();
+}
+
+static void wakeup_timer_fn(unsigned long data)
+{
+ struct backing_dev_info *bdi = (struct backing_dev_info *)data;
+
+ spin_lock_bh(&bdi->wb_lock);
+ if (bdi->wb.task) {
+ trace_writeback_wake_thread(bdi);
+ wake_up_process(bdi->wb.task);
+ } else if (bdi->dev) {
+ /*
+ * When bdi tasks are inactive for long time, they are killed.
+ * In this case we have to wake-up the forker thread which
+ * should create and run the bdi thread.
+ */
+ trace_writeback_wake_forker_thread(bdi);
+ wake_up_process(default_backing_dev_info.wb.task);
+ }
+ spin_unlock_bh(&bdi->wb_lock);
+}
+
+/*
+ * This function is used when the first inode for this bdi is marked dirty. It
+ * wakes-up the corresponding bdi thread which should then take care of the
+ * periodic background write-out of dirty inodes. Since the write-out would
+ * starts only 'dirty_writeback_interval' centisecs from now anyway, we just
+ * set up a timer which wakes the bdi thread up later.
+ *
+ * Note, we wouldn't bother setting up the timer, but this function is on the
+ * fast-path (used by '__mark_inode_dirty()'), so we save few context switches
+ * by delaying the wake-up.
+ */
+void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi)
+{
+ unsigned long timeout;
+
+ timeout = msecs_to_jiffies(dirty_writeback_interval * 10);
+ mod_timer(&bdi->wb.wakeup_timer, jiffies + timeout);
+}
+
+/*
+ * Calculate the longest interval (jiffies) bdi threads are allowed to be
+ * inactive.
+ */
+static unsigned long bdi_longest_inactive(void)
+{
+ unsigned long interval;
+
+ interval = msecs_to_jiffies(dirty_writeback_interval * 10);
+ return max(5UL * 60 * HZ, interval);
+}
+
+/*
+ * Clear pending bit and wakeup anybody waiting for flusher thread creation or
+ * shutdown
+ */
+static void bdi_clear_pending(struct backing_dev_info *bdi)
+{
+ clear_bit(BDI_pending, &bdi->state);
+ smp_mb__after_clear_bit();
+ wake_up_bit(&bdi->state, BDI_pending);
+}
+
+static int bdi_forker_thread(void *ptr)
+{
+ struct bdi_writeback *me = ptr;
+
+ current->flags |= PF_SWAPWRITE;
+ set_freezable();
+
+ /*
+ * Our parent may run at a different priority, just set us to normal
+ */
+ set_user_nice(current, 0);
+
+ for (;;) {
+ struct task_struct *task = NULL;
+ struct backing_dev_info *bdi;
+ enum {
+ NO_ACTION, /* Nothing to do */
+ FORK_THREAD, /* Fork bdi thread */
+ KILL_THREAD, /* Kill inactive bdi thread */
+ } action = NO_ACTION;
+
+ /*
+ * Temporary measure, we want to make sure we don't see
+ * dirty data on the default backing_dev_info
+ */
+ if (wb_has_dirty_io(me) || !list_empty(&me->bdi->work_list)) {
+ del_timer(&me->wakeup_timer);
+ wb_do_writeback(me, 0);
+ }
+
+ spin_lock_bh(&bdi_lock);
+ /*
+ * In the following loop we are going to check whether we have
+ * some work to do without any synchronization with tasks
+ * waking us up to do work for them. Set the task state here
+ * so that we don't miss wakeups after verifying conditions.
+ */
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ list_for_each_entry(bdi, &bdi_list, bdi_list) {
+ bool have_dirty_io;
+
+ if (!bdi_cap_writeback_dirty(bdi) ||
+ bdi_cap_flush_forker(bdi))
+ continue;
+
+ WARN(!test_bit(BDI_registered, &bdi->state),
+ "bdi %p/%s is not registered!\n", bdi, bdi->name);
+
+ have_dirty_io = !list_empty(&bdi->work_list) ||
+ wb_has_dirty_io(&bdi->wb);
+
+ /*
+ * If the bdi has work to do, but the thread does not
+ * exist - create it.
+ */
+ if (!bdi->wb.task && have_dirty_io) {
+ /*
+ * Set the pending bit - if someone will try to
+ * unregister this bdi - it'll wait on this bit.
+ */
+ set_bit(BDI_pending, &bdi->state);
+ action = FORK_THREAD;
+ break;
+ }
+
+ spin_lock(&bdi->wb_lock);
+
+ /*
+ * If there is no work to do and the bdi thread was
+ * inactive long enough - kill it. The wb_lock is taken
+ * to make sure no-one adds more work to this bdi and
+ * wakes the bdi thread up.
+ */
+ if (bdi->wb.task && !have_dirty_io &&
+ time_after(jiffies, bdi->wb.last_active +
+ bdi_longest_inactive())) {
+ task = bdi->wb.task;
+ bdi->wb.task = NULL;
+ spin_unlock(&bdi->wb_lock);
+ set_bit(BDI_pending, &bdi->state);
+ action = KILL_THREAD;
+ break;
+ }
+ spin_unlock(&bdi->wb_lock);
+ }
+ spin_unlock_bh(&bdi_lock);
+
+ /* Keep working if default bdi still has things to do */
+ if (!list_empty(&me->bdi->work_list))
+ __set_current_state(TASK_RUNNING);
+
+ switch (action) {
+ case FORK_THREAD:
+ __set_current_state(TASK_RUNNING);
+ task = kthread_create(bdi_writeback_thread, &bdi->wb,
+ "flush-%s", dev_name(bdi->dev));
+ if (IS_ERR(task)) {
+ /*
+ * If thread creation fails, force writeout of
+ * the bdi from the thread. Hopefully 1024 is
+ * large enough for efficient IO.
+ */
+ writeback_inodes_wb(&bdi->wb, 1024,
+ WB_REASON_FORKER_THREAD);
+ } else {
+ /*
+ * The spinlock makes sure we do not lose
+ * wake-ups when racing with 'bdi_queue_work()'.
+ * And as soon as the bdi thread is visible, we
+ * can start it.
+ */
+ spin_lock_bh(&bdi->wb_lock);
+ bdi->wb.task = task;
+ spin_unlock_bh(&bdi->wb_lock);
+ wake_up_process(task);
+ }
+ bdi_clear_pending(bdi);
+ break;
+
+ case KILL_THREAD:
+ __set_current_state(TASK_RUNNING);
+ kthread_stop(task);
+ bdi_clear_pending(bdi);
+ break;
+
+ case NO_ACTION:
+ if (!wb_has_dirty_io(me) || !dirty_writeback_interval)
+ /*
+ * There are no dirty data. The only thing we
+ * should now care about is checking for
+ * inactive bdi threads and killing them. Thus,
+ * let's sleep for longer time, save energy and
+ * be friendly for battery-driven devices.
+ */
+ schedule_timeout(bdi_longest_inactive());
+ else
+ schedule_timeout(msecs_to_jiffies(dirty_writeback_interval * 10));
+ try_to_freeze();
+ break;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Remove bdi from bdi_list, and ensure that it is no longer visible
+ */
+static void bdi_remove_from_list(struct backing_dev_info *bdi)
+{
+ spin_lock_bh(&bdi_lock);
+ list_del_rcu(&bdi->bdi_list);
+ spin_unlock_bh(&bdi_lock);
+
+ synchronize_rcu_expedited();
+}
+
+int bdi_register(struct backing_dev_info *bdi, struct device *parent,
+ const char *fmt, ...)
+{
+ va_list args;
+ struct device *dev;
+
+ if (bdi->dev) /* The driver needs to use separate queues per device */
+ return 0;
+
+ va_start(args, fmt);
+ dev = device_create_vargs(bdi_class, parent, MKDEV(0, 0), bdi, fmt, args);
+ va_end(args);
+ if (IS_ERR(dev))
+ return PTR_ERR(dev);
+
+ bdi->dev = dev;
+
+ /*
+ * Just start the forker thread for our default backing_dev_info,
+ * and add other bdi's to the list. They will get a thread created
+ * on-demand when they need it.
+ */
+ if (bdi_cap_flush_forker(bdi)) {
+ struct bdi_writeback *wb = &bdi->wb;
+
+ wb->task = kthread_run(bdi_forker_thread, wb, "bdi-%s",
+ dev_name(dev));
+ if (IS_ERR(wb->task))
+ return PTR_ERR(wb->task);
+ }
+
+ bdi_debug_register(bdi, dev_name(dev));
+ set_bit(BDI_registered, &bdi->state);
+
+ spin_lock_bh(&bdi_lock);
+ list_add_tail_rcu(&bdi->bdi_list, &bdi_list);
+ spin_unlock_bh(&bdi_lock);
+
+ trace_writeback_bdi_register(bdi);
+ return 0;
+}
+EXPORT_SYMBOL(bdi_register);
+
+int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev)
+{
+ return bdi_register(bdi, NULL, "%u:%u", MAJOR(dev), MINOR(dev));
+}
+EXPORT_SYMBOL(bdi_register_dev);
+
+/*
+ * Remove bdi from the global list and shutdown any threads we have running
+ */
+static void bdi_wb_shutdown(struct backing_dev_info *bdi)
+{
+ struct task_struct *task;
+
+ if (!bdi_cap_writeback_dirty(bdi))
+ return;
+
+ /*
+ * Make sure nobody finds us on the bdi_list anymore
+ */
+ bdi_remove_from_list(bdi);
+
+ /*
+ * If setup is pending, wait for that to complete first
+ */
+ wait_on_bit(&bdi->state, BDI_pending, bdi_sched_wait,
+ TASK_UNINTERRUPTIBLE);
+
+ /*
+ * Finally, kill the kernel thread. We don't need to be RCU
+ * safe anymore, since the bdi is gone from visibility.
+ */
+ spin_lock_bh(&bdi->wb_lock);
+ task = bdi->wb.task;
+ bdi->wb.task = NULL;
+ spin_unlock_bh(&bdi->wb_lock);
+
+ if (task)
+ kthread_stop(task);
+}
+
+/*
+ * This bdi is going away now, make sure that no super_blocks point to it
+ */
+static void bdi_prune_sb(struct backing_dev_info *bdi)
+{
+ struct super_block *sb;
+
+ spin_lock(&sb_lock);
+ list_for_each_entry(sb, &super_blocks, s_list) {
+ if (sb->s_bdi == bdi)
+ sb->s_bdi = &default_backing_dev_info;
+ }
+ spin_unlock(&sb_lock);
+}
+
+void bdi_unregister(struct backing_dev_info *bdi)
+{
+ struct device *dev = bdi->dev;
+
+ if (dev) {
+ bdi_set_min_ratio(bdi, 0);
+ trace_writeback_bdi_unregister(bdi);
+ bdi_prune_sb(bdi);
+ del_timer_sync(&bdi->wb.wakeup_timer);
+
+ if (!bdi_cap_flush_forker(bdi))
+ bdi_wb_shutdown(bdi);
+ bdi_debug_unregister(bdi);
+
+ spin_lock_bh(&bdi->wb_lock);
+ bdi->dev = NULL;
+ spin_unlock_bh(&bdi->wb_lock);
+
+ device_unregister(dev);
+ }
+}
+EXPORT_SYMBOL(bdi_unregister);
+
+static void bdi_wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi)
+{
+ memset(wb, 0, sizeof(*wb));
+
+ wb->bdi = bdi;
+ wb->last_old_flush = jiffies;
+ INIT_LIST_HEAD(&wb->b_dirty);
+ INIT_LIST_HEAD(&wb->b_io);
+ INIT_LIST_HEAD(&wb->b_more_io);
+ spin_lock_init(&wb->list_lock);
+ setup_timer(&wb->wakeup_timer, wakeup_timer_fn, (unsigned long)bdi);
+}
+
+/*
+ * Initial write bandwidth: 100 MB/s
+ */
+#define INIT_BW (100 << (20 - PAGE_SHIFT))
+
+int bdi_init(struct backing_dev_info *bdi)
+{
+ int i, err;
+
+ bdi->dev = NULL;
+
+ bdi->min_ratio = 0;
+ bdi->max_ratio = 100;
+ bdi->max_prop_frac = PROP_FRAC_BASE;
+ spin_lock_init(&bdi->wb_lock);
+ INIT_LIST_HEAD(&bdi->bdi_list);
+ INIT_LIST_HEAD(&bdi->work_list);
+
+ bdi_wb_init(&bdi->wb, bdi);
+
+ for (i = 0; i < NR_BDI_STAT_ITEMS; i++) {
+ err = percpu_counter_init(&bdi->bdi_stat[i], 0);
+ if (err)
+ goto err;
+ }
+
+ bdi->dirty_exceeded = 0;
+
+ bdi->bw_time_stamp = jiffies;
+ bdi->written_stamp = 0;
+
+ bdi->balanced_dirty_ratelimit = INIT_BW;
+ bdi->dirty_ratelimit = INIT_BW;
+ bdi->write_bandwidth = INIT_BW;
+ bdi->avg_write_bandwidth = INIT_BW;
+
+ err = prop_local_init_percpu(&bdi->completions);
+
+ if (err) {
+err:
+ while (i--)
+ percpu_counter_destroy(&bdi->bdi_stat[i]);
+ }
+
+ return err;
+}
+EXPORT_SYMBOL(bdi_init);
+
+void bdi_destroy(struct backing_dev_info *bdi)
+{
+ int i;
+
+ /*
+ * Splice our entries to the default_backing_dev_info, if this
+ * bdi disappears
+ */
+ if (bdi_has_dirty_io(bdi)) {
+ struct bdi_writeback *dst = &default_backing_dev_info.wb;
+
+ bdi_lock_two(&bdi->wb, dst);
+ list_splice(&bdi->wb.b_dirty, &dst->b_dirty);
+ list_splice(&bdi->wb.b_io, &dst->b_io);
+ list_splice(&bdi->wb.b_more_io, &dst->b_more_io);
+ spin_unlock(&bdi->wb.list_lock);
+ spin_unlock(&dst->list_lock);
+ }
+
+ bdi_unregister(bdi);
+
+ /*
+ * If bdi_unregister() had already been called earlier, the
+ * wakeup_timer could still be armed because bdi_prune_sb()
+ * can race with the bdi_wakeup_thread_delayed() calls from
+ * __mark_inode_dirty().
+ */
+ del_timer_sync(&bdi->wb.wakeup_timer);
+
+ for (i = 0; i < NR_BDI_STAT_ITEMS; i++)
+ percpu_counter_destroy(&bdi->bdi_stat[i]);
+
+ prop_local_destroy_percpu(&bdi->completions);
+}
+EXPORT_SYMBOL(bdi_destroy);
+
+/*
+ * For use from filesystems to quickly init and register a bdi associated
+ * with dirty writeback
+ */
+int bdi_setup_and_register(struct backing_dev_info *bdi, char *name,
+ unsigned int cap)
+{
+ char tmp[32];
+ int err;
+
+ bdi->name = name;
+ bdi->capabilities = cap;
+ err = bdi_init(bdi);
+ if (err)
+ return err;
+
+ sprintf(tmp, "%.28s%s", name, "-%d");
+ err = bdi_register(bdi, NULL, tmp, atomic_long_inc_return(&bdi_seq));
+ if (err) {
+ bdi_destroy(bdi);
+ return err;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(bdi_setup_and_register);
+
+static wait_queue_head_t congestion_wqh[2] = {
+ __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]),
+ __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1])
+ };
+static atomic_t nr_bdi_congested[2];
+
+void clear_bdi_congested(struct backing_dev_info *bdi, int sync)
+{
+ enum bdi_state bit;
+ wait_queue_head_t *wqh = &congestion_wqh[sync];
+
+ bit = sync ? BDI_sync_congested : BDI_async_congested;
+ if (test_and_clear_bit(bit, &bdi->state))
+ atomic_dec(&nr_bdi_congested[sync]);
+ smp_mb__after_clear_bit();
+ if (waitqueue_active(wqh))
+ wake_up(wqh);
+}
+EXPORT_SYMBOL(clear_bdi_congested);
+
+void set_bdi_congested(struct backing_dev_info *bdi, int sync)
+{
+ enum bdi_state bit;
+
+ bit = sync ? BDI_sync_congested : BDI_async_congested;
+ if (!test_and_set_bit(bit, &bdi->state))
+ atomic_inc(&nr_bdi_congested[sync]);
+}
+EXPORT_SYMBOL(set_bdi_congested);
+
+/**
+ * congestion_wait - wait for a backing_dev to become uncongested
+ * @sync: SYNC or ASYNC IO
+ * @timeout: timeout in jiffies
+ *
+ * Waits for up to @timeout jiffies for a backing_dev (any backing_dev) to exit
+ * write congestion. If no backing_devs are congested then just wait for the
+ * next write to be completed.
+ */
+long congestion_wait(int sync, long timeout)
+{
+ long ret;
+ unsigned long start = jiffies;
+ DEFINE_WAIT(wait);
+ wait_queue_head_t *wqh = &congestion_wqh[sync];
+
+ prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
+ ret = io_schedule_timeout(timeout);
+ finish_wait(wqh, &wait);
+
+ trace_writeback_congestion_wait(jiffies_to_usecs(timeout),
+ jiffies_to_usecs(jiffies - start));
+
+ return ret;
+}
+EXPORT_SYMBOL(congestion_wait);
+
+/**
+ * wait_iff_congested - Conditionally wait for a backing_dev to become uncongested or a zone to complete writes
+ * @zone: A zone to check if it is heavily congested
+ * @sync: SYNC or ASYNC IO
+ * @timeout: timeout in jiffies
+ *
+ * In the event of a congested backing_dev (any backing_dev) and the given
+ * @zone has experienced recent congestion, this waits for up to @timeout
+ * jiffies for either a BDI to exit congestion of the given @sync queue
+ * or a write to complete.
+ *
+ * In the absence of zone congestion, cond_resched() is called to yield
+ * the processor if necessary but otherwise does not sleep.
+ *
+ * The return value is 0 if the sleep is for the full timeout. Otherwise,
+ * it is the number of jiffies that were still remaining when the function
+ * returned. return_value == timeout implies the function did not sleep.
+ */
+long wait_iff_congested(struct zone *zone, int sync, long timeout)
+{
+ long ret;
+ unsigned long start = jiffies;
+ DEFINE_WAIT(wait);
+ wait_queue_head_t *wqh = &congestion_wqh[sync];
+
+ /*
+ * If there is no congestion, or heavy congestion is not being
+ * encountered in the current zone, yield if necessary instead
+ * of sleeping on the congestion queue
+ */
+ if (atomic_read(&nr_bdi_congested[sync]) == 0 ||
+ !zone_is_reclaim_congested(zone)) {
+ cond_resched();
+
+ /* In case we scheduled, work out time remaining */
+ ret = timeout - (jiffies - start);
+ if (ret < 0)
+ ret = 0;
+
+ goto out;
+ }
+
+ /* Sleep until uncongested or a write happens */
+ prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
+ ret = io_schedule_timeout(timeout);
+ finish_wait(wqh, &wait);
+
+out:
+ trace_writeback_wait_iff_congested(jiffies_to_usecs(timeout),
+ jiffies_to_usecs(jiffies - start));
+
+ return ret;
+}
+EXPORT_SYMBOL(wait_iff_congested);
diff --git a/ap/os/linux/linux-3.4.x/mm/bootmem.c b/ap/os/linux/linux-3.4.x/mm/bootmem.c
new file mode 100644
index 0000000..53cf62b
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/bootmem.c
@@ -0,0 +1,848 @@
+/*
+ * bootmem - A boot-time physical memory allocator and configurator
+ *
+ * Copyright (C) 1999 Ingo Molnar
+ * 1999 Kanoj Sarcar, SGI
+ * 2008 Johannes Weiner
+ *
+ * Access to this subsystem has to be serialized externally (which is true
+ * for the boot process anyway).
+ */
+#include <linux/init.h>
+#include <linux/pfn.h>
+#include <linux/slab.h>
+#include <linux/bootmem.h>
+#include <linux/export.h>
+#include <linux/kmemleak.h>
+#include <linux/range.h>
+#include <linux/memblock.h>
+
+#include <asm/bug.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+
+#include "internal.h"
+
+#ifndef CONFIG_NEED_MULTIPLE_NODES
+struct pglist_data __refdata contig_page_data = {
+ .bdata = &bootmem_node_data[0]
+};
+EXPORT_SYMBOL(contig_page_data);
+#endif
+
+unsigned long max_low_pfn;
+unsigned long min_low_pfn;
+unsigned long max_pfn;
+
+bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata;
+
+static struct list_head bdata_list __initdata = LIST_HEAD_INIT(bdata_list);
+
+static int bootmem_debug;
+
+static int __init bootmem_debug_setup(char *buf)
+{
+ bootmem_debug = 1;
+ return 0;
+}
+early_param("bootmem_debug", bootmem_debug_setup);
+
+#define bdebug(fmt, args...) ({ \
+ if (unlikely(bootmem_debug)) \
+ printk(KERN_INFO \
+ "bootmem::%s " fmt, \
+ __func__, ## args); \
+})
+
+static unsigned long __init bootmap_bytes(unsigned long pages)
+{
+ unsigned long bytes = DIV_ROUND_UP(pages, 8);
+
+ return ALIGN(bytes, sizeof(long));
+}
+
+/**
+ * bootmem_bootmap_pages - calculate bitmap size in pages
+ * @pages: number of pages the bitmap has to represent
+ */
+unsigned long __init bootmem_bootmap_pages(unsigned long pages)
+{
+ unsigned long bytes = bootmap_bytes(pages);
+
+ return PAGE_ALIGN(bytes) >> PAGE_SHIFT;
+}
+
+/*
+ * link bdata in order
+ */
+static void __init link_bootmem(bootmem_data_t *bdata)
+{
+ struct list_head *iter;
+
+ list_for_each(iter, &bdata_list) {
+ bootmem_data_t *ent;
+
+ ent = list_entry(iter, bootmem_data_t, list);
+ if (bdata->node_min_pfn < ent->node_min_pfn)
+ break;
+ }
+ list_add_tail(&bdata->list, iter);
+}
+
+/*
+ * Called once to set up the allocator itself.
+ */
+static unsigned long __init init_bootmem_core(bootmem_data_t *bdata,
+ unsigned long mapstart, unsigned long start, unsigned long end)
+{
+ unsigned long mapsize;
+
+ mminit_validate_memmodel_limits(&start, &end);
+ bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
+ bdata->node_min_pfn = start;
+ bdata->node_low_pfn = end;
+ link_bootmem(bdata);
+
+ /*
+ * Initially all pages are reserved - setup_arch() has to
+ * register free RAM areas explicitly.
+ */
+ mapsize = bootmap_bytes(end - start);
+ memset(bdata->node_bootmem_map, 0xff, mapsize);
+
+ bdebug("nid=%td start=%lx map=%lx end=%lx mapsize=%lx\n",
+ bdata - bootmem_node_data, start, mapstart, end, mapsize);
+
+ return mapsize;
+}
+
+/**
+ * init_bootmem_node - register a node as boot memory
+ * @pgdat: node to register
+ * @freepfn: pfn where the bitmap for this node is to be placed
+ * @startpfn: first pfn on the node
+ * @endpfn: first pfn after the node
+ *
+ * Returns the number of bytes needed to hold the bitmap for this node.
+ */
+unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
+ unsigned long startpfn, unsigned long endpfn)
+{
+ return init_bootmem_core(pgdat->bdata, freepfn, startpfn, endpfn);
+}
+
+/**
+ * init_bootmem - register boot memory
+ * @start: pfn where the bitmap is to be placed
+ * @pages: number of available physical pages
+ *
+ * Returns the number of bytes needed to hold the bitmap.
+ */
+unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
+{
+ max_low_pfn = pages;
+ min_low_pfn = start;
+ return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages);
+}
+
+/*
+ * free_bootmem_late - free bootmem pages directly to page allocator
+ * @addr: starting address of the range
+ * @size: size of the range in bytes
+ *
+ * This is only useful when the bootmem allocator has already been torn
+ * down, but we are still initializing the system. Pages are given directly
+ * to the page allocator, no bootmem metadata is updated because it is gone.
+ */
+void __init free_bootmem_late(unsigned long addr, unsigned long size)
+{
+ unsigned long cursor, end;
+
+ kmemleak_free_part(__va(addr), size);
+
+ cursor = PFN_UP(addr);
+ end = PFN_DOWN(addr + size);
+
+ for (; cursor < end; cursor++) {
+ __free_pages_bootmem(pfn_to_page(cursor), 0);
+ totalram_pages++;
+ }
+}
+
+static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
+{
+ struct page *page;
+ unsigned long start, end, pages, count = 0;
+
+ if (!bdata->node_bootmem_map)
+ return 0;
+
+ start = bdata->node_min_pfn;
+ end = bdata->node_low_pfn;
+
+ bdebug("nid=%td start=%lx end=%lx\n",
+ bdata - bootmem_node_data, start, end);
+
+ while (start < end) {
+ unsigned long *map, idx, vec;
+
+ map = bdata->node_bootmem_map;
+ idx = start - bdata->node_min_pfn;
+ vec = ~map[idx / BITS_PER_LONG];
+ /*
+ * If we have a properly aligned and fully unreserved
+ * BITS_PER_LONG block of pages in front of us, free
+ * it in one go.
+ */
+ if (IS_ALIGNED(start, BITS_PER_LONG) && vec == ~0UL) {
+ int order = ilog2(BITS_PER_LONG);
+
+ __free_pages_bootmem(pfn_to_page(start), order);
+ count += BITS_PER_LONG;
+ start += BITS_PER_LONG;
+ } else {
+ unsigned long off = 0;
+
+ while (vec && off < BITS_PER_LONG) {
+ if (vec & 1) {
+ page = pfn_to_page(start + off);
+ __free_pages_bootmem(page, 0);
+ count++;
+ }
+ vec >>= 1;
+ off++;
+ }
+ start = ALIGN(start + 1, BITS_PER_LONG);
+ }
+ }
+
+ page = virt_to_page(bdata->node_bootmem_map);
+ pages = bdata->node_low_pfn - bdata->node_min_pfn;
+ pages = bootmem_bootmap_pages(pages);
+ count += pages;
+ while (pages--)
+ __free_pages_bootmem(page++, 0);
+
+ bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count);
+
+ return count;
+}
+
+/**
+ * free_all_bootmem_node - release a node's free pages to the buddy allocator
+ * @pgdat: node to be released
+ *
+ * Returns the number of pages actually released.
+ */
+unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
+{
+ register_page_bootmem_info_node(pgdat);
+ return free_all_bootmem_core(pgdat->bdata);
+}
+
+/**
+ * free_all_bootmem - release free pages to the buddy allocator
+ *
+ * Returns the number of pages actually released.
+ */
+unsigned long __init free_all_bootmem(void)
+{
+ unsigned long total_pages = 0;
+ bootmem_data_t *bdata;
+
+ list_for_each_entry(bdata, &bdata_list, list)
+ total_pages += free_all_bootmem_core(bdata);
+
+ return total_pages;
+}
+
+static void __init __free(bootmem_data_t *bdata,
+ unsigned long sidx, unsigned long eidx)
+{
+ unsigned long idx;
+
+ bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data,
+ sidx + bdata->node_min_pfn,
+ eidx + bdata->node_min_pfn);
+
+ if (bdata->hint_idx > sidx)
+ bdata->hint_idx = sidx;
+
+ for (idx = sidx; idx < eidx; idx++)
+ if (!test_and_clear_bit(idx, bdata->node_bootmem_map))
+ BUG();
+}
+
+static int __init __reserve(bootmem_data_t *bdata, unsigned long sidx,
+ unsigned long eidx, int flags)
+{
+ unsigned long idx;
+ int exclusive = flags & BOOTMEM_EXCLUSIVE;
+
+ bdebug("nid=%td start=%lx end=%lx flags=%x\n",
+ bdata - bootmem_node_data,
+ sidx + bdata->node_min_pfn,
+ eidx + bdata->node_min_pfn,
+ flags);
+
+ for (idx = sidx; idx < eidx; idx++)
+ if (test_and_set_bit(idx, bdata->node_bootmem_map)) {
+ if (exclusive) {
+ __free(bdata, sidx, idx);
+ return -EBUSY;
+ }
+ bdebug("silent double reserve of PFN %lx\n",
+ idx + bdata->node_min_pfn);
+ }
+ return 0;
+}
+
+static int __init mark_bootmem_node(bootmem_data_t *bdata,
+ unsigned long start, unsigned long end,
+ int reserve, int flags)
+{
+ unsigned long sidx, eidx;
+
+ bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n",
+ bdata - bootmem_node_data, start, end, reserve, flags);
+
+ BUG_ON(start < bdata->node_min_pfn);
+ BUG_ON(end > bdata->node_low_pfn);
+
+ sidx = start - bdata->node_min_pfn;
+ eidx = end - bdata->node_min_pfn;
+
+ if (reserve)
+ return __reserve(bdata, sidx, eidx, flags);
+ else
+ __free(bdata, sidx, eidx);
+ return 0;
+}
+
+static int __init mark_bootmem(unsigned long start, unsigned long end,
+ int reserve, int flags)
+{
+ unsigned long pos;
+ bootmem_data_t *bdata;
+
+ pos = start;
+ list_for_each_entry(bdata, &bdata_list, list) {
+ int err;
+ unsigned long max;
+
+ if (pos < bdata->node_min_pfn ||
+ pos >= bdata->node_low_pfn) {
+ BUG_ON(pos != start);
+ continue;
+ }
+
+ max = min(bdata->node_low_pfn, end);
+
+ err = mark_bootmem_node(bdata, pos, max, reserve, flags);
+ if (reserve && err) {
+ mark_bootmem(start, pos, 0, 0);
+ return err;
+ }
+
+ if (max == end)
+ return 0;
+ pos = bdata->node_low_pfn;
+ }
+ BUG();
+}
+
+/**
+ * free_bootmem_node - mark a page range as usable
+ * @pgdat: node the range resides on
+ * @physaddr: starting address of the range
+ * @size: size of the range in bytes
+ *
+ * Partial pages will be considered reserved and left as they are.
+ *
+ * The range must reside completely on the specified node.
+ */
+void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
+ unsigned long size)
+{
+ unsigned long start, end;
+
+ kmemleak_free_part(__va(physaddr), size);
+
+ start = PFN_UP(physaddr);
+ end = PFN_DOWN(physaddr + size);
+
+ mark_bootmem_node(pgdat->bdata, start, end, 0, 0);
+}
+
+/**
+ * free_bootmem - mark a page range as usable
+ * @addr: starting address of the range
+ * @size: size of the range in bytes
+ *
+ * Partial pages will be considered reserved and left as they are.
+ *
+ * The range must be contiguous but may span node boundaries.
+ */
+void __init free_bootmem(unsigned long addr, unsigned long size)
+{
+ unsigned long start, end;
+
+ kmemleak_free_part(__va(addr), size);
+
+ start = PFN_UP(addr);
+ end = PFN_DOWN(addr + size);
+
+ mark_bootmem(start, end, 0, 0);
+}
+
+/**
+ * reserve_bootmem_node - mark a page range as reserved
+ * @pgdat: node the range resides on
+ * @physaddr: starting address of the range
+ * @size: size of the range in bytes
+ * @flags: reservation flags (see linux/bootmem.h)
+ *
+ * Partial pages will be reserved.
+ *
+ * The range must reside completely on the specified node.
+ */
+int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
+ unsigned long size, int flags)
+{
+ unsigned long start, end;
+
+ start = PFN_DOWN(physaddr);
+ end = PFN_UP(physaddr + size);
+
+ return mark_bootmem_node(pgdat->bdata, start, end, 1, flags);
+}
+
+/**
+ * reserve_bootmem - mark a page range as usable
+ * @addr: starting address of the range
+ * @size: size of the range in bytes
+ * @flags: reservation flags (see linux/bootmem.h)
+ *
+ * Partial pages will be reserved.
+ *
+ * The range must be contiguous but may span node boundaries.
+ */
+int __init reserve_bootmem(unsigned long addr, unsigned long size,
+ int flags)
+{
+ unsigned long start, end;
+
+ start = PFN_DOWN(addr);
+ end = PFN_UP(addr + size);
+
+ return mark_bootmem(start, end, 1, flags);
+}
+
+int __weak __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
+ int flags)
+{
+ return reserve_bootmem(phys, len, flags);
+}
+
+static unsigned long __init align_idx(struct bootmem_data *bdata,
+ unsigned long idx, unsigned long step)
+{
+ unsigned long base = bdata->node_min_pfn;
+
+ /*
+ * Align the index with respect to the node start so that the
+ * combination of both satisfies the requested alignment.
+ */
+
+ return ALIGN(base + idx, step) - base;
+}
+
+static unsigned long __init align_off(struct bootmem_data *bdata,
+ unsigned long off, unsigned long align)
+{
+ unsigned long base = PFN_PHYS(bdata->node_min_pfn);
+
+ /* Same as align_idx for byte offsets */
+
+ return ALIGN(base + off, align) - base;
+}
+
+static void * __init alloc_bootmem_core(struct bootmem_data *bdata,
+ unsigned long size, unsigned long align,
+ unsigned long goal, unsigned long limit)
+{
+ unsigned long fallback = 0;
+ unsigned long min, max, start, sidx, midx, step;
+
+ bdebug("nid=%td size=%lx [%lu pages] align=%lx goal=%lx limit=%lx\n",
+ bdata - bootmem_node_data, size, PAGE_ALIGN(size) >> PAGE_SHIFT,
+ align, goal, limit);
+
+ BUG_ON(!size);
+ BUG_ON(align & (align - 1));
+ BUG_ON(limit && goal + size > limit);
+
+ if (!bdata->node_bootmem_map)
+ return NULL;
+
+ min = bdata->node_min_pfn;
+ max = bdata->node_low_pfn;
+
+ goal >>= PAGE_SHIFT;
+ limit >>= PAGE_SHIFT;
+
+ if (limit && max > limit)
+ max = limit;
+ if (max <= min)
+ return NULL;
+
+ step = max(align >> PAGE_SHIFT, 1UL);
+
+ if (goal && min < goal && goal < max)
+ start = ALIGN(goal, step);
+ else
+ start = ALIGN(min, step);
+
+ sidx = start - bdata->node_min_pfn;
+ midx = max - bdata->node_min_pfn;
+
+ if (bdata->hint_idx > sidx) {
+ /*
+ * Handle the valid case of sidx being zero and still
+ * catch the fallback below.
+ */
+ fallback = sidx + 1;
+ sidx = align_idx(bdata, bdata->hint_idx, step);
+ }
+
+ while (1) {
+ int merge;
+ void *region;
+ unsigned long eidx, i, start_off, end_off;
+find_block:
+ sidx = find_next_zero_bit(bdata->node_bootmem_map, midx, sidx);
+ sidx = align_idx(bdata, sidx, step);
+ eidx = sidx + PFN_UP(size);
+
+ if (sidx >= midx || eidx > midx)
+ break;
+
+ for (i = sidx; i < eidx; i++)
+ if (test_bit(i, bdata->node_bootmem_map)) {
+ sidx = align_idx(bdata, i, step);
+ if (sidx == i)
+ sidx += step;
+ goto find_block;
+ }
+
+ if (bdata->last_end_off & (PAGE_SIZE - 1) &&
+ PFN_DOWN(bdata->last_end_off) + 1 == sidx)
+ start_off = align_off(bdata, bdata->last_end_off, align);
+ else
+ start_off = PFN_PHYS(sidx);
+
+ merge = PFN_DOWN(start_off) < sidx;
+ end_off = start_off + size;
+
+ bdata->last_end_off = end_off;
+ bdata->hint_idx = PFN_UP(end_off);
+
+ /*
+ * Reserve the area now:
+ */
+ if (__reserve(bdata, PFN_DOWN(start_off) + merge,
+ PFN_UP(end_off), BOOTMEM_EXCLUSIVE))
+ BUG();
+
+ region = phys_to_virt(PFN_PHYS(bdata->node_min_pfn) +
+ start_off);
+ memset(region, 0, size);
+ /*
+ * The min_count is set to 0 so that bootmem allocated blocks
+ * are never reported as leaks.
+ */
+ kmemleak_alloc(region, size, 0, 0);
+ return region;
+ }
+
+ if (fallback) {
+ sidx = align_idx(bdata, fallback - 1, step);
+ fallback = 0;
+ goto find_block;
+ }
+
+ return NULL;
+}
+
+static void * __init alloc_arch_preferred_bootmem(bootmem_data_t *bdata,
+ unsigned long size, unsigned long align,
+ unsigned long goal, unsigned long limit)
+{
+ if (WARN_ON_ONCE(slab_is_available()))
+ return kzalloc(size, GFP_NOWAIT);
+
+#ifdef CONFIG_HAVE_ARCH_BOOTMEM
+ {
+ bootmem_data_t *p_bdata;
+
+ p_bdata = bootmem_arch_preferred_node(bdata, size, align,
+ goal, limit);
+ if (p_bdata)
+ return alloc_bootmem_core(p_bdata, size, align,
+ goal, limit);
+ }
+#endif
+ return NULL;
+}
+
+static void * __init ___alloc_bootmem_nopanic(unsigned long size,
+ unsigned long align,
+ unsigned long goal,
+ unsigned long limit)
+{
+ bootmem_data_t *bdata;
+ void *region;
+
+restart:
+ region = alloc_arch_preferred_bootmem(NULL, size, align, goal, limit);
+ if (region)
+ return region;
+
+ list_for_each_entry(bdata, &bdata_list, list) {
+ if (goal && bdata->node_low_pfn <= PFN_DOWN(goal))
+ continue;
+ if (limit && bdata->node_min_pfn >= PFN_DOWN(limit))
+ break;
+
+ region = alloc_bootmem_core(bdata, size, align, goal, limit);
+ if (region)
+ return region;
+ }
+
+ if (goal) {
+ goal = 0;
+ goto restart;
+ }
+
+ return NULL;
+}
+
+/**
+ * __alloc_bootmem_nopanic - allocate boot memory without panicking
+ * @size: size of the request in bytes
+ * @align: alignment of the region
+ * @goal: preferred starting address of the region
+ *
+ * The goal is dropped if it can not be satisfied and the allocation will
+ * fall back to memory below @goal.
+ *
+ * Allocation may happen on any node in the system.
+ *
+ * Returns NULL on failure.
+ */
+void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
+ unsigned long goal)
+{
+ unsigned long limit = 0;
+
+ return ___alloc_bootmem_nopanic(size, align, goal, limit);
+}
+
+static void * __init ___alloc_bootmem(unsigned long size, unsigned long align,
+ unsigned long goal, unsigned long limit)
+{
+ void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit);
+
+ if (mem)
+ return mem;
+ /*
+ * Whoops, we cannot satisfy the allocation request.
+ */
+ printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
+ panic("Out of memory");
+ return NULL;
+}
+
+/**
+ * __alloc_bootmem - allocate boot memory
+ * @size: size of the request in bytes
+ * @align: alignment of the region
+ * @goal: preferred starting address of the region
+ *
+ * The goal is dropped if it can not be satisfied and the allocation will
+ * fall back to memory below @goal.
+ *
+ * Allocation may happen on any node in the system.
+ *
+ * The function panics if the request can not be satisfied.
+ */
+void * __init __alloc_bootmem(unsigned long size, unsigned long align,
+ unsigned long goal)
+{
+ unsigned long limit = 0;
+
+ return ___alloc_bootmem(size, align, goal, limit);
+}
+
+static void * __init ___alloc_bootmem_node(bootmem_data_t *bdata,
+ unsigned long size, unsigned long align,
+ unsigned long goal, unsigned long limit)
+{
+ void *ptr;
+
+ ptr = alloc_arch_preferred_bootmem(bdata, size, align, goal, limit);
+ if (ptr)
+ return ptr;
+
+ ptr = alloc_bootmem_core(bdata, size, align, goal, limit);
+ if (ptr)
+ return ptr;
+
+ return ___alloc_bootmem(size, align, goal, limit);
+}
+
+/**
+ * __alloc_bootmem_node - allocate boot memory from a specific node
+ * @pgdat: node to allocate from
+ * @size: size of the request in bytes
+ * @align: alignment of the region
+ * @goal: preferred starting address of the region
+ *
+ * The goal is dropped if it can not be satisfied and the allocation will
+ * fall back to memory below @goal.
+ *
+ * Allocation may fall back to any node in the system if the specified node
+ * can not hold the requested memory.
+ *
+ * The function panics if the request can not be satisfied.
+ */
+void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
+ unsigned long align, unsigned long goal)
+{
+ if (WARN_ON_ONCE(slab_is_available()))
+ return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
+
+ return ___alloc_bootmem_node(pgdat->bdata, size, align, goal, 0);
+}
+
+void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
+ unsigned long align, unsigned long goal)
+{
+#ifdef MAX_DMA32_PFN
+ unsigned long end_pfn;
+
+ if (WARN_ON_ONCE(slab_is_available()))
+ return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
+
+ /* update goal according ...MAX_DMA32_PFN */
+ end_pfn = pgdat->node_start_pfn + pgdat->node_spanned_pages;
+
+ if (end_pfn > MAX_DMA32_PFN + (128 >> (20 - PAGE_SHIFT)) &&
+ (goal >> PAGE_SHIFT) < MAX_DMA32_PFN) {
+ void *ptr;
+ unsigned long new_goal;
+
+ new_goal = MAX_DMA32_PFN << PAGE_SHIFT;
+ ptr = alloc_bootmem_core(pgdat->bdata, size, align,
+ new_goal, 0);
+ if (ptr)
+ return ptr;
+ }
+#endif
+
+ return __alloc_bootmem_node(pgdat, size, align, goal);
+
+}
+
+#ifdef CONFIG_SPARSEMEM
+/**
+ * alloc_bootmem_section - allocate boot memory from a specific section
+ * @size: size of the request in bytes
+ * @section_nr: sparse map section to allocate from
+ *
+ * Return NULL on failure.
+ */
+void * __init alloc_bootmem_section(unsigned long size,
+ unsigned long section_nr)
+{
+ bootmem_data_t *bdata;
+ unsigned long pfn, goal, limit;
+
+ pfn = section_nr_to_pfn(section_nr);
+ goal = pfn << PAGE_SHIFT;
+ limit = section_nr_to_pfn(section_nr + 1) << PAGE_SHIFT;
+ bdata = &bootmem_node_data[early_pfn_to_nid(pfn)];
+
+ if (goal + size > limit)
+ limit = 0;
+
+ return alloc_bootmem_core(bdata, size, SMP_CACHE_BYTES, goal, limit);
+}
+#endif
+
+void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size,
+ unsigned long align, unsigned long goal)
+{
+ void *ptr;
+
+ if (WARN_ON_ONCE(slab_is_available()))
+ return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
+
+ ptr = alloc_arch_preferred_bootmem(pgdat->bdata, size, align, goal, 0);
+ if (ptr)
+ return ptr;
+
+ ptr = alloc_bootmem_core(pgdat->bdata, size, align, goal, 0);
+ if (ptr)
+ return ptr;
+
+ return __alloc_bootmem_nopanic(size, align, goal);
+}
+
+#ifndef ARCH_LOW_ADDRESS_LIMIT
+#define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
+#endif
+
+/**
+ * __alloc_bootmem_low - allocate low boot memory
+ * @size: size of the request in bytes
+ * @align: alignment of the region
+ * @goal: preferred starting address of the region
+ *
+ * The goal is dropped if it can not be satisfied and the allocation will
+ * fall back to memory below @goal.
+ *
+ * Allocation may happen on any node in the system.
+ *
+ * The function panics if the request can not be satisfied.
+ */
+void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
+ unsigned long goal)
+{
+ return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
+}
+
+/**
+ * __alloc_bootmem_low_node - allocate low boot memory from a specific node
+ * @pgdat: node to allocate from
+ * @size: size of the request in bytes
+ * @align: alignment of the region
+ * @goal: preferred starting address of the region
+ *
+ * The goal is dropped if it can not be satisfied and the allocation will
+ * fall back to memory below @goal.
+ *
+ * Allocation may fall back to any node in the system if the specified node
+ * can not hold the requested memory.
+ *
+ * The function panics if the request can not be satisfied.
+ */
+void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
+ unsigned long align, unsigned long goal)
+{
+ if (WARN_ON_ONCE(slab_is_available()))
+ return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
+
+ return ___alloc_bootmem_node(pgdat->bdata, size, align,
+ goal, ARCH_LOW_ADDRESS_LIMIT);
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/bounce.c b/ap/os/linux/linux-3.4.x/mm/bounce.c
new file mode 100644
index 0000000..d1be02c
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/bounce.c
@@ -0,0 +1,299 @@
+/* bounce buffer handling for block devices
+ *
+ * - Split from highmem.c
+ */
+
+#include <linux/mm.h>
+#include <linux/export.h>
+#include <linux/swap.h>
+#include <linux/gfp.h>
+#include <linux/bio.h>
+#include <linux/pagemap.h>
+#include <linux/mempool.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/hash.h>
+#include <linux/highmem.h>
+#include <linux/bootmem.h>
+#include <asm/tlbflush.h>
+
+#include <trace/events/block.h>
+
+#define POOL_SIZE 64
+#define ISA_POOL_SIZE 16
+
+static mempool_t *page_pool, *isa_page_pool;
+
+#ifdef CONFIG_HIGHMEM
+static __init int init_emergency_pool(void)
+{
+#ifndef CONFIG_MEMORY_HOTPLUG
+ if (max_pfn <= max_low_pfn)
+ return 0;
+#endif
+
+ page_pool = mempool_create_page_pool(POOL_SIZE, 0);
+ BUG_ON(!page_pool);
+ printk("highmem bounce pool size: %d pages\n", POOL_SIZE);
+
+ return 0;
+}
+
+__initcall(init_emergency_pool);
+
+/*
+ * highmem version, map in to vec
+ */
+static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom)
+{
+ unsigned long flags;
+ unsigned char *vto;
+
+ local_irq_save(flags);
+ vto = kmap_atomic(to->bv_page);
+ memcpy(vto + to->bv_offset, vfrom, to->bv_len);
+ kunmap_atomic(vto);
+ local_irq_restore(flags);
+}
+
+#else /* CONFIG_HIGHMEM */
+
+#define bounce_copy_vec(to, vfrom) \
+ memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len)
+
+#endif /* CONFIG_HIGHMEM */
+
+/*
+ * allocate pages in the DMA region for the ISA pool
+ */
+static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data)
+{
+ return mempool_alloc_pages(gfp_mask | GFP_DMA, data);
+}
+
+/*
+ * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA
+ * as the max address, so check if the pool has already been created.
+ */
+int init_emergency_isa_pool(void)
+{
+ if (isa_page_pool)
+ return 0;
+
+ isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa,
+ mempool_free_pages, (void *) 0);
+ BUG_ON(!isa_page_pool);
+
+ printk("isa bounce pool size: %d pages\n", ISA_POOL_SIZE);
+ return 0;
+}
+
+/*
+ * Simple bounce buffer support for highmem pages. Depending on the
+ * queue gfp mask set, *to may or may not be a highmem page. kmap it
+ * always, it will do the Right Thing
+ */
+static void copy_to_high_bio_irq(struct bio *to, struct bio *from)
+{
+ unsigned char *vfrom;
+ struct bio_vec *tovec, *fromvec;
+ int i;
+
+ __bio_for_each_segment(tovec, to, i, 0) {
+ fromvec = from->bi_io_vec + i;
+
+ /*
+ * not bounced
+ */
+ if (tovec->bv_page == fromvec->bv_page)
+ continue;
+
+ /*
+ * fromvec->bv_offset and fromvec->bv_len might have been
+ * modified by the block layer, so use the original copy,
+ * bounce_copy_vec already uses tovec->bv_len
+ */
+ vfrom = page_address(fromvec->bv_page) + tovec->bv_offset;
+
+ bounce_copy_vec(tovec, vfrom);
+ flush_dcache_page(tovec->bv_page);
+ }
+}
+
+static void bounce_end_io(struct bio *bio, mempool_t *pool, int err)
+{
+ struct bio *bio_orig = bio->bi_private;
+ struct bio_vec *bvec, *org_vec;
+ int i;
+
+ if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags))
+ set_bit(BIO_EOPNOTSUPP, &bio_orig->bi_flags);
+
+ /*
+ * free up bounce indirect pages used
+ */
+ __bio_for_each_segment(bvec, bio, i, 0) {
+ org_vec = bio_orig->bi_io_vec + i;
+ if (bvec->bv_page == org_vec->bv_page)
+ continue;
+
+ dec_zone_page_state(bvec->bv_page, NR_BOUNCE);
+ mempool_free(bvec->bv_page, pool);
+ }
+
+ bio_endio(bio_orig, err);
+ bio_put(bio);
+}
+
+static void bounce_end_io_write(struct bio *bio, int err)
+{
+ bounce_end_io(bio, page_pool, err);
+}
+
+static void bounce_end_io_write_isa(struct bio *bio, int err)
+{
+
+ bounce_end_io(bio, isa_page_pool, err);
+}
+
+static void __bounce_end_io_read(struct bio *bio, mempool_t *pool, int err)
+{
+ struct bio *bio_orig = bio->bi_private;
+
+ if (test_bit(BIO_UPTODATE, &bio->bi_flags))
+ copy_to_high_bio_irq(bio_orig, bio);
+
+ bounce_end_io(bio, pool, err);
+}
+
+static void bounce_end_io_read(struct bio *bio, int err)
+{
+ __bounce_end_io_read(bio, page_pool, err);
+}
+
+static void bounce_end_io_read_isa(struct bio *bio, int err)
+{
+ __bounce_end_io_read(bio, isa_page_pool, err);
+}
+
+static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
+ mempool_t *pool)
+{
+ struct page *page;
+ struct bio *bio = NULL;
+ int i, rw = bio_data_dir(*bio_orig);
+ struct bio_vec *to, *from;
+
+ bio_for_each_segment(from, *bio_orig, i) {
+ page = from->bv_page;
+
+ /*
+ * is destination page below bounce pfn?
+ */
+ if (page_to_pfn(page) <= queue_bounce_pfn(q))
+ continue;
+
+ /*
+ * irk, bounce it
+ */
+ if (!bio) {
+ unsigned int cnt = (*bio_orig)->bi_vcnt;
+
+ bio = bio_alloc(GFP_NOIO, cnt);
+ memset(bio->bi_io_vec, 0, cnt * sizeof(struct bio_vec));
+ }
+
+
+ to = bio->bi_io_vec + i;
+
+ to->bv_page = mempool_alloc(pool, q->bounce_gfp);
+ to->bv_len = from->bv_len;
+ to->bv_offset = from->bv_offset;
+ inc_zone_page_state(to->bv_page, NR_BOUNCE);
+
+ if (rw == WRITE) {
+ char *vto, *vfrom;
+
+ flush_dcache_page(from->bv_page);
+ vto = page_address(to->bv_page) + to->bv_offset;
+ vfrom = kmap(from->bv_page) + from->bv_offset;
+ memcpy(vto, vfrom, to->bv_len);
+ kunmap(from->bv_page);
+ }
+ }
+
+ /*
+ * no pages bounced
+ */
+ if (!bio)
+ return;
+
+ trace_block_bio_bounce(q, *bio_orig);
+
+ /*
+ * at least one page was bounced, fill in possible non-highmem
+ * pages
+ */
+ __bio_for_each_segment(from, *bio_orig, i, 0) {
+ to = bio_iovec_idx(bio, i);
+ if (!to->bv_page) {
+ to->bv_page = from->bv_page;
+ to->bv_len = from->bv_len;
+ to->bv_offset = from->bv_offset;
+ }
+ }
+
+ bio->bi_bdev = (*bio_orig)->bi_bdev;
+ bio->bi_flags |= (1 << BIO_BOUNCED);
+ bio->bi_sector = (*bio_orig)->bi_sector;
+ bio->bi_rw = (*bio_orig)->bi_rw;
+
+ bio->bi_vcnt = (*bio_orig)->bi_vcnt;
+ bio->bi_idx = (*bio_orig)->bi_idx;
+ bio->bi_size = (*bio_orig)->bi_size;
+
+ if (pool == page_pool) {
+ bio->bi_end_io = bounce_end_io_write;
+ if (rw == READ)
+ bio->bi_end_io = bounce_end_io_read;
+ } else {
+ bio->bi_end_io = bounce_end_io_write_isa;
+ if (rw == READ)
+ bio->bi_end_io = bounce_end_io_read_isa;
+ }
+
+ bio->bi_private = *bio_orig;
+ *bio_orig = bio;
+}
+
+void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
+{
+ mempool_t *pool;
+
+ /*
+ * Data-less bio, nothing to bounce
+ */
+ if (!bio_has_data(*bio_orig))
+ return;
+
+ /*
+ * for non-isa bounce case, just check if the bounce pfn is equal
+ * to or bigger than the highest pfn in the system -- in that case,
+ * don't waste time iterating over bio segments
+ */
+ if (!(q->bounce_gfp & GFP_DMA)) {
+ if (queue_bounce_pfn(q) >= blk_max_pfn)
+ return;
+ pool = page_pool;
+ } else {
+ BUG_ON(!isa_page_pool);
+ pool = isa_page_pool;
+ }
+
+ /*
+ * slow path
+ */
+ __blk_queue_bounce(q, bio_orig, pool);
+}
+
+EXPORT_SYMBOL(blk_queue_bounce);
diff --git a/ap/os/linux/linux-3.4.x/mm/cleancache.c b/ap/os/linux/linux-3.4.x/mm/cleancache.c
new file mode 100644
index 0000000..5646c74
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/cleancache.c
@@ -0,0 +1,222 @@
+/*
+ * Cleancache frontend
+ *
+ * This code provides the generic "frontend" layer to call a matching
+ * "backend" driver implementation of cleancache. See
+ * Documentation/vm/cleancache.txt for more information.
+ *
+ * Copyright (C) 2009-2010 Oracle Corp. All rights reserved.
+ * Author: Dan Magenheimer
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/exportfs.h>
+#include <linux/mm.h>
+#include <linux/debugfs.h>
+#include <linux/cleancache.h>
+
+/*
+ * This global enablement flag may be read thousands of times per second
+ * by cleancache_get/put/invalidate even on systems where cleancache_ops
+ * is not claimed (e.g. cleancache is config'ed on but remains
+ * disabled), so is preferred to the slower alternative: a function
+ * call that checks a non-global.
+ */
+int cleancache_enabled __read_mostly;
+EXPORT_SYMBOL(cleancache_enabled);
+
+/*
+ * cleancache_ops is set by cleancache_ops_register to contain the pointers
+ * to the cleancache "backend" implementation functions.
+ */
+static struct cleancache_ops cleancache_ops __read_mostly;
+
+/*
+ * Counters available via /sys/kernel/debug/frontswap (if debugfs is
+ * properly configured. These are for information only so are not protected
+ * against increment races.
+ */
+static u64 cleancache_succ_gets;
+static u64 cleancache_failed_gets;
+static u64 cleancache_puts;
+static u64 cleancache_invalidates;
+
+/*
+ * register operations for cleancache, returning previous thus allowing
+ * detection of multiple backends and possible nesting
+ */
+struct cleancache_ops cleancache_register_ops(struct cleancache_ops *ops)
+{
+ struct cleancache_ops old = cleancache_ops;
+
+ cleancache_ops = *ops;
+ cleancache_enabled = 1;
+ return old;
+}
+EXPORT_SYMBOL(cleancache_register_ops);
+
+/* Called by a cleancache-enabled filesystem at time of mount */
+void __cleancache_init_fs(struct super_block *sb)
+{
+ sb->cleancache_poolid = (*cleancache_ops.init_fs)(PAGE_SIZE);
+}
+EXPORT_SYMBOL(__cleancache_init_fs);
+
+/* Called by a cleancache-enabled clustered filesystem at time of mount */
+void __cleancache_init_shared_fs(char *uuid, struct super_block *sb)
+{
+ sb->cleancache_poolid =
+ (*cleancache_ops.init_shared_fs)(uuid, PAGE_SIZE);
+}
+EXPORT_SYMBOL(__cleancache_init_shared_fs);
+
+/*
+ * If the filesystem uses exportable filehandles, use the filehandle as
+ * the key, else use the inode number.
+ */
+static int cleancache_get_key(struct inode *inode,
+ struct cleancache_filekey *key)
+{
+ int (*fhfn)(struct dentry *, __u32 *fh, int *, int);
+ int len = 0, maxlen = CLEANCACHE_KEY_MAX;
+ struct super_block *sb = inode->i_sb;
+
+ key->u.ino = inode->i_ino;
+ if (sb->s_export_op != NULL) {
+ fhfn = sb->s_export_op->encode_fh;
+ if (fhfn) {
+ struct dentry d;
+ d.d_inode = inode;
+ len = (*fhfn)(&d, &key->u.fh[0], &maxlen, 0);
+ if (len <= 0 || len == 255)
+ return -1;
+ if (maxlen > CLEANCACHE_KEY_MAX)
+ return -1;
+ }
+ }
+ return 0;
+}
+
+/*
+ * "Get" data from cleancache associated with the poolid/inode/index
+ * that were specified when the data was put to cleanache and, if
+ * successful, use it to fill the specified page with data and return 0.
+ * The pageframe is unchanged and returns -1 if the get fails.
+ * Page must be locked by caller.
+ */
+int __cleancache_get_page(struct page *page)
+{
+ int ret = -1;
+ int pool_id;
+ struct cleancache_filekey key = { .u.key = { 0 } };
+
+ VM_BUG_ON(!PageLocked(page));
+ pool_id = page->mapping->host->i_sb->cleancache_poolid;
+ if (pool_id < 0)
+ goto out;
+
+ if (cleancache_get_key(page->mapping->host, &key) < 0)
+ goto out;
+
+ ret = (*cleancache_ops.get_page)(pool_id, key, page->index, page);
+ if (ret == 0)
+ cleancache_succ_gets++;
+ else
+ cleancache_failed_gets++;
+out:
+ return ret;
+}
+EXPORT_SYMBOL(__cleancache_get_page);
+
+/*
+ * "Put" data from a page to cleancache and associate it with the
+ * (previously-obtained per-filesystem) poolid and the page's,
+ * inode and page index. Page must be locked. Note that a put_page
+ * always "succeeds", though a subsequent get_page may succeed or fail.
+ */
+void __cleancache_put_page(struct page *page)
+{
+ int pool_id;
+ struct cleancache_filekey key = { .u.key = { 0 } };
+
+ VM_BUG_ON(!PageLocked(page));
+ pool_id = page->mapping->host->i_sb->cleancache_poolid;
+ if (pool_id >= 0 &&
+ cleancache_get_key(page->mapping->host, &key) >= 0) {
+ (*cleancache_ops.put_page)(pool_id, key, page->index, page);
+ cleancache_puts++;
+ }
+}
+EXPORT_SYMBOL(__cleancache_put_page);
+
+/*
+ * Invalidate any data from cleancache associated with the poolid and the
+ * page's inode and page index so that a subsequent "get" will fail.
+ */
+void __cleancache_invalidate_page(struct address_space *mapping,
+ struct page *page)
+{
+ /* careful... page->mapping is NULL sometimes when this is called */
+ int pool_id = mapping->host->i_sb->cleancache_poolid;
+ struct cleancache_filekey key = { .u.key = { 0 } };
+
+ if (pool_id >= 0) {
+ VM_BUG_ON(!PageLocked(page));
+ if (cleancache_get_key(mapping->host, &key) >= 0) {
+ (*cleancache_ops.invalidate_page)(pool_id,
+ key, page->index);
+ cleancache_invalidates++;
+ }
+ }
+}
+EXPORT_SYMBOL(__cleancache_invalidate_page);
+
+/*
+ * Invalidate all data from cleancache associated with the poolid and the
+ * mappings's inode so that all subsequent gets to this poolid/inode
+ * will fail.
+ */
+void __cleancache_invalidate_inode(struct address_space *mapping)
+{
+ int pool_id = mapping->host->i_sb->cleancache_poolid;
+ struct cleancache_filekey key = { .u.key = { 0 } };
+
+ if (pool_id >= 0 && cleancache_get_key(mapping->host, &key) >= 0)
+ (*cleancache_ops.invalidate_inode)(pool_id, key);
+}
+EXPORT_SYMBOL(__cleancache_invalidate_inode);
+
+/*
+ * Called by any cleancache-enabled filesystem at time of unmount;
+ * note that pool_id is surrendered and may be reutrned by a subsequent
+ * cleancache_init_fs or cleancache_init_shared_fs
+ */
+void __cleancache_invalidate_fs(struct super_block *sb)
+{
+ if (sb->cleancache_poolid >= 0) {
+ int old_poolid = sb->cleancache_poolid;
+ sb->cleancache_poolid = -1;
+ (*cleancache_ops.invalidate_fs)(old_poolid);
+ }
+}
+EXPORT_SYMBOL(__cleancache_invalidate_fs);
+
+static int __init init_cleancache(void)
+{
+#ifdef CONFIG_DEBUG_FS
+ struct dentry *root = debugfs_create_dir("cleancache", NULL);
+ if (root == NULL)
+ return -ENXIO;
+ debugfs_create_u64("succ_gets", S_IRUGO, root, &cleancache_succ_gets);
+ debugfs_create_u64("failed_gets", S_IRUGO,
+ root, &cleancache_failed_gets);
+ debugfs_create_u64("puts", S_IRUGO, root, &cleancache_puts);
+ debugfs_create_u64("invalidates", S_IRUGO,
+ root, &cleancache_invalidates);
+#endif
+ return 0;
+}
+module_init(init_cleancache)
diff --git a/ap/os/linux/linux-3.4.x/mm/compaction.c b/ap/os/linux/linux-3.4.x/mm/compaction.c
new file mode 100644
index 0000000..3c8d7fe
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/compaction.c
@@ -0,0 +1,798 @@
+/*
+ * linux/mm/compaction.c
+ *
+ * Memory compaction for the reduction of external fragmentation. Note that
+ * this heavily depends upon page migration to do all the real heavy
+ * lifting
+ *
+ * Copyright IBM Corp. 2007-2010 Mel Gorman <mel@csn.ul.ie>
+ */
+#include <linux/swap.h>
+#include <linux/migrate.h>
+#include <linux/compaction.h>
+#include <linux/mm_inline.h>
+#include <linux/backing-dev.h>
+#include <linux/sysctl.h>
+#include <linux/sysfs.h>
+#include "internal.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/compaction.h>
+
+/*
+ * compact_control is used to track pages being migrated and the free pages
+ * they are being migrated to during memory compaction. The free_pfn starts
+ * at the end of a zone and migrate_pfn begins at the start. Movable pages
+ * are moved to the end of a zone during a compaction run and the run
+ * completes when free_pfn <= migrate_pfn
+ */
+struct compact_control {
+ struct list_head freepages; /* List of free pages to migrate to */
+ struct list_head migratepages; /* List of pages being migrated */
+ unsigned long nr_freepages; /* Number of isolated free pages */
+ unsigned long nr_migratepages; /* Number of pages to migrate */
+ unsigned long free_pfn; /* isolate_freepages search base */
+ unsigned long migrate_pfn; /* isolate_migratepages search base */
+ bool sync; /* Synchronous migration */
+
+ int order; /* order a direct compactor needs */
+ int migratetype; /* MOVABLE, RECLAIMABLE etc */
+ struct zone *zone;
+};
+
+static unsigned long release_freepages(struct list_head *freelist)
+{
+ struct page *page, *next;
+ unsigned long count = 0;
+
+ list_for_each_entry_safe(page, next, freelist, lru) {
+ list_del(&page->lru);
+ __free_page(page);
+ count++;
+ }
+
+ return count;
+}
+
+/* Isolate free pages onto a private freelist. Must hold zone->lock */
+static unsigned long isolate_freepages_block(struct zone *zone,
+ unsigned long blockpfn,
+ struct list_head *freelist)
+{
+ unsigned long zone_end_pfn, end_pfn;
+ int nr_scanned = 0, total_isolated = 0;
+ struct page *cursor;
+
+ /* Get the last PFN we should scan for free pages at */
+ zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
+ end_pfn = min(blockpfn + pageblock_nr_pages, zone_end_pfn);
+
+ /* Find the first usable PFN in the block to initialse page cursor */
+ for (; blockpfn < end_pfn; blockpfn++) {
+ if (pfn_valid_within(blockpfn))
+ break;
+ }
+ cursor = pfn_to_page(blockpfn);
+
+ /* Isolate free pages. This assumes the block is valid */
+ for (; blockpfn < end_pfn; blockpfn++, cursor++) {
+ int isolated, i;
+ struct page *page = cursor;
+
+ if (!pfn_valid_within(blockpfn))
+ continue;
+ nr_scanned++;
+
+ if (!PageBuddy(page))
+ continue;
+
+ /* Found a free page, break it into order-0 pages */
+ isolated = split_free_page(page);
+ total_isolated += isolated;
+ for (i = 0; i < isolated; i++) {
+ list_add(&page->lru, freelist);
+ page++;
+ }
+
+ /* If a page was split, advance to the end of it */
+ if (isolated) {
+ blockpfn += isolated - 1;
+ cursor += isolated - 1;
+ }
+ }
+
+ trace_mm_compaction_isolate_freepages(nr_scanned, total_isolated);
+ return total_isolated;
+}
+
+/* Returns true if the page is within a block suitable for migration to */
+static bool suitable_migration_target(struct page *page)
+{
+
+ int migratetype = get_pageblock_migratetype(page);
+
+ /* Don't interfere with memory hot-remove or the min_free_kbytes blocks */
+ if (migratetype == MIGRATE_ISOLATE || migratetype == MIGRATE_RESERVE)
+ return false;
+
+ /* If the page is a large free page, then allow migration */
+ if (PageBuddy(page) && page_order(page) >= pageblock_order)
+ return true;
+
+ /* If the block is MIGRATE_MOVABLE, allow migration */
+ if (migratetype == MIGRATE_MOVABLE)
+ return true;
+
+ /* Otherwise skip the block */
+ return false;
+}
+
+/*
+ * Based on information in the current compact_control, find blocks
+ * suitable for isolating free pages from and then isolate them.
+ */
+static void isolate_freepages(struct zone *zone,
+ struct compact_control *cc)
+{
+ struct page *page;
+ unsigned long high_pfn, low_pfn, pfn;
+ unsigned long flags;
+ int nr_freepages = cc->nr_freepages;
+ struct list_head *freelist = &cc->freepages;
+
+ /*
+ * Initialise the free scanner. The starting point is where we last
+ * scanned from (or the end of the zone if starting). The low point
+ * is the end of the pageblock the migration scanner is using.
+ */
+ pfn = cc->free_pfn;
+ low_pfn = cc->migrate_pfn + pageblock_nr_pages;
+
+ /*
+ * Take care that if the migration scanner is at the end of the zone
+ * that the free scanner does not accidentally move to the next zone
+ * in the next isolation cycle.
+ */
+ high_pfn = min(low_pfn, pfn);
+
+ /*
+ * Isolate free pages until enough are available to migrate the
+ * pages on cc->migratepages. We stop searching if the migrate
+ * and free page scanners meet or enough free pages are isolated.
+ */
+ for (; pfn > low_pfn && cc->nr_migratepages > nr_freepages;
+ pfn -= pageblock_nr_pages) {
+ unsigned long isolated;
+
+ if (!pfn_valid(pfn))
+ continue;
+
+ /*
+ * Check for overlapping nodes/zones. It's possible on some
+ * configurations to have a setup like
+ * node0 node1 node0
+ * i.e. it's possible that all pages within a zones range of
+ * pages do not belong to a single zone.
+ */
+ page = pfn_to_page(pfn);
+ if (page_zone(page) != zone)
+ continue;
+
+ /* Check the block is suitable for migration */
+ if (!suitable_migration_target(page))
+ continue;
+
+ /*
+ * Found a block suitable for isolating free pages from. Now
+ * we disabled interrupts, double check things are ok and
+ * isolate the pages. This is to minimise the time IRQs
+ * are disabled
+ */
+ isolated = 0;
+ spin_lock_irqsave(&zone->lock, flags);
+ if (suitable_migration_target(page)) {
+ isolated = isolate_freepages_block(zone, pfn, freelist);
+ nr_freepages += isolated;
+ }
+ spin_unlock_irqrestore(&zone->lock, flags);
+
+ /*
+ * Record the highest PFN we isolated pages from. When next
+ * looking for free pages, the search will restart here as
+ * page migration may have returned some pages to the allocator
+ */
+ if (isolated)
+ high_pfn = max(high_pfn, pfn);
+ }
+
+ /* split_free_page does not map the pages */
+ list_for_each_entry(page, freelist, lru) {
+ arch_alloc_page(page, 0);
+ kernel_map_pages(page, 1, 1);
+ }
+
+ cc->free_pfn = high_pfn;
+ cc->nr_freepages = nr_freepages;
+}
+
+/* Update the number of anon and file isolated pages in the zone */
+static void acct_isolated(struct zone *zone, struct compact_control *cc)
+{
+ struct page *page;
+ unsigned int count[2] = { 0, };
+
+ list_for_each_entry(page, &cc->migratepages, lru)
+ count[!!page_is_file_cache(page)]++;
+
+ __mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]);
+ __mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]);
+}
+
+/* Similar to reclaim, but different enough that they don't share logic */
+static bool too_many_isolated(struct zone *zone)
+{
+ unsigned long active, inactive, isolated;
+
+ inactive = zone_page_state(zone, NR_INACTIVE_FILE) +
+ zone_page_state(zone, NR_INACTIVE_ANON);
+ active = zone_page_state(zone, NR_ACTIVE_FILE) +
+ zone_page_state(zone, NR_ACTIVE_ANON);
+ isolated = zone_page_state(zone, NR_ISOLATED_FILE) +
+ zone_page_state(zone, NR_ISOLATED_ANON);
+
+ return isolated > (inactive + active) / 2;
+}
+
+/* possible outcome of isolate_migratepages */
+typedef enum {
+ ISOLATE_ABORT, /* Abort compaction now */
+ ISOLATE_NONE, /* No pages isolated, continue scanning */
+ ISOLATE_SUCCESS, /* Pages isolated, migrate */
+} isolate_migrate_t;
+
+/*
+ * Isolate all pages that can be migrated from the block pointed to by
+ * the migrate scanner within compact_control.
+ */
+static isolate_migrate_t isolate_migratepages(struct zone *zone,
+ struct compact_control *cc)
+{
+ unsigned long low_pfn, end_pfn;
+ unsigned long last_pageblock_nr = 0, pageblock_nr;
+ unsigned long nr_scanned = 0, nr_isolated = 0;
+ struct list_head *migratelist = &cc->migratepages;
+ isolate_mode_t mode = ISOLATE_ACTIVE|ISOLATE_INACTIVE;
+
+ /* Do not scan outside zone boundaries */
+ low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn);
+
+ /* Only scan within a pageblock boundary */
+ end_pfn = ALIGN(low_pfn + pageblock_nr_pages, pageblock_nr_pages);
+
+ /* Do not cross the free scanner or scan within a memory hole */
+ if (end_pfn > cc->free_pfn || !pfn_valid(low_pfn)) {
+ cc->migrate_pfn = end_pfn;
+ return ISOLATE_NONE;
+ }
+
+ /*
+ * Ensure that there are not too many pages isolated from the LRU
+ * list by either parallel reclaimers or compaction. If there are,
+ * delay for some time until fewer pages are isolated
+ */
+ while (unlikely(too_many_isolated(zone))) {
+ /* async migration should just abort */
+ if (!cc->sync)
+ return ISOLATE_ABORT;
+
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+
+ if (fatal_signal_pending(current))
+ return ISOLATE_ABORT;
+ }
+
+ /* Time to isolate some pages for migration */
+ cond_resched();
+ spin_lock_irq(&zone->lru_lock);
+ for (; low_pfn < end_pfn; low_pfn++) {
+ struct page *page;
+ bool locked = true;
+
+ /* give a chance to irqs before checking need_resched() */
+ if (!((low_pfn+1) % SWAP_CLUSTER_MAX)) {
+ spin_unlock_irq(&zone->lru_lock);
+ locked = false;
+ }
+ if (need_resched() || spin_is_contended(&zone->lru_lock)) {
+ if (locked)
+ spin_unlock_irq(&zone->lru_lock);
+ cond_resched();
+ spin_lock_irq(&zone->lru_lock);
+ if (fatal_signal_pending(current))
+ break;
+ } else if (!locked)
+ spin_lock_irq(&zone->lru_lock);
+
+ /*
+ * migrate_pfn does not necessarily start aligned to a
+ * pageblock. Ensure that pfn_valid is called when moving
+ * into a new MAX_ORDER_NR_PAGES range in case of large
+ * memory holes within the zone
+ */
+ if ((low_pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
+ if (!pfn_valid(low_pfn)) {
+ low_pfn += MAX_ORDER_NR_PAGES - 1;
+ continue;
+ }
+ }
+
+ if (!pfn_valid_within(low_pfn))
+ continue;
+ nr_scanned++;
+
+ /*
+ * Get the page and ensure the page is within the same zone.
+ * See the comment in isolate_freepages about overlapping
+ * nodes. It is deliberate that the new zone lock is not taken
+ * as memory compaction should not move pages between nodes.
+ */
+ page = pfn_to_page(low_pfn);
+ if (page_zone(page) != zone)
+ continue;
+
+ /* Skip if free */
+ if (PageBuddy(page))
+ continue;
+
+ /*
+ * For async migration, also only scan in MOVABLE blocks. Async
+ * migration is optimistic to see if the minimum amount of work
+ * satisfies the allocation
+ */
+ pageblock_nr = low_pfn >> pageblock_order;
+ if (!cc->sync && last_pageblock_nr != pageblock_nr &&
+ get_pageblock_migratetype(page) != MIGRATE_MOVABLE) {
+ low_pfn += pageblock_nr_pages;
+ low_pfn = ALIGN(low_pfn, pageblock_nr_pages) - 1;
+ last_pageblock_nr = pageblock_nr;
+ continue;
+ }
+
+ if (!PageLRU(page))
+ continue;
+
+ /*
+ * PageLRU is set, and lru_lock excludes isolation,
+ * splitting and collapsing (collapsing has already
+ * happened if PageLRU is set).
+ */
+ if (PageTransHuge(page)) {
+ low_pfn += (1 << compound_order(page)) - 1;
+ continue;
+ }
+
+ if (!cc->sync)
+ mode |= ISOLATE_ASYNC_MIGRATE;
+
+ /* Try isolate the page */
+ if (__isolate_lru_page(page, mode, 0) != 0)
+ continue;
+
+ VM_BUG_ON(PageTransCompound(page));
+
+ /* Successfully isolated */
+ del_page_from_lru_list(zone, page, page_lru(page));
+ list_add(&page->lru, migratelist);
+ cc->nr_migratepages++;
+ nr_isolated++;
+
+ /* Avoid isolating too much */
+ if (cc->nr_migratepages == COMPACT_CLUSTER_MAX) {
+ ++low_pfn;
+ break;
+ }
+ }
+
+ acct_isolated(zone, cc);
+
+ spin_unlock_irq(&zone->lru_lock);
+ cc->migrate_pfn = low_pfn;
+
+ trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated);
+
+ return ISOLATE_SUCCESS;
+}
+
+/*
+ * This is a migrate-callback that "allocates" freepages by taking pages
+ * from the isolated freelists in the block we are migrating to.
+ */
+static struct page *compaction_alloc(struct page *migratepage,
+ unsigned long data,
+ int **result)
+{
+ struct compact_control *cc = (struct compact_control *)data;
+ struct page *freepage;
+
+ /* Isolate free pages if necessary */
+ if (list_empty(&cc->freepages)) {
+ isolate_freepages(cc->zone, cc);
+
+ if (list_empty(&cc->freepages))
+ return NULL;
+ }
+
+ freepage = list_entry(cc->freepages.next, struct page, lru);
+ list_del(&freepage->lru);
+ cc->nr_freepages--;
+
+ return freepage;
+}
+
+/*
+ * We cannot control nr_migratepages and nr_freepages fully when migration is
+ * running as migrate_pages() has no knowledge of compact_control. When
+ * migration is complete, we count the number of pages on the lists by hand.
+ */
+static void update_nr_listpages(struct compact_control *cc)
+{
+ int nr_migratepages = 0;
+ int nr_freepages = 0;
+ struct page *page;
+
+ list_for_each_entry(page, &cc->migratepages, lru)
+ nr_migratepages++;
+ list_for_each_entry(page, &cc->freepages, lru)
+ nr_freepages++;
+
+ cc->nr_migratepages = nr_migratepages;
+ cc->nr_freepages = nr_freepages;
+}
+
+static int compact_finished(struct zone *zone,
+ struct compact_control *cc)
+{
+ unsigned int order;
+ unsigned long watermark;
+
+ if (fatal_signal_pending(current))
+ return COMPACT_PARTIAL;
+
+ /* Compaction run completes if the migrate and free scanner meet */
+ if (cc->free_pfn <= cc->migrate_pfn)
+ return COMPACT_COMPLETE;
+
+ /*
+ * order == -1 is expected when compacting via
+ * /proc/sys/vm/compact_memory
+ */
+ if (cc->order == -1)
+ return COMPACT_CONTINUE;
+
+ /* Compaction run is not finished if the watermark is not met */
+ watermark = low_wmark_pages(zone);
+ watermark += (1 << cc->order);
+
+ if (!zone_watermark_ok(zone, cc->order, watermark, 0, 0))
+ return COMPACT_CONTINUE;
+
+ /* Direct compactor: Is a suitable page free? */
+ for (order = cc->order; order < MAX_ORDER; order++) {
+ /* Job done if page is free of the right migratetype */
+ if (!list_empty(&zone->free_area[order].free_list[cc->migratetype]))
+ return COMPACT_PARTIAL;
+
+ /* Job done if allocation would set block type */
+ if (order >= pageblock_order && zone->free_area[order].nr_free)
+ return COMPACT_PARTIAL;
+ }
+
+ return COMPACT_CONTINUE;
+}
+
+/*
+ * compaction_suitable: Is this suitable to run compaction on this zone now?
+ * Returns
+ * COMPACT_SKIPPED - If there are too few free pages for compaction
+ * COMPACT_PARTIAL - If the allocation would succeed without compaction
+ * COMPACT_CONTINUE - If compaction should run now
+ */
+unsigned long compaction_suitable(struct zone *zone, int order)
+{
+ int fragindex;
+ unsigned long watermark;
+
+ /*
+ * order == -1 is expected when compacting via
+ * /proc/sys/vm/compact_memory
+ */
+ if (order == -1)
+ return COMPACT_CONTINUE;
+
+ /*
+ * Watermarks for order-0 must be met for compaction. Note the 2UL.
+ * This is because during migration, copies of pages need to be
+ * allocated and for a short time, the footprint is higher
+ */
+ watermark = low_wmark_pages(zone) + (2UL << order);
+ if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
+ return COMPACT_SKIPPED;
+
+ /*
+ * fragmentation index determines if allocation failures are due to
+ * low memory or external fragmentation
+ *
+ * index of -1000 implies allocations might succeed depending on
+ * watermarks
+ * index towards 0 implies failure is due to lack of memory
+ * index towards 1000 implies failure is due to fragmentation
+ *
+ * Only compact if a failure would be due to fragmentation.
+ */
+ fragindex = fragmentation_index(zone, order);
+ if (fragindex >= 0 && fragindex <= sysctl_extfrag_threshold)
+ return COMPACT_SKIPPED;
+
+ if (fragindex == -1000 && zone_watermark_ok(zone, order, watermark,
+ 0, 0))
+ return COMPACT_PARTIAL;
+
+ return COMPACT_CONTINUE;
+}
+
+static int compact_zone(struct zone *zone, struct compact_control *cc)
+{
+ int ret;
+
+ ret = compaction_suitable(zone, cc->order);
+ switch (ret) {
+ case COMPACT_PARTIAL:
+ case COMPACT_SKIPPED:
+ /* Compaction is likely to fail */
+ return ret;
+ case COMPACT_CONTINUE:
+ /* Fall through to compaction */
+ ;
+ }
+
+ /* Setup to move all movable pages to the end of the zone */
+ cc->migrate_pfn = zone->zone_start_pfn;
+ cc->free_pfn = cc->migrate_pfn + zone->spanned_pages;
+ cc->free_pfn &= ~(pageblock_nr_pages-1);
+
+ migrate_prep_local();
+
+ while ((ret = compact_finished(zone, cc)) == COMPACT_CONTINUE) {
+ unsigned long nr_migrate, nr_remaining;
+ int err;
+
+ switch (isolate_migratepages(zone, cc)) {
+ case ISOLATE_ABORT:
+ ret = COMPACT_PARTIAL;
+ goto out;
+ case ISOLATE_NONE:
+ continue;
+ case ISOLATE_SUCCESS:
+ ;
+ }
+
+ nr_migrate = cc->nr_migratepages;
+ err = migrate_pages(&cc->migratepages, compaction_alloc,
+ (unsigned long)cc, false,
+ cc->sync ? MIGRATE_SYNC_LIGHT : MIGRATE_ASYNC);
+ update_nr_listpages(cc);
+ nr_remaining = cc->nr_migratepages;
+
+ count_vm_event(COMPACTBLOCKS);
+ count_vm_events(COMPACTPAGES, nr_migrate - nr_remaining);
+ if (nr_remaining)
+ count_vm_events(COMPACTPAGEFAILED, nr_remaining);
+ trace_mm_compaction_migratepages(nr_migrate - nr_remaining,
+ nr_remaining);
+
+ /* Release LRU pages not migrated */
+ if (err) {
+ putback_lru_pages(&cc->migratepages);
+ cc->nr_migratepages = 0;
+ if (err == -ENOMEM) {
+ ret = COMPACT_PARTIAL;
+ goto out;
+ }
+ }
+ }
+
+out:
+ /* Release free pages and check accounting */
+ cc->nr_freepages -= release_freepages(&cc->freepages);
+ VM_BUG_ON(cc->nr_freepages != 0);
+
+ return ret;
+}
+
+static unsigned long compact_zone_order(struct zone *zone,
+ int order, gfp_t gfp_mask,
+ bool sync)
+{
+ struct compact_control cc = {
+ .nr_freepages = 0,
+ .nr_migratepages = 0,
+ .order = order,
+ .migratetype = allocflags_to_migratetype(gfp_mask),
+ .zone = zone,
+ .sync = sync,
+ };
+ INIT_LIST_HEAD(&cc.freepages);
+ INIT_LIST_HEAD(&cc.migratepages);
+
+ return compact_zone(zone, &cc);
+}
+
+int sysctl_extfrag_threshold = 500;
+
+/**
+ * try_to_compact_pages - Direct compact to satisfy a high-order allocation
+ * @zonelist: The zonelist used for the current allocation
+ * @order: The order of the current allocation
+ * @gfp_mask: The GFP mask of the current allocation
+ * @nodemask: The allowed nodes to allocate from
+ * @sync: Whether migration is synchronous or not
+ *
+ * This is the main entry point for direct page compaction.
+ */
+unsigned long try_to_compact_pages(struct zonelist *zonelist,
+ int order, gfp_t gfp_mask, nodemask_t *nodemask,
+ bool sync)
+{
+ enum zone_type high_zoneidx = gfp_zone(gfp_mask);
+ int may_enter_fs = gfp_mask & __GFP_FS;
+ int may_perform_io = gfp_mask & __GFP_IO;
+ struct zoneref *z;
+ struct zone *zone;
+ int rc = COMPACT_SKIPPED;
+
+ /*
+ * Check whether it is worth even starting compaction. The order check is
+ * made because an assumption is made that the page allocator can satisfy
+ * the "cheaper" orders without taking special steps
+ */
+ if (!order || !may_enter_fs || !may_perform_io)
+ return rc;
+
+ count_vm_event(COMPACTSTALL);
+
+ /* Compact each zone in the list */
+ for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx,
+ nodemask) {
+ int status;
+
+ status = compact_zone_order(zone, order, gfp_mask, sync);
+ rc = max(status, rc);
+
+ /* If a normal allocation would succeed, stop compacting */
+ if (zone_watermark_ok(zone, order, low_wmark_pages(zone), 0, 0))
+ break;
+ }
+
+ return rc;
+}
+
+
+/* Compact all zones within a node */
+static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
+{
+ int zoneid;
+ struct zone *zone;
+
+ for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) {
+
+ zone = &pgdat->node_zones[zoneid];
+ if (!populated_zone(zone))
+ continue;
+
+ cc->nr_freepages = 0;
+ cc->nr_migratepages = 0;
+ cc->zone = zone;
+ INIT_LIST_HEAD(&cc->freepages);
+ INIT_LIST_HEAD(&cc->migratepages);
+
+ if (cc->order == -1 || !compaction_deferred(zone, cc->order))
+ compact_zone(zone, cc);
+
+ if (cc->order > 0) {
+ int ok = zone_watermark_ok(zone, cc->order,
+ low_wmark_pages(zone), 0, 0);
+ if (ok && cc->order > zone->compact_order_failed)
+ zone->compact_order_failed = cc->order + 1;
+ /* Currently async compaction is never deferred. */
+ else if (!ok && cc->sync)
+ defer_compaction(zone, cc->order);
+ }
+
+ VM_BUG_ON(!list_empty(&cc->freepages));
+ VM_BUG_ON(!list_empty(&cc->migratepages));
+ }
+
+ return 0;
+}
+
+int compact_pgdat(pg_data_t *pgdat, int order)
+{
+ struct compact_control cc = {
+ .order = order,
+ .sync = false,
+ };
+
+ return __compact_pgdat(pgdat, &cc);
+}
+
+static int compact_node(int nid)
+{
+ struct compact_control cc = {
+ .order = -1,
+ .sync = true,
+ };
+
+ return __compact_pgdat(NODE_DATA(nid), &cc);
+}
+
+/* Compact all nodes in the system */
+static void compact_nodes(void)
+{
+ int nid;
+
+ /* Flush pending updates to the LRU lists */
+ lru_add_drain_all();
+
+ for_each_online_node(nid)
+ compact_node(nid);
+}
+
+/* The written value is actually unused, all memory is compacted */
+int sysctl_compact_memory;
+
+/* This is the entry point for compacting all nodes via /proc/sys/vm */
+int sysctl_compaction_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ if (write)
+ compact_nodes();
+
+ return 0;
+}
+
+int sysctl_extfrag_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ proc_dointvec_minmax(table, write, buffer, length, ppos);
+
+ return 0;
+}
+
+#if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
+ssize_t sysfs_compact_node(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int nid = dev->id;
+
+ if (nid >= 0 && nid < nr_node_ids && node_online(nid)) {
+ /* Flush pending updates to the LRU lists */
+ lru_add_drain_all();
+
+ compact_node(nid);
+ }
+
+ return count;
+}
+static DEVICE_ATTR(compact, S_IWUSR, NULL, sysfs_compact_node);
+
+int compaction_register_node(struct node *node)
+{
+ return device_create_file(&node->dev, &dev_attr_compact);
+}
+
+void compaction_unregister_node(struct node *node)
+{
+ return device_remove_file(&node->dev, &dev_attr_compact);
+}
+#endif /* CONFIG_SYSFS && CONFIG_NUMA */
diff --git a/ap/os/linux/linux-3.4.x/mm/debug-pagealloc.c b/ap/os/linux/linux-3.4.x/mm/debug-pagealloc.c
new file mode 100644
index 0000000..789ff70
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/debug-pagealloc.c
@@ -0,0 +1,102 @@
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/page-debug-flags.h>
+#include <linux/poison.h>
+#include <linux/ratelimit.h>
+
+static inline void set_page_poison(struct page *page)
+{
+ __set_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
+}
+
+static inline void clear_page_poison(struct page *page)
+{
+ __clear_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
+}
+
+static inline bool page_poison(struct page *page)
+{
+ return test_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
+}
+
+static void poison_page(struct page *page)
+{
+ void *addr = kmap_atomic(page);
+
+ set_page_poison(page);
+ memset(addr, PAGE_POISON, PAGE_SIZE);
+ kunmap_atomic(addr);
+}
+
+static void poison_pages(struct page *page, int n)
+{
+ int i;
+
+ for (i = 0; i < n; i++)
+ poison_page(page + i);
+}
+
+static bool single_bit_flip(unsigned char a, unsigned char b)
+{
+ unsigned char error = a ^ b;
+
+ return error && !(error & (error - 1));
+}
+
+static void check_poison_mem(unsigned char *mem, size_t bytes)
+{
+ static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 10);
+ unsigned char *start;
+ unsigned char *end;
+
+ start = memchr_inv(mem, PAGE_POISON, bytes);
+ if (!start)
+ return;
+
+ for (end = mem + bytes - 1; end > start; end--) {
+ if (*end != PAGE_POISON)
+ break;
+ }
+
+ if (!__ratelimit(&ratelimit))
+ return;
+ else if (start == end && single_bit_flip(*start, PAGE_POISON))
+ printk(KERN_ERR "pagealloc: single bit error\n");
+ else
+ printk(KERN_ERR "pagealloc: memory corruption\n");
+
+ print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1, start,
+ end - start + 1, 1);
+ dump_stack();
+}
+
+static void unpoison_page(struct page *page)
+{
+ void *addr;
+
+ if (!page_poison(page))
+ return;
+
+ addr = kmap_atomic(page);
+ check_poison_mem(addr, PAGE_SIZE);
+ clear_page_poison(page);
+ kunmap_atomic(addr);
+}
+
+static void unpoison_pages(struct page *page, int n)
+{
+ int i;
+
+ for (i = 0; i < n; i++)
+ unpoison_page(page + i);
+}
+
+void kernel_map_pages(struct page *page, int numpages, int enable)
+{
+ if (enable)
+ unpoison_pages(page, numpages);
+ else
+ poison_pages(page, numpages);
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/dmapool.c b/ap/os/linux/linux-3.4.x/mm/dmapool.c
new file mode 100644
index 0000000..da1b0f0
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/dmapool.c
@@ -0,0 +1,490 @@
+/*
+ * DMA Pool allocator
+ *
+ * Copyright 2001 David Brownell
+ * Copyright 2007 Intel Corporation
+ * Author: Matthew Wilcox <willy@linux.intel.com>
+ *
+ * This software may be redistributed and/or modified under the terms of
+ * the GNU General Public License ("GPL") version 2 as published by the
+ * Free Software Foundation.
+ *
+ * This allocator returns small blocks of a given size which are DMA-able by
+ * the given device. It uses the dma_alloc_coherent page allocator to get
+ * new pages, then splits them up into blocks of the required size.
+ * Many older drivers still have their own code to do this.
+ *
+ * The current design of this allocator is fairly simple. The pool is
+ * represented by the 'struct dma_pool' which keeps a doubly-linked list of
+ * allocated pages. Each page in the page_list is split into blocks of at
+ * least 'size' bytes. Free blocks are tracked in an unsorted singly-linked
+ * list of free blocks within the page. Used blocks aren't tracked, but we
+ * keep a count of how many are currently allocated from each page.
+ */
+
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/export.h>
+#include <linux/mutex.h>
+#include <linux/poison.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+
+#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB_DEBUG_ON)
+#define DMAPOOL_DEBUG 1
+#endif
+
+struct dma_pool { /* the pool */
+ struct list_head page_list;
+ spinlock_t lock;
+ size_t size;
+ struct device *dev;
+ size_t allocation;
+ size_t boundary;
+ char name[32];
+ struct list_head pools;
+};
+
+struct dma_page { /* cacheable header for 'allocation' bytes */
+ struct list_head page_list;
+ void *vaddr;
+ dma_addr_t dma;
+ unsigned int in_use;
+ unsigned int offset;
+};
+
+static DEFINE_MUTEX(pools_lock);
+
+static ssize_t
+show_pools(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ unsigned temp;
+ unsigned size;
+ char *next;
+ struct dma_page *page;
+ struct dma_pool *pool;
+
+ next = buf;
+ size = PAGE_SIZE;
+
+ temp = scnprintf(next, size, "poolinfo - 0.1\n");
+ size -= temp;
+ next += temp;
+
+ mutex_lock(&pools_lock);
+ list_for_each_entry(pool, &dev->dma_pools, pools) {
+ unsigned pages = 0;
+ unsigned blocks = 0;
+
+ spin_lock_irq(&pool->lock);
+ list_for_each_entry(page, &pool->page_list, page_list) {
+ pages++;
+ blocks += page->in_use;
+ }
+ spin_unlock_irq(&pool->lock);
+
+ /* per-pool info, no real statistics yet */
+ temp = scnprintf(next, size, "%-16s %4u %4Zu %4Zu %2u\n",
+ pool->name, blocks,
+ pages * (pool->allocation / pool->size),
+ pool->size, pages);
+ size -= temp;
+ next += temp;
+ }
+ mutex_unlock(&pools_lock);
+
+ return PAGE_SIZE - size;
+}
+
+static DEVICE_ATTR(pools, S_IRUGO, show_pools, NULL);
+
+/**
+ * dma_pool_create - Creates a pool of consistent memory blocks, for dma.
+ * @name: name of pool, for diagnostics
+ * @dev: device that will be doing the DMA
+ * @size: size of the blocks in this pool.
+ * @align: alignment requirement for blocks; must be a power of two
+ * @boundary: returned blocks won't cross this power of two boundary
+ * Context: !in_interrupt()
+ *
+ * Returns a dma allocation pool with the requested characteristics, or
+ * null if one can't be created. Given one of these pools, dma_pool_alloc()
+ * may be used to allocate memory. Such memory will all have "consistent"
+ * DMA mappings, accessible by the device and its driver without using
+ * cache flushing primitives. The actual size of blocks allocated may be
+ * larger than requested because of alignment.
+ *
+ * If @boundary is nonzero, objects returned from dma_pool_alloc() won't
+ * cross that size boundary. This is useful for devices which have
+ * addressing restrictions on individual DMA transfers, such as not crossing
+ * boundaries of 4KBytes.
+ */
+struct dma_pool *dma_pool_create(const char *name, struct device *dev,
+ size_t size, size_t align, size_t boundary)
+{
+ struct dma_pool *retval;
+ size_t allocation;
+
+ if (align == 0) {
+ align = 1;
+ } else if (align & (align - 1)) {
+ return NULL;
+ }
+
+ if (size == 0) {
+ return NULL;
+ } else if (size < 4) {
+ size = 4;
+ }
+
+ if ((size % align) != 0)
+ size = ALIGN(size, align);
+
+ allocation = max_t(size_t, size, PAGE_SIZE);
+
+ if (!boundary) {
+ boundary = allocation;
+ } else if ((boundary < size) || (boundary & (boundary - 1))) {
+ return NULL;
+ }
+
+ retval = kmalloc_node(sizeof(*retval), GFP_KERNEL, dev_to_node(dev));
+ if (!retval)
+ return retval;
+
+ strlcpy(retval->name, name, sizeof(retval->name));
+
+ retval->dev = dev;
+
+ INIT_LIST_HEAD(&retval->page_list);
+ spin_lock_init(&retval->lock);
+ retval->size = size;
+ retval->boundary = boundary;
+ retval->allocation = allocation;
+
+ if (dev) {
+ int ret;
+
+ mutex_lock(&pools_lock);
+ if (list_empty(&dev->dma_pools))
+ ret = device_create_file(dev, &dev_attr_pools);
+ else
+ ret = 0;
+ /* note: not currently insisting "name" be unique */
+ if (!ret)
+ list_add(&retval->pools, &dev->dma_pools);
+ else {
+ kfree(retval);
+ retval = NULL;
+ }
+ mutex_unlock(&pools_lock);
+ } else
+ INIT_LIST_HEAD(&retval->pools);
+
+ return retval;
+}
+EXPORT_SYMBOL(dma_pool_create);
+
+static void pool_initialise_page(struct dma_pool *pool, struct dma_page *page)
+{
+ unsigned int offset = 0;
+ unsigned int next_boundary = pool->boundary;
+
+ do {
+ unsigned int next = offset + pool->size;
+ if (unlikely((next + pool->size) >= next_boundary)) {
+ next = next_boundary;
+ next_boundary += pool->boundary;
+ }
+ *(int *)(page->vaddr + offset) = next;
+ offset = next;
+ } while (offset < pool->allocation);
+}
+
+static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags)
+{
+ struct dma_page *page;
+
+ page = kmalloc(sizeof(*page), mem_flags);
+ if (!page)
+ return NULL;
+ page->vaddr = dma_alloc_coherent(pool->dev, pool->allocation,
+ &page->dma, mem_flags);
+ if (page->vaddr) {
+#ifdef DMAPOOL_DEBUG
+ memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
+#endif
+ pool_initialise_page(pool, page);
+ page->in_use = 0;
+ page->offset = 0;
+ } else {
+ kfree(page);
+ page = NULL;
+ }
+ return page;
+}
+
+static inline int is_page_busy(struct dma_page *page)
+{
+ return page->in_use != 0;
+}
+
+static void pool_free_page(struct dma_pool *pool, struct dma_page *page)
+{
+ dma_addr_t dma = page->dma;
+
+#ifdef DMAPOOL_DEBUG
+ memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
+#endif
+ dma_free_coherent(pool->dev, pool->allocation, page->vaddr, dma);
+ list_del(&page->page_list);
+ kfree(page);
+}
+
+/**
+ * dma_pool_destroy - destroys a pool of dma memory blocks.
+ * @pool: dma pool that will be destroyed
+ * Context: !in_interrupt()
+ *
+ * Caller guarantees that no more memory from the pool is in use,
+ * and that nothing will try to use the pool after this call.
+ */
+void dma_pool_destroy(struct dma_pool *pool)
+{
+ mutex_lock(&pools_lock);
+ list_del(&pool->pools);
+ if (pool->dev && list_empty(&pool->dev->dma_pools))
+ device_remove_file(pool->dev, &dev_attr_pools);
+ mutex_unlock(&pools_lock);
+
+ while (!list_empty(&pool->page_list)) {
+ struct dma_page *page;
+ page = list_entry(pool->page_list.next,
+ struct dma_page, page_list);
+ if (is_page_busy(page)) {
+ if (pool->dev)
+ dev_err(pool->dev,
+ "dma_pool_destroy %s, %p busy\n",
+ pool->name, page->vaddr);
+ else
+ printk(KERN_ERR
+ "dma_pool_destroy %s, %p busy\n",
+ pool->name, page->vaddr);
+ /* leak the still-in-use consistent memory */
+ list_del(&page->page_list);
+ kfree(page);
+ } else
+ pool_free_page(pool, page);
+ }
+
+ kfree(pool);
+}
+EXPORT_SYMBOL(dma_pool_destroy);
+
+/**
+ * dma_pool_alloc - get a block of consistent memory
+ * @pool: dma pool that will produce the block
+ * @mem_flags: GFP_* bitmask
+ * @handle: pointer to dma address of block
+ *
+ * This returns the kernel virtual address of a currently unused block,
+ * and reports its dma address through the handle.
+ * If such a memory block can't be allocated, %NULL is returned.
+ */
+void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
+ dma_addr_t *handle)
+{
+ unsigned long flags;
+ struct dma_page *page;
+ size_t offset;
+ void *retval;
+
+ might_sleep_if(mem_flags & __GFP_WAIT);
+
+ spin_lock_irqsave(&pool->lock, flags);
+ list_for_each_entry(page, &pool->page_list, page_list) {
+ if (page->offset < pool->allocation)
+ goto ready;
+ }
+
+ /* pool_alloc_page() might sleep, so temporarily drop &pool->lock */
+ spin_unlock_irqrestore(&pool->lock, flags);
+
+ page = pool_alloc_page(pool, mem_flags);
+ if (!page)
+ return NULL;
+
+ spin_lock_irqsave(&pool->lock, flags);
+
+ list_add(&page->page_list, &pool->page_list);
+ ready:
+ page->in_use++;
+ offset = page->offset;
+ page->offset = *(int *)(page->vaddr + offset);
+ retval = offset + page->vaddr;
+ *handle = offset + page->dma;
+#ifdef DMAPOOL_DEBUG
+ memset(retval, POOL_POISON_ALLOCATED, pool->size);
+#endif
+ spin_unlock_irqrestore(&pool->lock, flags);
+ return retval;
+}
+EXPORT_SYMBOL(dma_pool_alloc);
+
+static struct dma_page *pool_find_page(struct dma_pool *pool, dma_addr_t dma)
+{
+ struct dma_page *page;
+
+ list_for_each_entry(page, &pool->page_list, page_list) {
+ if (dma < page->dma)
+ continue;
+ if (dma < (page->dma + pool->allocation))
+ return page;
+ }
+ return NULL;
+}
+
+/**
+ * dma_pool_free - put block back into dma pool
+ * @pool: the dma pool holding the block
+ * @vaddr: virtual address of block
+ * @dma: dma address of block
+ *
+ * Caller promises neither device nor driver will again touch this block
+ * unless it is first re-allocated.
+ */
+void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
+{
+ struct dma_page *page;
+ unsigned long flags;
+ unsigned int offset;
+
+ spin_lock_irqsave(&pool->lock, flags);
+ page = pool_find_page(pool, dma);
+ if (!page) {
+ spin_unlock_irqrestore(&pool->lock, flags);
+ if (pool->dev)
+ dev_err(pool->dev,
+ "dma_pool_free %s, %p/%lx (bad dma)\n",
+ pool->name, vaddr, (unsigned long)dma);
+ else
+ printk(KERN_ERR "dma_pool_free %s, %p/%lx (bad dma)\n",
+ pool->name, vaddr, (unsigned long)dma);
+ return;
+ }
+
+ offset = vaddr - page->vaddr;
+#ifdef DMAPOOL_DEBUG
+ if ((dma - page->dma) != offset) {
+ spin_unlock_irqrestore(&pool->lock, flags);
+ if (pool->dev)
+ dev_err(pool->dev,
+ "dma_pool_free %s, %p (bad vaddr)/%Lx\n",
+ pool->name, vaddr, (unsigned long long)dma);
+ else
+ printk(KERN_ERR
+ "dma_pool_free %s, %p (bad vaddr)/%Lx\n",
+ pool->name, vaddr, (unsigned long long)dma);
+ return;
+ }
+ {
+ unsigned int chain = page->offset;
+ while (chain < pool->allocation) {
+ if (chain != offset) {
+ chain = *(int *)(page->vaddr + chain);
+ continue;
+ }
+ spin_unlock_irqrestore(&pool->lock, flags);
+ if (pool->dev)
+ dev_err(pool->dev, "dma_pool_free %s, dma %Lx "
+ "already free\n", pool->name,
+ (unsigned long long)dma);
+ else
+ printk(KERN_ERR "dma_pool_free %s, dma %Lx "
+ "already free\n", pool->name,
+ (unsigned long long)dma);
+ return;
+ }
+ }
+ memset(vaddr, POOL_POISON_FREED, pool->size);
+#endif
+
+ page->in_use--;
+ *(int *)vaddr = page->offset;
+ page->offset = offset;
+ /*
+ * Resist a temptation to do
+ * if (!is_page_busy(page)) pool_free_page(pool, page);
+ * Better have a few empty pages hang around.
+ */
+ spin_unlock_irqrestore(&pool->lock, flags);
+}
+EXPORT_SYMBOL(dma_pool_free);
+
+/*
+ * Managed DMA pool
+ */
+static void dmam_pool_release(struct device *dev, void *res)
+{
+ struct dma_pool *pool = *(struct dma_pool **)res;
+
+ dma_pool_destroy(pool);
+}
+
+static int dmam_pool_match(struct device *dev, void *res, void *match_data)
+{
+ return *(struct dma_pool **)res == match_data;
+}
+
+/**
+ * dmam_pool_create - Managed dma_pool_create()
+ * @name: name of pool, for diagnostics
+ * @dev: device that will be doing the DMA
+ * @size: size of the blocks in this pool.
+ * @align: alignment requirement for blocks; must be a power of two
+ * @allocation: returned blocks won't cross this boundary (or zero)
+ *
+ * Managed dma_pool_create(). DMA pool created with this function is
+ * automatically destroyed on driver detach.
+ */
+struct dma_pool *dmam_pool_create(const char *name, struct device *dev,
+ size_t size, size_t align, size_t allocation)
+{
+ struct dma_pool **ptr, *pool;
+
+ ptr = devres_alloc(dmam_pool_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return NULL;
+
+ pool = *ptr = dma_pool_create(name, dev, size, align, allocation);
+ if (pool)
+ devres_add(dev, ptr);
+ else
+ devres_free(ptr);
+
+ return pool;
+}
+EXPORT_SYMBOL(dmam_pool_create);
+
+/**
+ * dmam_pool_destroy - Managed dma_pool_destroy()
+ * @pool: dma pool that will be destroyed
+ *
+ * Managed dma_pool_destroy().
+ */
+void dmam_pool_destroy(struct dma_pool *pool)
+{
+ struct device *dev = pool->dev;
+
+ WARN_ON(devres_destroy(dev, dmam_pool_release, dmam_pool_match, pool));
+ dma_pool_destroy(pool);
+}
+EXPORT_SYMBOL(dmam_pool_destroy);
diff --git a/ap/os/linux/linux-3.4.x/mm/fadvise.c b/ap/os/linux/linux-3.4.x/mm/fadvise.c
new file mode 100644
index 0000000..dcb9872
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/fadvise.c
@@ -0,0 +1,174 @@
+/*
+ * mm/fadvise.c
+ *
+ * Copyright (C) 2002, Linus Torvalds
+ *
+ * 11Jan2003 Andrew Morton
+ * Initial version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/backing-dev.h>
+#include <linux/pagevec.h>
+#include <linux/fadvise.h>
+#include <linux/writeback.h>
+#include <linux/syscalls.h>
+#include <linux/swap.h>
+
+#include <asm/unistd.h>
+
+/*
+ * POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could
+ * deactivate the pages and clear PG_Referenced.
+ */
+SYSCALL_DEFINE(fadvise64_64)(int fd, loff_t offset, loff_t len, int advice)
+{
+ struct file *file = fget(fd);
+ struct address_space *mapping;
+ struct backing_dev_info *bdi;
+ loff_t endbyte; /* inclusive */
+ pgoff_t start_index;
+ pgoff_t end_index;
+ unsigned long nrpages;
+ int ret = 0;
+
+ if (!file)
+ return -EBADF;
+
+ if (S_ISFIFO(file->f_path.dentry->d_inode->i_mode)) {
+ ret = -ESPIPE;
+ goto out;
+ }
+
+ mapping = file->f_mapping;
+ if (!mapping || len < 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (mapping->a_ops->get_xip_mem) {
+ switch (advice) {
+ case POSIX_FADV_NORMAL:
+ case POSIX_FADV_RANDOM:
+ case POSIX_FADV_SEQUENTIAL:
+ case POSIX_FADV_WILLNEED:
+ case POSIX_FADV_NOREUSE:
+ case POSIX_FADV_DONTNEED:
+ /* no bad return value, but ignore advice */
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ goto out;
+ }
+
+ /* Careful about overflows. Len == 0 means "as much as possible" */
+ endbyte = offset + len;
+ if (!len || endbyte < len)
+ endbyte = -1;
+ else
+ endbyte--; /* inclusive */
+
+ bdi = mapping->backing_dev_info;
+
+ switch (advice) {
+ case POSIX_FADV_NORMAL:
+ file->f_ra.ra_pages = bdi->ra_pages;
+ spin_lock(&file->f_lock);
+ file->f_mode &= ~FMODE_RANDOM;
+ spin_unlock(&file->f_lock);
+ break;
+ case POSIX_FADV_RANDOM:
+ spin_lock(&file->f_lock);
+ file->f_mode |= FMODE_RANDOM;
+ spin_unlock(&file->f_lock);
+ break;
+ case POSIX_FADV_SEQUENTIAL:
+ file->f_ra.ra_pages = bdi->ra_pages * 2;
+ spin_lock(&file->f_lock);
+ file->f_mode &= ~FMODE_RANDOM;
+ spin_unlock(&file->f_lock);
+ break;
+ case POSIX_FADV_WILLNEED:
+ if (!mapping->a_ops->readpage) {
+ ret = -EINVAL;
+ break;
+ }
+
+ /* First and last PARTIAL page! */
+ start_index = offset >> PAGE_CACHE_SHIFT;
+ end_index = endbyte >> PAGE_CACHE_SHIFT;
+
+ /* Careful about overflow on the "+1" */
+ nrpages = end_index - start_index + 1;
+ if (!nrpages)
+ nrpages = ~0UL;
+
+ ret = force_page_cache_readahead(mapping, file,
+ start_index,
+ nrpages);
+ if (ret > 0)
+ ret = 0;
+ break;
+ case POSIX_FADV_NOREUSE:
+ break;
+ case POSIX_FADV_DONTNEED:
+ if (!bdi_write_congested(mapping->backing_dev_info))
+ __filemap_fdatawrite_range(mapping, offset, endbyte,
+ WB_SYNC_NONE);
+
+ /* First and last FULL page! */
+ start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
+ end_index = (endbyte >> PAGE_CACHE_SHIFT);
+
+ if (end_index >= start_index) {
+ unsigned long count = invalidate_mapping_pages(mapping,
+ start_index, end_index);
+
+ /*
+ * If fewer pages were invalidated than expected then
+ * it is possible that some of the pages were on
+ * a per-cpu pagevec for a remote CPU. Drain all
+ * pagevecs and try again.
+ */
+ if (count < (end_index - start_index + 1)) {
+ lru_add_drain_all();
+ invalidate_mapping_pages(mapping, start_index,
+ end_index);
+ }
+ }
+ break;
+ default:
+ ret = -EINVAL;
+ }
+out:
+ fput(file);
+ return ret;
+}
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_fadvise64_64(long fd, loff_t offset, loff_t len, long advice)
+{
+ return SYSC_fadvise64_64((int) fd, offset, len, (int) advice);
+}
+SYSCALL_ALIAS(sys_fadvise64_64, SyS_fadvise64_64);
+#endif
+
+#ifdef __ARCH_WANT_SYS_FADVISE64
+
+SYSCALL_DEFINE(fadvise64)(int fd, loff_t offset, size_t len, int advice)
+{
+ return sys_fadvise64_64(fd, offset, len, advice);
+}
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_fadvise64(long fd, loff_t offset, long len, long advice)
+{
+ return SYSC_fadvise64((int) fd, offset, (size_t)len, (int)advice);
+}
+SYSCALL_ALIAS(sys_fadvise64, SyS_fadvise64);
+#endif
+
+#endif
diff --git a/ap/os/linux/linux-3.4.x/mm/failslab.c b/ap/os/linux/linux-3.4.x/mm/failslab.c
new file mode 100644
index 0000000..fefaaba
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/failslab.c
@@ -0,0 +1,60 @@
+#include <linux/fault-inject.h>
+#include <linux/slab.h>
+
+static struct {
+ struct fault_attr attr;
+ u32 ignore_gfp_wait;
+ int cache_filter;
+} failslab = {
+ .attr = FAULT_ATTR_INITIALIZER,
+ .ignore_gfp_wait = 1,
+ .cache_filter = 0,
+};
+
+bool should_failslab(size_t size, gfp_t gfpflags, unsigned long cache_flags)
+{
+ if (gfpflags & __GFP_NOFAIL)
+ return false;
+
+ if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT))
+ return false;
+
+ if (failslab.cache_filter && !(cache_flags & SLAB_FAILSLAB))
+ return false;
+
+ return should_fail(&failslab.attr, size);
+}
+
+static int __init setup_failslab(char *str)
+{
+ return setup_fault_attr(&failslab.attr, str);
+}
+__setup("failslab=", setup_failslab);
+
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+static int __init failslab_debugfs_init(void)
+{
+ struct dentry *dir;
+ umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
+
+ dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
+ if (IS_ERR(dir))
+ return PTR_ERR(dir);
+
+ if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
+ &failslab.ignore_gfp_wait))
+ goto fail;
+ if (!debugfs_create_bool("cache-filter", mode, dir,
+ &failslab.cache_filter))
+ goto fail;
+
+ return 0;
+fail:
+ debugfs_remove_recursive(dir);
+
+ return -ENOMEM;
+}
+
+late_initcall(failslab_debugfs_init);
+
+#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
diff --git a/ap/os/linux/linux-3.4.x/mm/filemap.c b/ap/os/linux/linux-3.4.x/mm/filemap.c
new file mode 100644
index 0000000..8da7574
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/filemap.c
@@ -0,0 +1,2681 @@
+/*
+ * linux/mm/filemap.c
+ *
+ * Copyright (C) 1994-1999 Linus Torvalds
+ */
+
+/*
+ * This file handles the generic file mmap semantics used by
+ * most "normal" filesystems (but you don't /have/ to use this:
+ * the NFS filesystem used to do this differently, for example)
+ */
+#include <linux/export.h>
+#include <linux/compiler.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/aio.h>
+#include <linux/capability.h>
+#include <linux/kernel_stat.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/mman.h>
+#include <linux/pagemap.h>
+#include <linux/file.h>
+#include <linux/uio.h>
+#include <linux/hash.h>
+#include <linux/writeback.h>
+#include <linux/backing-dev.h>
+#include <linux/pagevec.h>
+#include <linux/blkdev.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/cpuset.h>
+#include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */
+#include <linux/memcontrol.h>
+#include <linux/cleancache.h>
+#include "internal.h"
+
+/*
+ * FIXME: remove all knowledge of the buffer layer from the core VM
+ */
+#include <linux/buffer_head.h> /* for try_to_free_buffers */
+
+#include <asm/mman.h>
+
+/*
+ * Shared mappings implemented 30.11.1994. It's not fully working yet,
+ * though.
+ *
+ * Shared mappings now work. 15.8.1995 Bruno.
+ *
+ * finished 'unifying' the page and buffer cache and SMP-threaded the
+ * page-cache, 21.05.1999, Ingo Molnar <mingo@redhat.com>
+ *
+ * SMP-threaded pagemap-LRU 1999, Andrea Arcangeli <andrea@suse.de>
+ */
+
+/*
+ * Lock ordering:
+ *
+ * ->i_mmap_mutex (truncate_pagecache)
+ * ->private_lock (__free_pte->__set_page_dirty_buffers)
+ * ->swap_lock (exclusive_swap_page, others)
+ * ->mapping->tree_lock
+ *
+ * ->i_mutex
+ * ->i_mmap_mutex (truncate->unmap_mapping_range)
+ *
+ * ->mmap_sem
+ * ->i_mmap_mutex
+ * ->page_table_lock or pte_lock (various, mainly in memory.c)
+ * ->mapping->tree_lock (arch-dependent flush_dcache_mmap_lock)
+ *
+ * ->mmap_sem
+ * ->lock_page (access_process_vm)
+ *
+ * ->i_mutex (generic_file_buffered_write)
+ * ->mmap_sem (fault_in_pages_readable->do_page_fault)
+ *
+ * bdi->wb.list_lock
+ * sb_lock (fs/fs-writeback.c)
+ * ->mapping->tree_lock (__sync_single_inode)
+ *
+ * ->i_mmap_mutex
+ * ->anon_vma.lock (vma_adjust)
+ *
+ * ->anon_vma.lock
+ * ->page_table_lock or pte_lock (anon_vma_prepare and various)
+ *
+ * ->page_table_lock or pte_lock
+ * ->swap_lock (try_to_unmap_one)
+ * ->private_lock (try_to_unmap_one)
+ * ->tree_lock (try_to_unmap_one)
+ * ->zone.lru_lock (follow_page->mark_page_accessed)
+ * ->zone.lru_lock (check_pte_range->isolate_lru_page)
+ * ->private_lock (page_remove_rmap->set_page_dirty)
+ * ->tree_lock (page_remove_rmap->set_page_dirty)
+ * bdi.wb->list_lock (page_remove_rmap->set_page_dirty)
+ * ->inode->i_lock (page_remove_rmap->set_page_dirty)
+ * bdi.wb->list_lock (zap_pte_range->set_page_dirty)
+ * ->inode->i_lock (zap_pte_range->set_page_dirty)
+ * ->private_lock (zap_pte_range->__set_page_dirty_buffers)
+ *
+ * ->i_mmap_mutex
+ * ->tasklist_lock (memory_failure, collect_procs_ao)
+ */
+
+/*
+ * Delete a page from the page cache and free it. Caller has to make
+ * sure the page is locked and that nobody else uses it - or that usage
+ * is safe. The caller must hold the mapping's tree_lock.
+ */
+void __delete_from_page_cache(struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+
+ /*
+ * if we're uptodate, flush out into the cleancache, otherwise
+ * invalidate any existing cleancache entries. We can't leave
+ * stale data around in the cleancache once our page is gone
+ */
+ if (PageUptodate(page) && PageMappedToDisk(page))
+ cleancache_put_page(page);
+ else
+ cleancache_invalidate_page(mapping, page);
+
+ radix_tree_delete(&mapping->page_tree, page->index);
+ page->mapping = NULL;
+ /* Leave page->index set: truncation lookup relies upon it */
+ mapping->nrpages--;
+ __dec_zone_page_state(page, NR_FILE_PAGES);
+ if (PageSwapBacked(page))
+ __dec_zone_page_state(page, NR_SHMEM);
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+ if(mapping_gfp_mask(mapping) & __GFP_PAGERAMFS)
+ __dec_zone_page_state(page, NR_RAMFS_PAGES);
+ else if(mapping_gfp_mask(mapping) & __GFP_PAGETMPFS)
+ __dec_zone_page_state(page, NR_TMPFS_PAGES);
+#endif
+
+ BUG_ON(page_mapped(page));
+
+ /*
+ * Some filesystems seem to re-dirty the page even after
+ * the VM has canceled the dirty bit (eg ext3 journaling).
+ *
+ * Fix it up by doing a final dirty accounting check after
+ * having removed the page entirely.
+ */
+ if (PageDirty(page) && mapping_cap_account_dirty(mapping)) {
+ dec_zone_page_state(page, NR_FILE_DIRTY);
+ dec_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
+ }
+}
+
+/**
+ * delete_from_page_cache - delete page from page cache
+ * @page: the page which the kernel is trying to remove from page cache
+ *
+ * This must be called only on pages that have been verified to be in the page
+ * cache and locked. It will never put the page into the free list, the caller
+ * has a reference on the page.
+ */
+void delete_from_page_cache(struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+ void (*freepage)(struct page *);
+ unsigned long flags;
+
+ BUG_ON(!PageLocked(page));
+
+ freepage = mapping->a_ops->freepage;
+ spin_lock_irq(&mapping->tree_lock);
+ local_irq_save(flags);
+ __delete_from_page_cache(page);
+ local_irq_restore(flags);
+ spin_unlock_irq(&mapping->tree_lock);
+ mem_cgroup_uncharge_cache_page(page);
+
+ if (freepage)
+ freepage(page);
+ page_cache_release(page);
+}
+EXPORT_SYMBOL(delete_from_page_cache);
+
+static int sleep_on_page(void *word)
+{
+ io_schedule();
+ return 0;
+}
+
+static int sleep_on_page_killable(void *word)
+{
+ sleep_on_page(word);
+ return fatal_signal_pending(current) ? -EINTR : 0;
+}
+
+/**
+ * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range
+ * @mapping: address space structure to write
+ * @start: offset in bytes where the range starts
+ * @end: offset in bytes where the range ends (inclusive)
+ * @sync_mode: enable synchronous operation
+ *
+ * Start writeback against all of a mapping's dirty pages that lie
+ * within the byte offsets <start, end> inclusive.
+ *
+ * If sync_mode is WB_SYNC_ALL then this is a "data integrity" operation, as
+ * opposed to a regular memory cleansing writeback. The difference between
+ * these two operations is that if a dirty page/buffer is encountered, it must
+ * be waited upon, and not just skipped over.
+ */
+int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
+ loff_t end, int sync_mode)
+{
+ int ret;
+ struct writeback_control wbc = {
+ .sync_mode = sync_mode,
+ .nr_to_write = LONG_MAX,
+ .range_start = start,
+ .range_end = end,
+ };
+
+ if (!mapping_cap_writeback_dirty(mapping))
+ return 0;
+
+ ret = do_writepages(mapping, &wbc);
+ return ret;
+}
+
+static inline int __filemap_fdatawrite(struct address_space *mapping,
+ int sync_mode)
+{
+ return __filemap_fdatawrite_range(mapping, 0, LLONG_MAX, sync_mode);
+}
+
+int filemap_fdatawrite(struct address_space *mapping)
+{
+ return __filemap_fdatawrite(mapping, WB_SYNC_ALL);
+}
+EXPORT_SYMBOL(filemap_fdatawrite);
+
+int filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
+ loff_t end)
+{
+ return __filemap_fdatawrite_range(mapping, start, end, WB_SYNC_ALL);
+}
+EXPORT_SYMBOL(filemap_fdatawrite_range);
+
+/**
+ * filemap_flush - mostly a non-blocking flush
+ * @mapping: target address_space
+ *
+ * This is a mostly non-blocking flush. Not suitable for data-integrity
+ * purposes - I/O may not be started against all dirty pages.
+ */
+int filemap_flush(struct address_space *mapping)
+{
+ return __filemap_fdatawrite(mapping, WB_SYNC_NONE);
+}
+EXPORT_SYMBOL(filemap_flush);
+
+/**
+ * filemap_fdatawait_range - wait for writeback to complete
+ * @mapping: address space structure to wait for
+ * @start_byte: offset in bytes where the range starts
+ * @end_byte: offset in bytes where the range ends (inclusive)
+ *
+ * Walk the list of under-writeback pages of the given address space
+ * in the given range and wait for all of them.
+ */
+int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte,
+ loff_t end_byte)
+{
+ pgoff_t index = start_byte >> PAGE_CACHE_SHIFT;
+ pgoff_t end = end_byte >> PAGE_CACHE_SHIFT;
+ struct pagevec pvec;
+ int nr_pages;
+ int ret = 0;
+
+ if (end_byte < start_byte)
+ return 0;
+
+ pagevec_init(&pvec, 0);
+ while ((index <= end) &&
+ (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
+ PAGECACHE_TAG_WRITEBACK,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1)) != 0) {
+ unsigned i;
+
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page = pvec.pages[i];
+
+ /* until radix tree lookup accepts end_index */
+ if (page->index > end)
+ continue;
+
+ wait_on_page_writeback(page);
+ if (TestClearPageError(page))
+ ret = -EIO;
+ }
+ pagevec_release(&pvec);
+ cond_resched();
+ }
+
+ /* Check for outstanding write errors */
+ if (test_and_clear_bit(AS_ENOSPC, &mapping->flags))
+ ret = -ENOSPC;
+ if (test_and_clear_bit(AS_EIO, &mapping->flags))
+ ret = -EIO;
+
+ return ret;
+}
+EXPORT_SYMBOL(filemap_fdatawait_range);
+
+/**
+ * filemap_fdatawait - wait for all under-writeback pages to complete
+ * @mapping: address space structure to wait for
+ *
+ * Walk the list of under-writeback pages of the given address space
+ * and wait for all of them.
+ */
+int filemap_fdatawait(struct address_space *mapping)
+{
+ loff_t i_size = i_size_read(mapping->host);
+
+ if (i_size == 0)
+ return 0;
+
+ return filemap_fdatawait_range(mapping, 0, i_size - 1);
+}
+EXPORT_SYMBOL(filemap_fdatawait);
+
+int filemap_write_and_wait(struct address_space *mapping)
+{
+ int err = 0;
+
+ if (mapping->nrpages) {
+ err = filemap_fdatawrite(mapping);
+ /*
+ * Even if the above returned error, the pages may be
+ * written partially (e.g. -ENOSPC), so we wait for it.
+ * But the -EIO is special case, it may indicate the worst
+ * thing (e.g. bug) happened, so we avoid waiting for it.
+ */
+ if (err != -EIO) {
+ int err2 = filemap_fdatawait(mapping);
+ if (!err)
+ err = err2;
+ }
+ }
+ return err;
+}
+EXPORT_SYMBOL(filemap_write_and_wait);
+
+/**
+ * filemap_write_and_wait_range - write out & wait on a file range
+ * @mapping: the address_space for the pages
+ * @lstart: offset in bytes where the range starts
+ * @lend: offset in bytes where the range ends (inclusive)
+ *
+ * Write out and wait upon file offsets lstart->lend, inclusive.
+ *
+ * Note that `lend' is inclusive (describes the last byte to be written) so
+ * that this function can be used to write to the very end-of-file (end = -1).
+ */
+int filemap_write_and_wait_range(struct address_space *mapping,
+ loff_t lstart, loff_t lend)
+{
+ int err = 0;
+
+ if (mapping->nrpages) {
+ err = __filemap_fdatawrite_range(mapping, lstart, lend,
+ WB_SYNC_ALL);
+ /* See comment of filemap_write_and_wait() */
+ if (err != -EIO) {
+ int err2 = filemap_fdatawait_range(mapping,
+ lstart, lend);
+ if (!err)
+ err = err2;
+ }
+ }
+ return err;
+}
+EXPORT_SYMBOL(filemap_write_and_wait_range);
+
+/**
+ * replace_page_cache_page - replace a pagecache page with a new one
+ * @old: page to be replaced
+ * @new: page to replace with
+ * @gfp_mask: allocation mode
+ *
+ * This function replaces a page in the pagecache with a new one. On
+ * success it acquires the pagecache reference for the new page and
+ * drops it for the old page. Both the old and new pages must be
+ * locked. This function does not add the new page to the LRU, the
+ * caller must do that.
+ *
+ * The remove + add is atomic. The only way this function can fail is
+ * memory allocation failure.
+ */
+int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
+{
+ int error;
+
+ VM_BUG_ON(!PageLocked(old));
+ VM_BUG_ON(!PageLocked(new));
+ VM_BUG_ON(new->mapping);
+
+ error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM);
+ if (!error) {
+ struct address_space *mapping = old->mapping;
+ void (*freepage)(struct page *);
+
+ pgoff_t offset = old->index;
+ freepage = mapping->a_ops->freepage;
+
+ page_cache_get(new);
+ new->mapping = mapping;
+ new->index = offset;
+
+ spin_lock_irq(&mapping->tree_lock);
+ __delete_from_page_cache(old);
+ error = radix_tree_insert(&mapping->page_tree, offset, new);
+ BUG_ON(error);
+ mapping->nrpages++;
+ __inc_zone_page_state(new, NR_FILE_PAGES);
+ if (PageSwapBacked(new))
+ __inc_zone_page_state(new, NR_SHMEM);
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+ if(mapping_gfp_mask(mapping) & __GFP_PAGERAMFS)
+ __inc_zone_page_state(new, NR_RAMFS_PAGES);
+ else if(mapping_gfp_mask(mapping) & __GFP_PAGETMPFS)
+ __inc_zone_page_state(new, NR_TMPFS_PAGES);
+#endif
+ spin_unlock_irq(&mapping->tree_lock);
+ /* mem_cgroup codes must not be called under tree_lock */
+ mem_cgroup_replace_page_cache(old, new);
+ radix_tree_preload_end();
+ if (freepage)
+ freepage(old);
+ page_cache_release(old);
+ }
+
+ return error;
+}
+EXPORT_SYMBOL_GPL(replace_page_cache_page);
+
+/**
+ * add_to_page_cache_locked - add a locked page to the pagecache
+ * @page: page to add
+ * @mapping: the page's address_space
+ * @offset: page index
+ * @gfp_mask: page allocation mode
+ *
+ * This function is used to add a page to the pagecache. It must be locked.
+ * This function does not add the page to the LRU. The caller must do that.
+ */
+int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
+ pgoff_t offset, gfp_t gfp_mask)
+{
+ int error;
+
+ VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON(PageSwapBacked(page));
+
+ error = mem_cgroup_cache_charge(page, current->mm,
+ gfp_mask & GFP_RECLAIM_MASK);
+ if (error)
+ goto out;
+
+ error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM);
+ if (error == 0) {
+ page_cache_get(page);
+ page->mapping = mapping;
+ page->index = offset;
+
+ spin_lock_irq(&mapping->tree_lock);
+ error = radix_tree_insert(&mapping->page_tree, offset, page);
+ if (likely(!error)) {
+ mapping->nrpages++;
+ __inc_zone_page_state(page, NR_FILE_PAGES);
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+ if(mapping_gfp_mask(mapping) & __GFP_PAGERAMFS)
+ __inc_zone_page_state(page, NR_RAMFS_PAGES);
+ else if(mapping_gfp_mask(mapping) & __GFP_PAGETMPFS)
+ __inc_zone_page_state(page, NR_TMPFS_PAGES);
+#endif
+ spin_unlock_irq(&mapping->tree_lock);
+ } else {
+ page->mapping = NULL;
+ /* Leave page->index set: truncation relies upon it */
+ spin_unlock_irq(&mapping->tree_lock);
+ mem_cgroup_uncharge_cache_page(page);
+ page_cache_release(page);
+ }
+ radix_tree_preload_end();
+ } else
+ mem_cgroup_uncharge_cache_page(page);
+out:
+ return error;
+}
+EXPORT_SYMBOL(add_to_page_cache_locked);
+
+int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
+ pgoff_t offset, gfp_t gfp_mask)
+{
+ int ret;
+
+ ret = add_to_page_cache(page, mapping, offset, gfp_mask);
+ if (ret == 0)
+ lru_cache_add_file(page);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(add_to_page_cache_lru);
+
+#ifdef CONFIG_NUMA
+struct page *__page_cache_alloc(gfp_t gfp)
+{
+ int n;
+ struct page *page;
+
+ if (cpuset_do_page_mem_spread()) {
+ unsigned int cpuset_mems_cookie;
+ do {
+ cpuset_mems_cookie = get_mems_allowed();
+ n = cpuset_mem_spread_node();
+ page = alloc_pages_exact_node(n, gfp, 0);
+ } while (!put_mems_allowed(cpuset_mems_cookie) && !page);
+
+ return page;
+ }
+ return alloc_pages(gfp, 0);
+}
+EXPORT_SYMBOL(__page_cache_alloc);
+#endif
+
+/*
+ * In order to wait for pages to become available there must be
+ * waitqueues associated with pages. By using a hash table of
+ * waitqueues where the bucket discipline is to maintain all
+ * waiters on the same queue and wake all when any of the pages
+ * become available, and for the woken contexts to check to be
+ * sure the appropriate page became available, this saves space
+ * at a cost of "thundering herd" phenomena during rare hash
+ * collisions.
+ */
+static wait_queue_head_t *page_waitqueue(struct page *page)
+{
+ const struct zone *zone = page_zone(page);
+
+ return &zone->wait_table[hash_ptr(page, zone->wait_table_bits)];
+}
+
+static inline void wake_up_page(struct page *page, int bit)
+{
+ __wake_up_bit(page_waitqueue(page), &page->flags, bit);
+}
+
+void wait_on_page_bit(struct page *page, int bit_nr)
+{
+ DEFINE_WAIT_BIT(wait, &page->flags, bit_nr);
+
+ if (test_bit(bit_nr, &page->flags))
+ __wait_on_bit(page_waitqueue(page), &wait, sleep_on_page,
+ TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_on_page_bit);
+
+int wait_on_page_bit_killable(struct page *page, int bit_nr)
+{
+ DEFINE_WAIT_BIT(wait, &page->flags, bit_nr);
+
+ if (!test_bit(bit_nr, &page->flags))
+ return 0;
+
+ return __wait_on_bit(page_waitqueue(page), &wait,
+ sleep_on_page_killable, TASK_KILLABLE);
+}
+
+/**
+ * add_page_wait_queue - Add an arbitrary waiter to a page's wait queue
+ * @page: Page defining the wait queue of interest
+ * @waiter: Waiter to add to the queue
+ *
+ * Add an arbitrary @waiter to the wait queue for the nominated @page.
+ */
+void add_page_wait_queue(struct page *page, wait_queue_t *waiter)
+{
+ wait_queue_head_t *q = page_waitqueue(page);
+ unsigned long flags;
+
+ spin_lock_irqsave(&q->lock, flags);
+ __add_wait_queue(q, waiter);
+ spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL_GPL(add_page_wait_queue);
+
+/**
+ * unlock_page - unlock a locked page
+ * @page: the page
+ *
+ * Unlocks the page and wakes up sleepers in ___wait_on_page_locked().
+ * Also wakes sleepers in wait_on_page_writeback() because the wakeup
+ * mechananism between PageLocked pages and PageWriteback pages is shared.
+ * But that's OK - sleepers in wait_on_page_writeback() just go back to sleep.
+ *
+ * The mb is necessary to enforce ordering between the clear_bit and the read
+ * of the waitqueue (to avoid SMP races with a parallel wait_on_page_locked()).
+ */
+void unlock_page(struct page *page)
+{
+ VM_BUG_ON(!PageLocked(page));
+ clear_bit_unlock(PG_locked, &page->flags);
+ smp_mb__after_clear_bit();
+ wake_up_page(page, PG_locked);
+}
+EXPORT_SYMBOL(unlock_page);
+
+/**
+ * end_page_writeback - end writeback against a page
+ * @page: the page
+ */
+void end_page_writeback(struct page *page)
+{
+ if (TestClearPageReclaim(page))
+ rotate_reclaimable_page(page);
+
+ if (!test_clear_page_writeback(page))
+ BUG();
+
+ smp_mb__after_clear_bit();
+ wake_up_page(page, PG_writeback);
+}
+EXPORT_SYMBOL(end_page_writeback);
+
+/**
+ * __lock_page - get a lock on the page, assuming we need to sleep to get it
+ * @page: the page to lock
+ */
+void __lock_page(struct page *page)
+{
+ DEFINE_WAIT_BIT(wait, &page->flags, PG_locked);
+
+ __wait_on_bit_lock(page_waitqueue(page), &wait, sleep_on_page,
+ TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(__lock_page);
+
+int __lock_page_killable(struct page *page)
+{
+ DEFINE_WAIT_BIT(wait, &page->flags, PG_locked);
+
+ return __wait_on_bit_lock(page_waitqueue(page), &wait,
+ sleep_on_page_killable, TASK_KILLABLE);
+}
+EXPORT_SYMBOL_GPL(__lock_page_killable);
+
+int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
+ unsigned int flags)
+{
+ if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ /*
+ * CAUTION! In this case, mmap_sem is not released
+ * even though return 0.
+ */
+ if (flags & FAULT_FLAG_RETRY_NOWAIT)
+ return 0;
+
+ up_read(&mm->mmap_sem);
+ if (flags & FAULT_FLAG_KILLABLE)
+ wait_on_page_locked_killable(page);
+ else
+ wait_on_page_locked(page);
+ return 0;
+ } else {
+ if (flags & FAULT_FLAG_KILLABLE) {
+ int ret;
+
+ ret = __lock_page_killable(page);
+ if (ret) {
+ up_read(&mm->mmap_sem);
+ return 0;
+ }
+ } else
+ __lock_page(page);
+ return 1;
+ }
+}
+
+/**
+ * find_get_page - find and get a page reference
+ * @mapping: the address_space to search
+ * @offset: the page index
+ *
+ * Is there a pagecache struct page at the given (mapping, offset) tuple?
+ * If yes, increment its refcount and return it; if no, return NULL.
+ */
+struct page *find_get_page(struct address_space *mapping, pgoff_t offset)
+{
+ void **pagep;
+ struct page *page;
+
+ rcu_read_lock();
+repeat:
+ page = NULL;
+ pagep = radix_tree_lookup_slot(&mapping->page_tree, offset);
+ if (pagep) {
+ page = radix_tree_deref_slot(pagep);
+ if (unlikely(!page))
+ goto out;
+ if (radix_tree_exception(page)) {
+ if (radix_tree_deref_retry(page))
+ goto repeat;
+ /*
+ * Otherwise, shmem/tmpfs must be storing a swap entry
+ * here as an exceptional entry: so return it without
+ * attempting to raise page count.
+ */
+ goto out;
+ }
+ if (!page_cache_get_speculative(page))
+ goto repeat;
+
+ /*
+ * Has the page moved?
+ * This is part of the lockless pagecache protocol. See
+ * include/linux/pagemap.h for details.
+ */
+ if (unlikely(page != *pagep)) {
+ page_cache_release(page);
+ goto repeat;
+ }
+ }
+out:
+ rcu_read_unlock();
+
+ return page;
+}
+EXPORT_SYMBOL(find_get_page);
+
+/**
+ * find_lock_page - locate, pin and lock a pagecache page
+ * @mapping: the address_space to search
+ * @offset: the page index
+ *
+ * Locates the desired pagecache page, locks it, increments its reference
+ * count and returns its address.
+ *
+ * Returns zero if the page was not present. find_lock_page() may sleep.
+ */
+struct page *find_lock_page(struct address_space *mapping, pgoff_t offset)
+{
+ struct page *page;
+
+repeat:
+ page = find_get_page(mapping, offset);
+ if (page && !radix_tree_exception(page)) {
+ lock_page(page);
+ /* Has the page been truncated? */
+ if (unlikely(page->mapping != mapping)) {
+ unlock_page(page);
+ page_cache_release(page);
+ goto repeat;
+ }
+ VM_BUG_ON(page->index != offset);
+ }
+ return page;
+}
+EXPORT_SYMBOL(find_lock_page);
+
+/**
+ * find_or_create_page - locate or add a pagecache page
+ * @mapping: the page's address_space
+ * @index: the page's index into the mapping
+ * @gfp_mask: page allocation mode
+ *
+ * Locates a page in the pagecache. If the page is not present, a new page
+ * is allocated using @gfp_mask and is added to the pagecache and to the VM's
+ * LRU list. The returned page is locked and has its reference count
+ * incremented.
+ *
+ * find_or_create_page() may sleep, even if @gfp_flags specifies an atomic
+ * allocation!
+ *
+ * find_or_create_page() returns the desired page's address, or zero on
+ * memory exhaustion.
+ */
+struct page *find_or_create_page(struct address_space *mapping,
+ pgoff_t index, gfp_t gfp_mask)
+{
+ struct page *page;
+ int err;
+repeat:
+ page = find_lock_page(mapping, index);
+ if (!page) {
+ page = __page_cache_alloc(gfp_mask);
+ if (!page)
+ return NULL;
+ /*
+ * We want a regular kernel memory (not highmem or DMA etc)
+ * allocation for the radix tree nodes, but we need to honour
+ * the context-specific requirements the caller has asked for.
+ * GFP_RECLAIM_MASK collects those requirements.
+ */
+ err = add_to_page_cache_lru(page, mapping, index,
+ (gfp_mask & GFP_RECLAIM_MASK));
+ if (unlikely(err)) {
+ page_cache_release(page);
+ page = NULL;
+ if (err == -EEXIST)
+ goto repeat;
+ }
+ }
+ return page;
+}
+EXPORT_SYMBOL(find_or_create_page);
+
+/**
+ * find_get_pages - gang pagecache lookup
+ * @mapping: The address_space to search
+ * @start: The starting page index
+ * @nr_pages: The maximum number of pages
+ * @pages: Where the resulting pages are placed
+ *
+ * find_get_pages() will search for and return a group of up to
+ * @nr_pages pages in the mapping. The pages are placed at @pages.
+ * find_get_pages() takes a reference against the returned pages.
+ *
+ * The search returns a group of mapping-contiguous pages with ascending
+ * indexes. There may be holes in the indices due to not-present pages.
+ *
+ * find_get_pages() returns the number of pages which were found.
+ */
+unsigned find_get_pages(struct address_space *mapping, pgoff_t start,
+ unsigned int nr_pages, struct page **pages)
+{
+ struct radix_tree_iter iter;
+ void **slot;
+ unsigned ret = 0;
+
+ if (unlikely(!nr_pages))
+ return 0;
+
+ rcu_read_lock();
+restart:
+ radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
+ struct page *page;
+repeat:
+ page = radix_tree_deref_slot(slot);
+ if (unlikely(!page))
+ continue;
+
+ if (radix_tree_exception(page)) {
+ if (radix_tree_deref_retry(page)) {
+ /*
+ * Transient condition which can only trigger
+ * when entry at index 0 moves out of or back
+ * to root: none yet gotten, safe to restart.
+ */
+ WARN_ON(iter.index);
+ goto restart;
+ }
+ /*
+ * Otherwise, shmem/tmpfs must be storing a swap entry
+ * here as an exceptional entry: so skip over it -
+ * we only reach this from invalidate_mapping_pages().
+ */
+ continue;
+ }
+
+ if (!page_cache_get_speculative(page))
+ goto repeat;
+
+ /* Has the page moved? */
+ if (unlikely(page != *slot)) {
+ page_cache_release(page);
+ goto repeat;
+ }
+
+ pages[ret] = page;
+ if (++ret == nr_pages)
+ break;
+ }
+
+ rcu_read_unlock();
+ return ret;
+}
+
+/**
+ * find_get_pages_contig - gang contiguous pagecache lookup
+ * @mapping: The address_space to search
+ * @index: The starting page index
+ * @nr_pages: The maximum number of pages
+ * @pages: Where the resulting pages are placed
+ *
+ * find_get_pages_contig() works exactly like find_get_pages(), except
+ * that the returned number of pages are guaranteed to be contiguous.
+ *
+ * find_get_pages_contig() returns the number of pages which were found.
+ */
+unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
+ unsigned int nr_pages, struct page **pages)
+{
+ struct radix_tree_iter iter;
+ void **slot;
+ unsigned int ret = 0;
+
+ if (unlikely(!nr_pages))
+ return 0;
+
+ rcu_read_lock();
+restart:
+ radix_tree_for_each_contig(slot, &mapping->page_tree, &iter, index) {
+ struct page *page;
+repeat:
+ page = radix_tree_deref_slot(slot);
+ /* The hole, there no reason to continue */
+ if (unlikely(!page))
+ break;
+
+ if (radix_tree_exception(page)) {
+ if (radix_tree_deref_retry(page)) {
+ /*
+ * Transient condition which can only trigger
+ * when entry at index 0 moves out of or back
+ * to root: none yet gotten, safe to restart.
+ */
+ goto restart;
+ }
+ /*
+ * Otherwise, shmem/tmpfs must be storing a swap entry
+ * here as an exceptional entry: so stop looking for
+ * contiguous pages.
+ */
+ break;
+ }
+
+ if (!page_cache_get_speculative(page))
+ goto repeat;
+
+ /* Has the page moved? */
+ if (unlikely(page != *slot)) {
+ page_cache_release(page);
+ goto repeat;
+ }
+
+ /*
+ * must check mapping and index after taking the ref.
+ * otherwise we can get both false positives and false
+ * negatives, which is just confusing to the caller.
+ */
+ if (page->mapping == NULL || page->index != iter.index) {
+ page_cache_release(page);
+ break;
+ }
+
+ pages[ret] = page;
+ if (++ret == nr_pages)
+ break;
+ }
+ rcu_read_unlock();
+ return ret;
+}
+EXPORT_SYMBOL(find_get_pages_contig);
+
+/**
+ * find_get_pages_tag - find and return pages that match @tag
+ * @mapping: the address_space to search
+ * @index: the starting page index
+ * @tag: the tag index
+ * @nr_pages: the maximum number of pages
+ * @pages: where the resulting pages are placed
+ *
+ * Like find_get_pages, except we only return pages which are tagged with
+ * @tag. We update @index to index the next page for the traversal.
+ */
+unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index,
+ int tag, unsigned int nr_pages, struct page **pages)
+{
+ struct radix_tree_iter iter;
+ void **slot;
+ unsigned ret = 0;
+
+ if (unlikely(!nr_pages))
+ return 0;
+
+ rcu_read_lock();
+restart:
+ radix_tree_for_each_tagged(slot, &mapping->page_tree,
+ &iter, *index, tag) {
+ struct page *page;
+repeat:
+ page = radix_tree_deref_slot(slot);
+ if (unlikely(!page))
+ continue;
+
+ if (radix_tree_exception(page)) {
+ if (radix_tree_deref_retry(page)) {
+ /*
+ * Transient condition which can only trigger
+ * when entry at index 0 moves out of or back
+ * to root: none yet gotten, safe to restart.
+ */
+ goto restart;
+ }
+ /*
+ * This function is never used on a shmem/tmpfs
+ * mapping, so a swap entry won't be found here.
+ */
+ BUG();
+ }
+
+ if (!page_cache_get_speculative(page))
+ goto repeat;
+
+ /* Has the page moved? */
+ if (unlikely(page != *slot)) {
+ page_cache_release(page);
+ goto repeat;
+ }
+
+ pages[ret] = page;
+ if (++ret == nr_pages)
+ break;
+ }
+
+ rcu_read_unlock();
+
+ if (ret)
+ *index = pages[ret - 1]->index + 1;
+
+ return ret;
+}
+EXPORT_SYMBOL(find_get_pages_tag);
+
+/**
+ * grab_cache_page_nowait - returns locked page at given index in given cache
+ * @mapping: target address_space
+ * @index: the page index
+ *
+ * Same as grab_cache_page(), but do not wait if the page is unavailable.
+ * This is intended for speculative data generators, where the data can
+ * be regenerated if the page couldn't be grabbed. This routine should
+ * be safe to call while holding the lock for another page.
+ *
+ * Clear __GFP_FS when allocating the page to avoid recursion into the fs
+ * and deadlock against the caller's locked page.
+ */
+struct page *
+grab_cache_page_nowait(struct address_space *mapping, pgoff_t index)
+{
+ struct page *page = find_get_page(mapping, index);
+
+ if (page) {
+ if (trylock_page(page))
+ return page;
+ page_cache_release(page);
+ return NULL;
+ }
+ page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~__GFP_FS);
+ if (page && add_to_page_cache_lru(page, mapping, index, GFP_NOFS)) {
+ page_cache_release(page);
+ page = NULL;
+ }
+ return page;
+}
+EXPORT_SYMBOL(grab_cache_page_nowait);
+
+/*
+ * CD/DVDs are error prone. When a medium error occurs, the driver may fail
+ * a _large_ part of the i/o request. Imagine the worst scenario:
+ *
+ * ---R__________________________________________B__________
+ * ^ reading here ^ bad block(assume 4k)
+ *
+ * read(R) => miss => readahead(R...B) => media error => frustrating retries
+ * => failing the whole request => read(R) => read(R+1) =>
+ * readahead(R+1...B+1) => bang => read(R+2) => read(R+3) =>
+ * readahead(R+3...B+2) => bang => read(R+3) => read(R+4) =>
+ * readahead(R+4...B+3) => bang => read(R+4) => read(R+5) => ......
+ *
+ * It is going insane. Fix it by quickly scaling down the readahead size.
+ */
+static void shrink_readahead_size_eio(struct file *filp,
+ struct file_ra_state *ra)
+{
+ ra->ra_pages /= 4;
+}
+
+/**
+ * do_generic_file_read - generic file read routine
+ * @filp: the file to read
+ * @ppos: current file position
+ * @desc: read_descriptor
+ * @actor: read method
+ *
+ * This is a generic file read routine, and uses the
+ * mapping->a_ops->readpage() function for the actual low-level stuff.
+ *
+ * This is really ugly. But the goto's actually try to clarify some
+ * of the logic when it comes to error handling etc.
+ */
+static void do_generic_file_read(struct file *filp, loff_t *ppos,
+ read_descriptor_t *desc, read_actor_t actor)
+{
+ struct address_space *mapping = filp->f_mapping;
+ struct inode *inode = mapping->host;
+ struct file_ra_state *ra = &filp->f_ra;
+ pgoff_t index;
+ pgoff_t last_index;
+ pgoff_t prev_index;
+ unsigned long offset; /* offset into pagecache page */
+ unsigned int prev_offset;
+ int error;
+
+ index = *ppos >> PAGE_CACHE_SHIFT;
+ prev_index = ra->prev_pos >> PAGE_CACHE_SHIFT;
+ prev_offset = ra->prev_pos & (PAGE_CACHE_SIZE-1);
+ last_index = (*ppos + desc->count + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT;
+ offset = *ppos & ~PAGE_CACHE_MASK;
+
+ for (;;) {
+ struct page *page;
+ pgoff_t end_index;
+ loff_t isize;
+ unsigned long nr, ret;
+
+ cond_resched();
+find_page:
+ page = find_get_page(mapping, index);
+ if (!page) {
+ page_cache_sync_readahead(mapping,
+ ra, filp,
+ index, last_index - index);
+ page = find_get_page(mapping, index);
+ if (unlikely(page == NULL))
+ goto no_cached_page;
+ }
+ if (PageReadahead(page)) {
+ page_cache_async_readahead(mapping,
+ ra, filp, page,
+ index, last_index - index);
+ }
+ if (!PageUptodate(page)) {
+ if (inode->i_blkbits == PAGE_CACHE_SHIFT ||
+ !mapping->a_ops->is_partially_uptodate)
+ goto page_not_up_to_date;
+ if (!trylock_page(page))
+ goto page_not_up_to_date;
+ /* Did it get truncated before we got the lock? */
+ if (!page->mapping)
+ goto page_not_up_to_date_locked;
+ if (!mapping->a_ops->is_partially_uptodate(page,
+ desc, offset))
+ goto page_not_up_to_date_locked;
+ unlock_page(page);
+ }
+page_ok:
+ /*
+ * i_size must be checked after we know the page is Uptodate.
+ *
+ * Checking i_size after the check allows us to calculate
+ * the correct value for "nr", which means the zero-filled
+ * part of the page is not copied back to userspace (unless
+ * another truncate extends the file - this is desired though).
+ */
+
+ isize = i_size_read(inode);
+ end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
+ if (unlikely(!isize || index > end_index)) {
+ page_cache_release(page);
+ goto out;
+ }
+
+ /* nr is the maximum number of bytes to copy from this page */
+ nr = PAGE_CACHE_SIZE;
+ if (index == end_index) {
+ nr = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
+ if (nr <= offset) {
+ page_cache_release(page);
+ goto out;
+ }
+ }
+ nr = nr - offset;
+
+ /* If users can be writing to this page using arbitrary
+ * virtual addresses, take care about potential aliasing
+ * before reading the page on the kernel side.
+ */
+ if (mapping_writably_mapped(mapping))
+ flush_dcache_page(page);
+
+ /*
+ * When a sequential read accesses a page several times,
+ * only mark it as accessed the first time.
+ */
+ if (prev_index != index || offset != prev_offset)
+ mark_page_accessed(page);
+ prev_index = index;
+
+ /*
+ * Ok, we have the page, and it's up-to-date, so
+ * now we can copy it to user space...
+ *
+ * The actor routine returns how many bytes were actually used..
+ * NOTE! This may not be the same as how much of a user buffer
+ * we filled up (we may be padding etc), so we can only update
+ * "pos" here (the actor routine has to update the user buffer
+ * pointers and the remaining count).
+ */
+ ret = actor(desc, page, offset, nr);
+ offset += ret;
+ index += offset >> PAGE_CACHE_SHIFT;
+ offset &= ~PAGE_CACHE_MASK;
+ prev_offset = offset;
+
+ page_cache_release(page);
+ if (ret == nr && desc->count)
+ continue;
+ goto out;
+
+page_not_up_to_date:
+ /* Get exclusive access to the page ... */
+ error = lock_page_killable(page);
+ if (unlikely(error))
+ goto readpage_error;
+
+page_not_up_to_date_locked:
+ /* Did it get truncated before we got the lock? */
+ if (!page->mapping) {
+ unlock_page(page);
+ page_cache_release(page);
+ continue;
+ }
+
+ /* Did somebody else fill it already? */
+ if (PageUptodate(page)) {
+ unlock_page(page);
+ goto page_ok;
+ }
+
+readpage:
+ /*
+ * A previous I/O error may have been due to temporary
+ * failures, eg. multipath errors.
+ * PG_error will be set again if readpage fails.
+ */
+ ClearPageError(page);
+ /* Start the actual read. The read will unlock the page. */
+ error = mapping->a_ops->readpage(filp, page);
+
+ if (unlikely(error)) {
+ if (error == AOP_TRUNCATED_PAGE) {
+ page_cache_release(page);
+ goto find_page;
+ }
+ goto readpage_error;
+ }
+
+ if (!PageUptodate(page)) {
+ error = lock_page_killable(page);
+ if (unlikely(error))
+ goto readpage_error;
+ if (!PageUptodate(page)) {
+ if (page->mapping == NULL) {
+ /*
+ * invalidate_mapping_pages got it
+ */
+ unlock_page(page);
+ page_cache_release(page);
+ goto find_page;
+ }
+ unlock_page(page);
+ shrink_readahead_size_eio(filp, ra);
+ error = -EIO;
+ goto readpage_error;
+ }
+ unlock_page(page);
+ }
+
+ goto page_ok;
+
+readpage_error:
+ /* UHHUH! A synchronous read error occurred. Report it */
+ desc->error = error;
+ page_cache_release(page);
+ goto out;
+
+no_cached_page:
+ /*
+ * Ok, it wasn't cached, so we need to create a new
+ * page..
+ */
+ page = page_cache_alloc_cold(mapping);
+ if (!page) {
+ desc->error = -ENOMEM;
+ goto out;
+ }
+ error = add_to_page_cache_lru(page, mapping,
+ index, GFP_KERNEL);
+ if (error) {
+ page_cache_release(page);
+ if (error == -EEXIST)
+ goto find_page;
+ desc->error = error;
+ goto out;
+ }
+ goto readpage;
+ }
+
+out:
+ ra->prev_pos = prev_index;
+ ra->prev_pos <<= PAGE_CACHE_SHIFT;
+ ra->prev_pos |= prev_offset;
+
+ *ppos = ((loff_t)index << PAGE_CACHE_SHIFT) + offset;
+ file_accessed(filp);
+}
+
+int file_read_actor(read_descriptor_t *desc, struct page *page,
+ unsigned long offset, unsigned long size)
+{
+ char *kaddr;
+ unsigned long left, count = desc->count;
+
+ if (size > count)
+ size = count;
+
+ /*
+ * Faults on the destination of a read are common, so do it before
+ * taking the kmap.
+ */
+ if (!fault_in_pages_writeable(desc->arg.buf, size)) {
+ kaddr = kmap_atomic(page);
+ left = __copy_to_user_inatomic(desc->arg.buf,
+ kaddr + offset, size);
+ kunmap_atomic(kaddr);
+ if (left == 0)
+ goto success;
+ }
+
+ /* Do it the slow way */
+ kaddr = kmap(page);
+ left = __copy_to_user(desc->arg.buf, kaddr + offset, size);
+ kunmap(page);
+
+ if (left) {
+ size -= left;
+ desc->error = -EFAULT;
+ }
+success:
+ desc->count = count - size;
+ desc->written += size;
+ desc->arg.buf += size;
+ return size;
+}
+
+/*
+ * Performs necessary checks before doing a write
+ * @iov: io vector request
+ * @nr_segs: number of segments in the iovec
+ * @count: number of bytes to write
+ * @access_flags: type of access: %VERIFY_READ or %VERIFY_WRITE
+ *
+ * Adjust number of segments and amount of bytes to write (nr_segs should be
+ * properly initialized first). Returns appropriate error code that caller
+ * should return or zero in case that write should be allowed.
+ */
+int generic_segment_checks(const struct iovec *iov,
+ unsigned long *nr_segs, size_t *count, int access_flags)
+{
+ unsigned long seg;
+ size_t cnt = 0;
+ for (seg = 0; seg < *nr_segs; seg++) {
+ const struct iovec *iv = &iov[seg];
+
+ /*
+ * If any segment has a negative length, or the cumulative
+ * length ever wraps negative then return -EINVAL.
+ */
+ cnt += iv->iov_len;
+ if (unlikely((ssize_t)(cnt|iv->iov_len) < 0))
+ return -EINVAL;
+ if (access_ok(access_flags, iv->iov_base, iv->iov_len))
+ continue;
+ if (seg == 0)
+ return -EFAULT;
+ *nr_segs = seg;
+ cnt -= iv->iov_len; /* This segment is no good */
+ break;
+ }
+ *count = cnt;
+ return 0;
+}
+EXPORT_SYMBOL(generic_segment_checks);
+
+/**
+ * generic_file_aio_read - generic filesystem read routine
+ * @iocb: kernel I/O control block
+ * @iov: io vector request
+ * @nr_segs: number of segments in the iovec
+ * @pos: current file position
+ *
+ * This is the "read()" routine for all filesystems
+ * that can use the page cache directly.
+ */
+ssize_t
+generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
+{
+ struct file *filp = iocb->ki_filp;
+ ssize_t retval;
+ unsigned long seg = 0;
+ size_t count;
+ loff_t *ppos = &iocb->ki_pos;
+
+ count = 0;
+ retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
+ if (retval)
+ return retval;
+
+ /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
+ if (filp->f_flags & O_DIRECT) {
+ loff_t size;
+ struct address_space *mapping;
+ struct inode *inode;
+
+ mapping = filp->f_mapping;
+ inode = mapping->host;
+ if (!count)
+ goto out; /* skip atime */
+ size = i_size_read(inode);
+ if (pos < size) {
+ retval = filemap_write_and_wait_range(mapping, pos,
+ pos + iov_length(iov, nr_segs) - 1);
+ if (!retval) {
+ struct blk_plug plug;
+
+ blk_start_plug(&plug);
+ retval = mapping->a_ops->direct_IO(READ, iocb,
+ iov, pos, nr_segs);
+ blk_finish_plug(&plug);
+ }
+ if (retval > 0) {
+ *ppos = pos + retval;
+ count -= retval;
+ }
+
+ /*
+ * Btrfs can have a short DIO read if we encounter
+ * compressed extents, so if there was an error, or if
+ * we've already read everything we wanted to, or if
+ * there was a short read because we hit EOF, go ahead
+ * and return. Otherwise fallthrough to buffered io for
+ * the rest of the read.
+ */
+ if (retval < 0 || !count || *ppos >= size) {
+ file_accessed(filp);
+ goto out;
+ }
+ }
+ }
+
+ count = retval;
+ for (seg = 0; seg < nr_segs; seg++) {
+ read_descriptor_t desc;
+ loff_t offset = 0;
+
+ /*
+ * If we did a short DIO read we need to skip the section of the
+ * iov that we've already read data into.
+ */
+ if (count) {
+ if (count > iov[seg].iov_len) {
+ count -= iov[seg].iov_len;
+ continue;
+ }
+ offset = count;
+ count = 0;
+ }
+
+ desc.written = 0;
+ desc.arg.buf = iov[seg].iov_base + offset;
+ desc.count = iov[seg].iov_len - offset;
+ if (desc.count == 0)
+ continue;
+ desc.error = 0;
+ do_generic_file_read(filp, ppos, &desc, file_read_actor);
+ retval += desc.written;
+ if (desc.error) {
+ retval = retval ?: desc.error;
+ break;
+ }
+ if (desc.count > 0)
+ break;
+ }
+out:
+ return retval;
+}
+EXPORT_SYMBOL(generic_file_aio_read);
+
+static ssize_t
+do_readahead(struct address_space *mapping, struct file *filp,
+ pgoff_t index, unsigned long nr)
+{
+ if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage)
+ return -EINVAL;
+
+ force_page_cache_readahead(mapping, filp, index, nr);
+ return 0;
+}
+
+SYSCALL_DEFINE(readahead)(int fd, loff_t offset, size_t count)
+{
+ ssize_t ret;
+ struct file *file;
+
+ ret = -EBADF;
+ file = fget(fd);
+ if (file) {
+ if (file->f_mode & FMODE_READ) {
+ struct address_space *mapping = file->f_mapping;
+ pgoff_t start = offset >> PAGE_CACHE_SHIFT;
+ pgoff_t end = (offset + count - 1) >> PAGE_CACHE_SHIFT;
+ unsigned long len = end - start + 1;
+ ret = do_readahead(mapping, file, start, len);
+ }
+ fput(file);
+ }
+ return ret;
+}
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_readahead(long fd, loff_t offset, long count)
+{
+ return SYSC_readahead((int) fd, offset, (size_t) count);
+}
+SYSCALL_ALIAS(sys_readahead, SyS_readahead);
+#endif
+
+#ifdef CONFIG_MMU
+/**
+ * page_cache_read - adds requested page to the page cache if not already there
+ * @file: file to read
+ * @offset: page index
+ *
+ * This adds the requested page to the page cache if it isn't already there,
+ * and schedules an I/O to read in its contents from disk.
+ */
+static int page_cache_read(struct file *file, pgoff_t offset)
+{
+ struct address_space *mapping = file->f_mapping;
+ struct page *page;
+ int ret;
+
+ do {
+ page = page_cache_alloc_cold(mapping);
+ if (!page)
+ return -ENOMEM;
+
+ ret = add_to_page_cache_lru(page, mapping, offset, GFP_KERNEL);
+ if (ret == 0)
+ ret = mapping->a_ops->readpage(file, page);
+ else if (ret == -EEXIST)
+ ret = 0; /* losing race to add is OK */
+
+ page_cache_release(page);
+
+ } while (ret == AOP_TRUNCATED_PAGE);
+
+ return ret;
+}
+
+#define MMAP_LOTSAMISS (100)
+
+/*
+ * Synchronous readahead happens when we don't even find
+ * a page in the page cache at all.
+ */
+static void do_sync_mmap_readahead(struct vm_area_struct *vma,
+ struct file_ra_state *ra,
+ struct file *file,
+ pgoff_t offset)
+{
+ unsigned long ra_pages;
+ struct address_space *mapping = file->f_mapping;
+
+ /* If we don't want any read-ahead, don't bother */
+ if (VM_RandomReadHint(vma))
+ return;
+ if (!ra->ra_pages)
+ return;
+
+ if (VM_SequentialReadHint(vma)) {
+ page_cache_sync_readahead(mapping, ra, file, offset,
+ ra->ra_pages);
+ return;
+ }
+
+ /* Avoid banging the cache line if not needed */
+ if (ra->mmap_miss < MMAP_LOTSAMISS * 10)
+ ra->mmap_miss++;
+
+ /*
+ * Do we miss much more than hit in this file? If so,
+ * stop bothering with read-ahead. It will only hurt.
+ */
+ if (ra->mmap_miss > MMAP_LOTSAMISS)
+ return;
+
+ /*
+ * mmap read-around
+ */
+ ra_pages = max_sane_readahead(ra->ra_pages);
+ ra->start = max_t(long, 0, offset - ra_pages / 2);
+ ra->size = ra_pages;
+ ra->async_size = ra_pages / 4;
+ ra_submit(ra, mapping, file);
+}
+
+/*
+ * Asynchronous readahead happens when we find the page and PG_readahead,
+ * so we want to possibly extend the readahead further..
+ */
+static void do_async_mmap_readahead(struct vm_area_struct *vma,
+ struct file_ra_state *ra,
+ struct file *file,
+ struct page *page,
+ pgoff_t offset)
+{
+ struct address_space *mapping = file->f_mapping;
+
+ /* If we don't want any read-ahead, don't bother */
+ if (VM_RandomReadHint(vma))
+ return;
+ if (ra->mmap_miss > 0)
+ ra->mmap_miss--;
+ if (PageReadahead(page))
+ page_cache_async_readahead(mapping, ra, file,
+ page, offset, ra->ra_pages);
+}
+
+/**
+ * filemap_fault - read in file data for page fault handling
+ * @vma: vma in which the fault was taken
+ * @vmf: struct vm_fault containing details of the fault
+ *
+ * filemap_fault() is invoked via the vma operations vector for a
+ * mapped memory region to read in file data during a page fault.
+ *
+ * The goto's are kind of ugly, but this streamlines the normal case of having
+ * it in the page cache, and handles the special cases reasonably without
+ * having a lot of duplicated code.
+ */
+int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ int error;
+ struct file *file = vma->vm_file;
+ struct address_space *mapping = file->f_mapping;
+ struct file_ra_state *ra = &file->f_ra;
+ struct inode *inode = mapping->host;
+ pgoff_t offset = vmf->pgoff;
+ struct page *page;
+ pgoff_t size;
+ int ret = 0;
+
+ size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ if (offset >= size)
+ return VM_FAULT_SIGBUS;
+
+ /*
+ * Do we have something in the page cache already?
+ */
+ page = find_get_page(mapping, offset);
+ if (likely(page)) {
+ /*
+ * We found the page, so try async readahead before
+ * waiting for the lock.
+ */
+ do_async_mmap_readahead(vma, ra, file, page, offset);
+ } else {
+ /* No page in the page cache at all */
+ do_sync_mmap_readahead(vma, ra, file, offset);
+ count_vm_event(PGMAJFAULT);
+ mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT);
+ ret = VM_FAULT_MAJOR;
+retry_find:
+ page = find_get_page(mapping, offset);
+ if (!page)
+ goto no_cached_page;
+ }
+
+ if (!lock_page_or_retry(page, vma->vm_mm, vmf->flags)) {
+ page_cache_release(page);
+ return ret | VM_FAULT_RETRY;
+ }
+
+ /* Did it get truncated? */
+ if (unlikely(page->mapping != mapping)) {
+ unlock_page(page);
+ put_page(page);
+ goto retry_find;
+ }
+ VM_BUG_ON(page->index != offset);
+
+ /*
+ * We have a locked page in the page cache, now we need to check
+ * that it's up-to-date. If not, it is going to be due to an error.
+ */
+ if (unlikely(!PageUptodate(page)))
+ goto page_not_uptodate;
+
+ /*
+ * Found the page and have a reference on it.
+ * We must recheck i_size under page lock.
+ */
+ size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ if (unlikely(offset >= size)) {
+ unlock_page(page);
+ page_cache_release(page);
+ return VM_FAULT_SIGBUS;
+ }
+
+ vmf->page = page;
+ return ret | VM_FAULT_LOCKED;
+
+no_cached_page:
+ /*
+ * We're only likely to ever get here if MADV_RANDOM is in
+ * effect.
+ */
+ error = page_cache_read(file, offset);
+
+ /*
+ * The page we want has now been added to the page cache.
+ * In the unlikely event that someone removed it in the
+ * meantime, we'll just come back here and read it again.
+ */
+ if (error >= 0)
+ goto retry_find;
+
+ /*
+ * An error return from page_cache_read can result if the
+ * system is low on memory, or a problem occurs while trying
+ * to schedule I/O.
+ */
+ if (error == -ENOMEM)
+ return VM_FAULT_OOM;
+ return VM_FAULT_SIGBUS;
+
+page_not_uptodate:
+ /*
+ * Umm, take care of errors if the page isn't up-to-date.
+ * Try to re-read it _once_. We do this synchronously,
+ * because there really aren't any performance issues here
+ * and we need to check for errors.
+ */
+ ClearPageError(page);
+ error = mapping->a_ops->readpage(file, page);
+ if (!error) {
+ wait_on_page_locked(page);
+ if (!PageUptodate(page))
+ error = -EIO;
+ }
+ page_cache_release(page);
+
+ if (!error || error == AOP_TRUNCATED_PAGE)
+ goto retry_find;
+
+ /* Things didn't work out. Return zero to tell the mm layer so. */
+ shrink_readahead_size_eio(file, ra);
+ return VM_FAULT_SIGBUS;
+}
+EXPORT_SYMBOL(filemap_fault);
+
+const struct vm_operations_struct generic_file_vm_ops = {
+ .fault = filemap_fault,
+};
+
+/* This is used for a general mmap of a disk file */
+
+int generic_file_mmap(struct file * file, struct vm_area_struct * vma)
+{
+ struct address_space *mapping = file->f_mapping;
+
+ if (!mapping->a_ops->readpage)
+ return -ENOEXEC;
+ file_accessed(file);
+ vma->vm_ops = &generic_file_vm_ops;
+ vma->vm_flags |= VM_CAN_NONLINEAR;
+ return 0;
+}
+
+/*
+ * This is for filesystems which do not implement ->writepage.
+ */
+int generic_file_readonly_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
+ return -EINVAL;
+ return generic_file_mmap(file, vma);
+}
+#else
+int generic_file_mmap(struct file * file, struct vm_area_struct * vma)
+{
+ return -ENOSYS;
+}
+int generic_file_readonly_mmap(struct file * file, struct vm_area_struct * vma)
+{
+ return -ENOSYS;
+}
+#endif /* CONFIG_MMU */
+
+EXPORT_SYMBOL(generic_file_mmap);
+EXPORT_SYMBOL(generic_file_readonly_mmap);
+
+static struct page *__read_cache_page(struct address_space *mapping,
+ pgoff_t index,
+ int (*filler)(void *, struct page *),
+ void *data,
+ gfp_t gfp)
+{
+ struct page *page;
+ int err;
+repeat:
+ page = find_get_page(mapping, index);
+ if (!page) {
+ page = __page_cache_alloc(gfp | __GFP_COLD);
+ if (!page)
+ return ERR_PTR(-ENOMEM);
+ err = add_to_page_cache_lru(page, mapping, index, gfp);
+ if (unlikely(err)) {
+ page_cache_release(page);
+ if (err == -EEXIST)
+ goto repeat;
+ /* Presumably ENOMEM for radix tree node */
+ return ERR_PTR(err);
+ }
+ err = filler(data, page);
+ if (err < 0) {
+ page_cache_release(page);
+ page = ERR_PTR(err);
+ }
+ }
+ return page;
+}
+
+static struct page *do_read_cache_page(struct address_space *mapping,
+ pgoff_t index,
+ int (*filler)(void *, struct page *),
+ void *data,
+ gfp_t gfp)
+
+{
+ struct page *page;
+ int err;
+
+retry:
+ page = __read_cache_page(mapping, index, filler, data, gfp);
+ if (IS_ERR(page))
+ return page;
+ if (PageUptodate(page))
+ goto out;
+
+ lock_page(page);
+ if (!page->mapping) {
+ unlock_page(page);
+ page_cache_release(page);
+ goto retry;
+ }
+ if (PageUptodate(page)) {
+ unlock_page(page);
+ goto out;
+ }
+ err = filler(data, page);
+ if (err < 0) {
+ page_cache_release(page);
+ return ERR_PTR(err);
+ }
+out:
+ mark_page_accessed(page);
+ return page;
+}
+
+/**
+ * read_cache_page_async - read into page cache, fill it if needed
+ * @mapping: the page's address_space
+ * @index: the page index
+ * @filler: function to perform the read
+ * @data: first arg to filler(data, page) function, often left as NULL
+ *
+ * Same as read_cache_page, but don't wait for page to become unlocked
+ * after submitting it to the filler.
+ *
+ * Read into the page cache. If a page already exists, and PageUptodate() is
+ * not set, try to fill the page but don't wait for it to become unlocked.
+ *
+ * If the page does not get brought uptodate, return -EIO.
+ */
+struct page *read_cache_page_async(struct address_space *mapping,
+ pgoff_t index,
+ int (*filler)(void *, struct page *),
+ void *data)
+{
+ return do_read_cache_page(mapping, index, filler, data, mapping_gfp_mask(mapping));
+}
+EXPORT_SYMBOL(read_cache_page_async);
+
+static struct page *wait_on_page_read(struct page *page)
+{
+ if (!IS_ERR(page)) {
+ wait_on_page_locked(page);
+ if (!PageUptodate(page)) {
+ page_cache_release(page);
+ page = ERR_PTR(-EIO);
+ }
+ }
+ return page;
+}
+
+/**
+ * read_cache_page_gfp - read into page cache, using specified page allocation flags.
+ * @mapping: the page's address_space
+ * @index: the page index
+ * @gfp: the page allocator flags to use if allocating
+ *
+ * This is the same as "read_mapping_page(mapping, index, NULL)", but with
+ * any new page allocations done using the specified allocation flags.
+ *
+ * If the page does not get brought uptodate, return -EIO.
+ */
+struct page *read_cache_page_gfp(struct address_space *mapping,
+ pgoff_t index,
+ gfp_t gfp)
+{
+ filler_t *filler = (filler_t *)mapping->a_ops->readpage;
+
+ return wait_on_page_read(do_read_cache_page(mapping, index, filler, NULL, gfp));
+}
+EXPORT_SYMBOL(read_cache_page_gfp);
+
+/**
+ * read_cache_page - read into page cache, fill it if needed
+ * @mapping: the page's address_space
+ * @index: the page index
+ * @filler: function to perform the read
+ * @data: first arg to filler(data, page) function, often left as NULL
+ *
+ * Read into the page cache. If a page already exists, and PageUptodate() is
+ * not set, try to fill the page then wait for it to become unlocked.
+ *
+ * If the page does not get brought uptodate, return -EIO.
+ */
+struct page *read_cache_page(struct address_space *mapping,
+ pgoff_t index,
+ int (*filler)(void *, struct page *),
+ void *data)
+{
+ return wait_on_page_read(read_cache_page_async(mapping, index, filler, data));
+}
+EXPORT_SYMBOL(read_cache_page);
+
+/*
+ * The logic we want is
+ *
+ * if suid or (sgid and xgrp)
+ * remove privs
+ */
+int should_remove_suid(struct dentry *dentry)
+{
+ umode_t mode = dentry->d_inode->i_mode;
+ int kill = 0;
+
+ /* suid always must be killed */
+ if (unlikely(mode & S_ISUID))
+ kill = ATTR_KILL_SUID;
+
+ /*
+ * sgid without any exec bits is just a mandatory locking mark; leave
+ * it alone. If some exec bits are set, it's a real sgid; kill it.
+ */
+ if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
+ kill |= ATTR_KILL_SGID;
+
+ if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))
+ return kill;
+
+ return 0;
+}
+EXPORT_SYMBOL(should_remove_suid);
+
+static int __remove_suid(struct dentry *dentry, int kill)
+{
+ struct iattr newattrs;
+
+ newattrs.ia_valid = ATTR_FORCE | kill;
+ return notify_change(dentry, &newattrs);
+}
+
+int file_remove_suid(struct file *file)
+{
+ struct dentry *dentry = file->f_path.dentry;
+ struct inode *inode = dentry->d_inode;
+ int killsuid;
+ int killpriv;
+ int error = 0;
+
+ /* Fast path for nothing security related */
+ if (IS_NOSEC(inode))
+ return 0;
+
+ killsuid = should_remove_suid(dentry);
+ killpriv = security_inode_need_killpriv(dentry);
+
+ if (killpriv < 0)
+ return killpriv;
+ if (killpriv)
+ error = security_inode_killpriv(dentry);
+ if (!error && killsuid)
+ error = __remove_suid(dentry, killsuid);
+ if (!error && (inode->i_sb->s_flags & MS_NOSEC))
+ inode->i_flags |= S_NOSEC;
+
+ return error;
+}
+EXPORT_SYMBOL(file_remove_suid);
+
+static size_t __iovec_copy_from_user_inatomic(char *vaddr,
+ const struct iovec *iov, size_t base, size_t bytes)
+{
+ size_t copied = 0, left = 0;
+
+ while (bytes) {
+ char __user *buf = iov->iov_base + base;
+ int copy = min(bytes, iov->iov_len - base);
+
+ base = 0;
+ left = __copy_from_user_inatomic(vaddr, buf, copy);
+ copied += copy;
+ bytes -= copy;
+ vaddr += copy;
+ iov++;
+
+ if (unlikely(left))
+ break;
+ }
+ return copied - left;
+}
+
+/*
+ * Copy as much as we can into the page and return the number of bytes which
+ * were successfully copied. If a fault is encountered then return the number of
+ * bytes which were copied.
+ */
+size_t iov_iter_copy_from_user_atomic(struct page *page,
+ struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+ char *kaddr;
+ size_t copied;
+
+ BUG_ON(!pagefault_disabled());
+ kaddr = kmap_atomic(page);
+ if (likely(i->nr_segs == 1)) {
+ int left;
+ char __user *buf = i->iov->iov_base + i->iov_offset;
+ left = __copy_from_user_inatomic(kaddr + offset, buf, bytes);
+ copied = bytes - left;
+ } else {
+ copied = __iovec_copy_from_user_inatomic(kaddr + offset,
+ i->iov, i->iov_offset, bytes);
+ }
+ kunmap_atomic(kaddr);
+
+ return copied;
+}
+EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
+
+/*
+ * This has the same sideeffects and return value as
+ * iov_iter_copy_from_user_atomic().
+ * The difference is that it attempts to resolve faults.
+ * Page must not be locked.
+ */
+size_t iov_iter_copy_from_user(struct page *page,
+ struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+ char *kaddr;
+ size_t copied;
+
+ kaddr = kmap(page);
+ if (likely(i->nr_segs == 1)) {
+ int left;
+ char __user *buf = i->iov->iov_base + i->iov_offset;
+ left = __copy_from_user(kaddr + offset, buf, bytes);
+ copied = bytes - left;
+ } else {
+ copied = __iovec_copy_from_user_inatomic(kaddr + offset,
+ i->iov, i->iov_offset, bytes);
+ }
+ kunmap(page);
+ return copied;
+}
+EXPORT_SYMBOL(iov_iter_copy_from_user);
+
+void iov_iter_advance(struct iov_iter *i, size_t bytes)
+{
+ BUG_ON(i->count < bytes);
+
+ if (likely(i->nr_segs == 1)) {
+ i->iov_offset += bytes;
+ i->count -= bytes;
+ } else {
+ const struct iovec *iov = i->iov;
+ size_t base = i->iov_offset;
+ unsigned long nr_segs = i->nr_segs;
+
+ /*
+ * The !iov->iov_len check ensures we skip over unlikely
+ * zero-length segments (without overruning the iovec).
+ */
+ while (bytes || unlikely(i->count && !iov->iov_len)) {
+ int copy;
+
+ copy = min(bytes, iov->iov_len - base);
+ BUG_ON(!i->count || i->count < copy);
+ i->count -= copy;
+ bytes -= copy;
+ base += copy;
+ if (iov->iov_len == base) {
+ iov++;
+ nr_segs--;
+ base = 0;
+ }
+ }
+ i->iov = iov;
+ i->iov_offset = base;
+ i->nr_segs = nr_segs;
+ }
+}
+EXPORT_SYMBOL(iov_iter_advance);
+
+/*
+ * Fault in the first iovec of the given iov_iter, to a maximum length
+ * of bytes. Returns 0 on success, or non-zero if the memory could not be
+ * accessed (ie. because it is an invalid address).
+ *
+ * writev-intensive code may want this to prefault several iovecs -- that
+ * would be possible (callers must not rely on the fact that _only_ the
+ * first iovec will be faulted with the current implementation).
+ */
+int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
+{
+ char __user *buf = i->iov->iov_base + i->iov_offset;
+ bytes = min(bytes, i->iov->iov_len - i->iov_offset);
+ return fault_in_pages_readable(buf, bytes);
+}
+EXPORT_SYMBOL(iov_iter_fault_in_readable);
+
+/*
+ * Return the count of just the current iov_iter segment.
+ */
+size_t iov_iter_single_seg_count(struct iov_iter *i)
+{
+ const struct iovec *iov = i->iov;
+ if (i->nr_segs == 1)
+ return i->count;
+ else
+ return min(i->count, iov->iov_len - i->iov_offset);
+}
+EXPORT_SYMBOL(iov_iter_single_seg_count);
+
+/*
+ * Performs necessary checks before doing a write
+ *
+ * Can adjust writing position or amount of bytes to write.
+ * Returns appropriate error code that caller should return or
+ * zero in case that write should be allowed.
+ */
+inline int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk)
+{
+ struct inode *inode = file->f_mapping->host;
+ unsigned long limit = rlimit(RLIMIT_FSIZE);
+
+ if (unlikely(*pos < 0))
+ return -EINVAL;
+
+ if (!isblk) {
+ /* FIXME: this is for backwards compatibility with 2.4 */
+ if (file->f_flags & O_APPEND)
+ *pos = i_size_read(inode);
+
+ if (limit != RLIM_INFINITY) {
+ if (*pos >= limit) {
+ send_sig(SIGXFSZ, current, 0);
+ return -EFBIG;
+ }
+ if (*count > limit - (typeof(limit))*pos) {
+ *count = limit - (typeof(limit))*pos;
+ }
+ }
+ }
+
+ /*
+ * LFS rule
+ */
+ if (unlikely(*pos + *count > MAX_NON_LFS &&
+ !(file->f_flags & O_LARGEFILE))) {
+ if (*pos >= MAX_NON_LFS) {
+ return -EFBIG;
+ }
+ if (*count > MAX_NON_LFS - (unsigned long)*pos) {
+ *count = MAX_NON_LFS - (unsigned long)*pos;
+ }
+ }
+
+ /*
+ * Are we about to exceed the fs block limit ?
+ *
+ * If we have written data it becomes a short write. If we have
+ * exceeded without writing data we send a signal and return EFBIG.
+ * Linus frestrict idea will clean these up nicely..
+ */
+ if (likely(!isblk)) {
+ if (unlikely(*pos >= inode->i_sb->s_maxbytes)) {
+ if (*count || *pos > inode->i_sb->s_maxbytes) {
+ return -EFBIG;
+ }
+ /* zero-length writes at ->s_maxbytes are OK */
+ }
+
+ if (unlikely(*pos + *count > inode->i_sb->s_maxbytes))
+ *count = inode->i_sb->s_maxbytes - *pos;
+ } else {
+#ifdef CONFIG_BLOCK
+ loff_t isize;
+ if (bdev_read_only(I_BDEV(inode)))
+ return -EPERM;
+ isize = i_size_read(inode);
+ if (*pos >= isize) {
+ if (*count || *pos > isize)
+ return -ENOSPC;
+ }
+
+ if (*pos + *count > isize)
+ *count = isize - *pos;
+#else
+ return -EPERM;
+#endif
+ }
+ return 0;
+}
+EXPORT_SYMBOL(generic_write_checks);
+
+int pagecache_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ const struct address_space_operations *aops = mapping->a_ops;
+
+ return aops->write_begin(file, mapping, pos, len, flags,
+ pagep, fsdata);
+}
+EXPORT_SYMBOL(pagecache_write_begin);
+
+int pagecache_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ const struct address_space_operations *aops = mapping->a_ops;
+
+ mark_page_accessed(page);
+ return aops->write_end(file, mapping, pos, len, copied, page, fsdata);
+}
+EXPORT_SYMBOL(pagecache_write_end);
+
+ssize_t
+generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long *nr_segs, loff_t pos, loff_t *ppos,
+ size_t count, size_t ocount)
+{
+ struct file *file = iocb->ki_filp;
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ ssize_t written;
+ size_t write_len;
+ pgoff_t end;
+
+ if (count != ocount)
+ *nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count);
+
+ write_len = iov_length(iov, *nr_segs);
+ end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT;
+
+ written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1);
+ if (written)
+ goto out;
+
+ /*
+ * After a write we want buffered reads to be sure to go to disk to get
+ * the new data. We invalidate clean cached page from the region we're
+ * about to write. We do this *before* the write so that we can return
+ * without clobbering -EIOCBQUEUED from ->direct_IO().
+ */
+ if (mapping->nrpages) {
+ written = invalidate_inode_pages2_range(mapping,
+ pos >> PAGE_CACHE_SHIFT, end);
+ /*
+ * If a page can not be invalidated, return 0 to fall back
+ * to buffered write.
+ */
+ if (written) {
+ if (written == -EBUSY)
+ return 0;
+ goto out;
+ }
+ }
+
+ written = mapping->a_ops->direct_IO(WRITE, iocb, iov, pos, *nr_segs);
+
+ /*
+ * Finally, try again to invalidate clean pages which might have been
+ * cached by non-direct readahead, or faulted in by get_user_pages()
+ * if the source of the write was an mmap'ed region of the file
+ * we're writing. Either one is a pretty crazy thing to do,
+ * so we don't support it 100%. If this invalidation
+ * fails, tough, the write still worked...
+ */
+ if (mapping->nrpages) {
+ invalidate_inode_pages2_range(mapping,
+ pos >> PAGE_CACHE_SHIFT, end);
+ }
+
+ if (written > 0) {
+ pos += written;
+ if (pos > i_size_read(inode) && !S_ISBLK(inode->i_mode)) {
+ i_size_write(inode, pos);
+ mark_inode_dirty(inode);
+ }
+ *ppos = pos;
+ }
+out:
+ return written;
+}
+EXPORT_SYMBOL(generic_file_direct_write);
+
+/*
+ * Find or create a page at the given pagecache position. Return the locked
+ * page. This function is specifically for buffered writes.
+ */
+struct page *grab_cache_page_write_begin(struct address_space *mapping,
+ pgoff_t index, unsigned flags)
+{
+ int status;
+ gfp_t gfp_mask;
+ struct page *page;
+ gfp_t gfp_notmask = 0;
+
+ gfp_mask = mapping_gfp_mask(mapping);
+ if (mapping_cap_account_dirty(mapping))
+ gfp_mask |= __GFP_WRITE;
+ if (flags & AOP_FLAG_NOFS)
+ gfp_notmask = __GFP_FS;
+repeat:
+ page = find_lock_page(mapping, index);
+ if (page)
+ goto found;
+
+ page = __page_cache_alloc(gfp_mask & ~gfp_notmask);
+ if (!page)
+ return NULL;
+ status = add_to_page_cache_lru(page, mapping, index,
+ GFP_KERNEL & ~gfp_notmask);
+ if (unlikely(status)) {
+ page_cache_release(page);
+ if (status == -EEXIST)
+ goto repeat;
+ return NULL;
+ }
+found:
+ wait_on_page_writeback(page);
+ return page;
+}
+EXPORT_SYMBOL(grab_cache_page_write_begin);
+
+static ssize_t generic_perform_write(struct file *file,
+ struct iov_iter *i, loff_t pos)
+{
+ struct address_space *mapping = file->f_mapping;
+ const struct address_space_operations *a_ops = mapping->a_ops;
+ long status = 0;
+ ssize_t written = 0;
+ unsigned int flags = 0;
+
+ /*
+ * Copies from kernel address space cannot fail (NFSD is a big user).
+ */
+ if (segment_eq(get_fs(), KERNEL_DS))
+ flags |= AOP_FLAG_UNINTERRUPTIBLE;
+
+ do {
+ struct page *page;
+ unsigned long offset; /* Offset into pagecache page */
+ unsigned long bytes; /* Bytes to write to page */
+ size_t copied; /* Bytes copied from user */
+ void *fsdata;
+
+ offset = (pos & (PAGE_CACHE_SIZE - 1));
+ bytes = min_t(unsigned long, PAGE_CACHE_SIZE - offset,
+ iov_iter_count(i));
+
+again:
+ /*
+ * Bring in the user page that we will copy from _first_.
+ * Otherwise there's a nasty deadlock on copying from the
+ * same page as we're writing to, without it being marked
+ * up-to-date.
+ *
+ * Not only is this an optimisation, but it is also required
+ * to check that the address is actually valid, when atomic
+ * usercopies are used, below.
+ */
+ if (unlikely(iov_iter_fault_in_readable(i, bytes))) {
+ status = -EFAULT;
+ break;
+ }
+
+ status = a_ops->write_begin(file, mapping, pos, bytes, flags,
+ &page, &fsdata);
+ if (unlikely(status))
+ break;
+
+ if (mapping_writably_mapped(mapping))
+ flush_dcache_page(page);
+
+ pagefault_disable();
+ copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes);
+ pagefault_enable();
+ flush_dcache_page(page);
+
+ mark_page_accessed(page);
+ status = a_ops->write_end(file, mapping, pos, bytes, copied,
+ page, fsdata);
+ if (unlikely(status < 0))
+ break;
+ copied = status;
+
+ cond_resched();
+
+ iov_iter_advance(i, copied);
+ if (unlikely(copied == 0)) {
+ /*
+ * If we were unable to copy any data at all, we must
+ * fall back to a single segment length write.
+ *
+ * If we didn't fallback here, we could livelock
+ * because not all segments in the iov can be copied at
+ * once without a pagefault.
+ */
+ bytes = min_t(unsigned long, PAGE_CACHE_SIZE - offset,
+ iov_iter_single_seg_count(i));
+ goto again;
+ }
+ pos += copied;
+ written += copied;
+
+ balance_dirty_pages_ratelimited(mapping);
+ if (fatal_signal_pending(current)) {
+ status = -EINTR;
+ break;
+ }
+ } while (iov_iter_count(i));
+
+ return written ? written : status;
+}
+
+ssize_t
+generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos, loff_t *ppos,
+ size_t count, ssize_t written)
+{
+ struct file *file = iocb->ki_filp;
+ ssize_t status;
+ struct iov_iter i;
+
+ iov_iter_init(&i, iov, nr_segs, count, written);
+ status = generic_perform_write(file, &i, pos);
+
+ if (likely(status >= 0)) {
+ written += status;
+ *ppos = pos + status;
+ }
+
+ return written ? written : status;
+}
+EXPORT_SYMBOL(generic_file_buffered_write);
+
+/**
+ * __generic_file_aio_write - write data to a file
+ * @iocb: IO state structure (file, offset, etc.)
+ * @iov: vector with data to write
+ * @nr_segs: number of segments in the vector
+ * @ppos: position where to write
+ *
+ * This function does all the work needed for actually writing data to a
+ * file. It does all basic checks, removes SUID from the file, updates
+ * modification times and calls proper subroutines depending on whether we
+ * do direct IO or a standard buffered write.
+ *
+ * It expects i_mutex to be grabbed unless we work on a block device or similar
+ * object which does not need locking at all.
+ *
+ * This function does *not* take care of syncing data in case of O_SYNC write.
+ * A caller has to handle it. This is mainly due to the fact that we want to
+ * avoid syncing under i_mutex.
+ */
+ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t *ppos)
+{
+ struct file *file = iocb->ki_filp;
+ struct address_space * mapping = file->f_mapping;
+ size_t ocount; /* original count */
+ size_t count; /* after file limit checks */
+ struct inode *inode = mapping->host;
+ loff_t pos;
+ ssize_t written;
+ ssize_t err;
+
+ ocount = 0;
+ err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
+ if (err)
+ return err;
+
+ count = ocount;
+ pos = *ppos;
+
+ vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+
+ /* We can write back this queue in page reclaim */
+ current->backing_dev_info = mapping->backing_dev_info;
+ written = 0;
+
+ err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
+ if (err)
+ goto out;
+
+ if (count == 0)
+ goto out;
+
+ err = file_remove_suid(file);
+ if (err)
+ goto out;
+
+ file_update_time(file);
+
+ /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
+ if (unlikely(file->f_flags & O_DIRECT)) {
+ loff_t endbyte;
+ ssize_t written_buffered;
+
+ written = generic_file_direct_write(iocb, iov, &nr_segs, pos,
+ ppos, count, ocount);
+ if (written < 0 || written == count)
+ goto out;
+ /*
+ * direct-io write to a hole: fall through to buffered I/O
+ * for completing the rest of the request.
+ */
+ pos += written;
+ count -= written;
+ written_buffered = generic_file_buffered_write(iocb, iov,
+ nr_segs, pos, ppos, count,
+ written);
+ /*
+ * If generic_file_buffered_write() retuned a synchronous error
+ * then we want to return the number of bytes which were
+ * direct-written, or the error code if that was zero. Note
+ * that this differs from normal direct-io semantics, which
+ * will return -EFOO even if some bytes were written.
+ */
+ if (written_buffered < 0) {
+ err = written_buffered;
+ goto out;
+ }
+
+ /*
+ * We need to ensure that the page cache pages are written to
+ * disk and invalidated to preserve the expected O_DIRECT
+ * semantics.
+ */
+ endbyte = pos + written_buffered - written - 1;
+ err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
+ if (err == 0) {
+ written = written_buffered;
+ invalidate_mapping_pages(mapping,
+ pos >> PAGE_CACHE_SHIFT,
+ endbyte >> PAGE_CACHE_SHIFT);
+ } else {
+ /*
+ * We don't know how much we wrote, so just return
+ * the number of bytes which were direct-written
+ */
+ }
+ } else {
+ written = generic_file_buffered_write(iocb, iov, nr_segs,
+ pos, ppos, count, written);
+ }
+out:
+ current->backing_dev_info = NULL;
+ return written ? written : err;
+}
+EXPORT_SYMBOL(__generic_file_aio_write);
+
+/**
+ * generic_file_aio_write - write data to a file
+ * @iocb: IO state structure
+ * @iov: vector with data to write
+ * @nr_segs: number of segments in the vector
+ * @pos: position in file where to write
+ *
+ * This is a wrapper around __generic_file_aio_write() to be used by most
+ * filesystems. It takes care of syncing the file in case of O_SYNC file
+ * and acquires i_mutex as needed.
+ */
+ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ struct blk_plug plug;
+ ssize_t ret;
+
+ BUG_ON(iocb->ki_pos != pos);
+
+ mutex_lock(&inode->i_mutex);
+ blk_start_plug(&plug);
+ ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
+ mutex_unlock(&inode->i_mutex);
+
+ if (ret > 0 || ret == -EIOCBQUEUED) {
+ ssize_t err;
+
+ err = generic_write_sync(file, pos, ret);
+ if (err < 0 && ret > 0)
+ ret = err;
+ }
+ blk_finish_plug(&plug);
+ return ret;
+}
+EXPORT_SYMBOL(generic_file_aio_write);
+
+/**
+ * try_to_release_page() - release old fs-specific metadata on a page
+ *
+ * @page: the page which the kernel is trying to free
+ * @gfp_mask: memory allocation flags (and I/O mode)
+ *
+ * The address_space is to try to release any data against the page
+ * (presumably at page->private). If the release was successful, return `1'.
+ * Otherwise return zero.
+ *
+ * This may also be called if PG_fscache is set on a page, indicating that the
+ * page is known to the local caching routines.
+ *
+ * The @gfp_mask argument specifies whether I/O may be performed to release
+ * this page (__GFP_IO), and whether the call may block (__GFP_WAIT & __GFP_FS).
+ *
+ */
+int try_to_release_page(struct page *page, gfp_t gfp_mask)
+{
+ struct address_space * const mapping = page->mapping;
+
+ BUG_ON(!PageLocked(page));
+ if (PageWriteback(page))
+ return 0;
+
+ if (mapping && mapping->a_ops->releasepage)
+ return mapping->a_ops->releasepage(page, gfp_mask);
+ return try_to_free_buffers(page);
+}
+
+EXPORT_SYMBOL(try_to_release_page);
diff --git a/ap/os/linux/linux-3.4.x/mm/filemap_xip.c b/ap/os/linux/linux-3.4.x/mm/filemap_xip.c
new file mode 100644
index 0000000..a4eb311
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/filemap_xip.c
@@ -0,0 +1,480 @@
+/*
+ * linux/mm/filemap_xip.c
+ *
+ * Copyright (C) 2005 IBM Corporation
+ * Author: Carsten Otte <cotte@de.ibm.com>
+ *
+ * derived from linux/mm/filemap.c - Copyright (C) Linus Torvalds
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/export.h>
+#include <linux/uio.h>
+#include <linux/rmap.h>
+#include <linux/mmu_notifier.h>
+#include <linux/sched.h>
+#include <linux/seqlock.h>
+#include <linux/mutex.h>
+#include <linux/gfp.h>
+#include <asm/tlbflush.h>
+#include <asm/io.h>
+
+/*
+ * We do use our own empty page to avoid interference with other users
+ * of ZERO_PAGE(), such as /dev/zero
+ */
+static DEFINE_MUTEX(xip_sparse_mutex);
+static seqcount_t xip_sparse_seq = SEQCNT_ZERO;
+static struct page *__xip_sparse_page;
+
+/* called under xip_sparse_mutex */
+static struct page *xip_sparse_page(void)
+{
+ if (!__xip_sparse_page) {
+ struct page *page = alloc_page(GFP_HIGHUSER | __GFP_ZERO);
+
+ if (page)
+ __xip_sparse_page = page;
+ }
+ return __xip_sparse_page;
+}
+
+/*
+ * This is a file read routine for execute in place files, and uses
+ * the mapping->a_ops->get_xip_mem() function for the actual low-level
+ * stuff.
+ *
+ * Note the struct file* is not used at all. It may be NULL.
+ */
+static ssize_t
+do_xip_mapping_read(struct address_space *mapping,
+ struct file_ra_state *_ra,
+ struct file *filp,
+ char __user *buf,
+ size_t len,
+ loff_t *ppos)
+{
+ struct inode *inode = mapping->host;
+ pgoff_t index, end_index;
+ unsigned long offset;
+ loff_t isize, pos;
+ size_t copied = 0, error = 0;
+
+ BUG_ON(!mapping->a_ops->get_xip_mem);
+
+ pos = *ppos;
+ index = pos >> PAGE_CACHE_SHIFT;
+ offset = pos & ~PAGE_CACHE_MASK;
+
+ isize = i_size_read(inode);
+ if (!isize)
+ goto out;
+
+ end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
+ do {
+ unsigned long nr, left;
+ void *xip_mem;
+ unsigned long xip_pfn;
+ int zero = 0;
+
+ /* nr is the maximum number of bytes to copy from this page */
+ nr = PAGE_CACHE_SIZE;
+ if (index >= end_index) {
+ if (index > end_index)
+ goto out;
+ nr = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
+ if (nr <= offset) {
+ goto out;
+ }
+ }
+ nr = nr - offset;
+ if (nr > len - copied)
+ nr = len - copied;
+
+ error = mapping->a_ops->get_xip_mem(mapping, index, 0,
+ &xip_mem, &xip_pfn);
+ if (unlikely(error)) {
+ if (error == -ENODATA) {
+ /* sparse */
+ zero = 1;
+ } else
+ goto out;
+ }
+
+ /* If users can be writing to this page using arbitrary
+ * virtual addresses, take care about potential aliasing
+ * before reading the page on the kernel side.
+ */
+ if (mapping_writably_mapped(mapping))
+ /* address based flush */ ;
+
+ /*
+ * Ok, we have the mem, so now we can copy it to user space...
+ *
+ * The actor routine returns how many bytes were actually used..
+ * NOTE! This may not be the same as how much of a user buffer
+ * we filled up (we may be padding etc), so we can only update
+ * "pos" here (the actor routine has to update the user buffer
+ * pointers and the remaining count).
+ */
+ if (!zero)
+ left = __copy_to_user(buf+copied, xip_mem+offset, nr);
+ else
+ left = __clear_user(buf + copied, nr);
+
+ if (left) {
+ error = -EFAULT;
+ goto out;
+ }
+
+ copied += (nr - left);
+ offset += (nr - left);
+ index += offset >> PAGE_CACHE_SHIFT;
+ offset &= ~PAGE_CACHE_MASK;
+ } while (copied < len);
+
+out:
+ *ppos = pos + copied;
+ if (filp)
+ file_accessed(filp);
+
+ return (copied ? copied : error);
+}
+
+ssize_t
+xip_file_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
+{
+ if (!access_ok(VERIFY_WRITE, buf, len))
+ return -EFAULT;
+
+ return do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp,
+ buf, len, ppos);
+}
+EXPORT_SYMBOL_GPL(xip_file_read);
+
+/*
+ * __xip_unmap is invoked from xip_unmap and
+ * xip_write
+ *
+ * This function walks all vmas of the address_space and unmaps the
+ * __xip_sparse_page when found at pgoff.
+ */
+static void
+__xip_unmap (struct address_space * mapping,
+ unsigned long pgoff)
+{
+ struct vm_area_struct *vma;
+ struct mm_struct *mm;
+ struct prio_tree_iter iter;
+ unsigned long address;
+ pte_t *pte;
+ pte_t pteval;
+ spinlock_t *ptl;
+ struct page *page;
+ unsigned count;
+ int locked = 0;
+
+ count = read_seqcount_begin(&xip_sparse_seq);
+
+ page = __xip_sparse_page;
+ if (!page)
+ return;
+
+retry:
+ mutex_lock(&mapping->i_mmap_mutex);
+ vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+ mm = vma->vm_mm;
+ address = vma->vm_start +
+ ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+ BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+ pte = page_check_address(page, mm, address, &ptl, 1);
+ if (pte) {
+ /* Nuke the page table entry. */
+ flush_cache_page(vma, address, pte_pfn(*pte));
+ pteval = ptep_clear_flush_notify(vma, address, pte);
+ page_remove_rmap(page);
+ dec_mm_counter(mm, MM_FILEPAGES);
+ BUG_ON(pte_dirty(pteval));
+ pte_unmap_unlock(pte, ptl);
+ page_cache_release(page);
+ }
+ }
+ mutex_unlock(&mapping->i_mmap_mutex);
+
+ if (locked) {
+ mutex_unlock(&xip_sparse_mutex);
+ } else if (read_seqcount_retry(&xip_sparse_seq, count)) {
+ mutex_lock(&xip_sparse_mutex);
+ locked = 1;
+ goto retry;
+ }
+}
+
+/*
+ * xip_fault() is invoked via the vma operations vector for a
+ * mapped memory region to read in file data during a page fault.
+ *
+ * This function is derived from filemap_fault, but used for execute in place
+ */
+static int xip_file_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ struct file *file = vma->vm_file;
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ pgoff_t size;
+ void *xip_mem;
+ unsigned long xip_pfn;
+ struct page *page;
+ int error;
+
+ /* XXX: are VM_FAULT_ codes OK? */
+again:
+ size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ if (vmf->pgoff >= size)
+ return VM_FAULT_SIGBUS;
+
+ error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 0,
+ &xip_mem, &xip_pfn);
+ if (likely(!error))
+ goto found;
+ if (error != -ENODATA)
+ return VM_FAULT_OOM;
+
+ /* sparse block */
+ if ((vma->vm_flags & (VM_WRITE | VM_MAYWRITE)) &&
+ (vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) &&
+ (!(mapping->host->i_sb->s_flags & MS_RDONLY))) {
+ int err;
+
+ /* maybe shared writable, allocate new block */
+ mutex_lock(&xip_sparse_mutex);
+ error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 1,
+ &xip_mem, &xip_pfn);
+ mutex_unlock(&xip_sparse_mutex);
+ if (error)
+ return VM_FAULT_SIGBUS;
+ /* unmap sparse mappings at pgoff from all other vmas */
+ __xip_unmap(mapping, vmf->pgoff);
+
+found:
+ err = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address,
+ xip_pfn);
+ if (err == -ENOMEM)
+ return VM_FAULT_OOM;
+ /*
+ * err == -EBUSY is fine, we've raced against another thread
+ * that faulted-in the same page
+ */
+ if (err != -EBUSY)
+ BUG_ON(err);
+ return VM_FAULT_NOPAGE;
+ } else {
+ int err, ret = VM_FAULT_OOM;
+
+ mutex_lock(&xip_sparse_mutex);
+ write_seqcount_begin(&xip_sparse_seq);
+ error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 0,
+ &xip_mem, &xip_pfn);
+ if (unlikely(!error)) {
+ write_seqcount_end(&xip_sparse_seq);
+ mutex_unlock(&xip_sparse_mutex);
+ goto again;
+ }
+ if (error != -ENODATA)
+ goto out;
+ /* not shared and writable, use xip_sparse_page() */
+ page = xip_sparse_page();
+ if (!page)
+ goto out;
+ err = vm_insert_page(vma, (unsigned long)vmf->virtual_address,
+ page);
+ if (err == -ENOMEM)
+ goto out;
+
+ ret = VM_FAULT_NOPAGE;
+out:
+ write_seqcount_end(&xip_sparse_seq);
+ mutex_unlock(&xip_sparse_mutex);
+
+ return ret;
+ }
+}
+
+static const struct vm_operations_struct xip_file_vm_ops = {
+ .fault = xip_file_fault,
+};
+
+int xip_file_mmap(struct file * file, struct vm_area_struct * vma)
+{
+ BUG_ON(!file->f_mapping->a_ops->get_xip_mem);
+
+ file_accessed(file);
+ vma->vm_ops = &xip_file_vm_ops;
+ vma->vm_flags |= VM_CAN_NONLINEAR | VM_MIXEDMAP;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xip_file_mmap);
+
+static ssize_t
+__xip_file_write(struct file *filp, const char __user *buf,
+ size_t count, loff_t pos, loff_t *ppos)
+{
+ struct address_space * mapping = filp->f_mapping;
+ const struct address_space_operations *a_ops = mapping->a_ops;
+ struct inode *inode = mapping->host;
+ long status = 0;
+ size_t bytes;
+ ssize_t written = 0;
+
+ BUG_ON(!mapping->a_ops->get_xip_mem);
+
+ do {
+ unsigned long index;
+ unsigned long offset;
+ size_t copied;
+ void *xip_mem;
+ unsigned long xip_pfn;
+
+ offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
+ index = pos >> PAGE_CACHE_SHIFT;
+ bytes = PAGE_CACHE_SIZE - offset;
+ if (bytes > count)
+ bytes = count;
+
+ status = a_ops->get_xip_mem(mapping, index, 0,
+ &xip_mem, &xip_pfn);
+ if (status == -ENODATA) {
+ /* we allocate a new page unmap it */
+ mutex_lock(&xip_sparse_mutex);
+ status = a_ops->get_xip_mem(mapping, index, 1,
+ &xip_mem, &xip_pfn);
+ mutex_unlock(&xip_sparse_mutex);
+ if (!status)
+ /* unmap page at pgoff from all other vmas */
+ __xip_unmap(mapping, index);
+ }
+
+ if (status)
+ break;
+
+ copied = bytes -
+ __copy_from_user_nocache(xip_mem + offset, buf, bytes);
+
+ if (likely(copied > 0)) {
+ status = copied;
+
+ if (status >= 0) {
+ written += status;
+ count -= status;
+ pos += status;
+ buf += status;
+ }
+ }
+ if (unlikely(copied != bytes))
+ if (status >= 0)
+ status = -EFAULT;
+ if (status < 0)
+ break;
+ } while (count);
+ *ppos = pos;
+ /*
+ * No need to use i_size_read() here, the i_size
+ * cannot change under us because we hold i_mutex.
+ */
+ if (pos > inode->i_size) {
+ i_size_write(inode, pos);
+ mark_inode_dirty(inode);
+ }
+
+ return written ? written : status;
+}
+
+ssize_t
+xip_file_write(struct file *filp, const char __user *buf, size_t len,
+ loff_t *ppos)
+{
+ struct address_space *mapping = filp->f_mapping;
+ struct inode *inode = mapping->host;
+ size_t count;
+ loff_t pos;
+ ssize_t ret;
+
+ mutex_lock(&inode->i_mutex);
+
+ if (!access_ok(VERIFY_READ, buf, len)) {
+ ret=-EFAULT;
+ goto out_up;
+ }
+
+ pos = *ppos;
+ count = len;
+
+ vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+
+ /* We can write back this queue in page reclaim */
+ current->backing_dev_info = mapping->backing_dev_info;
+
+ ret = generic_write_checks(filp, &pos, &count, S_ISBLK(inode->i_mode));
+ if (ret)
+ goto out_backing;
+ if (count == 0)
+ goto out_backing;
+
+ ret = file_remove_suid(filp);
+ if (ret)
+ goto out_backing;
+
+ file_update_time(filp);
+
+ ret = __xip_file_write (filp, buf, count, pos, ppos);
+
+ out_backing:
+ current->backing_dev_info = NULL;
+ out_up:
+ mutex_unlock(&inode->i_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(xip_file_write);
+
+/*
+ * truncate a page used for execute in place
+ * functionality is analog to block_truncate_page but does use get_xip_mem
+ * to get the page instead of page cache
+ */
+int
+xip_truncate_page(struct address_space *mapping, loff_t from)
+{
+ pgoff_t index = from >> PAGE_CACHE_SHIFT;
+ unsigned offset = from & (PAGE_CACHE_SIZE-1);
+ unsigned blocksize;
+ unsigned length;
+ void *xip_mem;
+ unsigned long xip_pfn;
+ int err;
+
+ BUG_ON(!mapping->a_ops->get_xip_mem);
+
+ blocksize = 1 << mapping->host->i_blkbits;
+ length = offset & (blocksize - 1);
+
+ /* Block boundary? Nothing to do */
+ if (!length)
+ return 0;
+
+ length = blocksize - length;
+
+ err = mapping->a_ops->get_xip_mem(mapping, index, 0,
+ &xip_mem, &xip_pfn);
+ if (unlikely(err)) {
+ if (err == -ENODATA)
+ /* Hole? No need to truncate */
+ return 0;
+ else
+ return err;
+ }
+ memset(xip_mem + offset, 0, length);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xip_truncate_page);
diff --git a/ap/os/linux/linux-3.4.x/mm/fremap.c b/ap/os/linux/linux-3.4.x/mm/fremap.c
new file mode 100644
index 0000000..9ed4fd4
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/fremap.c
@@ -0,0 +1,262 @@
+/*
+ * linux/mm/fremap.c
+ *
+ * Explicit pagetable population and nonlinear (random) mappings support.
+ *
+ * started by Ingo Molnar, Copyright (C) 2002, 2003
+ */
+#include <linux/backing-dev.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/file.h>
+#include <linux/mman.h>
+#include <linux/pagemap.h>
+#include <linux/swapops.h>
+#include <linux/rmap.h>
+#include <linux/syscalls.h>
+#include <linux/mmu_notifier.h>
+
+#include <asm/mmu_context.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+
+#include "internal.h"
+
+static void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep)
+{
+ pte_t pte = *ptep;
+
+ if (pte_present(pte)) {
+ struct page *page;
+
+ flush_cache_page(vma, addr, pte_pfn(pte));
+ pte = ptep_clear_flush(vma, addr, ptep);
+ page = vm_normal_page(vma, addr, pte);
+ if (page) {
+ if (pte_dirty(pte))
+ set_page_dirty(page);
+ page_remove_rmap(page);
+ page_cache_release(page);
+ update_hiwater_rss(mm);
+ dec_mm_counter(mm, MM_FILEPAGES);
+ }
+ } else {
+ if (!pte_file(pte))
+ free_swap_and_cache(pte_to_swp_entry(pte));
+ pte_clear_not_present_full(mm, addr, ptep, 0);
+ }
+}
+
+/*
+ * Install a file pte to a given virtual memory address, release any
+ * previously existing mapping.
+ */
+static int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long pgoff, pgprot_t prot)
+{
+ int err = -ENOMEM;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ pte = get_locked_pte(mm, addr, &ptl);
+ if (!pte)
+ goto out;
+
+ if (!pte_none(*pte))
+ zap_pte(mm, vma, addr, pte);
+
+ set_pte_at(mm, addr, pte, pgoff_to_pte(pgoff));
+ /*
+ * We don't need to run update_mmu_cache() here because the "file pte"
+ * being installed by install_file_pte() is not a real pte - it's a
+ * non-present entry (like a swap entry), noting what file offset should
+ * be mapped there when there's a fault (in a non-linear vma where
+ * that's not obvious).
+ */
+ pte_unmap_unlock(pte, ptl);
+ err = 0;
+out:
+ return err;
+}
+
+static int populate_range(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long size, pgoff_t pgoff)
+{
+ int err;
+
+ do {
+ err = install_file_pte(mm, vma, addr, pgoff, vma->vm_page_prot);
+ if (err)
+ return err;
+
+ size -= PAGE_SIZE;
+ addr += PAGE_SIZE;
+ pgoff++;
+ } while (size);
+
+ return 0;
+
+}
+
+/**
+ * sys_remap_file_pages - remap arbitrary pages of an existing VM_SHARED vma
+ * @start: start of the remapped virtual memory range
+ * @size: size of the remapped virtual memory range
+ * @prot: new protection bits of the range (see NOTE)
+ * @pgoff: to-be-mapped page of the backing store file
+ * @flags: 0 or MAP_NONBLOCKED - the later will cause no IO.
+ *
+ * sys_remap_file_pages remaps arbitrary pages of an existing VM_SHARED vma
+ * (shared backing store file).
+ *
+ * This syscall works purely via pagetables, so it's the most efficient
+ * way to map the same (large) file into a given virtual window. Unlike
+ * mmap()/mremap() it does not create any new vmas. The new mappings are
+ * also safe across swapout.
+ *
+ * NOTE: the @prot parameter right now is ignored (but must be zero),
+ * and the vma's default protection is used. Arbitrary protections
+ * might be implemented in the future.
+ */
+SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
+ unsigned long, prot, unsigned long, pgoff, unsigned long, flags)
+{
+ struct mm_struct *mm = current->mm;
+ struct address_space *mapping;
+ struct vm_area_struct *vma;
+ int err = -EINVAL;
+ int has_write_lock = 0;
+
+ if (prot)
+ return err;
+ /*
+ * Sanitize the syscall parameters:
+ */
+ start = start & PAGE_MASK;
+ size = size & PAGE_MASK;
+
+ /* Does the address range wrap, or is the span zero-sized? */
+ if (start + size <= start)
+ return err;
+
+ /* Does pgoff wrap? */
+ if (pgoff + (size >> PAGE_SHIFT) < pgoff)
+ return err;
+
+ /* Can we represent this offset inside this architecture's pte's? */
+#if PTE_FILE_MAX_BITS < BITS_PER_LONG
+ if (pgoff + (size >> PAGE_SHIFT) >= (1UL << PTE_FILE_MAX_BITS))
+ return err;
+#endif
+
+ /* We need down_write() to change vma->vm_flags. */
+ down_read(&mm->mmap_sem);
+ retry:
+ vma = find_vma(mm, start);
+
+ /*
+ * Make sure the vma is shared, that it supports prefaulting,
+ * and that the remapped range is valid and fully within
+ * the single existing vma. vm_private_data is used as a
+ * swapout cursor in a VM_NONLINEAR vma.
+ */
+ if (!vma || !(vma->vm_flags & VM_SHARED))
+ goto out;
+
+ if (vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR))
+ goto out;
+
+ if (!(vma->vm_flags & VM_CAN_NONLINEAR))
+ goto out;
+
+ if (start < vma->vm_start || start + size > vma->vm_end)
+ goto out;
+
+ /* Must set VM_NONLINEAR before any pages are populated. */
+ if (!(vma->vm_flags & VM_NONLINEAR)) {
+ /* Don't need a nonlinear mapping, exit success */
+ if (pgoff == linear_page_index(vma, start)) {
+ err = 0;
+ goto out;
+ }
+
+ if (!has_write_lock) {
+ up_read(&mm->mmap_sem);
+ down_write(&mm->mmap_sem);
+ has_write_lock = 1;
+ goto retry;
+ }
+ mapping = vma->vm_file->f_mapping;
+ /*
+ * page_mkclean doesn't work on nonlinear vmas, so if
+ * dirty pages need to be accounted, emulate with linear
+ * vmas.
+ */
+ if (mapping_cap_account_dirty(mapping)) {
+ unsigned long addr;
+ struct file *file = vma->vm_file;
+
+ flags &= MAP_NONBLOCK;
+ get_file(file);
+ addr = mmap_region(file, start, size,
+ flags, vma->vm_flags, pgoff);
+ fput(file);
+ if (IS_ERR_VALUE(addr)) {
+ err = addr;
+ } else {
+ BUG_ON(addr != start);
+ err = 0;
+ }
+ goto out;
+ }
+ mutex_lock(&mapping->i_mmap_mutex);
+ flush_dcache_mmap_lock(mapping);
+ vma->vm_flags |= VM_NONLINEAR;
+ vma_prio_tree_remove(vma, &mapping->i_mmap);
+ vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
+ flush_dcache_mmap_unlock(mapping);
+ mutex_unlock(&mapping->i_mmap_mutex);
+ }
+
+ if (vma->vm_flags & VM_LOCKED) {
+ /*
+ * drop PG_Mlocked flag for over-mapped range
+ */
+ vm_flags_t saved_flags = vma->vm_flags;
+ munlock_vma_pages_range(vma, start, start + size);
+ vma->vm_flags = saved_flags;
+ }
+
+ mmu_notifier_invalidate_range_start(mm, start, start + size);
+ err = populate_range(mm, vma, start, size, pgoff);
+ mmu_notifier_invalidate_range_end(mm, start, start + size);
+ if (!err && !(flags & MAP_NONBLOCK)) {
+ if (vma->vm_flags & VM_LOCKED) {
+ /*
+ * might be mapping previously unmapped range of file
+ */
+ mlock_vma_pages_range(vma, start, start + size);
+ } else {
+ if (unlikely(has_write_lock)) {
+ downgrade_write(&mm->mmap_sem);
+ has_write_lock = 0;
+ }
+ make_pages_present(start, start+size);
+ }
+ }
+
+ /*
+ * We can't clear VM_NONLINEAR because we'd have to do
+ * it after ->populate completes, and that would prevent
+ * downgrading the lock. (Locks can't be upgraded).
+ */
+
+out:
+ if (likely(!has_write_lock))
+ up_read(&mm->mmap_sem);
+ else
+ up_write(&mm->mmap_sem);
+
+ return err;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/highmem.c b/ap/os/linux/linux-3.4.x/mm/highmem.c
new file mode 100644
index 0000000..09fc744
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/highmem.c
@@ -0,0 +1,445 @@
+/*
+ * High memory handling common code and variables.
+ *
+ * (C) 1999 Andrea Arcangeli, SuSE GmbH, andrea@suse.de
+ * Gerhard Wichert, Siemens AG, Gerhard.Wichert@pdb.siemens.de
+ *
+ *
+ * Redesigned the x86 32-bit VM architecture to deal with
+ * 64-bit physical space. With current x86 CPUs this
+ * means up to 64 Gigabytes physical RAM.
+ *
+ * Rewrote high memory support to move the page cache into
+ * high memory. Implemented permanent (schedulable) kmaps
+ * based on Linus' idea.
+ *
+ * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/export.h>
+#include <linux/swap.h>
+#include <linux/bio.h>
+#include <linux/pagemap.h>
+#include <linux/mempool.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/hash.h>
+#include <linux/highmem.h>
+#include <linux/kgdb.h>
+#include <asm/tlbflush.h>
+
+
+#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+DEFINE_PER_CPU(int, __kmap_atomic_idx);
+#endif
+
+/*
+ * Virtual_count is not a pure "count".
+ * 0 means that it is not mapped, and has not been mapped
+ * since a TLB flush - it is usable.
+ * 1 means that there are no users, but it has been mapped
+ * since the last TLB flush - so we can't use it.
+ * n means that there are (n-1) current users of it.
+ */
+#ifdef CONFIG_HIGHMEM
+
+unsigned long totalhigh_pages __read_mostly;
+EXPORT_SYMBOL(totalhigh_pages);
+
+
+EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
+
+unsigned int nr_free_highpages (void)
+{
+ pg_data_t *pgdat;
+ unsigned int pages = 0;
+
+ for_each_online_pgdat(pgdat) {
+ pages += zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
+ NR_FREE_PAGES);
+ if (zone_movable_is_highmem())
+ pages += zone_page_state(
+ &pgdat->node_zones[ZONE_MOVABLE],
+ NR_FREE_PAGES);
+ }
+
+ return pages;
+}
+
+static int pkmap_count[LAST_PKMAP];
+static unsigned int last_pkmap_nr;
+static __cacheline_aligned_in_smp DEFINE_SPINLOCK(kmap_lock);
+
+pte_t * pkmap_page_table;
+
+static DECLARE_WAIT_QUEUE_HEAD(pkmap_map_wait);
+
+/*
+ * Most architectures have no use for kmap_high_get(), so let's abstract
+ * the disabling of IRQ out of the locking in that case to save on a
+ * potential useless overhead.
+ */
+#ifdef ARCH_NEEDS_KMAP_HIGH_GET
+#define lock_kmap() spin_lock_irq(&kmap_lock)
+#define unlock_kmap() spin_unlock_irq(&kmap_lock)
+#define lock_kmap_any(flags) spin_lock_irqsave(&kmap_lock, flags)
+#define unlock_kmap_any(flags) spin_unlock_irqrestore(&kmap_lock, flags)
+#else
+#define lock_kmap() spin_lock(&kmap_lock)
+#define unlock_kmap() spin_unlock(&kmap_lock)
+#define lock_kmap_any(flags) \
+ do { spin_lock(&kmap_lock); (void)(flags); } while (0)
+#define unlock_kmap_any(flags) \
+ do { spin_unlock(&kmap_lock); (void)(flags); } while (0)
+#endif
+
+struct page *kmap_to_page(void *vaddr)
+{
+ unsigned long addr = (unsigned long)vaddr;
+
+ if (addr >= PKMAP_ADDR(0) && addr < PKMAP_ADDR(LAST_PKMAP)) {
+ int i = (addr - PKMAP_ADDR(0)) >> PAGE_SHIFT;
+ return pte_page(pkmap_page_table[i]);
+ }
+
+ return virt_to_page(addr);
+}
+EXPORT_SYMBOL(kmap_to_page);
+
+static void flush_all_zero_pkmaps(void)
+{
+ int i;
+ int need_flush = 0;
+
+ flush_cache_kmaps();
+
+ for (i = 0; i < LAST_PKMAP; i++) {
+ struct page *page;
+
+ /*
+ * zero means we don't have anything to do,
+ * >1 means that it is still in use. Only
+ * a count of 1 means that it is free but
+ * needs to be unmapped
+ */
+ if (pkmap_count[i] != 1)
+ continue;
+ pkmap_count[i] = 0;
+
+ /* sanity check */
+ BUG_ON(pte_none(pkmap_page_table[i]));
+
+ /*
+ * Don't need an atomic fetch-and-clear op here;
+ * no-one has the page mapped, and cannot get at
+ * its virtual address (and hence PTE) without first
+ * getting the kmap_lock (which is held here).
+ * So no dangers, even with speculative execution.
+ */
+ page = pte_page(pkmap_page_table[i]);
+ pte_clear(&init_mm, (unsigned long)page_address(page),
+ &pkmap_page_table[i]);
+
+ set_page_address(page, NULL);
+ need_flush = 1;
+ }
+ if (need_flush)
+ flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP));
+}
+
+/**
+ * kmap_flush_unused - flush all unused kmap mappings in order to remove stray mappings
+ */
+void kmap_flush_unused(void)
+{
+ lock_kmap();
+ flush_all_zero_pkmaps();
+ unlock_kmap();
+}
+
+static inline unsigned long map_new_virtual(struct page *page)
+{
+ unsigned long vaddr;
+ int count;
+
+start:
+ count = LAST_PKMAP;
+ /* Find an empty entry */
+ for (;;) {
+ last_pkmap_nr = (last_pkmap_nr + 1) & LAST_PKMAP_MASK;
+ if (!last_pkmap_nr) {
+ flush_all_zero_pkmaps();
+ count = LAST_PKMAP;
+ }
+ if (!pkmap_count[last_pkmap_nr])
+ break; /* Found a usable entry */
+ if (--count)
+ continue;
+
+ /*
+ * Sleep for somebody else to unmap their entries
+ */
+ {
+ DECLARE_WAITQUEUE(wait, current);
+
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ add_wait_queue(&pkmap_map_wait, &wait);
+ unlock_kmap();
+ schedule();
+ remove_wait_queue(&pkmap_map_wait, &wait);
+ lock_kmap();
+
+ /* Somebody else might have mapped it while we slept */
+ if (page_address(page))
+ return (unsigned long)page_address(page);
+
+ /* Re-start */
+ goto start;
+ }
+ }
+ vaddr = PKMAP_ADDR(last_pkmap_nr);
+ set_pte_at(&init_mm, vaddr,
+ &(pkmap_page_table[last_pkmap_nr]), mk_pte(page, kmap_prot));
+
+ pkmap_count[last_pkmap_nr] = 1;
+ set_page_address(page, (void *)vaddr);
+
+ return vaddr;
+}
+
+/**
+ * kmap_high - map a highmem page into memory
+ * @page: &struct page to map
+ *
+ * Returns the page's virtual memory address.
+ *
+ * We cannot call this from interrupts, as it may block.
+ */
+void *kmap_high(struct page *page)
+{
+ unsigned long vaddr;
+
+ /*
+ * For highmem pages, we can't trust "virtual" until
+ * after we have the lock.
+ */
+ lock_kmap();
+ vaddr = (unsigned long)page_address(page);
+ if (!vaddr)
+ vaddr = map_new_virtual(page);
+ pkmap_count[PKMAP_NR(vaddr)]++;
+ BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 2);
+ unlock_kmap();
+ return (void*) vaddr;
+}
+
+EXPORT_SYMBOL(kmap_high);
+
+#ifdef ARCH_NEEDS_KMAP_HIGH_GET
+/**
+ * kmap_high_get - pin a highmem page into memory
+ * @page: &struct page to pin
+ *
+ * Returns the page's current virtual memory address, or NULL if no mapping
+ * exists. If and only if a non null address is returned then a
+ * matching call to kunmap_high() is necessary.
+ *
+ * This can be called from any context.
+ */
+void *kmap_high_get(struct page *page)
+{
+ unsigned long vaddr, flags;
+
+ lock_kmap_any(flags);
+ vaddr = (unsigned long)page_address(page);
+ if (vaddr) {
+ BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 1);
+ pkmap_count[PKMAP_NR(vaddr)]++;
+ }
+ unlock_kmap_any(flags);
+ return (void*) vaddr;
+}
+#endif
+
+/**
+ * kunmap_high - unmap a highmem page into memory
+ * @page: &struct page to unmap
+ *
+ * If ARCH_NEEDS_KMAP_HIGH_GET is not defined then this may be called
+ * only from user context.
+ */
+void kunmap_high(struct page *page)
+{
+ unsigned long vaddr;
+ unsigned long nr;
+ unsigned long flags;
+ int need_wakeup;
+
+ lock_kmap_any(flags);
+ vaddr = (unsigned long)page_address(page);
+ BUG_ON(!vaddr);
+ nr = PKMAP_NR(vaddr);
+
+ /*
+ * A count must never go down to zero
+ * without a TLB flush!
+ */
+ need_wakeup = 0;
+ switch (--pkmap_count[nr]) {
+ case 0:
+ BUG();
+ case 1:
+ /*
+ * Avoid an unnecessary wake_up() function call.
+ * The common case is pkmap_count[] == 1, but
+ * no waiters.
+ * The tasks queued in the wait-queue are guarded
+ * by both the lock in the wait-queue-head and by
+ * the kmap_lock. As the kmap_lock is held here,
+ * no need for the wait-queue-head's lock. Simply
+ * test if the queue is empty.
+ */
+ need_wakeup = waitqueue_active(&pkmap_map_wait);
+ }
+ unlock_kmap_any(flags);
+
+ /* do wake-up, if needed, race-free outside of the spin lock */
+ if (need_wakeup)
+ wake_up(&pkmap_map_wait);
+}
+
+EXPORT_SYMBOL(kunmap_high);
+#endif
+
+#if defined(HASHED_PAGE_VIRTUAL)
+
+#define PA_HASH_ORDER 7
+
+/*
+ * Describes one page->virtual association
+ */
+struct page_address_map {
+ struct page *page;
+ void *virtual;
+ struct list_head list;
+};
+
+/*
+ * page_address_map freelist, allocated from page_address_maps.
+ */
+static struct list_head page_address_pool; /* freelist */
+static spinlock_t pool_lock; /* protects page_address_pool */
+
+/*
+ * Hash table bucket
+ */
+static struct page_address_slot {
+ struct list_head lh; /* List of page_address_maps */
+ spinlock_t lock; /* Protect this bucket's list */
+} ____cacheline_aligned_in_smp page_address_htable[1<<PA_HASH_ORDER];
+
+static struct page_address_slot *page_slot(const struct page *page)
+{
+ return &page_address_htable[hash_ptr(page, PA_HASH_ORDER)];
+}
+
+/**
+ * page_address - get the mapped virtual address of a page
+ * @page: &struct page to get the virtual address of
+ *
+ * Returns the page's virtual address.
+ */
+void *page_address(const struct page *page)
+{
+ unsigned long flags;
+ void *ret;
+ struct page_address_slot *pas;
+
+ if (!PageHighMem(page))
+ return lowmem_page_address(page);
+
+ pas = page_slot(page);
+ ret = NULL;
+ spin_lock_irqsave(&pas->lock, flags);
+ if (!list_empty(&pas->lh)) {
+ struct page_address_map *pam;
+
+ list_for_each_entry(pam, &pas->lh, list) {
+ if (pam->page == page) {
+ ret = pam->virtual;
+ goto done;
+ }
+ }
+ }
+done:
+ spin_unlock_irqrestore(&pas->lock, flags);
+ return ret;
+}
+
+EXPORT_SYMBOL(page_address);
+
+/**
+ * set_page_address - set a page's virtual address
+ * @page: &struct page to set
+ * @virtual: virtual address to use
+ */
+void set_page_address(struct page *page, void *virtual)
+{
+ unsigned long flags;
+ struct page_address_slot *pas;
+ struct page_address_map *pam;
+
+ BUG_ON(!PageHighMem(page));
+
+ pas = page_slot(page);
+ if (virtual) { /* Add */
+ BUG_ON(list_empty(&page_address_pool));
+
+ spin_lock_irqsave(&pool_lock, flags);
+ pam = list_entry(page_address_pool.next,
+ struct page_address_map, list);
+ list_del(&pam->list);
+ spin_unlock_irqrestore(&pool_lock, flags);
+
+ pam->page = page;
+ pam->virtual = virtual;
+
+ spin_lock_irqsave(&pas->lock, flags);
+ list_add_tail(&pam->list, &pas->lh);
+ spin_unlock_irqrestore(&pas->lock, flags);
+ } else { /* Remove */
+ spin_lock_irqsave(&pas->lock, flags);
+ list_for_each_entry(pam, &pas->lh, list) {
+ if (pam->page == page) {
+ list_del(&pam->list);
+ spin_unlock_irqrestore(&pas->lock, flags);
+ spin_lock_irqsave(&pool_lock, flags);
+ list_add_tail(&pam->list, &page_address_pool);
+ spin_unlock_irqrestore(&pool_lock, flags);
+ goto done;
+ }
+ }
+ spin_unlock_irqrestore(&pas->lock, flags);
+ }
+done:
+ return;
+}
+
+static struct page_address_map page_address_maps[LAST_PKMAP];
+
+void __init page_address_init(void)
+{
+ int i;
+
+ INIT_LIST_HEAD(&page_address_pool);
+ for (i = 0; i < ARRAY_SIZE(page_address_maps); i++)
+ list_add(&page_address_maps[i].list, &page_address_pool);
+ for (i = 0; i < ARRAY_SIZE(page_address_htable); i++) {
+ INIT_LIST_HEAD(&page_address_htable[i].lh);
+ spin_lock_init(&page_address_htable[i].lock);
+ }
+ spin_lock_init(&pool_lock);
+}
+
+#endif /* defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL) */
diff --git a/ap/os/linux/linux-3.4.x/mm/huge_memory.c b/ap/os/linux/linux-3.4.x/mm/huge_memory.c
new file mode 100644
index 0000000..8978c1b
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/huge_memory.c
@@ -0,0 +1,2467 @@
+/*
+ * Copyright (C) 2009 Red Hat, Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/highmem.h>
+#include <linux/hugetlb.h>
+#include <linux/mmu_notifier.h>
+#include <linux/rmap.h>
+#include <linux/swap.h>
+#include <linux/mm_inline.h>
+#include <linux/kthread.h>
+#include <linux/khugepaged.h>
+#include <linux/freezer.h>
+#include <linux/mman.h>
+#include <asm/tlb.h>
+#include <asm/pgalloc.h>
+#include "internal.h"
+
+/*
+ * By default transparent hugepage support is enabled for all mappings
+ * and khugepaged scans all mappings. Defrag is only invoked by
+ * khugepaged hugepage allocations and by page faults inside
+ * MADV_HUGEPAGE regions to avoid the risk of slowing down short lived
+ * allocations.
+ */
+unsigned long transparent_hugepage_flags __read_mostly =
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS
+ (1<<TRANSPARENT_HUGEPAGE_FLAG)|
+#endif
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE_MADVISE
+ (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)|
+#endif
+ (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)|
+ (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG);
+
+/* default scan 8*512 pte (or vmas) every 30 second */
+static unsigned int khugepaged_pages_to_scan __read_mostly = HPAGE_PMD_NR*8;
+static unsigned int khugepaged_pages_collapsed;
+static unsigned int khugepaged_full_scans;
+static unsigned int khugepaged_scan_sleep_millisecs __read_mostly = 10000;
+/* during fragmentation poll the hugepage allocator once every minute */
+static unsigned int khugepaged_alloc_sleep_millisecs __read_mostly = 60000;
+static struct task_struct *khugepaged_thread __read_mostly;
+static DEFINE_MUTEX(khugepaged_mutex);
+static DEFINE_SPINLOCK(khugepaged_mm_lock);
+static DECLARE_WAIT_QUEUE_HEAD(khugepaged_wait);
+/*
+ * default collapse hugepages if there is at least one pte mapped like
+ * it would have happened if the vma was large enough during page
+ * fault.
+ */
+static unsigned int khugepaged_max_ptes_none __read_mostly = HPAGE_PMD_NR-1;
+
+static int khugepaged(void *none);
+static int mm_slots_hash_init(void);
+static int khugepaged_slab_init(void);
+static void khugepaged_slab_free(void);
+
+#define MM_SLOTS_HASH_HEADS 1024
+static struct hlist_head *mm_slots_hash __read_mostly;
+static struct kmem_cache *mm_slot_cache __read_mostly;
+
+/**
+ * struct mm_slot - hash lookup from mm to mm_slot
+ * @hash: hash collision list
+ * @mm_node: khugepaged scan list headed in khugepaged_scan.mm_head
+ * @mm: the mm that this information is valid for
+ */
+struct mm_slot {
+ struct hlist_node hash;
+ struct list_head mm_node;
+ struct mm_struct *mm;
+};
+
+/**
+ * struct khugepaged_scan - cursor for scanning
+ * @mm_head: the head of the mm list to scan
+ * @mm_slot: the current mm_slot we are scanning
+ * @address: the next address inside that to be scanned
+ *
+ * There is only the one khugepaged_scan instance of this cursor structure.
+ */
+struct khugepaged_scan {
+ struct list_head mm_head;
+ struct mm_slot *mm_slot;
+ unsigned long address;
+};
+static struct khugepaged_scan khugepaged_scan = {
+ .mm_head = LIST_HEAD_INIT(khugepaged_scan.mm_head),
+};
+
+
+static int set_recommended_min_free_kbytes(void)
+{
+ struct zone *zone;
+ int nr_zones = 0;
+ unsigned long recommended_min;
+ extern int min_free_kbytes;
+
+ if (!test_bit(TRANSPARENT_HUGEPAGE_FLAG,
+ &transparent_hugepage_flags) &&
+ !test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
+ &transparent_hugepage_flags))
+ return 0;
+
+ for_each_populated_zone(zone)
+ nr_zones++;
+
+ /* Make sure at least 2 hugepages are free for MIGRATE_RESERVE */
+ recommended_min = pageblock_nr_pages * nr_zones * 2;
+
+ /*
+ * Make sure that on average at least two pageblocks are almost free
+ * of another type, one for a migratetype to fall back to and a
+ * second to avoid subsequent fallbacks of other types There are 3
+ * MIGRATE_TYPES we care about.
+ */
+ recommended_min += pageblock_nr_pages * nr_zones *
+ MIGRATE_PCPTYPES * MIGRATE_PCPTYPES;
+
+ /* don't ever allow to reserve more than 5% of the lowmem */
+ recommended_min = min(recommended_min,
+ (unsigned long) nr_free_buffer_pages() / 20);
+ recommended_min <<= (PAGE_SHIFT-10);
+
+ if (recommended_min > min_free_kbytes)
+ min_free_kbytes = recommended_min;
+ setup_per_zone_wmarks();
+ return 0;
+}
+late_initcall(set_recommended_min_free_kbytes);
+
+static int start_khugepaged(void)
+{
+ int err = 0;
+ if (khugepaged_enabled()) {
+ int wakeup;
+ if (unlikely(!mm_slot_cache || !mm_slots_hash)) {
+ err = -ENOMEM;
+ goto out;
+ }
+ mutex_lock(&khugepaged_mutex);
+ if (!khugepaged_thread)
+ khugepaged_thread = kthread_run(khugepaged, NULL,
+ "khugepaged");
+ if (unlikely(IS_ERR(khugepaged_thread))) {
+ printk(KERN_ERR
+ "khugepaged: kthread_run(khugepaged) failed\n");
+ err = PTR_ERR(khugepaged_thread);
+ khugepaged_thread = NULL;
+ }
+ wakeup = !list_empty(&khugepaged_scan.mm_head);
+ mutex_unlock(&khugepaged_mutex);
+ if (wakeup)
+ wake_up_interruptible(&khugepaged_wait);
+
+ set_recommended_min_free_kbytes();
+ } else
+ /* wakeup to exit */
+ wake_up_interruptible(&khugepaged_wait);
+out:
+ return err;
+}
+
+#ifdef CONFIG_SYSFS
+
+static ssize_t double_flag_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf,
+ enum transparent_hugepage_flag enabled,
+ enum transparent_hugepage_flag req_madv)
+{
+ if (test_bit(enabled, &transparent_hugepage_flags)) {
+ VM_BUG_ON(test_bit(req_madv, &transparent_hugepage_flags));
+ return sprintf(buf, "[always] madvise never\n");
+ } else if (test_bit(req_madv, &transparent_hugepage_flags))
+ return sprintf(buf, "always [madvise] never\n");
+ else
+ return sprintf(buf, "always madvise [never]\n");
+}
+static ssize_t double_flag_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count,
+ enum transparent_hugepage_flag enabled,
+ enum transparent_hugepage_flag req_madv)
+{
+ if (!memcmp("always", buf,
+ min(sizeof("always")-1, count))) {
+ set_bit(enabled, &transparent_hugepage_flags);
+ clear_bit(req_madv, &transparent_hugepage_flags);
+ } else if (!memcmp("madvise", buf,
+ min(sizeof("madvise")-1, count))) {
+ clear_bit(enabled, &transparent_hugepage_flags);
+ set_bit(req_madv, &transparent_hugepage_flags);
+ } else if (!memcmp("never", buf,
+ min(sizeof("never")-1, count))) {
+ clear_bit(enabled, &transparent_hugepage_flags);
+ clear_bit(req_madv, &transparent_hugepage_flags);
+ } else
+ return -EINVAL;
+
+ return count;
+}
+
+static ssize_t enabled_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return double_flag_show(kobj, attr, buf,
+ TRANSPARENT_HUGEPAGE_FLAG,
+ TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG);
+}
+static ssize_t enabled_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ ssize_t ret;
+
+ ret = double_flag_store(kobj, attr, buf, count,
+ TRANSPARENT_HUGEPAGE_FLAG,
+ TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG);
+
+ if (ret > 0) {
+ int err = start_khugepaged();
+ if (err)
+ ret = err;
+ }
+
+ if (ret > 0 &&
+ (test_bit(TRANSPARENT_HUGEPAGE_FLAG,
+ &transparent_hugepage_flags) ||
+ test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
+ &transparent_hugepage_flags)))
+ set_recommended_min_free_kbytes();
+
+ return ret;
+}
+static struct kobj_attribute enabled_attr =
+ __ATTR(enabled, 0644, enabled_show, enabled_store);
+
+static ssize_t single_flag_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf,
+ enum transparent_hugepage_flag flag)
+{
+ return sprintf(buf, "%d\n",
+ !!test_bit(flag, &transparent_hugepage_flags));
+}
+
+static ssize_t single_flag_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count,
+ enum transparent_hugepage_flag flag)
+{
+ unsigned long value;
+ int ret;
+
+ ret = kstrtoul(buf, 10, &value);
+ if (ret < 0)
+ return ret;
+ if (value > 1)
+ return -EINVAL;
+
+ if (value)
+ set_bit(flag, &transparent_hugepage_flags);
+ else
+ clear_bit(flag, &transparent_hugepage_flags);
+
+ return count;
+}
+
+/*
+ * Currently defrag only disables __GFP_NOWAIT for allocation. A blind
+ * __GFP_REPEAT is too aggressive, it's never worth swapping tons of
+ * memory just to allocate one more hugepage.
+ */
+static ssize_t defrag_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return double_flag_show(kobj, attr, buf,
+ TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
+ TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG);
+}
+static ssize_t defrag_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ return double_flag_store(kobj, attr, buf, count,
+ TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
+ TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG);
+}
+static struct kobj_attribute defrag_attr =
+ __ATTR(defrag, 0644, defrag_show, defrag_store);
+
+#ifdef CONFIG_DEBUG_VM
+static ssize_t debug_cow_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return single_flag_show(kobj, attr, buf,
+ TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG);
+}
+static ssize_t debug_cow_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ return single_flag_store(kobj, attr, buf, count,
+ TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG);
+}
+static struct kobj_attribute debug_cow_attr =
+ __ATTR(debug_cow, 0644, debug_cow_show, debug_cow_store);
+#endif /* CONFIG_DEBUG_VM */
+
+static struct attribute *hugepage_attr[] = {
+ &enabled_attr.attr,
+ &defrag_attr.attr,
+#ifdef CONFIG_DEBUG_VM
+ &debug_cow_attr.attr,
+#endif
+ NULL,
+};
+
+static struct attribute_group hugepage_attr_group = {
+ .attrs = hugepage_attr,
+};
+
+static ssize_t scan_sleep_millisecs_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%u\n", khugepaged_scan_sleep_millisecs);
+}
+
+static ssize_t scan_sleep_millisecs_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned long msecs;
+ int err;
+
+ err = strict_strtoul(buf, 10, &msecs);
+ if (err || msecs > UINT_MAX)
+ return -EINVAL;
+
+ khugepaged_scan_sleep_millisecs = msecs;
+ wake_up_interruptible(&khugepaged_wait);
+
+ return count;
+}
+static struct kobj_attribute scan_sleep_millisecs_attr =
+ __ATTR(scan_sleep_millisecs, 0644, scan_sleep_millisecs_show,
+ scan_sleep_millisecs_store);
+
+static ssize_t alloc_sleep_millisecs_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%u\n", khugepaged_alloc_sleep_millisecs);
+}
+
+static ssize_t alloc_sleep_millisecs_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned long msecs;
+ int err;
+
+ err = strict_strtoul(buf, 10, &msecs);
+ if (err || msecs > UINT_MAX)
+ return -EINVAL;
+
+ khugepaged_alloc_sleep_millisecs = msecs;
+ wake_up_interruptible(&khugepaged_wait);
+
+ return count;
+}
+static struct kobj_attribute alloc_sleep_millisecs_attr =
+ __ATTR(alloc_sleep_millisecs, 0644, alloc_sleep_millisecs_show,
+ alloc_sleep_millisecs_store);
+
+static ssize_t pages_to_scan_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%u\n", khugepaged_pages_to_scan);
+}
+static ssize_t pages_to_scan_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int err;
+ unsigned long pages;
+
+ err = strict_strtoul(buf, 10, &pages);
+ if (err || !pages || pages > UINT_MAX)
+ return -EINVAL;
+
+ khugepaged_pages_to_scan = pages;
+
+ return count;
+}
+static struct kobj_attribute pages_to_scan_attr =
+ __ATTR(pages_to_scan, 0644, pages_to_scan_show,
+ pages_to_scan_store);
+
+static ssize_t pages_collapsed_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%u\n", khugepaged_pages_collapsed);
+}
+static struct kobj_attribute pages_collapsed_attr =
+ __ATTR_RO(pages_collapsed);
+
+static ssize_t full_scans_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%u\n", khugepaged_full_scans);
+}
+static struct kobj_attribute full_scans_attr =
+ __ATTR_RO(full_scans);
+
+static ssize_t khugepaged_defrag_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return single_flag_show(kobj, attr, buf,
+ TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG);
+}
+static ssize_t khugepaged_defrag_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ return single_flag_store(kobj, attr, buf, count,
+ TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG);
+}
+static struct kobj_attribute khugepaged_defrag_attr =
+ __ATTR(defrag, 0644, khugepaged_defrag_show,
+ khugepaged_defrag_store);
+
+/*
+ * max_ptes_none controls if khugepaged should collapse hugepages over
+ * any unmapped ptes in turn potentially increasing the memory
+ * footprint of the vmas. When max_ptes_none is 0 khugepaged will not
+ * reduce the available free memory in the system as it
+ * runs. Increasing max_ptes_none will instead potentially reduce the
+ * free memory in the system during the khugepaged scan.
+ */
+static ssize_t khugepaged_max_ptes_none_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%u\n", khugepaged_max_ptes_none);
+}
+static ssize_t khugepaged_max_ptes_none_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int err;
+ unsigned long max_ptes_none;
+
+ err = strict_strtoul(buf, 10, &max_ptes_none);
+ if (err || max_ptes_none > HPAGE_PMD_NR-1)
+ return -EINVAL;
+
+ khugepaged_max_ptes_none = max_ptes_none;
+
+ return count;
+}
+static struct kobj_attribute khugepaged_max_ptes_none_attr =
+ __ATTR(max_ptes_none, 0644, khugepaged_max_ptes_none_show,
+ khugepaged_max_ptes_none_store);
+
+static struct attribute *khugepaged_attr[] = {
+ &khugepaged_defrag_attr.attr,
+ &khugepaged_max_ptes_none_attr.attr,
+ &pages_to_scan_attr.attr,
+ &pages_collapsed_attr.attr,
+ &full_scans_attr.attr,
+ &scan_sleep_millisecs_attr.attr,
+ &alloc_sleep_millisecs_attr.attr,
+ NULL,
+};
+
+static struct attribute_group khugepaged_attr_group = {
+ .attrs = khugepaged_attr,
+ .name = "khugepaged",
+};
+
+static int __init hugepage_init_sysfs(struct kobject **hugepage_kobj)
+{
+ int err;
+
+ *hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj);
+ if (unlikely(!*hugepage_kobj)) {
+ printk(KERN_ERR "hugepage: failed kobject create\n");
+ return -ENOMEM;
+ }
+
+ err = sysfs_create_group(*hugepage_kobj, &hugepage_attr_group);
+ if (err) {
+ printk(KERN_ERR "hugepage: failed register hugeage group\n");
+ goto delete_obj;
+ }
+
+ err = sysfs_create_group(*hugepage_kobj, &khugepaged_attr_group);
+ if (err) {
+ printk(KERN_ERR "hugepage: failed register hugeage group\n");
+ goto remove_hp_group;
+ }
+
+ return 0;
+
+remove_hp_group:
+ sysfs_remove_group(*hugepage_kobj, &hugepage_attr_group);
+delete_obj:
+ kobject_put(*hugepage_kobj);
+ return err;
+}
+
+static void __init hugepage_exit_sysfs(struct kobject *hugepage_kobj)
+{
+ sysfs_remove_group(hugepage_kobj, &khugepaged_attr_group);
+ sysfs_remove_group(hugepage_kobj, &hugepage_attr_group);
+ kobject_put(hugepage_kobj);
+}
+#else
+static inline int hugepage_init_sysfs(struct kobject **hugepage_kobj)
+{
+ return 0;
+}
+
+static inline void hugepage_exit_sysfs(struct kobject *hugepage_kobj)
+{
+}
+#endif /* CONFIG_SYSFS */
+
+static int __init hugepage_init(void)
+{
+ int err;
+ struct kobject *hugepage_kobj;
+
+ if (!has_transparent_hugepage()) {
+ transparent_hugepage_flags = 0;
+ return -EINVAL;
+ }
+
+ err = hugepage_init_sysfs(&hugepage_kobj);
+ if (err)
+ return err;
+
+ err = khugepaged_slab_init();
+ if (err)
+ goto out;
+
+ err = mm_slots_hash_init();
+ if (err) {
+ khugepaged_slab_free();
+ goto out;
+ }
+
+ /*
+ * By default disable transparent hugepages on smaller systems,
+ * where the extra memory used could hurt more than TLB overhead
+ * is likely to save. The admin can still enable it through /sys.
+ */
+ if (totalram_pages < (512 << (20 - PAGE_SHIFT)))
+ transparent_hugepage_flags = 0;
+
+ start_khugepaged();
+
+ set_recommended_min_free_kbytes();
+
+ return 0;
+out:
+ hugepage_exit_sysfs(hugepage_kobj);
+ return err;
+}
+module_init(hugepage_init)
+
+static int __init setup_transparent_hugepage(char *str)
+{
+ int ret = 0;
+ if (!str)
+ goto out;
+ if (!strcmp(str, "always")) {
+ set_bit(TRANSPARENT_HUGEPAGE_FLAG,
+ &transparent_hugepage_flags);
+ clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
+ &transparent_hugepage_flags);
+ ret = 1;
+ } else if (!strcmp(str, "madvise")) {
+ clear_bit(TRANSPARENT_HUGEPAGE_FLAG,
+ &transparent_hugepage_flags);
+ set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
+ &transparent_hugepage_flags);
+ ret = 1;
+ } else if (!strcmp(str, "never")) {
+ clear_bit(TRANSPARENT_HUGEPAGE_FLAG,
+ &transparent_hugepage_flags);
+ clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
+ &transparent_hugepage_flags);
+ ret = 1;
+ }
+out:
+ if (!ret)
+ printk(KERN_WARNING
+ "transparent_hugepage= cannot parse, ignored\n");
+ return ret;
+}
+__setup("transparent_hugepage=", setup_transparent_hugepage);
+
+static void prepare_pmd_huge_pte(pgtable_t pgtable,
+ struct mm_struct *mm)
+{
+ assert_spin_locked(&mm->page_table_lock);
+
+ /* FIFO */
+ if (!mm->pmd_huge_pte)
+ INIT_LIST_HEAD(&pgtable->lru);
+ else
+ list_add(&pgtable->lru, &mm->pmd_huge_pte->lru);
+ mm->pmd_huge_pte = pgtable;
+}
+
+static inline pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
+{
+ if (likely(vma->vm_flags & VM_WRITE))
+ pmd = pmd_mkwrite(pmd);
+ return pmd;
+}
+
+static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long haddr, pmd_t *pmd,
+ struct page *page)
+{
+ int ret = 0;
+ pgtable_t pgtable;
+
+ VM_BUG_ON(!PageCompound(page));
+ pgtable = pte_alloc_one(mm, haddr);
+ if (unlikely(!pgtable)) {
+ mem_cgroup_uncharge_page(page);
+ put_page(page);
+ return VM_FAULT_OOM;
+ }
+
+ clear_huge_page(page, haddr, HPAGE_PMD_NR);
+ __SetPageUptodate(page);
+
+ spin_lock(&mm->page_table_lock);
+ if (unlikely(!pmd_none(*pmd))) {
+ spin_unlock(&mm->page_table_lock);
+ mem_cgroup_uncharge_page(page);
+ put_page(page);
+ pte_free(mm, pgtable);
+ } else {
+ pmd_t entry;
+ entry = mk_pmd(page, vma->vm_page_prot);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+ entry = pmd_mkhuge(entry);
+ /*
+ * The spinlocking to take the lru_lock inside
+ * page_add_new_anon_rmap() acts as a full memory
+ * barrier to be sure clear_huge_page writes become
+ * visible after the set_pmd_at() write.
+ */
+ page_add_new_anon_rmap(page, vma, haddr);
+ set_pmd_at(mm, haddr, pmd, entry);
+ prepare_pmd_huge_pte(pgtable, mm);
+ add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
+ mm->nr_ptes++;
+ spin_unlock(&mm->page_table_lock);
+ }
+
+ return ret;
+}
+
+static inline gfp_t alloc_hugepage_gfpmask(int defrag, gfp_t extra_gfp)
+{
+ return (GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT)) | extra_gfp;
+}
+
+static inline struct page *alloc_hugepage_vma(int defrag,
+ struct vm_area_struct *vma,
+ unsigned long haddr, int nd,
+ gfp_t extra_gfp)
+{
+ return alloc_pages_vma(alloc_hugepage_gfpmask(defrag, extra_gfp),
+ HPAGE_PMD_ORDER, vma, haddr, nd);
+}
+
+#ifndef CONFIG_NUMA
+static inline struct page *alloc_hugepage(int defrag)
+{
+ return alloc_pages(alloc_hugepage_gfpmask(defrag, 0),
+ HPAGE_PMD_ORDER);
+}
+#endif
+
+int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmd,
+ unsigned int flags)
+{
+ struct page *page;
+ unsigned long haddr = address & HPAGE_PMD_MASK;
+ pte_t *pte;
+
+ if (haddr >= vma->vm_start && haddr + HPAGE_PMD_SIZE <= vma->vm_end) {
+ if (unlikely(anon_vma_prepare(vma)))
+ return VM_FAULT_OOM;
+ if (unlikely(khugepaged_enter(vma, vma->vm_flags)))
+ return VM_FAULT_OOM;
+ page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
+ vma, haddr, numa_node_id(), 0);
+ if (unlikely(!page)) {
+ count_vm_event(THP_FAULT_FALLBACK);
+ goto out;
+ }
+ count_vm_event(THP_FAULT_ALLOC);
+ if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) {
+ put_page(page);
+ goto out;
+ }
+
+ return __do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page);
+ }
+out:
+ /*
+ * Use __pte_alloc instead of pte_alloc_map, because we can't
+ * run pte_offset_map on the pmd, if an huge pmd could
+ * materialize from under us from a different thread.
+ */
+ if (unlikely(__pte_alloc(mm, vma, pmd, address)))
+ return VM_FAULT_OOM;
+ /* if an huge pmd materialized from under us just retry later */
+ if (unlikely(pmd_trans_huge(*pmd)))
+ return 0;
+ /*
+ * A regular pmd is established and it can't morph into a huge pmd
+ * from under us anymore at this point because we hold the mmap_sem
+ * read mode and khugepaged takes it in write mode. So now it's
+ * safe to run pte_offset_map().
+ */
+ pte = pte_offset_map(pmd, address);
+ return handle_pte_fault(mm, vma, address, pte, pmd, flags);
+}
+
+int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
+ pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
+ struct vm_area_struct *vma)
+{
+ struct page *src_page;
+ pmd_t pmd;
+ pgtable_t pgtable;
+ int ret;
+
+ ret = -ENOMEM;
+ pgtable = pte_alloc_one(dst_mm, addr);
+ if (unlikely(!pgtable))
+ goto out;
+
+ spin_lock(&dst_mm->page_table_lock);
+ spin_lock_nested(&src_mm->page_table_lock, SINGLE_DEPTH_NESTING);
+
+ ret = -EAGAIN;
+ pmd = *src_pmd;
+ if (unlikely(!pmd_trans_huge(pmd))) {
+ pte_free(dst_mm, pgtable);
+ goto out_unlock;
+ }
+ if (unlikely(pmd_trans_splitting(pmd))) {
+ /* split huge page running from under us */
+ spin_unlock(&src_mm->page_table_lock);
+ spin_unlock(&dst_mm->page_table_lock);
+ pte_free(dst_mm, pgtable);
+
+ wait_split_huge_page(vma->anon_vma, src_pmd); /* src_vma */
+ goto out;
+ }
+ src_page = pmd_page(pmd);
+ VM_BUG_ON(!PageHead(src_page));
+ get_page(src_page);
+ page_dup_rmap(src_page);
+ add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR);
+
+ pmdp_set_wrprotect(src_mm, addr, src_pmd);
+ pmd = pmd_mkold(pmd_wrprotect(pmd));
+ set_pmd_at(dst_mm, addr, dst_pmd, pmd);
+ prepare_pmd_huge_pte(pgtable, dst_mm);
+ dst_mm->nr_ptes++;
+
+ ret = 0;
+out_unlock:
+ spin_unlock(&src_mm->page_table_lock);
+ spin_unlock(&dst_mm->page_table_lock);
+out:
+ return ret;
+}
+
+/* no "address" argument so destroys page coloring of some arch */
+pgtable_t get_pmd_huge_pte(struct mm_struct *mm)
+{
+ pgtable_t pgtable;
+
+ assert_spin_locked(&mm->page_table_lock);
+
+ /* FIFO */
+ pgtable = mm->pmd_huge_pte;
+ if (list_empty(&pgtable->lru))
+ mm->pmd_huge_pte = NULL;
+ else {
+ mm->pmd_huge_pte = list_entry(pgtable->lru.next,
+ struct page, lru);
+ list_del(&pgtable->lru);
+ }
+ return pgtable;
+}
+
+static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long address,
+ pmd_t *pmd, pmd_t orig_pmd,
+ struct page *page,
+ unsigned long haddr)
+{
+ pgtable_t pgtable;
+ pmd_t _pmd;
+ int ret = 0, i;
+ struct page **pages;
+
+ pages = kmalloc(sizeof(struct page *) * HPAGE_PMD_NR,
+ GFP_KERNEL);
+ if (unlikely(!pages)) {
+ ret |= VM_FAULT_OOM;
+ goto out;
+ }
+
+ for (i = 0; i < HPAGE_PMD_NR; i++) {
+ pages[i] = alloc_page_vma_node(GFP_HIGHUSER_MOVABLE |
+ __GFP_OTHER_NODE,
+ vma, address, page_to_nid(page));
+ if (unlikely(!pages[i] ||
+ mem_cgroup_newpage_charge(pages[i], mm,
+ GFP_KERNEL))) {
+ if (pages[i])
+ put_page(pages[i]);
+ mem_cgroup_uncharge_start();
+ while (--i >= 0) {
+ mem_cgroup_uncharge_page(pages[i]);
+ put_page(pages[i]);
+ }
+ mem_cgroup_uncharge_end();
+ kfree(pages);
+ ret |= VM_FAULT_OOM;
+ goto out;
+ }
+ }
+
+ for (i = 0; i < HPAGE_PMD_NR; i++) {
+ copy_user_highpage(pages[i], page + i,
+ haddr + PAGE_SIZE * i, vma);
+ __SetPageUptodate(pages[i]);
+ cond_resched();
+ }
+
+ spin_lock(&mm->page_table_lock);
+ if (unlikely(!pmd_same(*pmd, orig_pmd)))
+ goto out_free_pages;
+ VM_BUG_ON(!PageHead(page));
+
+ pmdp_clear_flush_notify(vma, haddr, pmd);
+ /* leave pmd empty until pte is filled */
+
+ pgtable = get_pmd_huge_pte(mm);
+ pmd_populate(mm, &_pmd, pgtable);
+
+ for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
+ pte_t *pte, entry;
+ entry = mk_pte(pages[i], vma->vm_page_prot);
+ entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ page_add_new_anon_rmap(pages[i], vma, haddr);
+ pte = pte_offset_map(&_pmd, haddr);
+ VM_BUG_ON(!pte_none(*pte));
+ set_pte_at(mm, haddr, pte, entry);
+ pte_unmap(pte);
+ }
+ kfree(pages);
+
+ smp_wmb(); /* make pte visible before pmd */
+ pmd_populate(mm, pmd, pgtable);
+ page_remove_rmap(page);
+ spin_unlock(&mm->page_table_lock);
+
+ ret |= VM_FAULT_WRITE;
+ put_page(page);
+
+out:
+ return ret;
+
+out_free_pages:
+ spin_unlock(&mm->page_table_lock);
+ mem_cgroup_uncharge_start();
+ for (i = 0; i < HPAGE_PMD_NR; i++) {
+ mem_cgroup_uncharge_page(pages[i]);
+ put_page(pages[i]);
+ }
+ mem_cgroup_uncharge_end();
+ kfree(pages);
+ goto out;
+}
+
+int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmd, pmd_t orig_pmd)
+{
+ int ret = 0;
+ struct page *page, *new_page;
+ unsigned long haddr;
+
+ VM_BUG_ON(!vma->anon_vma);
+ spin_lock(&mm->page_table_lock);
+ if (unlikely(!pmd_same(*pmd, orig_pmd)))
+ goto out_unlock;
+
+ page = pmd_page(orig_pmd);
+ VM_BUG_ON(!PageCompound(page) || !PageHead(page));
+ haddr = address & HPAGE_PMD_MASK;
+ if (page_mapcount(page) == 1) {
+ pmd_t entry;
+ entry = pmd_mkyoung(orig_pmd);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+ if (pmdp_set_access_flags(vma, haddr, pmd, entry, 1))
+ update_mmu_cache(vma, address, entry);
+ ret |= VM_FAULT_WRITE;
+ goto out_unlock;
+ }
+ get_page(page);
+ spin_unlock(&mm->page_table_lock);
+
+ if (transparent_hugepage_enabled(vma) &&
+ !transparent_hugepage_debug_cow())
+ new_page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
+ vma, haddr, numa_node_id(), 0);
+ else
+ new_page = NULL;
+
+ if (unlikely(!new_page)) {
+ count_vm_event(THP_FAULT_FALLBACK);
+ ret = do_huge_pmd_wp_page_fallback(mm, vma, address,
+ pmd, orig_pmd, page, haddr);
+ if (ret & VM_FAULT_OOM)
+ split_huge_page(page);
+ put_page(page);
+ goto out;
+ }
+ count_vm_event(THP_FAULT_ALLOC);
+
+ if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
+ put_page(new_page);
+ split_huge_page(page);
+ put_page(page);
+ ret |= VM_FAULT_OOM;
+ goto out;
+ }
+
+ copy_user_huge_page(new_page, page, haddr, vma, HPAGE_PMD_NR);
+ __SetPageUptodate(new_page);
+
+ spin_lock(&mm->page_table_lock);
+ put_page(page);
+ if (unlikely(!pmd_same(*pmd, orig_pmd))) {
+ mem_cgroup_uncharge_page(new_page);
+ put_page(new_page);
+ } else {
+ pmd_t entry;
+ VM_BUG_ON(!PageHead(page));
+ entry = mk_pmd(new_page, vma->vm_page_prot);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+ entry = pmd_mkhuge(entry);
+ pmdp_clear_flush_notify(vma, haddr, pmd);
+ page_add_new_anon_rmap(new_page, vma, haddr);
+ set_pmd_at(mm, haddr, pmd, entry);
+ update_mmu_cache(vma, address, entry);
+ page_remove_rmap(page);
+ put_page(page);
+ ret |= VM_FAULT_WRITE;
+ }
+out_unlock:
+ spin_unlock(&mm->page_table_lock);
+out:
+ return ret;
+}
+
+struct page *follow_trans_huge_pmd(struct mm_struct *mm,
+ unsigned long addr,
+ pmd_t *pmd,
+ unsigned int flags)
+{
+ struct page *page = NULL;
+
+ assert_spin_locked(&mm->page_table_lock);
+
+ if (flags & FOLL_WRITE && !pmd_write(*pmd))
+ goto out;
+
+ page = pmd_page(*pmd);
+ VM_BUG_ON(!PageHead(page));
+ if (flags & FOLL_TOUCH) {
+ pmd_t _pmd;
+ /*
+ * We should set the dirty bit only for FOLL_WRITE but
+ * for now the dirty bit in the pmd is meaningless.
+ * And if the dirty bit will become meaningful and
+ * we'll only set it with FOLL_WRITE, an atomic
+ * set_bit will be required on the pmd to set the
+ * young bit, instead of the current set_pmd_at.
+ */
+ _pmd = pmd_mkyoung(pmd_mkdirty(*pmd));
+ set_pmd_at(mm, addr & HPAGE_PMD_MASK, pmd, _pmd);
+ }
+ page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT;
+ VM_BUG_ON(!PageCompound(page));
+ if (flags & FOLL_GET)
+ get_page_foll(page);
+
+out:
+ return page;
+}
+
+int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
+ pmd_t *pmd, unsigned long addr)
+{
+ int ret = 0;
+
+ if (__pmd_trans_huge_lock(pmd, vma) == 1) {
+ struct page *page;
+ pgtable_t pgtable;
+ pgtable = get_pmd_huge_pte(tlb->mm);
+ page = pmd_page(*pmd);
+ pmd_clear(pmd);
+ tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
+ page_remove_rmap(page);
+ VM_BUG_ON(page_mapcount(page) < 0);
+ add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
+ VM_BUG_ON(!PageHead(page));
+ tlb->mm->nr_ptes--;
+ spin_unlock(&tlb->mm->page_table_lock);
+ tlb_remove_page(tlb, page);
+ pte_free(tlb->mm, pgtable);
+ ret = 1;
+ }
+ return ret;
+}
+
+int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
+{
+ int ret = 0;
+
+ if (__pmd_trans_huge_lock(pmd, vma) == 1) {
+ /*
+ * All logical pages in the range are present
+ * if backed by a huge page.
+ */
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ memset(vec, 1, (end - addr) >> PAGE_SHIFT);
+ ret = 1;
+ }
+
+ return ret;
+}
+
+int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
+ unsigned long old_addr,
+ unsigned long new_addr, unsigned long old_end,
+ pmd_t *old_pmd, pmd_t *new_pmd)
+{
+ int ret = 0;
+ pmd_t pmd;
+
+ struct mm_struct *mm = vma->vm_mm;
+
+ if ((old_addr & ~HPAGE_PMD_MASK) ||
+ (new_addr & ~HPAGE_PMD_MASK) ||
+ old_end - old_addr < HPAGE_PMD_SIZE ||
+ (new_vma->vm_flags & VM_NOHUGEPAGE))
+ goto out;
+
+ /*
+ * The destination pmd shouldn't be established, free_pgtables()
+ * should have release it.
+ */
+ if (WARN_ON(!pmd_none(*new_pmd))) {
+ VM_BUG_ON(pmd_trans_huge(*new_pmd));
+ goto out;
+ }
+
+ ret = __pmd_trans_huge_lock(old_pmd, vma);
+ if (ret == 1) {
+ pmd = pmdp_get_and_clear(mm, old_addr, old_pmd);
+ VM_BUG_ON(!pmd_none(*new_pmd));
+ set_pmd_at(mm, new_addr, new_pmd, pmd);
+ spin_unlock(&mm->page_table_lock);
+ }
+out:
+ return ret;
+}
+
+int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, pgprot_t newprot)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int ret = 0;
+
+ if (__pmd_trans_huge_lock(pmd, vma) == 1) {
+ pmd_t entry;
+ entry = pmdp_get_and_clear(mm, addr, pmd);
+ entry = pmd_modify(entry, newprot);
+ set_pmd_at(mm, addr, pmd, entry);
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ ret = 1;
+ }
+
+ return ret;
+}
+
+/*
+ * Returns 1 if a given pmd maps a stable (not under splitting) thp.
+ * Returns -1 if it maps a thp under splitting. Returns 0 otherwise.
+ *
+ * Note that if it returns 1, this routine returns without unlocking page
+ * table locks. So callers must unlock them.
+ */
+int __pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma)
+{
+ spin_lock(&vma->vm_mm->page_table_lock);
+ if (likely(pmd_trans_huge(*pmd))) {
+ if (unlikely(pmd_trans_splitting(*pmd))) {
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ wait_split_huge_page(vma->anon_vma, pmd);
+ return -1;
+ } else {
+ /* Thp mapped by 'pmd' is stable, so we can
+ * handle it as it is. */
+ return 1;
+ }
+ }
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ return 0;
+}
+
+pmd_t *page_check_address_pmd(struct page *page,
+ struct mm_struct *mm,
+ unsigned long address,
+ enum page_check_address_pmd_flag flag)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd, *ret = NULL;
+
+ if (address & ~HPAGE_PMD_MASK)
+ goto out;
+
+ pgd = pgd_offset(mm, address);
+ if (!pgd_present(*pgd))
+ goto out;
+
+ pud = pud_offset(pgd, address);
+ if (!pud_present(*pud))
+ goto out;
+
+ pmd = pmd_offset(pud, address);
+ if (pmd_none(*pmd))
+ goto out;
+ if (pmd_page(*pmd) != page)
+ goto out;
+ /*
+ * split_vma() may create temporary aliased mappings. There is
+ * no risk as long as all huge pmd are found and have their
+ * splitting bit set before __split_huge_page_refcount
+ * runs. Finding the same huge pmd more than once during the
+ * same rmap walk is not a problem.
+ */
+ if (flag == PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG &&
+ pmd_trans_splitting(*pmd))
+ goto out;
+ if (pmd_trans_huge(*pmd)) {
+ VM_BUG_ON(flag == PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG &&
+ !pmd_trans_splitting(*pmd));
+ ret = pmd;
+ }
+out:
+ return ret;
+}
+
+static int __split_huge_page_splitting(struct page *page,
+ struct vm_area_struct *vma,
+ unsigned long address)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pmd_t *pmd;
+ int ret = 0;
+
+ spin_lock(&mm->page_table_lock);
+ pmd = page_check_address_pmd(page, mm, address,
+ PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG);
+ if (pmd) {
+ /*
+ * We can't temporarily set the pmd to null in order
+ * to split it, the pmd must remain marked huge at all
+ * times or the VM won't take the pmd_trans_huge paths
+ * and it won't wait on the anon_vma->root->mutex to
+ * serialize against split_huge_page*.
+ */
+ pmdp_splitting_flush_notify(vma, address, pmd);
+ ret = 1;
+ }
+ spin_unlock(&mm->page_table_lock);
+
+ return ret;
+}
+
+static void __split_huge_page_refcount(struct page *page)
+{
+ int i;
+ struct zone *zone = page_zone(page);
+ int tail_count = 0;
+
+ /* prevent PageLRU to go away from under us, and freeze lru stats */
+ spin_lock_irq(&zone->lru_lock);
+ compound_lock(page);
+ /* complete memcg works before add pages to LRU */
+ mem_cgroup_split_huge_fixup(page);
+
+ for (i = HPAGE_PMD_NR - 1; i >= 1; i--) {
+ struct page *page_tail = page + i;
+
+ /* tail_page->_mapcount cannot change */
+ BUG_ON(page_mapcount(page_tail) < 0);
+ tail_count += page_mapcount(page_tail);
+ /* check for overflow */
+ BUG_ON(tail_count < 0);
+ BUG_ON(atomic_read(&page_tail->_count) != 0);
+ /*
+ * tail_page->_count is zero and not changing from
+ * under us. But get_page_unless_zero() may be running
+ * from under us on the tail_page. If we used
+ * atomic_set() below instead of atomic_add(), we
+ * would then run atomic_set() concurrently with
+ * get_page_unless_zero(), and atomic_set() is
+ * implemented in C not using locked ops. spin_unlock
+ * on x86 sometime uses locked ops because of PPro
+ * errata 66, 92, so unless somebody can guarantee
+ * atomic_set() here would be safe on all archs (and
+ * not only on x86), it's safer to use atomic_add().
+ */
+ atomic_add(page_mapcount(page) + page_mapcount(page_tail) + 1,
+ &page_tail->_count);
+
+ /* after clearing PageTail the gup refcount can be released */
+ smp_mb();
+
+ /*
+ * retain hwpoison flag of the poisoned tail page:
+ * fix for the unsuitable process killed on Guest Machine(KVM)
+ * by the memory-failure.
+ */
+ page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP | __PG_HWPOISON;
+ page_tail->flags |= (page->flags &
+ ((1L << PG_referenced) |
+ (1L << PG_swapbacked) |
+ (1L << PG_mlocked) |
+ (1L << PG_uptodate)));
+ page_tail->flags |= (1L << PG_dirty);
+
+ /* clear PageTail before overwriting first_page */
+ smp_wmb();
+
+ /*
+ * __split_huge_page_splitting() already set the
+ * splitting bit in all pmd that could map this
+ * hugepage, that will ensure no CPU can alter the
+ * mapcount on the head page. The mapcount is only
+ * accounted in the head page and it has to be
+ * transferred to all tail pages in the below code. So
+ * for this code to be safe, the split the mapcount
+ * can't change. But that doesn't mean userland can't
+ * keep changing and reading the page contents while
+ * we transfer the mapcount, so the pmd splitting
+ * status is achieved setting a reserved bit in the
+ * pmd, not by clearing the present bit.
+ */
+ page_tail->_mapcount = page->_mapcount;
+
+ BUG_ON(page_tail->mapping);
+ page_tail->mapping = page->mapping;
+
+ page_tail->index = page->index + i;
+
+ BUG_ON(!PageAnon(page_tail));
+ BUG_ON(!PageUptodate(page_tail));
+ BUG_ON(!PageDirty(page_tail));
+ BUG_ON(!PageSwapBacked(page_tail));
+
+
+ lru_add_page_tail(zone, page, page_tail);
+ }
+ atomic_sub(tail_count, &page->_count);
+ BUG_ON(atomic_read(&page->_count) <= 0);
+
+ __dec_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
+ __mod_zone_page_state(zone, NR_ANON_PAGES, HPAGE_PMD_NR);
+
+ ClearPageCompound(page);
+ compound_unlock(page);
+ spin_unlock_irq(&zone->lru_lock);
+
+ for (i = 1; i < HPAGE_PMD_NR; i++) {
+ struct page *page_tail = page + i;
+ BUG_ON(page_count(page_tail) <= 0);
+ /*
+ * Tail pages may be freed if there wasn't any mapping
+ * like if add_to_swap() is running on a lru page that
+ * had its mapping zapped. And freeing these pages
+ * requires taking the lru_lock so we do the put_page
+ * of the tail pages after the split is complete.
+ */
+ put_page(page_tail);
+ }
+
+ /*
+ * Only the head page (now become a regular page) is required
+ * to be pinned by the caller.
+ */
+ BUG_ON(page_count(page) <= 0);
+}
+
+static int __split_huge_page_map(struct page *page,
+ struct vm_area_struct *vma,
+ unsigned long address)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pmd_t *pmd, _pmd;
+ int ret = 0, i;
+ pgtable_t pgtable;
+ unsigned long haddr;
+
+ spin_lock(&mm->page_table_lock);
+ pmd = page_check_address_pmd(page, mm, address,
+ PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG);
+ if (pmd) {
+ pgtable = get_pmd_huge_pte(mm);
+ pmd_populate(mm, &_pmd, pgtable);
+
+ for (i = 0, haddr = address; i < HPAGE_PMD_NR;
+ i++, haddr += PAGE_SIZE) {
+ pte_t *pte, entry;
+ BUG_ON(PageCompound(page+i));
+ entry = mk_pte(page + i, vma->vm_page_prot);
+ entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ if (!pmd_write(*pmd))
+ entry = pte_wrprotect(entry);
+ else
+ BUG_ON(page_mapcount(page) != 1);
+ if (!pmd_young(*pmd))
+ entry = pte_mkold(entry);
+ pte = pte_offset_map(&_pmd, haddr);
+ BUG_ON(!pte_none(*pte));
+ set_pte_at(mm, haddr, pte, entry);
+ pte_unmap(pte);
+ }
+
+ smp_wmb(); /* make pte visible before pmd */
+ /*
+ * Up to this point the pmd is present and huge and
+ * userland has the whole access to the hugepage
+ * during the split (which happens in place). If we
+ * overwrite the pmd with the not-huge version
+ * pointing to the pte here (which of course we could
+ * if all CPUs were bug free), userland could trigger
+ * a small page size TLB miss on the small sized TLB
+ * while the hugepage TLB entry is still established
+ * in the huge TLB. Some CPU doesn't like that. See
+ * http://support.amd.com/us/Processor_TechDocs/41322.pdf,
+ * Erratum 383 on page 93. Intel should be safe but is
+ * also warns that it's only safe if the permission
+ * and cache attributes of the two entries loaded in
+ * the two TLB is identical (which should be the case
+ * here). But it is generally safer to never allow
+ * small and huge TLB entries for the same virtual
+ * address to be loaded simultaneously. So instead of
+ * doing "pmd_populate(); flush_tlb_range();" we first
+ * mark the current pmd notpresent (atomically because
+ * here the pmd_trans_huge and pmd_trans_splitting
+ * must remain set at all times on the pmd until the
+ * split is complete for this pmd), then we flush the
+ * SMP TLB and finally we write the non-huge version
+ * of the pmd entry with pmd_populate.
+ */
+ set_pmd_at(mm, address, pmd, pmd_mknotpresent(*pmd));
+ flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+ pmd_populate(mm, pmd, pgtable);
+ ret = 1;
+ }
+ spin_unlock(&mm->page_table_lock);
+
+ return ret;
+}
+
+/* must be called with anon_vma->root->mutex hold */
+static void __split_huge_page(struct page *page,
+ struct anon_vma *anon_vma)
+{
+ int mapcount, mapcount2;
+ struct anon_vma_chain *avc;
+
+ BUG_ON(!PageHead(page));
+ BUG_ON(PageTail(page));
+
+ mapcount = 0;
+ list_for_each_entry(avc, &anon_vma->head, same_anon_vma) {
+ struct vm_area_struct *vma = avc->vma;
+ unsigned long addr = vma_address(page, vma);
+ BUG_ON(is_vma_temporary_stack(vma));
+ if (addr == -EFAULT)
+ continue;
+ mapcount += __split_huge_page_splitting(page, vma, addr);
+ }
+ /*
+ * It is critical that new vmas are added to the tail of the
+ * anon_vma list. This guarantes that if copy_huge_pmd() runs
+ * and establishes a child pmd before
+ * __split_huge_page_splitting() freezes the parent pmd (so if
+ * we fail to prevent copy_huge_pmd() from running until the
+ * whole __split_huge_page() is complete), we will still see
+ * the newly established pmd of the child later during the
+ * walk, to be able to set it as pmd_trans_splitting too.
+ */
+ if (mapcount != page_mapcount(page))
+ printk(KERN_ERR "mapcount %d page_mapcount %d\n",
+ mapcount, page_mapcount(page));
+ BUG_ON(mapcount != page_mapcount(page));
+
+ __split_huge_page_refcount(page);
+
+ mapcount2 = 0;
+ list_for_each_entry(avc, &anon_vma->head, same_anon_vma) {
+ struct vm_area_struct *vma = avc->vma;
+ unsigned long addr = vma_address(page, vma);
+ BUG_ON(is_vma_temporary_stack(vma));
+ if (addr == -EFAULT)
+ continue;
+ mapcount2 += __split_huge_page_map(page, vma, addr);
+ }
+ if (mapcount != mapcount2)
+ printk(KERN_ERR "mapcount %d mapcount2 %d page_mapcount %d\n",
+ mapcount, mapcount2, page_mapcount(page));
+ BUG_ON(mapcount != mapcount2);
+}
+
+int split_huge_page(struct page *page)
+{
+ struct anon_vma *anon_vma;
+ int ret = 1;
+
+ BUG_ON(!PageAnon(page));
+ anon_vma = page_lock_anon_vma(page);
+ if (!anon_vma)
+ goto out;
+ ret = 0;
+ if (!PageCompound(page))
+ goto out_unlock;
+
+ BUG_ON(!PageSwapBacked(page));
+ __split_huge_page(page, anon_vma);
+ count_vm_event(THP_SPLIT);
+
+ BUG_ON(PageCompound(page));
+out_unlock:
+ page_unlock_anon_vma(anon_vma);
+out:
+ return ret;
+}
+
+#define VM_NO_THP (VM_SPECIAL|VM_INSERTPAGE|VM_MIXEDMAP|VM_SAO| \
+ VM_HUGETLB|VM_SHARED|VM_MAYSHARE)
+
+int hugepage_madvise(struct vm_area_struct *vma,
+ unsigned long *vm_flags, int advice)
+{
+ switch (advice) {
+ case MADV_HUGEPAGE:
+ /*
+ * Be somewhat over-protective like KSM for now!
+ */
+ if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP))
+ return -EINVAL;
+ *vm_flags &= ~VM_NOHUGEPAGE;
+ *vm_flags |= VM_HUGEPAGE;
+ /*
+ * If the vma become good for khugepaged to scan,
+ * register it here without waiting a page fault that
+ * may not happen any time soon.
+ */
+ if (unlikely(khugepaged_enter_vma_merge(vma, *vm_flags)))
+ return -ENOMEM;
+ break;
+ case MADV_NOHUGEPAGE:
+ /*
+ * Be somewhat over-protective like KSM for now!
+ */
+ if (*vm_flags & (VM_NOHUGEPAGE | VM_NO_THP))
+ return -EINVAL;
+ *vm_flags &= ~VM_HUGEPAGE;
+ *vm_flags |= VM_NOHUGEPAGE;
+ /*
+ * Setting VM_NOHUGEPAGE will prevent khugepaged from scanning
+ * this vma even if we leave the mm registered in khugepaged if
+ * it got registered before VM_NOHUGEPAGE was set.
+ */
+ break;
+ }
+
+ return 0;
+}
+
+static int __init khugepaged_slab_init(void)
+{
+ mm_slot_cache = kmem_cache_create("khugepaged_mm_slot",
+ sizeof(struct mm_slot),
+ __alignof__(struct mm_slot), 0, NULL);
+ if (!mm_slot_cache)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void __init khugepaged_slab_free(void)
+{
+ kmem_cache_destroy(mm_slot_cache);
+ mm_slot_cache = NULL;
+}
+
+static inline struct mm_slot *alloc_mm_slot(void)
+{
+ if (!mm_slot_cache) /* initialization failed */
+ return NULL;
+ return kmem_cache_zalloc(mm_slot_cache, GFP_KERNEL);
+}
+
+static inline void free_mm_slot(struct mm_slot *mm_slot)
+{
+ kmem_cache_free(mm_slot_cache, mm_slot);
+}
+
+static int __init mm_slots_hash_init(void)
+{
+ mm_slots_hash = kzalloc(MM_SLOTS_HASH_HEADS * sizeof(struct hlist_head),
+ GFP_KERNEL);
+ if (!mm_slots_hash)
+ return -ENOMEM;
+ return 0;
+}
+
+#if 0
+static void __init mm_slots_hash_free(void)
+{
+ kfree(mm_slots_hash);
+ mm_slots_hash = NULL;
+}
+#endif
+
+static struct mm_slot *get_mm_slot(struct mm_struct *mm)
+{
+ struct mm_slot *mm_slot;
+ struct hlist_head *bucket;
+ struct hlist_node *node;
+
+ bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct))
+ % MM_SLOTS_HASH_HEADS];
+ hlist_for_each_entry(mm_slot, node, bucket, hash) {
+ if (mm == mm_slot->mm)
+ return mm_slot;
+ }
+ return NULL;
+}
+
+static void insert_to_mm_slots_hash(struct mm_struct *mm,
+ struct mm_slot *mm_slot)
+{
+ struct hlist_head *bucket;
+
+ bucket = &mm_slots_hash[((unsigned long)mm / sizeof(struct mm_struct))
+ % MM_SLOTS_HASH_HEADS];
+ mm_slot->mm = mm;
+ hlist_add_head(&mm_slot->hash, bucket);
+}
+
+static inline int khugepaged_test_exit(struct mm_struct *mm)
+{
+ return atomic_read(&mm->mm_users) == 0;
+}
+
+int __khugepaged_enter(struct mm_struct *mm)
+{
+ struct mm_slot *mm_slot;
+ int wakeup;
+
+ mm_slot = alloc_mm_slot();
+ if (!mm_slot)
+ return -ENOMEM;
+
+ /* __khugepaged_exit() must not run from under us */
+ VM_BUG_ON(khugepaged_test_exit(mm));
+ if (unlikely(test_and_set_bit(MMF_VM_HUGEPAGE, &mm->flags))) {
+ free_mm_slot(mm_slot);
+ return 0;
+ }
+
+ spin_lock(&khugepaged_mm_lock);
+ insert_to_mm_slots_hash(mm, mm_slot);
+ /*
+ * Insert just behind the scanning cursor, to let the area settle
+ * down a little.
+ */
+ wakeup = list_empty(&khugepaged_scan.mm_head);
+ list_add_tail(&mm_slot->mm_node, &khugepaged_scan.mm_head);
+ spin_unlock(&khugepaged_mm_lock);
+
+ atomic_inc(&mm->mm_count);
+ if (wakeup)
+ wake_up_interruptible(&khugepaged_wait);
+
+ return 0;
+}
+
+int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
+ unsigned long vm_flags)
+{
+ unsigned long hstart, hend;
+ if (!vma->anon_vma)
+ /*
+ * Not yet faulted in so we will register later in the
+ * page fault if needed.
+ */
+ return 0;
+ if (vma->vm_ops)
+ /* khugepaged not yet working on file or special mappings */
+ return 0;
+ /*
+ * If is_pfn_mapping() is true is_learn_pfn_mapping() must be
+ * true too, verify it here.
+ */
+ VM_BUG_ON(is_linear_pfn_mapping(vma) || vm_flags & VM_NO_THP);
+ hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
+ hend = vma->vm_end & HPAGE_PMD_MASK;
+ if (hstart < hend)
+ return khugepaged_enter(vma, vm_flags);
+ return 0;
+}
+
+void __khugepaged_exit(struct mm_struct *mm)
+{
+ struct mm_slot *mm_slot;
+ int free = 0;
+
+ spin_lock(&khugepaged_mm_lock);
+ mm_slot = get_mm_slot(mm);
+ if (mm_slot && khugepaged_scan.mm_slot != mm_slot) {
+ hlist_del(&mm_slot->hash);
+ list_del(&mm_slot->mm_node);
+ free = 1;
+ }
+ spin_unlock(&khugepaged_mm_lock);
+
+ if (free) {
+ clear_bit(MMF_VM_HUGEPAGE, &mm->flags);
+ free_mm_slot(mm_slot);
+ mmdrop(mm);
+ } else if (mm_slot) {
+ /*
+ * This is required to serialize against
+ * khugepaged_test_exit() (which is guaranteed to run
+ * under mmap sem read mode). Stop here (after we
+ * return all pagetables will be destroyed) until
+ * khugepaged has finished working on the pagetables
+ * under the mmap_sem.
+ */
+ down_write(&mm->mmap_sem);
+ up_write(&mm->mmap_sem);
+ }
+}
+
+static void release_pte_page(struct page *page)
+{
+ /* 0 stands for page_is_file_cache(page) == false */
+ dec_zone_page_state(page, NR_ISOLATED_ANON + 0);
+ unlock_page(page);
+ putback_lru_page(page);
+}
+
+static void release_pte_pages(pte_t *pte, pte_t *_pte)
+{
+ while (--_pte >= pte) {
+ pte_t pteval = *_pte;
+ if (!pte_none(pteval))
+ release_pte_page(pte_page(pteval));
+ }
+}
+
+static void release_all_pte_pages(pte_t *pte)
+{
+ release_pte_pages(pte, pte + HPAGE_PMD_NR);
+}
+
+static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
+ unsigned long address,
+ pte_t *pte)
+{
+ struct page *page;
+ pte_t *_pte;
+ int referenced = 0, isolated = 0, none = 0;
+ for (_pte = pte; _pte < pte+HPAGE_PMD_NR;
+ _pte++, address += PAGE_SIZE) {
+ pte_t pteval = *_pte;
+ if (pte_none(pteval)) {
+ if (++none <= khugepaged_max_ptes_none)
+ continue;
+ else {
+ release_pte_pages(pte, _pte);
+ goto out;
+ }
+ }
+ if (!pte_present(pteval) || !pte_write(pteval)) {
+ release_pte_pages(pte, _pte);
+ goto out;
+ }
+ page = vm_normal_page(vma, address, pteval);
+ if (unlikely(!page)) {
+ release_pte_pages(pte, _pte);
+ goto out;
+ }
+ VM_BUG_ON(PageCompound(page));
+ BUG_ON(!PageAnon(page));
+ VM_BUG_ON(!PageSwapBacked(page));
+
+ /* cannot use mapcount: can't collapse if there's a gup pin */
+ if (page_count(page) != 1) {
+ release_pte_pages(pte, _pte);
+ goto out;
+ }
+ /*
+ * We can do it before isolate_lru_page because the
+ * page can't be freed from under us. NOTE: PG_lock
+ * is needed to serialize against split_huge_page
+ * when invoked from the VM.
+ */
+ if (!trylock_page(page)) {
+ release_pte_pages(pte, _pte);
+ goto out;
+ }
+ /*
+ * Isolate the page to avoid collapsing an hugepage
+ * currently in use by the VM.
+ */
+ if (isolate_lru_page(page)) {
+ unlock_page(page);
+ release_pte_pages(pte, _pte);
+ goto out;
+ }
+ /* 0 stands for page_is_file_cache(page) == false */
+ inc_zone_page_state(page, NR_ISOLATED_ANON + 0);
+ VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON(PageLRU(page));
+
+ /* If there is no mapped pte young don't collapse the page */
+ if (pte_young(pteval) || PageReferenced(page) ||
+ mmu_notifier_test_young(vma->vm_mm, address))
+ referenced = 1;
+ }
+ if (unlikely(!referenced))
+ release_all_pte_pages(pte);
+ else
+ isolated = 1;
+out:
+ return isolated;
+}
+
+static void __collapse_huge_page_copy(pte_t *pte, struct page *page,
+ struct vm_area_struct *vma,
+ unsigned long address,
+ spinlock_t *ptl)
+{
+ pte_t *_pte;
+ for (_pte = pte; _pte < pte+HPAGE_PMD_NR; _pte++) {
+ pte_t pteval = *_pte;
+ struct page *src_page;
+
+ if (pte_none(pteval)) {
+ clear_user_highpage(page, address);
+ add_mm_counter(vma->vm_mm, MM_ANONPAGES, 1);
+ } else {
+ src_page = pte_page(pteval);
+ copy_user_highpage(page, src_page, address, vma);
+ VM_BUG_ON(page_mapcount(src_page) != 1);
+ VM_BUG_ON(page_count(src_page) != 2);
+ release_pte_page(src_page);
+ /*
+ * ptl mostly unnecessary, but preempt has to
+ * be disabled to update the per-cpu stats
+ * inside page_remove_rmap().
+ */
+ spin_lock(ptl);
+ /*
+ * paravirt calls inside pte_clear here are
+ * superfluous.
+ */
+ pte_clear(vma->vm_mm, address, _pte);
+ page_remove_rmap(src_page);
+ spin_unlock(ptl);
+ free_page_and_swap_cache(src_page);
+ }
+
+ address += PAGE_SIZE;
+ page++;
+ }
+}
+
+static void collapse_huge_page(struct mm_struct *mm,
+ unsigned long address,
+ struct page **hpage,
+ struct vm_area_struct *vma,
+ int node)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd, _pmd;
+ pte_t *pte;
+ pgtable_t pgtable;
+ struct page *new_page;
+ spinlock_t *ptl;
+ int isolated;
+ unsigned long hstart, hend;
+
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+#ifndef CONFIG_NUMA
+ up_read(&mm->mmap_sem);
+ VM_BUG_ON(!*hpage);
+ new_page = *hpage;
+#else
+ VM_BUG_ON(*hpage);
+ /*
+ * Allocate the page while the vma is still valid and under
+ * the mmap_sem read mode so there is no memory allocation
+ * later when we take the mmap_sem in write mode. This is more
+ * friendly behavior (OTOH it may actually hide bugs) to
+ * filesystems in userland with daemons allocating memory in
+ * the userland I/O paths. Allocating memory with the
+ * mmap_sem in read mode is good idea also to allow greater
+ * scalability.
+ */
+ new_page = alloc_hugepage_vma(khugepaged_defrag(), vma, address,
+ node, __GFP_OTHER_NODE);
+
+ /*
+ * After allocating the hugepage, release the mmap_sem read lock in
+ * preparation for taking it in write mode.
+ */
+ up_read(&mm->mmap_sem);
+ if (unlikely(!new_page)) {
+ count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
+ *hpage = ERR_PTR(-ENOMEM);
+ return;
+ }
+#endif
+
+ count_vm_event(THP_COLLAPSE_ALLOC);
+ if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
+#ifdef CONFIG_NUMA
+ put_page(new_page);
+#endif
+ return;
+ }
+
+ /*
+ * Prevent all access to pagetables with the exception of
+ * gup_fast later hanlded by the ptep_clear_flush and the VM
+ * handled by the anon_vma lock + PG_lock.
+ */
+ down_write(&mm->mmap_sem);
+ if (unlikely(khugepaged_test_exit(mm)))
+ goto out;
+
+ vma = find_vma(mm, address);
+ if (!vma)
+ goto out;
+ hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
+ hend = vma->vm_end & HPAGE_PMD_MASK;
+ if (address < hstart || address + HPAGE_PMD_SIZE > hend)
+ goto out;
+
+ if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) ||
+ (vma->vm_flags & VM_NOHUGEPAGE))
+ goto out;
+
+ if (!vma->anon_vma || vma->vm_ops)
+ goto out;
+ if (is_vma_temporary_stack(vma))
+ goto out;
+ /*
+ * If is_pfn_mapping() is true is_learn_pfn_mapping() must be
+ * true too, verify it here.
+ */
+ VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP);
+
+ pgd = pgd_offset(mm, address);
+ if (!pgd_present(*pgd))
+ goto out;
+
+ pud = pud_offset(pgd, address);
+ if (!pud_present(*pud))
+ goto out;
+
+ pmd = pmd_offset(pud, address);
+ /* pmd can't go away or become huge under us */
+ if (!pmd_present(*pmd) || pmd_trans_huge(*pmd))
+ goto out;
+
+ anon_vma_lock(vma->anon_vma);
+
+ pte = pte_offset_map(pmd, address);
+ ptl = pte_lockptr(mm, pmd);
+
+ spin_lock(&mm->page_table_lock); /* probably unnecessary */
+ /*
+ * After this gup_fast can't run anymore. This also removes
+ * any huge TLB entry from the CPU so we won't allow
+ * huge and small TLB entries for the same virtual address
+ * to avoid the risk of CPU bugs in that area.
+ */
+ _pmd = pmdp_clear_flush_notify(vma, address, pmd);
+ spin_unlock(&mm->page_table_lock);
+
+ spin_lock(ptl);
+ isolated = __collapse_huge_page_isolate(vma, address, pte);
+ spin_unlock(ptl);
+
+ if (unlikely(!isolated)) {
+ pte_unmap(pte);
+ spin_lock(&mm->page_table_lock);
+ BUG_ON(!pmd_none(*pmd));
+ /*
+ * We can only use set_pmd_at when establishing
+ * hugepmds and never for establishing regular pmds that
+ * points to regular pagetables. Use pmd_populate for that
+ */
+ pmd_populate(mm, pmd, pmd_pgtable(_pmd));
+ spin_unlock(&mm->page_table_lock);
+ anon_vma_unlock(vma->anon_vma);
+ goto out;
+ }
+
+ /*
+ * All pages are isolated and locked so anon_vma rmap
+ * can't run anymore.
+ */
+ anon_vma_unlock(vma->anon_vma);
+
+ __collapse_huge_page_copy(pte, new_page, vma, address, ptl);
+ pte_unmap(pte);
+ __SetPageUptodate(new_page);
+ pgtable = pmd_pgtable(_pmd);
+ VM_BUG_ON(page_count(pgtable) != 1);
+ VM_BUG_ON(page_mapcount(pgtable) != 0);
+
+ _pmd = mk_pmd(new_page, vma->vm_page_prot);
+ _pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma);
+ _pmd = pmd_mkhuge(_pmd);
+
+ /*
+ * spin_lock() below is not the equivalent of smp_wmb(), so
+ * this is needed to avoid the copy_huge_page writes to become
+ * visible after the set_pmd_at() write.
+ */
+ smp_wmb();
+
+ spin_lock(&mm->page_table_lock);
+ BUG_ON(!pmd_none(*pmd));
+ page_add_new_anon_rmap(new_page, vma, address);
+ set_pmd_at(mm, address, pmd, _pmd);
+ update_mmu_cache(vma, address, _pmd);
+ prepare_pmd_huge_pte(pgtable, mm);
+ spin_unlock(&mm->page_table_lock);
+
+#ifndef CONFIG_NUMA
+ *hpage = NULL;
+#endif
+ khugepaged_pages_collapsed++;
+out_up_write:
+ up_write(&mm->mmap_sem);
+ return;
+
+out:
+ mem_cgroup_uncharge_page(new_page);
+#ifdef CONFIG_NUMA
+ put_page(new_page);
+#endif
+ goto out_up_write;
+}
+
+static int khugepaged_scan_pmd(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long address,
+ struct page **hpage)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte, *_pte;
+ int ret = 0, referenced = 0, none = 0;
+ struct page *page;
+ unsigned long _address;
+ spinlock_t *ptl;
+ int node = -1;
+
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+
+ pgd = pgd_offset(mm, address);
+ if (!pgd_present(*pgd))
+ goto out;
+
+ pud = pud_offset(pgd, address);
+ if (!pud_present(*pud))
+ goto out;
+
+ pmd = pmd_offset(pud, address);
+ if (!pmd_present(*pmd) || pmd_trans_huge(*pmd))
+ goto out;
+
+ pte = pte_offset_map_lock(mm, pmd, address, &ptl);
+ for (_address = address, _pte = pte; _pte < pte+HPAGE_PMD_NR;
+ _pte++, _address += PAGE_SIZE) {
+ pte_t pteval = *_pte;
+ if (pte_none(pteval)) {
+ if (++none <= khugepaged_max_ptes_none)
+ continue;
+ else
+ goto out_unmap;
+ }
+ if (!pte_present(pteval) || !pte_write(pteval))
+ goto out_unmap;
+ page = vm_normal_page(vma, _address, pteval);
+ if (unlikely(!page))
+ goto out_unmap;
+ /*
+ * Chose the node of the first page. This could
+ * be more sophisticated and look at more pages,
+ * but isn't for now.
+ */
+ if (node == -1)
+ node = page_to_nid(page);
+ VM_BUG_ON(PageCompound(page));
+ if (!PageLRU(page) || PageLocked(page) || !PageAnon(page))
+ goto out_unmap;
+ /* cannot use mapcount: can't collapse if there's a gup pin */
+ if (page_count(page) != 1)
+ goto out_unmap;
+ if (pte_young(pteval) || PageReferenced(page) ||
+ mmu_notifier_test_young(vma->vm_mm, address))
+ referenced = 1;
+ }
+ if (referenced)
+ ret = 1;
+out_unmap:
+ pte_unmap_unlock(pte, ptl);
+ if (ret)
+ /* collapse_huge_page will return with the mmap_sem released */
+ collapse_huge_page(mm, address, hpage, vma, node);
+out:
+ return ret;
+}
+
+static void collect_mm_slot(struct mm_slot *mm_slot)
+{
+ struct mm_struct *mm = mm_slot->mm;
+
+ VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
+
+ if (khugepaged_test_exit(mm)) {
+ /* free mm_slot */
+ hlist_del(&mm_slot->hash);
+ list_del(&mm_slot->mm_node);
+
+ /*
+ * Not strictly needed because the mm exited already.
+ *
+ * clear_bit(MMF_VM_HUGEPAGE, &mm->flags);
+ */
+
+ /* khugepaged_mm_lock actually not necessary for the below */
+ free_mm_slot(mm_slot);
+ mmdrop(mm);
+ }
+}
+
+static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
+ struct page **hpage)
+ __releases(&khugepaged_mm_lock)
+ __acquires(&khugepaged_mm_lock)
+{
+ struct mm_slot *mm_slot;
+ struct mm_struct *mm;
+ struct vm_area_struct *vma;
+ int progress = 0;
+
+ VM_BUG_ON(!pages);
+ VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
+
+ if (khugepaged_scan.mm_slot)
+ mm_slot = khugepaged_scan.mm_slot;
+ else {
+ mm_slot = list_entry(khugepaged_scan.mm_head.next,
+ struct mm_slot, mm_node);
+ khugepaged_scan.address = 0;
+ khugepaged_scan.mm_slot = mm_slot;
+ }
+ spin_unlock(&khugepaged_mm_lock);
+
+ mm = mm_slot->mm;
+ down_read(&mm->mmap_sem);
+ if (unlikely(khugepaged_test_exit(mm)))
+ vma = NULL;
+ else
+ vma = find_vma(mm, khugepaged_scan.address);
+
+ progress++;
+ for (; vma; vma = vma->vm_next) {
+ unsigned long hstart, hend;
+
+ cond_resched();
+ if (unlikely(khugepaged_test_exit(mm))) {
+ progress++;
+ break;
+ }
+
+ if ((!(vma->vm_flags & VM_HUGEPAGE) &&
+ !khugepaged_always()) ||
+ (vma->vm_flags & VM_NOHUGEPAGE)) {
+ skip:
+ progress++;
+ continue;
+ }
+ if (!vma->anon_vma || vma->vm_ops)
+ goto skip;
+ if (is_vma_temporary_stack(vma))
+ goto skip;
+ /*
+ * If is_pfn_mapping() is true is_learn_pfn_mapping()
+ * must be true too, verify it here.
+ */
+ VM_BUG_ON(is_linear_pfn_mapping(vma) ||
+ vma->vm_flags & VM_NO_THP);
+
+ hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
+ hend = vma->vm_end & HPAGE_PMD_MASK;
+ if (hstart >= hend)
+ goto skip;
+ if (khugepaged_scan.address > hend)
+ goto skip;
+ if (khugepaged_scan.address < hstart)
+ khugepaged_scan.address = hstart;
+ VM_BUG_ON(khugepaged_scan.address & ~HPAGE_PMD_MASK);
+
+ while (khugepaged_scan.address < hend) {
+ int ret;
+ cond_resched();
+ if (unlikely(khugepaged_test_exit(mm)))
+ goto breakouterloop;
+
+ VM_BUG_ON(khugepaged_scan.address < hstart ||
+ khugepaged_scan.address + HPAGE_PMD_SIZE >
+ hend);
+ ret = khugepaged_scan_pmd(mm, vma,
+ khugepaged_scan.address,
+ hpage);
+ /* move to next address */
+ khugepaged_scan.address += HPAGE_PMD_SIZE;
+ progress += HPAGE_PMD_NR;
+ if (ret)
+ /* we released mmap_sem so break loop */
+ goto breakouterloop_mmap_sem;
+ if (progress >= pages)
+ goto breakouterloop;
+ }
+ }
+breakouterloop:
+ up_read(&mm->mmap_sem); /* exit_mmap will destroy ptes after this */
+breakouterloop_mmap_sem:
+
+ spin_lock(&khugepaged_mm_lock);
+ VM_BUG_ON(khugepaged_scan.mm_slot != mm_slot);
+ /*
+ * Release the current mm_slot if this mm is about to die, or
+ * if we scanned all vmas of this mm.
+ */
+ if (khugepaged_test_exit(mm) || !vma) {
+ /*
+ * Make sure that if mm_users is reaching zero while
+ * khugepaged runs here, khugepaged_exit will find
+ * mm_slot not pointing to the exiting mm.
+ */
+ if (mm_slot->mm_node.next != &khugepaged_scan.mm_head) {
+ khugepaged_scan.mm_slot = list_entry(
+ mm_slot->mm_node.next,
+ struct mm_slot, mm_node);
+ khugepaged_scan.address = 0;
+ } else {
+ khugepaged_scan.mm_slot = NULL;
+ khugepaged_full_scans++;
+ }
+
+ collect_mm_slot(mm_slot);
+ }
+
+ return progress;
+}
+
+static int khugepaged_has_work(void)
+{
+ return !list_empty(&khugepaged_scan.mm_head) &&
+ khugepaged_enabled();
+}
+
+static int khugepaged_wait_event(void)
+{
+ return !list_empty(&khugepaged_scan.mm_head) ||
+ !khugepaged_enabled();
+}
+
+static void khugepaged_do_scan(struct page **hpage)
+{
+ unsigned int progress = 0, pass_through_head = 0;
+ unsigned int pages = khugepaged_pages_to_scan;
+
+ barrier(); /* write khugepaged_pages_to_scan to local stack */
+
+ while (progress < pages) {
+ cond_resched();
+
+#ifndef CONFIG_NUMA
+ if (!*hpage) {
+ *hpage = alloc_hugepage(khugepaged_defrag());
+ if (unlikely(!*hpage)) {
+ count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
+ break;
+ }
+ count_vm_event(THP_COLLAPSE_ALLOC);
+ }
+#else
+ if (IS_ERR(*hpage))
+ break;
+#endif
+
+ if (unlikely(kthread_should_stop() || freezing(current)))
+ break;
+
+ spin_lock(&khugepaged_mm_lock);
+ if (!khugepaged_scan.mm_slot)
+ pass_through_head++;
+ if (khugepaged_has_work() &&
+ pass_through_head < 2)
+ progress += khugepaged_scan_mm_slot(pages - progress,
+ hpage);
+ else
+ progress = pages;
+ spin_unlock(&khugepaged_mm_lock);
+ }
+}
+
+static void khugepaged_alloc_sleep(void)
+{
+ wait_event_freezable_timeout(khugepaged_wait, false,
+ msecs_to_jiffies(khugepaged_alloc_sleep_millisecs));
+}
+
+#ifndef CONFIG_NUMA
+static struct page *khugepaged_alloc_hugepage(void)
+{
+ struct page *hpage;
+
+ do {
+ hpage = alloc_hugepage(khugepaged_defrag());
+ if (!hpage) {
+ count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
+ khugepaged_alloc_sleep();
+ } else
+ count_vm_event(THP_COLLAPSE_ALLOC);
+ } while (unlikely(!hpage) &&
+ likely(khugepaged_enabled()));
+ return hpage;
+}
+#endif
+
+static void khugepaged_loop(void)
+{
+ struct page *hpage;
+
+#ifdef CONFIG_NUMA
+ hpage = NULL;
+#endif
+ while (likely(khugepaged_enabled())) {
+#ifndef CONFIG_NUMA
+ hpage = khugepaged_alloc_hugepage();
+ if (unlikely(!hpage))
+ break;
+#else
+ if (IS_ERR(hpage)) {
+ khugepaged_alloc_sleep();
+ hpage = NULL;
+ }
+#endif
+
+ khugepaged_do_scan(&hpage);
+#ifndef CONFIG_NUMA
+ if (hpage)
+ put_page(hpage);
+#endif
+ try_to_freeze();
+ if (unlikely(kthread_should_stop()))
+ break;
+ if (khugepaged_has_work()) {
+ if (!khugepaged_scan_sleep_millisecs)
+ continue;
+ wait_event_freezable_timeout(khugepaged_wait, false,
+ msecs_to_jiffies(khugepaged_scan_sleep_millisecs));
+ } else if (khugepaged_enabled())
+ wait_event_freezable(khugepaged_wait,
+ khugepaged_wait_event());
+ }
+}
+
+static int khugepaged(void *none)
+{
+ struct mm_slot *mm_slot;
+
+ set_freezable();
+ set_user_nice(current, 19);
+
+ /* serialize with start_khugepaged() */
+ mutex_lock(&khugepaged_mutex);
+
+ for (;;) {
+ mutex_unlock(&khugepaged_mutex);
+ VM_BUG_ON(khugepaged_thread != current);
+ khugepaged_loop();
+ VM_BUG_ON(khugepaged_thread != current);
+
+ mutex_lock(&khugepaged_mutex);
+ if (!khugepaged_enabled())
+ break;
+ if (unlikely(kthread_should_stop()))
+ break;
+ }
+
+ spin_lock(&khugepaged_mm_lock);
+ mm_slot = khugepaged_scan.mm_slot;
+ khugepaged_scan.mm_slot = NULL;
+ if (mm_slot)
+ collect_mm_slot(mm_slot);
+ spin_unlock(&khugepaged_mm_lock);
+
+ khugepaged_thread = NULL;
+ mutex_unlock(&khugepaged_mutex);
+
+ return 0;
+}
+
+void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd)
+{
+ struct page *page;
+
+ spin_lock(&mm->page_table_lock);
+ if (unlikely(!pmd_trans_huge(*pmd))) {
+ spin_unlock(&mm->page_table_lock);
+ return;
+ }
+ page = pmd_page(*pmd);
+ VM_BUG_ON(!page_count(page));
+ get_page(page);
+ spin_unlock(&mm->page_table_lock);
+
+ split_huge_page(page);
+
+ put_page(page);
+ BUG_ON(pmd_trans_huge(*pmd));
+}
+
+static void split_huge_page_address(struct mm_struct *mm,
+ unsigned long address)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ VM_BUG_ON(!(address & ~HPAGE_PMD_MASK));
+
+ pgd = pgd_offset(mm, address);
+ if (!pgd_present(*pgd))
+ return;
+
+ pud = pud_offset(pgd, address);
+ if (!pud_present(*pud))
+ return;
+
+ pmd = pmd_offset(pud, address);
+ if (!pmd_present(*pmd))
+ return;
+ /*
+ * Caller holds the mmap_sem write mode, so a huge pmd cannot
+ * materialize from under us.
+ */
+ split_huge_page_pmd(mm, pmd);
+}
+
+void __vma_adjust_trans_huge(struct vm_area_struct *vma,
+ unsigned long start,
+ unsigned long end,
+ long adjust_next)
+{
+ /*
+ * If the new start address isn't hpage aligned and it could
+ * previously contain an hugepage: check if we need to split
+ * an huge pmd.
+ */
+ if (start & ~HPAGE_PMD_MASK &&
+ (start & HPAGE_PMD_MASK) >= vma->vm_start &&
+ (start & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= vma->vm_end)
+ split_huge_page_address(vma->vm_mm, start);
+
+ /*
+ * If the new end address isn't hpage aligned and it could
+ * previously contain an hugepage: check if we need to split
+ * an huge pmd.
+ */
+ if (end & ~HPAGE_PMD_MASK &&
+ (end & HPAGE_PMD_MASK) >= vma->vm_start &&
+ (end & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= vma->vm_end)
+ split_huge_page_address(vma->vm_mm, end);
+
+ /*
+ * If we're also updating the vma->vm_next->vm_start, if the new
+ * vm_next->vm_start isn't page aligned and it could previously
+ * contain an hugepage: check if we need to split an huge pmd.
+ */
+ if (adjust_next > 0) {
+ struct vm_area_struct *next = vma->vm_next;
+ unsigned long nstart = next->vm_start;
+ nstart += adjust_next << PAGE_SHIFT;
+ if (nstart & ~HPAGE_PMD_MASK &&
+ (nstart & HPAGE_PMD_MASK) >= next->vm_start &&
+ (nstart & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= next->vm_end)
+ split_huge_page_address(next->vm_mm, nstart);
+ }
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/hugetlb.c b/ap/os/linux/linux-3.4.x/mm/hugetlb.c
new file mode 100644
index 0000000..bc36e28
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/hugetlb.c
@@ -0,0 +1,3216 @@
+/*
+ * Generic hugetlb support.
+ * (C) William Irwin, April 2004
+ */
+#include <linux/list.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/seq_file.h>
+#include <linux/sysctl.h>
+#include <linux/highmem.h>
+#include <linux/mmu_notifier.h>
+#include <linux/nodemask.h>
+#include <linux/pagemap.h>
+#include <linux/mempolicy.h>
+#include <linux/cpuset.h>
+#include <linux/mutex.h>
+#include <linux/bootmem.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/rmap.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <linux/io.h>
+
+#include <linux/hugetlb.h>
+#include <linux/node.h>
+#include "internal.h"
+
+const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
+static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
+unsigned long hugepages_treat_as_movable;
+
+static int max_hstate;
+unsigned int default_hstate_idx;
+struct hstate hstates[HUGE_MAX_HSTATE];
+
+__initdata LIST_HEAD(huge_boot_pages);
+
+/* for command line parsing */
+static struct hstate * __initdata parsed_hstate;
+static unsigned long __initdata default_hstate_max_huge_pages;
+static unsigned long __initdata default_hstate_size;
+
+#define for_each_hstate(h) \
+ for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++)
+
+/*
+ * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
+ */
+static DEFINE_SPINLOCK(hugetlb_lock);
+
+static inline void unlock_or_release_subpool(struct hugepage_subpool *spool)
+{
+ bool free = (spool->count == 0) && (spool->used_hpages == 0);
+
+ spin_unlock(&spool->lock);
+
+ /* If no pages are used, and no other handles to the subpool
+ * remain, free the subpool the subpool remain */
+ if (free)
+ kfree(spool);
+}
+
+struct hugepage_subpool *hugepage_new_subpool(long nr_blocks)
+{
+ struct hugepage_subpool *spool;
+
+ spool = kmalloc(sizeof(*spool), GFP_KERNEL);
+ if (!spool)
+ return NULL;
+
+ spin_lock_init(&spool->lock);
+ spool->count = 1;
+ spool->max_hpages = nr_blocks;
+ spool->used_hpages = 0;
+
+ return spool;
+}
+
+void hugepage_put_subpool(struct hugepage_subpool *spool)
+{
+ spin_lock(&spool->lock);
+ BUG_ON(!spool->count);
+ spool->count--;
+ unlock_or_release_subpool(spool);
+}
+
+static int hugepage_subpool_get_pages(struct hugepage_subpool *spool,
+ long delta)
+{
+ int ret = 0;
+
+ if (!spool)
+ return 0;
+
+ spin_lock(&spool->lock);
+ if ((spool->used_hpages + delta) <= spool->max_hpages) {
+ spool->used_hpages += delta;
+ } else {
+ ret = -ENOMEM;
+ }
+ spin_unlock(&spool->lock);
+
+ return ret;
+}
+
+static void hugepage_subpool_put_pages(struct hugepage_subpool *spool,
+ long delta)
+{
+ if (!spool)
+ return;
+
+ spin_lock(&spool->lock);
+ spool->used_hpages -= delta;
+ /* If hugetlbfs_put_super couldn't free spool due to
+ * an outstanding quota reference, free it now. */
+ unlock_or_release_subpool(spool);
+}
+
+static inline struct hugepage_subpool *subpool_inode(struct inode *inode)
+{
+ return HUGETLBFS_SB(inode->i_sb)->spool;
+}
+
+static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma)
+{
+ return subpool_inode(vma->vm_file->f_dentry->d_inode);
+}
+
+/*
+ * Region tracking -- allows tracking of reservations and instantiated pages
+ * across the pages in a mapping.
+ *
+ * The region data structures are protected by a combination of the mmap_sem
+ * and the hugetlb_instantion_mutex. To access or modify a region the caller
+ * must either hold the mmap_sem for write, or the mmap_sem for read and
+ * the hugetlb_instantiation mutex:
+ *
+ * down_write(&mm->mmap_sem);
+ * or
+ * down_read(&mm->mmap_sem);
+ * mutex_lock(&hugetlb_instantiation_mutex);
+ */
+struct file_region {
+ struct list_head link;
+ long from;
+ long to;
+};
+
+static long region_add(struct list_head *head, long f, long t)
+{
+ struct file_region *rg, *nrg, *trg;
+
+ /* Locate the region we are either in or before. */
+ list_for_each_entry(rg, head, link)
+ if (f <= rg->to)
+ break;
+
+ /* Round our left edge to the current segment if it encloses us. */
+ if (f > rg->from)
+ f = rg->from;
+
+ /* Check for and consume any regions we now overlap with. */
+ nrg = rg;
+ list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ if (rg->from > t)
+ break;
+
+ /* If this area reaches higher then extend our area to
+ * include it completely. If this is not the first area
+ * which we intend to reuse, free it. */
+ if (rg->to > t)
+ t = rg->to;
+ if (rg != nrg) {
+ list_del(&rg->link);
+ kfree(rg);
+ }
+ }
+ nrg->from = f;
+ nrg->to = t;
+ return 0;
+}
+
+static long region_chg(struct list_head *head, long f, long t)
+{
+ struct file_region *rg, *nrg;
+ long chg = 0;
+
+ /* Locate the region we are before or in. */
+ list_for_each_entry(rg, head, link)
+ if (f <= rg->to)
+ break;
+
+ /* If we are below the current region then a new region is required.
+ * Subtle, allocate a new region at the position but make it zero
+ * size such that we can guarantee to record the reservation. */
+ if (&rg->link == head || t < rg->from) {
+ nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
+ if (!nrg)
+ return -ENOMEM;
+ nrg->from = f;
+ nrg->to = f;
+ INIT_LIST_HEAD(&nrg->link);
+ list_add(&nrg->link, rg->link.prev);
+
+ return t - f;
+ }
+
+ /* Round our left edge to the current segment if it encloses us. */
+ if (f > rg->from)
+ f = rg->from;
+ chg = t - f;
+
+ /* Check for and consume any regions we now overlap with. */
+ list_for_each_entry(rg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ if (rg->from > t)
+ return chg;
+
+ /* We overlap with this area, if it extends further than
+ * us then we must extend ourselves. Account for its
+ * existing reservation. */
+ if (rg->to > t) {
+ chg += rg->to - t;
+ t = rg->to;
+ }
+ chg -= rg->to - rg->from;
+ }
+ return chg;
+}
+
+static long region_truncate(struct list_head *head, long end)
+{
+ struct file_region *rg, *trg;
+ long chg = 0;
+
+ /* Locate the region we are either in or before. */
+ list_for_each_entry(rg, head, link)
+ if (end <= rg->to)
+ break;
+ if (&rg->link == head)
+ return 0;
+
+ /* If we are in the middle of a region then adjust it. */
+ if (end > rg->from) {
+ chg = rg->to - end;
+ rg->to = end;
+ rg = list_entry(rg->link.next, typeof(*rg), link);
+ }
+
+ /* Drop any remaining regions. */
+ list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ chg += rg->to - rg->from;
+ list_del(&rg->link);
+ kfree(rg);
+ }
+ return chg;
+}
+
+static long region_count(struct list_head *head, long f, long t)
+{
+ struct file_region *rg;
+ long chg = 0;
+
+ /* Locate each segment we overlap with, and count that overlap. */
+ list_for_each_entry(rg, head, link) {
+ int seg_from;
+ int seg_to;
+
+ if (rg->to <= f)
+ continue;
+ if (rg->from >= t)
+ break;
+
+ seg_from = max(rg->from, f);
+ seg_to = min(rg->to, t);
+
+ chg += seg_to - seg_from;
+ }
+
+ return chg;
+}
+
+/*
+ * Convert the address within this vma to the page offset within
+ * the mapping, in pagecache page units; huge pages here.
+ */
+static pgoff_t vma_hugecache_offset(struct hstate *h,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ return ((address - vma->vm_start) >> huge_page_shift(h)) +
+ (vma->vm_pgoff >> huge_page_order(h));
+}
+
+pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
+ unsigned long address)
+{
+ return vma_hugecache_offset(hstate_vma(vma), vma, address);
+}
+
+/*
+ * Return the size of the pages allocated when backing a VMA. In the majority
+ * cases this will be same size as used by the page table entries.
+ */
+unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
+{
+ struct hstate *hstate;
+
+ if (!is_vm_hugetlb_page(vma))
+ return PAGE_SIZE;
+
+ hstate = hstate_vma(vma);
+
+ return 1UL << (hstate->order + PAGE_SHIFT);
+}
+EXPORT_SYMBOL_GPL(vma_kernel_pagesize);
+
+/*
+ * Return the page size being used by the MMU to back a VMA. In the majority
+ * of cases, the page size used by the kernel matches the MMU size. On
+ * architectures where it differs, an architecture-specific version of this
+ * function is required.
+ */
+#ifndef vma_mmu_pagesize
+unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
+{
+ return vma_kernel_pagesize(vma);
+}
+#endif
+
+/*
+ * Flags for MAP_PRIVATE reservations. These are stored in the bottom
+ * bits of the reservation map pointer, which are always clear due to
+ * alignment.
+ */
+#define HPAGE_RESV_OWNER (1UL << 0)
+#define HPAGE_RESV_UNMAPPED (1UL << 1)
+#define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
+
+/*
+ * These helpers are used to track how many pages are reserved for
+ * faults in a MAP_PRIVATE mapping. Only the process that called mmap()
+ * is guaranteed to have their future faults succeed.
+ *
+ * With the exception of reset_vma_resv_huge_pages() which is called at fork(),
+ * the reserve counters are updated with the hugetlb_lock held. It is safe
+ * to reset the VMA at fork() time as it is not in use yet and there is no
+ * chance of the global counters getting corrupted as a result of the values.
+ *
+ * The private mapping reservation is represented in a subtly different
+ * manner to a shared mapping. A shared mapping has a region map associated
+ * with the underlying file, this region map represents the backing file
+ * pages which have ever had a reservation assigned which this persists even
+ * after the page is instantiated. A private mapping has a region map
+ * associated with the original mmap which is attached to all VMAs which
+ * reference it, this region map represents those offsets which have consumed
+ * reservation ie. where pages have been instantiated.
+ */
+static unsigned long get_vma_private_data(struct vm_area_struct *vma)
+{
+ return (unsigned long)vma->vm_private_data;
+}
+
+static void set_vma_private_data(struct vm_area_struct *vma,
+ unsigned long value)
+{
+ vma->vm_private_data = (void *)value;
+}
+
+struct resv_map {
+ struct kref refs;
+ struct list_head regions;
+};
+
+static struct resv_map *resv_map_alloc(void)
+{
+ struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
+ if (!resv_map)
+ return NULL;
+
+ kref_init(&resv_map->refs);
+ INIT_LIST_HEAD(&resv_map->regions);
+
+ return resv_map;
+}
+
+static void resv_map_release(struct kref *ref)
+{
+ struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
+
+ /* Clear out any active regions before we release the map. */
+ region_truncate(&resv_map->regions, 0);
+ kfree(resv_map);
+}
+
+static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
+{
+ VM_BUG_ON(!is_vm_hugetlb_page(vma));
+ if (!(vma->vm_flags & VM_MAYSHARE))
+ return (struct resv_map *)(get_vma_private_data(vma) &
+ ~HPAGE_RESV_MASK);
+ return NULL;
+}
+
+static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
+{
+ VM_BUG_ON(!is_vm_hugetlb_page(vma));
+ VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
+
+ set_vma_private_data(vma, (get_vma_private_data(vma) &
+ HPAGE_RESV_MASK) | (unsigned long)map);
+}
+
+static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
+{
+ VM_BUG_ON(!is_vm_hugetlb_page(vma));
+ VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
+
+ set_vma_private_data(vma, get_vma_private_data(vma) | flags);
+}
+
+static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag)
+{
+ VM_BUG_ON(!is_vm_hugetlb_page(vma));
+
+ return (get_vma_private_data(vma) & flag) != 0;
+}
+
+/* Decrement the reserved pages in the hugepage pool by one */
+static void decrement_hugepage_resv_vma(struct hstate *h,
+ struct vm_area_struct *vma)
+{
+ if (vma->vm_flags & VM_NORESERVE)
+ return;
+
+ if (vma->vm_flags & VM_MAYSHARE) {
+ /* Shared mappings always use reserves */
+ h->resv_huge_pages--;
+ } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+ /*
+ * Only the process that called mmap() has reserves for
+ * private mappings.
+ */
+ h->resv_huge_pages--;
+ }
+}
+
+/* Reset counters to 0 and clear all HPAGE_RESV_* flags */
+void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
+{
+ VM_BUG_ON(!is_vm_hugetlb_page(vma));
+ if (!(vma->vm_flags & VM_MAYSHARE))
+ vma->vm_private_data = (void *)0;
+}
+
+/* Returns true if the VMA has associated reserve pages */
+static int vma_has_reserves(struct vm_area_struct *vma)
+{
+ if (vma->vm_flags & VM_MAYSHARE)
+ return 1;
+ if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
+ return 1;
+ return 0;
+}
+
+static void copy_gigantic_page(struct page *dst, struct page *src)
+{
+ int i;
+ struct hstate *h = page_hstate(src);
+ struct page *dst_base = dst;
+ struct page *src_base = src;
+
+ for (i = 0; i < pages_per_huge_page(h); ) {
+ cond_resched();
+ copy_highpage(dst, src);
+
+ i++;
+ dst = mem_map_next(dst, dst_base, i);
+ src = mem_map_next(src, src_base, i);
+ }
+}
+
+void copy_huge_page(struct page *dst, struct page *src)
+{
+ int i;
+ struct hstate *h = page_hstate(src);
+
+ if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
+ copy_gigantic_page(dst, src);
+ return;
+ }
+
+ might_sleep();
+ for (i = 0; i < pages_per_huge_page(h); i++) {
+ cond_resched();
+ copy_highpage(dst + i, src + i);
+ }
+}
+
+static void enqueue_huge_page(struct hstate *h, struct page *page)
+{
+ int nid = page_to_nid(page);
+ list_add(&page->lru, &h->hugepage_freelists[nid]);
+ h->free_huge_pages++;
+ h->free_huge_pages_node[nid]++;
+}
+
+static struct page *dequeue_huge_page_node(struct hstate *h, int nid)
+{
+ struct page *page;
+
+ if (list_empty(&h->hugepage_freelists[nid]))
+ return NULL;
+ page = list_entry(h->hugepage_freelists[nid].next, struct page, lru);
+ list_del(&page->lru);
+ set_page_refcounted(page);
+ h->free_huge_pages--;
+ h->free_huge_pages_node[nid]--;
+ return page;
+}
+
+static struct page *dequeue_huge_page_vma(struct hstate *h,
+ struct vm_area_struct *vma,
+ unsigned long address, int avoid_reserve)
+{
+ struct page *page = NULL;
+ struct mempolicy *mpol;
+ nodemask_t *nodemask;
+ struct zonelist *zonelist;
+ struct zone *zone;
+ struct zoneref *z;
+ unsigned int cpuset_mems_cookie;
+
+retry_cpuset:
+ cpuset_mems_cookie = get_mems_allowed();
+ zonelist = huge_zonelist(vma, address,
+ htlb_alloc_mask, &mpol, &nodemask);
+ /*
+ * A child process with MAP_PRIVATE mappings created by their parent
+ * have no page reserves. This check ensures that reservations are
+ * not "stolen". The child may still get SIGKILLed
+ */
+ if (!vma_has_reserves(vma) &&
+ h->free_huge_pages - h->resv_huge_pages == 0)
+ goto err;
+
+ /* If reserves cannot be used, ensure enough pages are in the pool */
+ if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
+ goto err;
+
+ for_each_zone_zonelist_nodemask(zone, z, zonelist,
+ MAX_NR_ZONES - 1, nodemask) {
+ if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask)) {
+ page = dequeue_huge_page_node(h, zone_to_nid(zone));
+ if (page) {
+ if (!avoid_reserve)
+ decrement_hugepage_resv_vma(h, vma);
+ break;
+ }
+ }
+ }
+
+ mpol_cond_put(mpol);
+ if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
+ goto retry_cpuset;
+ return page;
+
+err:
+ mpol_cond_put(mpol);
+ return NULL;
+}
+
+static void update_and_free_page(struct hstate *h, struct page *page)
+{
+ int i;
+
+ VM_BUG_ON(h->order >= MAX_ORDER);
+
+ h->nr_huge_pages--;
+ h->nr_huge_pages_node[page_to_nid(page)]--;
+ for (i = 0; i < pages_per_huge_page(h); i++) {
+ page[i].flags &= ~(1 << PG_locked | 1 << PG_error |
+ 1 << PG_referenced | 1 << PG_dirty |
+ 1 << PG_active | 1 << PG_reserved |
+ 1 << PG_private | 1 << PG_writeback);
+ }
+ set_compound_page_dtor(page, NULL);
+ set_page_refcounted(page);
+ arch_release_hugepage(page);
+ __free_pages(page, huge_page_order(h));
+}
+
+struct hstate *size_to_hstate(unsigned long size)
+{
+ struct hstate *h;
+
+ for_each_hstate(h) {
+ if (huge_page_size(h) == size)
+ return h;
+ }
+ return NULL;
+}
+
+static void free_huge_page(struct page *page)
+{
+ /*
+ * Can't pass hstate in here because it is called from the
+ * compound page destructor.
+ */
+ struct hstate *h = page_hstate(page);
+ int nid = page_to_nid(page);
+ struct hugepage_subpool *spool =
+ (struct hugepage_subpool *)page_private(page);
+
+ set_page_private(page, 0);
+ page->mapping = NULL;
+ BUG_ON(page_count(page));
+ BUG_ON(page_mapcount(page));
+ INIT_LIST_HEAD(&page->lru);
+
+ spin_lock(&hugetlb_lock);
+ if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) {
+ update_and_free_page(h, page);
+ h->surplus_huge_pages--;
+ h->surplus_huge_pages_node[nid]--;
+ } else {
+ enqueue_huge_page(h, page);
+ }
+ spin_unlock(&hugetlb_lock);
+ hugepage_subpool_put_pages(spool, 1);
+}
+
+static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
+{
+ set_compound_page_dtor(page, free_huge_page);
+ spin_lock(&hugetlb_lock);
+ h->nr_huge_pages++;
+ h->nr_huge_pages_node[nid]++;
+ spin_unlock(&hugetlb_lock);
+ put_page(page); /* free it into the hugepage allocator */
+}
+
+static void prep_compound_gigantic_page(struct page *page, unsigned long order)
+{
+ int i;
+ int nr_pages = 1 << order;
+ struct page *p = page + 1;
+
+ /* we rely on prep_new_huge_page to set the destructor */
+ set_compound_order(page, order);
+ __SetPageHead(page);
+ for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
+ __SetPageTail(p);
+ set_page_count(p, 0);
+ p->first_page = page;
+ }
+}
+
+int PageHuge(struct page *page)
+{
+ compound_page_dtor *dtor;
+
+ if (!PageCompound(page))
+ return 0;
+
+ page = compound_head(page);
+ dtor = get_compound_page_dtor(page);
+
+ return dtor == free_huge_page;
+}
+EXPORT_SYMBOL_GPL(PageHuge);
+
+/*
+ * PageHeadHuge() only returns true for hugetlbfs head page, but not for
+ * normal or transparent huge pages.
+ */
+int PageHeadHuge(struct page *page_head)
+{
+ compound_page_dtor *dtor;
+
+ if (!PageHead(page_head))
+ return 0;
+
+ dtor = get_compound_page_dtor(page_head);
+
+ return dtor == free_huge_page;
+}
+EXPORT_SYMBOL_GPL(PageHeadHuge);
+
+pgoff_t __basepage_index(struct page *page)
+{
+ struct page *page_head = compound_head(page);
+ pgoff_t index = page_index(page_head);
+ unsigned long compound_idx;
+
+ if (!PageHuge(page_head))
+ return page_index(page);
+
+ if (compound_order(page_head) >= MAX_ORDER)
+ compound_idx = page_to_pfn(page) - page_to_pfn(page_head);
+ else
+ compound_idx = page - page_head;
+
+ return (index << compound_order(page_head)) + compound_idx;
+}
+
+static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
+{
+ struct page *page;
+
+ if (h->order >= MAX_ORDER)
+ return NULL;
+
+ page = alloc_pages_exact_node(nid,
+ htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
+ __GFP_REPEAT|__GFP_NOWARN,
+ huge_page_order(h));
+ if (page) {
+ if (arch_prepare_hugepage(page)) {
+ __free_pages(page, huge_page_order(h));
+ return NULL;
+ }
+ prep_new_huge_page(h, page, nid);
+ }
+
+ return page;
+}
+
+/*
+ * common helper functions for hstate_next_node_to_{alloc|free}.
+ * We may have allocated or freed a huge page based on a different
+ * nodes_allowed previously, so h->next_node_to_{alloc|free} might
+ * be outside of *nodes_allowed. Ensure that we use an allowed
+ * node for alloc or free.
+ */
+static int next_node_allowed(int nid, nodemask_t *nodes_allowed)
+{
+ nid = next_node(nid, *nodes_allowed);
+ if (nid == MAX_NUMNODES)
+ nid = first_node(*nodes_allowed);
+ VM_BUG_ON(nid >= MAX_NUMNODES);
+
+ return nid;
+}
+
+static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed)
+{
+ if (!node_isset(nid, *nodes_allowed))
+ nid = next_node_allowed(nid, nodes_allowed);
+ return nid;
+}
+
+/*
+ * returns the previously saved node ["this node"] from which to
+ * allocate a persistent huge page for the pool and advance the
+ * next node from which to allocate, handling wrap at end of node
+ * mask.
+ */
+static int hstate_next_node_to_alloc(struct hstate *h,
+ nodemask_t *nodes_allowed)
+{
+ int nid;
+
+ VM_BUG_ON(!nodes_allowed);
+
+ nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed);
+ h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed);
+
+ return nid;
+}
+
+static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed)
+{
+ struct page *page;
+ int start_nid;
+ int next_nid;
+ int ret = 0;
+
+ start_nid = hstate_next_node_to_alloc(h, nodes_allowed);
+ next_nid = start_nid;
+
+ do {
+ page = alloc_fresh_huge_page_node(h, next_nid);
+ if (page) {
+ ret = 1;
+ break;
+ }
+ next_nid = hstate_next_node_to_alloc(h, nodes_allowed);
+ } while (next_nid != start_nid);
+
+ if (ret)
+ count_vm_event(HTLB_BUDDY_PGALLOC);
+ else
+ count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
+
+ return ret;
+}
+
+/*
+ * helper for free_pool_huge_page() - return the previously saved
+ * node ["this node"] from which to free a huge page. Advance the
+ * next node id whether or not we find a free huge page to free so
+ * that the next attempt to free addresses the next node.
+ */
+static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
+{
+ int nid;
+
+ VM_BUG_ON(!nodes_allowed);
+
+ nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed);
+ h->next_nid_to_free = next_node_allowed(nid, nodes_allowed);
+
+ return nid;
+}
+
+/*
+ * Free huge page from pool from next node to free.
+ * Attempt to keep persistent huge pages more or less
+ * balanced over allowed nodes.
+ * Called with hugetlb_lock locked.
+ */
+static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed,
+ bool acct_surplus)
+{
+ int start_nid;
+ int next_nid;
+ int ret = 0;
+
+ start_nid = hstate_next_node_to_free(h, nodes_allowed);
+ next_nid = start_nid;
+
+ do {
+ /*
+ * If we're returning unused surplus pages, only examine
+ * nodes with surplus pages.
+ */
+ if ((!acct_surplus || h->surplus_huge_pages_node[next_nid]) &&
+ !list_empty(&h->hugepage_freelists[next_nid])) {
+ struct page *page =
+ list_entry(h->hugepage_freelists[next_nid].next,
+ struct page, lru);
+ list_del(&page->lru);
+ h->free_huge_pages--;
+ h->free_huge_pages_node[next_nid]--;
+ if (acct_surplus) {
+ h->surplus_huge_pages--;
+ h->surplus_huge_pages_node[next_nid]--;
+ }
+ update_and_free_page(h, page);
+ ret = 1;
+ break;
+ }
+ next_nid = hstate_next_node_to_free(h, nodes_allowed);
+ } while (next_nid != start_nid);
+
+ return ret;
+}
+
+static struct page *alloc_buddy_huge_page(struct hstate *h, int nid)
+{
+ struct page *page;
+ unsigned int r_nid;
+
+ if (h->order >= MAX_ORDER)
+ return NULL;
+
+ /*
+ * Assume we will successfully allocate the surplus page to
+ * prevent racing processes from causing the surplus to exceed
+ * overcommit
+ *
+ * This however introduces a different race, where a process B
+ * tries to grow the static hugepage pool while alloc_pages() is
+ * called by process A. B will only examine the per-node
+ * counters in determining if surplus huge pages can be
+ * converted to normal huge pages in adjust_pool_surplus(). A
+ * won't be able to increment the per-node counter, until the
+ * lock is dropped by B, but B doesn't drop hugetlb_lock until
+ * no more huge pages can be converted from surplus to normal
+ * state (and doesn't try to convert again). Thus, we have a
+ * case where a surplus huge page exists, the pool is grown, and
+ * the surplus huge page still exists after, even though it
+ * should just have been converted to a normal huge page. This
+ * does not leak memory, though, as the hugepage will be freed
+ * once it is out of use. It also does not allow the counters to
+ * go out of whack in adjust_pool_surplus() as we don't modify
+ * the node values until we've gotten the hugepage and only the
+ * per-node value is checked there.
+ */
+ spin_lock(&hugetlb_lock);
+ if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
+ spin_unlock(&hugetlb_lock);
+ return NULL;
+ } else {
+ h->nr_huge_pages++;
+ h->surplus_huge_pages++;
+ }
+ spin_unlock(&hugetlb_lock);
+
+ if (nid == NUMA_NO_NODE)
+ page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
+ __GFP_REPEAT|__GFP_NOWARN,
+ huge_page_order(h));
+ else
+ page = alloc_pages_exact_node(nid,
+ htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
+ __GFP_REPEAT|__GFP_NOWARN, huge_page_order(h));
+
+ if (page && arch_prepare_hugepage(page)) {
+ __free_pages(page, huge_page_order(h));
+ page = NULL;
+ }
+
+ spin_lock(&hugetlb_lock);
+ if (page) {
+ r_nid = page_to_nid(page);
+ set_compound_page_dtor(page, free_huge_page);
+ /*
+ * We incremented the global counters already
+ */
+ h->nr_huge_pages_node[r_nid]++;
+ h->surplus_huge_pages_node[r_nid]++;
+ __count_vm_event(HTLB_BUDDY_PGALLOC);
+ } else {
+ h->nr_huge_pages--;
+ h->surplus_huge_pages--;
+ __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
+ }
+ spin_unlock(&hugetlb_lock);
+
+ return page;
+}
+
+/*
+ * This allocation function is useful in the context where vma is irrelevant.
+ * E.g. soft-offlining uses this function because it only cares physical
+ * address of error page.
+ */
+struct page *alloc_huge_page_node(struct hstate *h, int nid)
+{
+ struct page *page;
+
+ spin_lock(&hugetlb_lock);
+ page = dequeue_huge_page_node(h, nid);
+ spin_unlock(&hugetlb_lock);
+
+ if (!page)
+ page = alloc_buddy_huge_page(h, nid);
+
+ return page;
+}
+
+/*
+ * Increase the hugetlb pool such that it can accommodate a reservation
+ * of size 'delta'.
+ */
+static int gather_surplus_pages(struct hstate *h, int delta)
+{
+ struct list_head surplus_list;
+ struct page *page, *tmp;
+ int ret, i;
+ int needed, allocated;
+ bool alloc_ok = true;
+
+ needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
+ if (needed <= 0) {
+ h->resv_huge_pages += delta;
+ return 0;
+ }
+
+ allocated = 0;
+ INIT_LIST_HEAD(&surplus_list);
+
+ ret = -ENOMEM;
+retry:
+ spin_unlock(&hugetlb_lock);
+ for (i = 0; i < needed; i++) {
+ page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
+ if (!page) {
+ alloc_ok = false;
+ break;
+ }
+ list_add(&page->lru, &surplus_list);
+ }
+ allocated += i;
+
+ /*
+ * After retaking hugetlb_lock, we need to recalculate 'needed'
+ * because either resv_huge_pages or free_huge_pages may have changed.
+ */
+ spin_lock(&hugetlb_lock);
+ needed = (h->resv_huge_pages + delta) -
+ (h->free_huge_pages + allocated);
+ if (needed > 0) {
+ if (alloc_ok)
+ goto retry;
+ /*
+ * We were not able to allocate enough pages to
+ * satisfy the entire reservation so we free what
+ * we've allocated so far.
+ */
+ goto free;
+ }
+ /*
+ * The surplus_list now contains _at_least_ the number of extra pages
+ * needed to accommodate the reservation. Add the appropriate number
+ * of pages to the hugetlb pool and free the extras back to the buddy
+ * allocator. Commit the entire reservation here to prevent another
+ * process from stealing the pages as they are added to the pool but
+ * before they are reserved.
+ */
+ needed += allocated;
+ h->resv_huge_pages += delta;
+ ret = 0;
+
+ /* Free the needed pages to the hugetlb pool */
+ list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
+ if ((--needed) < 0)
+ break;
+ list_del(&page->lru);
+ /*
+ * This page is now managed by the hugetlb allocator and has
+ * no users -- drop the buddy allocator's reference.
+ */
+ put_page_testzero(page);
+ VM_BUG_ON(page_count(page));
+ enqueue_huge_page(h, page);
+ }
+free:
+ spin_unlock(&hugetlb_lock);
+
+ /* Free unnecessary surplus pages to the buddy allocator */
+ if (!list_empty(&surplus_list)) {
+ list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
+ list_del(&page->lru);
+ put_page(page);
+ }
+ }
+ spin_lock(&hugetlb_lock);
+
+ return ret;
+}
+
+/*
+ * When releasing a hugetlb pool reservation, any surplus pages that were
+ * allocated to satisfy the reservation must be explicitly freed if they were
+ * never used.
+ * Called with hugetlb_lock held.
+ */
+static void return_unused_surplus_pages(struct hstate *h,
+ unsigned long unused_resv_pages)
+{
+ unsigned long nr_pages;
+
+ /* Uncommit the reservation */
+ h->resv_huge_pages -= unused_resv_pages;
+
+ /* Cannot return gigantic pages currently */
+ if (h->order >= MAX_ORDER)
+ return;
+
+ nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
+
+ /*
+ * We want to release as many surplus pages as possible, spread
+ * evenly across all nodes with memory. Iterate across these nodes
+ * until we can no longer free unreserved surplus pages. This occurs
+ * when the nodes with surplus pages have no free pages.
+ * free_pool_huge_page() will balance the the freed pages across the
+ * on-line nodes with memory and will handle the hstate accounting.
+ */
+ while (nr_pages--) {
+ if (!free_pool_huge_page(h, &node_states[N_HIGH_MEMORY], 1))
+ break;
+ cond_resched_lock(&hugetlb_lock);
+ }
+}
+
+/*
+ * Determine if the huge page at addr within the vma has an associated
+ * reservation. Where it does not we will need to logically increase
+ * reservation and actually increase subpool usage before an allocation
+ * can occur. Where any new reservation would be required the
+ * reservation change is prepared, but not committed. Once the page
+ * has been allocated from the subpool and instantiated the change should
+ * be committed via vma_commit_reservation. No action is required on
+ * failure.
+ */
+static long vma_needs_reservation(struct hstate *h,
+ struct vm_area_struct *vma, unsigned long addr)
+{
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ struct inode *inode = mapping->host;
+
+ if (vma->vm_flags & VM_MAYSHARE) {
+ pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+ return region_chg(&inode->i_mapping->private_list,
+ idx, idx + 1);
+
+ } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+ return 1;
+
+ } else {
+ long err;
+ pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+ struct resv_map *reservations = vma_resv_map(vma);
+
+ err = region_chg(&reservations->regions, idx, idx + 1);
+ if (err < 0)
+ return err;
+ return 0;
+ }
+}
+static void vma_commit_reservation(struct hstate *h,
+ struct vm_area_struct *vma, unsigned long addr)
+{
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ struct inode *inode = mapping->host;
+
+ if (vma->vm_flags & VM_MAYSHARE) {
+ pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+ region_add(&inode->i_mapping->private_list, idx, idx + 1);
+
+ } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+ pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+ struct resv_map *reservations = vma_resv_map(vma);
+
+ /* Mark this page used in the map. */
+ region_add(&reservations->regions, idx, idx + 1);
+ }
+}
+
+static struct page *alloc_huge_page(struct vm_area_struct *vma,
+ unsigned long addr, int avoid_reserve)
+{
+ struct hugepage_subpool *spool = subpool_vma(vma);
+ struct hstate *h = hstate_vma(vma);
+ struct page *page;
+ long chg;
+
+ /*
+ * Processes that did not create the mapping will have no
+ * reserves and will not have accounted against subpool
+ * limit. Check that the subpool limit can be made before
+ * satisfying the allocation MAP_NORESERVE mappings may also
+ * need pages and subpool limit allocated allocated if no reserve
+ * mapping overlaps.
+ */
+ chg = vma_needs_reservation(h, vma, addr);
+ if (chg < 0)
+ return ERR_PTR(-VM_FAULT_OOM);
+ if (chg)
+ if (hugepage_subpool_get_pages(spool, chg))
+ return ERR_PTR(-VM_FAULT_SIGBUS);
+
+ spin_lock(&hugetlb_lock);
+ page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
+ spin_unlock(&hugetlb_lock);
+
+ if (!page) {
+ page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
+ if (!page) {
+ hugepage_subpool_put_pages(spool, chg);
+ return ERR_PTR(-VM_FAULT_SIGBUS);
+ }
+ }
+
+ set_page_private(page, (unsigned long)spool);
+
+ vma_commit_reservation(h, vma, addr);
+
+ return page;
+}
+
+int __weak alloc_bootmem_huge_page(struct hstate *h)
+{
+ struct huge_bootmem_page *m;
+ int nr_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
+
+ while (nr_nodes) {
+ void *addr;
+
+ addr = __alloc_bootmem_node_nopanic(
+ NODE_DATA(hstate_next_node_to_alloc(h,
+ &node_states[N_HIGH_MEMORY])),
+ huge_page_size(h), huge_page_size(h), 0);
+
+ if (addr) {
+ /*
+ * Use the beginning of the huge page to store the
+ * huge_bootmem_page struct (until gather_bootmem
+ * puts them into the mem_map).
+ */
+ m = addr;
+ goto found;
+ }
+ nr_nodes--;
+ }
+ return 0;
+
+found:
+ BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1));
+ /* Put them into a private list first because mem_map is not up yet */
+ list_add(&m->list, &huge_boot_pages);
+ m->hstate = h;
+ return 1;
+}
+
+static void prep_compound_huge_page(struct page *page, int order)
+{
+ if (unlikely(order > (MAX_ORDER - 1)))
+ prep_compound_gigantic_page(page, order);
+ else
+ prep_compound_page(page, order);
+}
+
+/* Put bootmem huge pages into the standard lists after mem_map is up */
+static void __init gather_bootmem_prealloc(void)
+{
+ struct huge_bootmem_page *m;
+
+ list_for_each_entry(m, &huge_boot_pages, list) {
+ struct hstate *h = m->hstate;
+ struct page *page;
+
+#ifdef CONFIG_HIGHMEM
+ page = pfn_to_page(m->phys >> PAGE_SHIFT);
+ free_bootmem_late((unsigned long)m,
+ sizeof(struct huge_bootmem_page));
+#else
+ page = virt_to_page(m);
+#endif
+ __ClearPageReserved(page);
+ WARN_ON(page_count(page) != 1);
+ prep_compound_huge_page(page, h->order);
+ prep_new_huge_page(h, page, page_to_nid(page));
+ /*
+ * If we had gigantic hugepages allocated at boot time, we need
+ * to restore the 'stolen' pages to totalram_pages in order to
+ * fix confusing memory reports from free(1) and another
+ * side-effects, like CommitLimit going negative.
+ */
+ if (h->order > (MAX_ORDER - 1))
+ totalram_pages += 1 << h->order;
+ }
+}
+
+static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
+{
+ unsigned long i;
+
+ for (i = 0; i < h->max_huge_pages; ++i) {
+ if (h->order >= MAX_ORDER) {
+ if (!alloc_bootmem_huge_page(h))
+ break;
+ } else if (!alloc_fresh_huge_page(h,
+ &node_states[N_HIGH_MEMORY]))
+ break;
+ }
+ h->max_huge_pages = i;
+}
+
+static void __init hugetlb_init_hstates(void)
+{
+ struct hstate *h;
+
+ for_each_hstate(h) {
+ /* oversize hugepages were init'ed in early boot */
+ if (h->order < MAX_ORDER)
+ hugetlb_hstate_alloc_pages(h);
+ }
+}
+
+static char * __init memfmt(char *buf, unsigned long n)
+{
+ if (n >= (1UL << 30))
+ sprintf(buf, "%lu GB", n >> 30);
+ else if (n >= (1UL << 20))
+ sprintf(buf, "%lu MB", n >> 20);
+ else
+ sprintf(buf, "%lu KB", n >> 10);
+ return buf;
+}
+
+static void __init report_hugepages(void)
+{
+ struct hstate *h;
+
+ for_each_hstate(h) {
+ char buf[32];
+ printk(KERN_INFO "HugeTLB registered %s page size, "
+ "pre-allocated %ld pages\n",
+ memfmt(buf, huge_page_size(h)),
+ h->free_huge_pages);
+ }
+}
+
+#ifdef CONFIG_HIGHMEM
+static void try_to_free_low(struct hstate *h, unsigned long count,
+ nodemask_t *nodes_allowed)
+{
+ int i;
+
+ if (h->order >= MAX_ORDER)
+ return;
+
+ for_each_node_mask(i, *nodes_allowed) {
+ struct page *page, *next;
+ struct list_head *freel = &h->hugepage_freelists[i];
+ list_for_each_entry_safe(page, next, freel, lru) {
+ if (count >= h->nr_huge_pages)
+ return;
+ if (PageHighMem(page))
+ continue;
+ list_del(&page->lru);
+ update_and_free_page(h, page);
+ h->free_huge_pages--;
+ h->free_huge_pages_node[page_to_nid(page)]--;
+ }
+ }
+}
+#else
+static inline void try_to_free_low(struct hstate *h, unsigned long count,
+ nodemask_t *nodes_allowed)
+{
+}
+#endif
+
+/*
+ * Increment or decrement surplus_huge_pages. Keep node-specific counters
+ * balanced by operating on them in a round-robin fashion.
+ * Returns 1 if an adjustment was made.
+ */
+static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed,
+ int delta)
+{
+ int start_nid, next_nid;
+ int ret = 0;
+
+ VM_BUG_ON(delta != -1 && delta != 1);
+
+ if (delta < 0)
+ start_nid = hstate_next_node_to_alloc(h, nodes_allowed);
+ else
+ start_nid = hstate_next_node_to_free(h, nodes_allowed);
+ next_nid = start_nid;
+
+ do {
+ int nid = next_nid;
+ if (delta < 0) {
+ /*
+ * To shrink on this node, there must be a surplus page
+ */
+ if (!h->surplus_huge_pages_node[nid]) {
+ next_nid = hstate_next_node_to_alloc(h,
+ nodes_allowed);
+ continue;
+ }
+ }
+ if (delta > 0) {
+ /*
+ * Surplus cannot exceed the total number of pages
+ */
+ if (h->surplus_huge_pages_node[nid] >=
+ h->nr_huge_pages_node[nid]) {
+ next_nid = hstate_next_node_to_free(h,
+ nodes_allowed);
+ continue;
+ }
+ }
+
+ h->surplus_huge_pages += delta;
+ h->surplus_huge_pages_node[nid] += delta;
+ ret = 1;
+ break;
+ } while (next_nid != start_nid);
+
+ return ret;
+}
+
+#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
+static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
+ nodemask_t *nodes_allowed)
+{
+ unsigned long min_count, ret;
+
+ if (h->order >= MAX_ORDER)
+ return h->max_huge_pages;
+
+ /*
+ * Increase the pool size
+ * First take pages out of surplus state. Then make up the
+ * remaining difference by allocating fresh huge pages.
+ *
+ * We might race with alloc_buddy_huge_page() here and be unable
+ * to convert a surplus huge page to a normal huge page. That is
+ * not critical, though, it just means the overall size of the
+ * pool might be one hugepage larger than it needs to be, but
+ * within all the constraints specified by the sysctls.
+ */
+ spin_lock(&hugetlb_lock);
+ while (h->surplus_huge_pages && count > persistent_huge_pages(h)) {
+ if (!adjust_pool_surplus(h, nodes_allowed, -1))
+ break;
+ }
+
+ while (count > persistent_huge_pages(h)) {
+ /*
+ * If this allocation races such that we no longer need the
+ * page, free_huge_page will handle it by freeing the page
+ * and reducing the surplus.
+ */
+ spin_unlock(&hugetlb_lock);
+ ret = alloc_fresh_huge_page(h, nodes_allowed);
+ spin_lock(&hugetlb_lock);
+ if (!ret)
+ goto out;
+
+ /* Bail for signals. Probably ctrl-c from user */
+ if (signal_pending(current))
+ goto out;
+ }
+
+ /*
+ * Decrease the pool size
+ * First return free pages to the buddy allocator (being careful
+ * to keep enough around to satisfy reservations). Then place
+ * pages into surplus state as needed so the pool will shrink
+ * to the desired size as pages become free.
+ *
+ * By placing pages into the surplus state independent of the
+ * overcommit value, we are allowing the surplus pool size to
+ * exceed overcommit. There are few sane options here. Since
+ * alloc_buddy_huge_page() is checking the global counter,
+ * though, we'll note that we're not allowed to exceed surplus
+ * and won't grow the pool anywhere else. Not until one of the
+ * sysctls are changed, or the surplus pages go out of use.
+ */
+ min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages;
+ min_count = max(count, min_count);
+ try_to_free_low(h, min_count, nodes_allowed);
+ while (min_count < persistent_huge_pages(h)) {
+ if (!free_pool_huge_page(h, nodes_allowed, 0))
+ break;
+ cond_resched_lock(&hugetlb_lock);
+ }
+ while (count < persistent_huge_pages(h)) {
+ if (!adjust_pool_surplus(h, nodes_allowed, 1))
+ break;
+ }
+out:
+ ret = persistent_huge_pages(h);
+ spin_unlock(&hugetlb_lock);
+ return ret;
+}
+
+#define HSTATE_ATTR_RO(_name) \
+ static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
+
+#define HSTATE_ATTR(_name) \
+ static struct kobj_attribute _name##_attr = \
+ __ATTR(_name, 0644, _name##_show, _name##_store)
+
+static struct kobject *hugepages_kobj;
+static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
+
+static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp);
+
+static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp)
+{
+ int i;
+
+ for (i = 0; i < HUGE_MAX_HSTATE; i++)
+ if (hstate_kobjs[i] == kobj) {
+ if (nidp)
+ *nidp = NUMA_NO_NODE;
+ return &hstates[i];
+ }
+
+ return kobj_to_node_hstate(kobj, nidp);
+}
+
+static ssize_t nr_hugepages_show_common(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct hstate *h;
+ unsigned long nr_huge_pages;
+ int nid;
+
+ h = kobj_to_hstate(kobj, &nid);
+ if (nid == NUMA_NO_NODE)
+ nr_huge_pages = h->nr_huge_pages;
+ else
+ nr_huge_pages = h->nr_huge_pages_node[nid];
+
+ return sprintf(buf, "%lu\n", nr_huge_pages);
+}
+
+static ssize_t nr_hugepages_store_common(bool obey_mempolicy,
+ struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t len)
+{
+ int err;
+ int nid;
+ unsigned long count;
+ struct hstate *h;
+ NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY);
+
+ err = strict_strtoul(buf, 10, &count);
+ if (err)
+ goto out;
+
+ h = kobj_to_hstate(kobj, &nid);
+ if (h->order >= MAX_ORDER) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (nid == NUMA_NO_NODE) {
+ /*
+ * global hstate attribute
+ */
+ if (!(obey_mempolicy &&
+ init_nodemask_of_mempolicy(nodes_allowed))) {
+ NODEMASK_FREE(nodes_allowed);
+ nodes_allowed = &node_states[N_HIGH_MEMORY];
+ }
+ } else if (nodes_allowed) {
+ /*
+ * per node hstate attribute: adjust count to global,
+ * but restrict alloc/free to the specified node.
+ */
+ count += h->nr_huge_pages - h->nr_huge_pages_node[nid];
+ init_nodemask_of_node(nodes_allowed, nid);
+ } else
+ nodes_allowed = &node_states[N_HIGH_MEMORY];
+
+ h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed);
+
+ if (nodes_allowed != &node_states[N_HIGH_MEMORY])
+ NODEMASK_FREE(nodes_allowed);
+
+ return len;
+out:
+ NODEMASK_FREE(nodes_allowed);
+ return err;
+}
+
+static ssize_t nr_hugepages_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return nr_hugepages_show_common(kobj, attr, buf);
+}
+
+static ssize_t nr_hugepages_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t len)
+{
+ return nr_hugepages_store_common(false, kobj, attr, buf, len);
+}
+HSTATE_ATTR(nr_hugepages);
+
+#ifdef CONFIG_NUMA
+
+/*
+ * hstate attribute for optionally mempolicy-based constraint on persistent
+ * huge page alloc/free.
+ */
+static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return nr_hugepages_show_common(kobj, attr, buf);
+}
+
+static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t len)
+{
+ return nr_hugepages_store_common(true, kobj, attr, buf, len);
+}
+HSTATE_ATTR(nr_hugepages_mempolicy);
+#endif
+
+
+static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct hstate *h = kobj_to_hstate(kobj, NULL);
+ return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
+}
+
+static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ int err;
+ unsigned long input;
+ struct hstate *h = kobj_to_hstate(kobj, NULL);
+
+ if (h->order >= MAX_ORDER)
+ return -EINVAL;
+
+ err = strict_strtoul(buf, 10, &input);
+ if (err)
+ return err;
+
+ spin_lock(&hugetlb_lock);
+ h->nr_overcommit_huge_pages = input;
+ spin_unlock(&hugetlb_lock);
+
+ return count;
+}
+HSTATE_ATTR(nr_overcommit_hugepages);
+
+static ssize_t free_hugepages_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct hstate *h;
+ unsigned long free_huge_pages;
+ int nid;
+
+ h = kobj_to_hstate(kobj, &nid);
+ if (nid == NUMA_NO_NODE)
+ free_huge_pages = h->free_huge_pages;
+ else
+ free_huge_pages = h->free_huge_pages_node[nid];
+
+ return sprintf(buf, "%lu\n", free_huge_pages);
+}
+HSTATE_ATTR_RO(free_hugepages);
+
+static ssize_t resv_hugepages_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct hstate *h = kobj_to_hstate(kobj, NULL);
+ return sprintf(buf, "%lu\n", h->resv_huge_pages);
+}
+HSTATE_ATTR_RO(resv_hugepages);
+
+static ssize_t surplus_hugepages_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct hstate *h;
+ unsigned long surplus_huge_pages;
+ int nid;
+
+ h = kobj_to_hstate(kobj, &nid);
+ if (nid == NUMA_NO_NODE)
+ surplus_huge_pages = h->surplus_huge_pages;
+ else
+ surplus_huge_pages = h->surplus_huge_pages_node[nid];
+
+ return sprintf(buf, "%lu\n", surplus_huge_pages);
+}
+HSTATE_ATTR_RO(surplus_hugepages);
+
+static struct attribute *hstate_attrs[] = {
+ &nr_hugepages_attr.attr,
+ &nr_overcommit_hugepages_attr.attr,
+ &free_hugepages_attr.attr,
+ &resv_hugepages_attr.attr,
+ &surplus_hugepages_attr.attr,
+#ifdef CONFIG_NUMA
+ &nr_hugepages_mempolicy_attr.attr,
+#endif
+ NULL,
+};
+
+static struct attribute_group hstate_attr_group = {
+ .attrs = hstate_attrs,
+};
+
+static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
+ struct kobject **hstate_kobjs,
+ struct attribute_group *hstate_attr_group)
+{
+ int retval;
+ int hi = h - hstates;
+
+ hstate_kobjs[hi] = kobject_create_and_add(h->name, parent);
+ if (!hstate_kobjs[hi])
+ return -ENOMEM;
+
+ retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group);
+ if (retval)
+ kobject_put(hstate_kobjs[hi]);
+
+ return retval;
+}
+
+static void __init hugetlb_sysfs_init(void)
+{
+ struct hstate *h;
+ int err;
+
+ hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj);
+ if (!hugepages_kobj)
+ return;
+
+ for_each_hstate(h) {
+ err = hugetlb_sysfs_add_hstate(h, hugepages_kobj,
+ hstate_kobjs, &hstate_attr_group);
+ if (err)
+ printk(KERN_ERR "Hugetlb: Unable to add hstate %s",
+ h->name);
+ }
+}
+
+#ifdef CONFIG_NUMA
+
+/*
+ * node_hstate/s - associate per node hstate attributes, via their kobjects,
+ * with node devices in node_devices[] using a parallel array. The array
+ * index of a node device or _hstate == node id.
+ * This is here to avoid any static dependency of the node device driver, in
+ * the base kernel, on the hugetlb module.
+ */
+struct node_hstate {
+ struct kobject *hugepages_kobj;
+ struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
+};
+struct node_hstate node_hstates[MAX_NUMNODES];
+
+/*
+ * A subset of global hstate attributes for node devices
+ */
+static struct attribute *per_node_hstate_attrs[] = {
+ &nr_hugepages_attr.attr,
+ &free_hugepages_attr.attr,
+ &surplus_hugepages_attr.attr,
+ NULL,
+};
+
+static struct attribute_group per_node_hstate_attr_group = {
+ .attrs = per_node_hstate_attrs,
+};
+
+/*
+ * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj.
+ * Returns node id via non-NULL nidp.
+ */
+static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
+{
+ int nid;
+
+ for (nid = 0; nid < nr_node_ids; nid++) {
+ struct node_hstate *nhs = &node_hstates[nid];
+ int i;
+ for (i = 0; i < HUGE_MAX_HSTATE; i++)
+ if (nhs->hstate_kobjs[i] == kobj) {
+ if (nidp)
+ *nidp = nid;
+ return &hstates[i];
+ }
+ }
+
+ BUG();
+ return NULL;
+}
+
+/*
+ * Unregister hstate attributes from a single node device.
+ * No-op if no hstate attributes attached.
+ */
+void hugetlb_unregister_node(struct node *node)
+{
+ struct hstate *h;
+ struct node_hstate *nhs = &node_hstates[node->dev.id];
+
+ if (!nhs->hugepages_kobj)
+ return; /* no hstate attributes */
+
+ for_each_hstate(h)
+ if (nhs->hstate_kobjs[h - hstates]) {
+ kobject_put(nhs->hstate_kobjs[h - hstates]);
+ nhs->hstate_kobjs[h - hstates] = NULL;
+ }
+
+ kobject_put(nhs->hugepages_kobj);
+ nhs->hugepages_kobj = NULL;
+}
+
+/*
+ * hugetlb module exit: unregister hstate attributes from node devices
+ * that have them.
+ */
+static void hugetlb_unregister_all_nodes(void)
+{
+ int nid;
+
+ /*
+ * disable node device registrations.
+ */
+ register_hugetlbfs_with_node(NULL, NULL);
+
+ /*
+ * remove hstate attributes from any nodes that have them.
+ */
+ for (nid = 0; nid < nr_node_ids; nid++)
+ hugetlb_unregister_node(&node_devices[nid]);
+}
+
+/*
+ * Register hstate attributes for a single node device.
+ * No-op if attributes already registered.
+ */
+void hugetlb_register_node(struct node *node)
+{
+ struct hstate *h;
+ struct node_hstate *nhs = &node_hstates[node->dev.id];
+ int err;
+
+ if (nhs->hugepages_kobj)
+ return; /* already allocated */
+
+ nhs->hugepages_kobj = kobject_create_and_add("hugepages",
+ &node->dev.kobj);
+ if (!nhs->hugepages_kobj)
+ return;
+
+ for_each_hstate(h) {
+ err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj,
+ nhs->hstate_kobjs,
+ &per_node_hstate_attr_group);
+ if (err) {
+ printk(KERN_ERR "Hugetlb: Unable to add hstate %s"
+ " for node %d\n",
+ h->name, node->dev.id);
+ hugetlb_unregister_node(node);
+ break;
+ }
+ }
+}
+
+/*
+ * hugetlb init time: register hstate attributes for all registered node
+ * devices of nodes that have memory. All on-line nodes should have
+ * registered their associated device by this time.
+ */
+static void hugetlb_register_all_nodes(void)
+{
+ int nid;
+
+ for_each_node_state(nid, N_HIGH_MEMORY) {
+ struct node *node = &node_devices[nid];
+ if (node->dev.id == nid)
+ hugetlb_register_node(node);
+ }
+
+ /*
+ * Let the node device driver know we're here so it can
+ * [un]register hstate attributes on node hotplug.
+ */
+ register_hugetlbfs_with_node(hugetlb_register_node,
+ hugetlb_unregister_node);
+}
+#else /* !CONFIG_NUMA */
+
+static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
+{
+ BUG();
+ if (nidp)
+ *nidp = -1;
+ return NULL;
+}
+
+static void hugetlb_unregister_all_nodes(void) { }
+
+static void hugetlb_register_all_nodes(void) { }
+
+#endif
+
+static void __exit hugetlb_exit(void)
+{
+ struct hstate *h;
+
+ hugetlb_unregister_all_nodes();
+
+ for_each_hstate(h) {
+ kobject_put(hstate_kobjs[h - hstates]);
+ }
+
+ kobject_put(hugepages_kobj);
+}
+module_exit(hugetlb_exit);
+
+static int __init hugetlb_init(void)
+{
+ /* Some platform decide whether they support huge pages at boot
+ * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when
+ * there is no such support
+ */
+ if (HPAGE_SHIFT == 0)
+ return 0;
+
+ if (!size_to_hstate(default_hstate_size)) {
+ default_hstate_size = HPAGE_SIZE;
+ if (!size_to_hstate(default_hstate_size))
+ hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
+ }
+ default_hstate_idx = size_to_hstate(default_hstate_size) - hstates;
+ if (default_hstate_max_huge_pages)
+ default_hstate.max_huge_pages = default_hstate_max_huge_pages;
+
+ hugetlb_init_hstates();
+
+ gather_bootmem_prealloc();
+
+ report_hugepages();
+
+ hugetlb_sysfs_init();
+
+ hugetlb_register_all_nodes();
+
+ return 0;
+}
+module_init(hugetlb_init);
+
+/* Should be called on processing a hugepagesz=... option */
+void __init hugetlb_add_hstate(unsigned order)
+{
+ struct hstate *h;
+ unsigned long i;
+
+ if (size_to_hstate(PAGE_SIZE << order)) {
+ printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
+ return;
+ }
+ BUG_ON(max_hstate >= HUGE_MAX_HSTATE);
+ BUG_ON(order == 0);
+ h = &hstates[max_hstate++];
+ h->order = order;
+ h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
+ h->nr_huge_pages = 0;
+ h->free_huge_pages = 0;
+ for (i = 0; i < MAX_NUMNODES; ++i)
+ INIT_LIST_HEAD(&h->hugepage_freelists[i]);
+ h->next_nid_to_alloc = first_node(node_states[N_HIGH_MEMORY]);
+ h->next_nid_to_free = first_node(node_states[N_HIGH_MEMORY]);
+ snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
+ huge_page_size(h)/1024);
+
+ parsed_hstate = h;
+}
+
+static int __init hugetlb_nrpages_setup(char *s)
+{
+ unsigned long *mhp;
+ static unsigned long *last_mhp;
+
+ /*
+ * !max_hstate means we haven't parsed a hugepagesz= parameter yet,
+ * so this hugepages= parameter goes to the "default hstate".
+ */
+ if (!max_hstate)
+ mhp = &default_hstate_max_huge_pages;
+ else
+ mhp = &parsed_hstate->max_huge_pages;
+
+ if (mhp == last_mhp) {
+ printk(KERN_WARNING "hugepages= specified twice without "
+ "interleaving hugepagesz=, ignoring\n");
+ return 1;
+ }
+
+ if (sscanf(s, "%lu", mhp) <= 0)
+ *mhp = 0;
+
+ /*
+ * Global state is always initialized later in hugetlb_init.
+ * But we need to allocate >= MAX_ORDER hstates here early to still
+ * use the bootmem allocator.
+ */
+ if (max_hstate && parsed_hstate->order >= MAX_ORDER)
+ hugetlb_hstate_alloc_pages(parsed_hstate);
+
+ last_mhp = mhp;
+
+ return 1;
+}
+__setup("hugepages=", hugetlb_nrpages_setup);
+
+static int __init hugetlb_default_setup(char *s)
+{
+ default_hstate_size = memparse(s, &s);
+ return 1;
+}
+__setup("default_hugepagesz=", hugetlb_default_setup);
+
+static unsigned int cpuset_mems_nr(unsigned int *array)
+{
+ int node;
+ unsigned int nr = 0;
+
+ for_each_node_mask(node, cpuset_current_mems_allowed)
+ nr += array[node];
+
+ return nr;
+}
+
+#ifdef CONFIG_SYSCTL
+static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
+ struct ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ struct hstate *h = &default_hstate;
+ unsigned long tmp;
+ int ret;
+
+ tmp = h->max_huge_pages;
+
+ if (write && h->order >= MAX_ORDER)
+ return -EINVAL;
+
+ table->data = &tmp;
+ table->maxlen = sizeof(unsigned long);
+ ret = proc_doulongvec_minmax(table, write, buffer, length, ppos);
+ if (ret)
+ goto out;
+
+ if (write) {
+ NODEMASK_ALLOC(nodemask_t, nodes_allowed,
+ GFP_KERNEL | __GFP_NORETRY);
+ if (!(obey_mempolicy &&
+ init_nodemask_of_mempolicy(nodes_allowed))) {
+ NODEMASK_FREE(nodes_allowed);
+ nodes_allowed = &node_states[N_HIGH_MEMORY];
+ }
+ h->max_huge_pages = set_max_huge_pages(h, tmp, nodes_allowed);
+
+ if (nodes_allowed != &node_states[N_HIGH_MEMORY])
+ NODEMASK_FREE(nodes_allowed);
+ }
+out:
+ return ret;
+}
+
+int hugetlb_sysctl_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+
+ return hugetlb_sysctl_handler_common(false, table, write,
+ buffer, length, ppos);
+}
+
+#ifdef CONFIG_NUMA
+int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ return hugetlb_sysctl_handler_common(true, table, write,
+ buffer, length, ppos);
+}
+#endif /* CONFIG_NUMA */
+
+int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
+ void __user *buffer,
+ size_t *length, loff_t *ppos)
+{
+ proc_dointvec(table, write, buffer, length, ppos);
+ if (hugepages_treat_as_movable)
+ htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
+ else
+ htlb_alloc_mask = GFP_HIGHUSER;
+ return 0;
+}
+
+int hugetlb_overcommit_handler(struct ctl_table *table, int write,
+ void __user *buffer,
+ size_t *length, loff_t *ppos)
+{
+ struct hstate *h = &default_hstate;
+ unsigned long tmp;
+ int ret;
+
+ tmp = h->nr_overcommit_huge_pages;
+
+ if (write && h->order >= MAX_ORDER)
+ return -EINVAL;
+
+ table->data = &tmp;
+ table->maxlen = sizeof(unsigned long);
+ ret = proc_doulongvec_minmax(table, write, buffer, length, ppos);
+ if (ret)
+ goto out;
+
+ if (write) {
+ spin_lock(&hugetlb_lock);
+ h->nr_overcommit_huge_pages = tmp;
+ spin_unlock(&hugetlb_lock);
+ }
+out:
+ return ret;
+}
+
+#endif /* CONFIG_SYSCTL */
+
+void hugetlb_report_meminfo(struct seq_file *m)
+{
+ struct hstate *h = &default_hstate;
+ seq_printf(m,
+ "HugePages_Total: %5lu\n"
+ "HugePages_Free: %5lu\n"
+ "HugePages_Rsvd: %5lu\n"
+ "HugePages_Surp: %5lu\n"
+ "Hugepagesize: %8lu kB\n",
+ h->nr_huge_pages,
+ h->free_huge_pages,
+ h->resv_huge_pages,
+ h->surplus_huge_pages,
+ 1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
+}
+
+int hugetlb_report_node_meminfo(int nid, char *buf)
+{
+ struct hstate *h = &default_hstate;
+ return sprintf(buf,
+ "Node %d HugePages_Total: %5u\n"
+ "Node %d HugePages_Free: %5u\n"
+ "Node %d HugePages_Surp: %5u\n",
+ nid, h->nr_huge_pages_node[nid],
+ nid, h->free_huge_pages_node[nid],
+ nid, h->surplus_huge_pages_node[nid]);
+}
+
+/* Return the number pages of memory we physically have, in PAGE_SIZE units. */
+unsigned long hugetlb_total_pages(void)
+{
+ struct hstate *h;
+ unsigned long nr_total_pages = 0;
+
+ for_each_hstate(h)
+ nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h);
+ return nr_total_pages;
+}
+
+static int hugetlb_acct_memory(struct hstate *h, long delta)
+{
+ int ret = -ENOMEM;
+
+ spin_lock(&hugetlb_lock);
+ /*
+ * When cpuset is configured, it breaks the strict hugetlb page
+ * reservation as the accounting is done on a global variable. Such
+ * reservation is completely rubbish in the presence of cpuset because
+ * the reservation is not checked against page availability for the
+ * current cpuset. Application can still potentially OOM'ed by kernel
+ * with lack of free htlb page in cpuset that the task is in.
+ * Attempt to enforce strict accounting with cpuset is almost
+ * impossible (or too ugly) because cpuset is too fluid that
+ * task or memory node can be dynamically moved between cpusets.
+ *
+ * The change of semantics for shared hugetlb mapping with cpuset is
+ * undesirable. However, in order to preserve some of the semantics,
+ * we fall back to check against current free page availability as
+ * a best attempt and hopefully to minimize the impact of changing
+ * semantics that cpuset has.
+ */
+ if (delta > 0) {
+ if (gather_surplus_pages(h, delta) < 0)
+ goto out;
+
+ if (delta > cpuset_mems_nr(h->free_huge_pages_node)) {
+ return_unused_surplus_pages(h, delta);
+ goto out;
+ }
+ }
+
+ ret = 0;
+ if (delta < 0)
+ return_unused_surplus_pages(h, (unsigned long) -delta);
+
+out:
+ spin_unlock(&hugetlb_lock);
+ return ret;
+}
+
+static void hugetlb_vm_op_open(struct vm_area_struct *vma)
+{
+ struct resv_map *reservations = vma_resv_map(vma);
+
+ /*
+ * This new VMA should share its siblings reservation map if present.
+ * The VMA will only ever have a valid reservation map pointer where
+ * it is being copied for another still existing VMA. As that VMA
+ * has a reference to the reservation map it cannot disappear until
+ * after this open call completes. It is therefore safe to take a
+ * new reference here without additional locking.
+ */
+ if (reservations)
+ kref_get(&reservations->refs);
+}
+
+static void resv_map_put(struct vm_area_struct *vma)
+{
+ struct resv_map *reservations = vma_resv_map(vma);
+
+ if (!reservations)
+ return;
+ kref_put(&reservations->refs, resv_map_release);
+}
+
+static void hugetlb_vm_op_close(struct vm_area_struct *vma)
+{
+ struct hstate *h = hstate_vma(vma);
+ struct resv_map *reservations = vma_resv_map(vma);
+ struct hugepage_subpool *spool = subpool_vma(vma);
+ unsigned long reserve;
+ unsigned long start;
+ unsigned long end;
+
+ if (reservations) {
+ start = vma_hugecache_offset(h, vma, vma->vm_start);
+ end = vma_hugecache_offset(h, vma, vma->vm_end);
+
+ reserve = (end - start) -
+ region_count(&reservations->regions, start, end);
+
+ resv_map_put(vma);
+
+ if (reserve) {
+ hugetlb_acct_memory(h, -reserve);
+ hugepage_subpool_put_pages(spool, reserve);
+ }
+ }
+}
+
+/*
+ * We cannot handle pagefaults against hugetlb pages at all. They cause
+ * handle_mm_fault() to try to instantiate regular-sized pages in the
+ * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get
+ * this far.
+ */
+static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ BUG();
+ return 0;
+}
+
+const struct vm_operations_struct hugetlb_vm_ops = {
+ .fault = hugetlb_vm_op_fault,
+ .open = hugetlb_vm_op_open,
+ .close = hugetlb_vm_op_close,
+};
+
+static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
+ int writable)
+{
+ pte_t entry;
+
+ if (writable) {
+ entry =
+ pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
+ } else {
+ entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot));
+ }
+ entry = pte_mkyoung(entry);
+ entry = pte_mkhuge(entry);
+
+ return entry;
+}
+
+static void set_huge_ptep_writable(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep)
+{
+ pte_t entry;
+
+ entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep)));
+ if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1))
+ update_mmu_cache(vma, address, ptep);
+}
+
+static int is_hugetlb_entry_migration(pte_t pte)
+{
+ swp_entry_t swp;
+
+ if (huge_pte_none(pte) || pte_present(pte))
+ return 0;
+ swp = pte_to_swp_entry(pte);
+ if (non_swap_entry(swp) && is_migration_entry(swp))
+ return 1;
+ else
+ return 0;
+}
+
+static int is_hugetlb_entry_hwpoisoned(pte_t pte)
+{
+ swp_entry_t swp;
+
+ if (huge_pte_none(pte) || pte_present(pte))
+ return 0;
+ swp = pte_to_swp_entry(pte);
+ if (non_swap_entry(swp) && is_hwpoison_entry(swp))
+ return 1;
+ else
+ return 0;
+}
+
+int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
+ struct vm_area_struct *vma)
+{
+ pte_t *src_pte, *dst_pte, entry;
+ struct page *ptepage;
+ unsigned long addr;
+ int cow;
+ struct hstate *h = hstate_vma(vma);
+ unsigned long sz = huge_page_size(h);
+
+ cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
+
+ for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
+ src_pte = huge_pte_offset(src, addr);
+ if (!src_pte)
+ continue;
+ dst_pte = huge_pte_alloc(dst, addr, sz);
+ if (!dst_pte)
+ goto nomem;
+
+ /* If the pagetables are shared don't copy or take references */
+ if (dst_pte == src_pte)
+ continue;
+
+ spin_lock(&dst->page_table_lock);
+ spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING);
+ entry = huge_ptep_get(src_pte);
+ if (huge_pte_none(entry)) { /* skip none entry */
+ ;
+ } else if (unlikely(is_hugetlb_entry_migration(entry) ||
+ is_hugetlb_entry_hwpoisoned(entry))) {
+ swp_entry_t swp_entry = pte_to_swp_entry(entry);
+
+ if (is_write_migration_entry(swp_entry) && cow) {
+ /*
+ * COW mappings require pages in both
+ * parent and child to be set to read.
+ */
+ make_migration_entry_read(&swp_entry);
+ entry = swp_entry_to_pte(swp_entry);
+ set_huge_pte_at(src, addr, src_pte, entry);
+ }
+ set_huge_pte_at(dst, addr, dst_pte, entry);
+ } else {
+ if (cow)
+ huge_ptep_set_wrprotect(src, addr, src_pte);
+ entry = huge_ptep_get(src_pte);
+ ptepage = pte_page(entry);
+ get_page(ptepage);
+ page_dup_rmap(ptepage);
+ set_huge_pte_at(dst, addr, dst_pte, entry);
+ }
+ spin_unlock(&src->page_table_lock);
+ spin_unlock(&dst->page_table_lock);
+ }
+ return 0;
+
+nomem:
+ return -ENOMEM;
+}
+
+void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end, struct page *ref_page)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long address;
+ pte_t *ptep;
+ pte_t pte;
+ struct page *page;
+ struct page *tmp;
+ struct hstate *h = hstate_vma(vma);
+ unsigned long sz = huge_page_size(h);
+
+ /*
+ * A page gathering list, protected by per file i_mmap_mutex. The
+ * lock is used to avoid list corruption from multiple unmapping
+ * of the same page since we are using page->lru.
+ */
+ LIST_HEAD(page_list);
+
+ WARN_ON(!is_vm_hugetlb_page(vma));
+ BUG_ON(start & ~huge_page_mask(h));
+ BUG_ON(end & ~huge_page_mask(h));
+
+ mmu_notifier_invalidate_range_start(mm, start, end);
+ spin_lock(&mm->page_table_lock);
+ for (address = start; address < end; address += sz) {
+ ptep = huge_pte_offset(mm, address);
+ if (!ptep)
+ continue;
+
+ if (huge_pmd_unshare(mm, &address, ptep))
+ continue;
+
+ pte = huge_ptep_get(ptep);
+ if (huge_pte_none(pte))
+ continue;
+
+ /*
+ * Migrating hugepage or HWPoisoned hugepage is already
+ * unmapped and its refcount is dropped
+ */
+ if (unlikely(!pte_present(pte)))
+ continue;
+
+ page = pte_page(pte);
+ /*
+ * If a reference page is supplied, it is because a specific
+ * page is being unmapped, not a range. Ensure the page we
+ * are about to unmap is the actual page of interest.
+ */
+ if (ref_page) {
+ if (page != ref_page)
+ continue;
+
+ /*
+ * Mark the VMA as having unmapped its page so that
+ * future faults in this VMA will fail rather than
+ * looking like data was lost
+ */
+ set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
+ }
+
+ pte = huge_ptep_get_and_clear(mm, address, ptep);
+ if (pte_dirty(pte))
+ set_page_dirty(page);
+ list_add(&page->lru, &page_list);
+
+ /* Bail out after unmapping reference page if supplied */
+ if (ref_page)
+ break;
+ }
+ flush_tlb_range(vma, start, end);
+ spin_unlock(&mm->page_table_lock);
+ mmu_notifier_invalidate_range_end(mm, start, end);
+ list_for_each_entry_safe(page, tmp, &page_list, lru) {
+ page_remove_rmap(page);
+ list_del(&page->lru);
+ put_page(page);
+ }
+}
+
+void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end, struct page *ref_page)
+{
+ mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
+ __unmap_hugepage_range(vma, start, end, ref_page);
+ /*
+ * Clear this flag so that x86's huge_pmd_share page_table_shareable
+ * test will fail on a vma being torn down, and not grab a page table
+ * on its way out. We're lucky that the flag has such an appropriate
+ * name, and can in fact be safely cleared here. We could clear it
+ * before the __unmap_hugepage_range above, but all that's necessary
+ * is to clear it before releasing the i_mmap_mutex below.
+ *
+ * This works because in the contexts this is called, the VMA is
+ * going to be destroyed. It is not vunerable to madvise(DONTNEED)
+ * because madvise is not supported on hugetlbfs. The same applies
+ * for direct IO. unmap_hugepage_range() is only being called just
+ * before free_pgtables() so clearing VM_MAYSHARE will not cause
+ * surprises later.
+ */
+ vma->vm_flags &= ~VM_MAYSHARE;
+ mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
+}
+
+/*
+ * This is called when the original mapper is failing to COW a MAP_PRIVATE
+ * mappping it owns the reserve page for. The intention is to unmap the page
+ * from other VMAs and let the children be SIGKILLed if they are faulting the
+ * same region.
+ */
+static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct page *page, unsigned long address)
+{
+ struct hstate *h = hstate_vma(vma);
+ struct vm_area_struct *iter_vma;
+ struct address_space *mapping;
+ struct prio_tree_iter iter;
+ pgoff_t pgoff;
+
+ /*
+ * vm_pgoff is in PAGE_SIZE units, hence the different calculation
+ * from page cache lookup which is in HPAGE_SIZE units.
+ */
+ address = address & huge_page_mask(h);
+ pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) +
+ vma->vm_pgoff;
+ mapping = vma->vm_file->f_dentry->d_inode->i_mapping;
+
+ /*
+ * Take the mapping lock for the duration of the table walk. As
+ * this mapping should be shared between all the VMAs,
+ * __unmap_hugepage_range() is called as the lock is already held
+ */
+ mutex_lock(&mapping->i_mmap_mutex);
+ vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+ /* Do not unmap the current VMA */
+ if (iter_vma == vma)
+ continue;
+
+ /*
+ * Unmap the page from other VMAs without their own reserves.
+ * They get marked to be SIGKILLed if they fault in these
+ * areas. This is because a future no-page fault on this VMA
+ * could insert a zeroed page instead of the data existing
+ * from the time of fork. This would look like data corruption
+ */
+ if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
+ __unmap_hugepage_range(iter_vma,
+ address, address + huge_page_size(h),
+ page);
+ }
+ mutex_unlock(&mapping->i_mmap_mutex);
+
+ return 1;
+}
+
+/*
+ * Hugetlb_cow() should be called with page lock of the original hugepage held.
+ * Called with hugetlb_instantiation_mutex held and pte_page locked so we
+ * cannot race with other handlers or page migration.
+ * Keep the pte_same checks anyway to make transition from the mutex easier.
+ */
+static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep, pte_t pte,
+ struct page *pagecache_page)
+{
+ struct hstate *h = hstate_vma(vma);
+ struct page *old_page, *new_page;
+ int avoidcopy;
+ int outside_reserve = 0;
+
+ old_page = pte_page(pte);
+
+retry_avoidcopy:
+ /* If no-one else is actually using this page, avoid the copy
+ * and just make the page writable */
+ avoidcopy = (page_mapcount(old_page) == 1);
+ if (avoidcopy) {
+ if (PageAnon(old_page))
+ page_move_anon_rmap(old_page, vma, address);
+ set_huge_ptep_writable(vma, address, ptep);
+ return 0;
+ }
+
+ /*
+ * If the process that created a MAP_PRIVATE mapping is about to
+ * perform a COW due to a shared page count, attempt to satisfy
+ * the allocation without using the existing reserves. The pagecache
+ * page is used to determine if the reserve at this address was
+ * consumed or not. If reserves were used, a partial faulted mapping
+ * at the time of fork() could consume its reserves on COW instead
+ * of the full address range.
+ */
+ if (!(vma->vm_flags & VM_MAYSHARE) &&
+ is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
+ old_page != pagecache_page)
+ outside_reserve = 1;
+
+ page_cache_get(old_page);
+
+ /* Drop page_table_lock as buddy allocator may be called */
+ spin_unlock(&mm->page_table_lock);
+ new_page = alloc_huge_page(vma, address, outside_reserve);
+
+ if (IS_ERR(new_page)) {
+ page_cache_release(old_page);
+
+ /*
+ * If a process owning a MAP_PRIVATE mapping fails to COW,
+ * it is due to references held by a child and an insufficient
+ * huge page pool. To guarantee the original mappers
+ * reliability, unmap the page from child processes. The child
+ * may get SIGKILLed if it later faults.
+ */
+ if (outside_reserve) {
+ BUG_ON(huge_pte_none(pte));
+ if (unmap_ref_private(mm, vma, old_page, address)) {
+ BUG_ON(huge_pte_none(pte));
+ spin_lock(&mm->page_table_lock);
+ ptep = huge_pte_offset(mm, address & huge_page_mask(h));
+ if (likely(pte_same(huge_ptep_get(ptep), pte)))
+ goto retry_avoidcopy;
+ /*
+ * race occurs while re-acquiring page_table_lock, and
+ * our job is done.
+ */
+ return 0;
+ }
+ WARN_ON_ONCE(1);
+ }
+
+ /* Caller expects lock to be held */
+ spin_lock(&mm->page_table_lock);
+ return -PTR_ERR(new_page);
+ }
+
+ /*
+ * When the original hugepage is shared one, it does not have
+ * anon_vma prepared.
+ */
+ if (unlikely(anon_vma_prepare(vma))) {
+ page_cache_release(new_page);
+ page_cache_release(old_page);
+ /* Caller expects lock to be held */
+ spin_lock(&mm->page_table_lock);
+ return VM_FAULT_OOM;
+ }
+
+ copy_user_huge_page(new_page, old_page, address, vma,
+ pages_per_huge_page(h));
+ __SetPageUptodate(new_page);
+
+ /*
+ * Retake the page_table_lock to check for racing updates
+ * before the page tables are altered
+ */
+ spin_lock(&mm->page_table_lock);
+ ptep = huge_pte_offset(mm, address & huge_page_mask(h));
+ if (likely(pte_same(huge_ptep_get(ptep), pte))) {
+ /* Break COW */
+ mmu_notifier_invalidate_range_start(mm,
+ address & huge_page_mask(h),
+ (address & huge_page_mask(h)) + huge_page_size(h));
+ huge_ptep_clear_flush(vma, address, ptep);
+ set_huge_pte_at(mm, address, ptep,
+ make_huge_pte(vma, new_page, 1));
+ page_remove_rmap(old_page);
+ hugepage_add_new_anon_rmap(new_page, vma, address);
+ /* Make the old page be freed below */
+ new_page = old_page;
+ mmu_notifier_invalidate_range_end(mm,
+ address & huge_page_mask(h),
+ (address & huge_page_mask(h)) + huge_page_size(h));
+ }
+ page_cache_release(new_page);
+ page_cache_release(old_page);
+ return 0;
+}
+
+/* Return the pagecache page at a given address within a VMA */
+static struct page *hugetlbfs_pagecache_page(struct hstate *h,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ struct address_space *mapping;
+ pgoff_t idx;
+
+ mapping = vma->vm_file->f_mapping;
+ idx = vma_hugecache_offset(h, vma, address);
+
+ return find_lock_page(mapping, idx);
+}
+
+/*
+ * Return whether there is a pagecache page to back given address within VMA.
+ * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page.
+ */
+static bool hugetlbfs_pagecache_present(struct hstate *h,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ struct address_space *mapping;
+ pgoff_t idx;
+ struct page *page;
+
+ mapping = vma->vm_file->f_mapping;
+ idx = vma_hugecache_offset(h, vma, address);
+
+ page = find_get_page(mapping, idx);
+ if (page)
+ put_page(page);
+ return page != NULL;
+}
+
+static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep, unsigned int flags)
+{
+ struct hstate *h = hstate_vma(vma);
+ int ret = VM_FAULT_SIGBUS;
+ int anon_rmap = 0;
+ pgoff_t idx;
+ unsigned long size;
+ struct page *page;
+ struct address_space *mapping;
+ pte_t new_pte;
+
+ /*
+ * Currently, we are forced to kill the process in the event the
+ * original mapper has unmapped pages from the child due to a failed
+ * COW. Warn that such a situation has occurred as it may not be obvious
+ */
+ if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) {
+ printk(KERN_WARNING
+ "PID %d killed due to inadequate hugepage pool\n",
+ current->pid);
+ return ret;
+ }
+
+ mapping = vma->vm_file->f_mapping;
+ idx = vma_hugecache_offset(h, vma, address);
+
+ /*
+ * Use page lock to guard against racing truncation
+ * before we get page_table_lock.
+ */
+retry:
+ page = find_lock_page(mapping, idx);
+ if (!page) {
+ size = i_size_read(mapping->host) >> huge_page_shift(h);
+ if (idx >= size)
+ goto out;
+ page = alloc_huge_page(vma, address, 0);
+ if (IS_ERR(page)) {
+ ret = -PTR_ERR(page);
+ goto out;
+ }
+ clear_huge_page(page, address, pages_per_huge_page(h));
+ __SetPageUptodate(page);
+
+ if (vma->vm_flags & VM_MAYSHARE) {
+ int err;
+ struct inode *inode = mapping->host;
+
+ err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
+ if (err) {
+ put_page(page);
+ if (err == -EEXIST)
+ goto retry;
+ goto out;
+ }
+
+ spin_lock(&inode->i_lock);
+ inode->i_blocks += blocks_per_huge_page(h);
+ spin_unlock(&inode->i_lock);
+ } else {
+ lock_page(page);
+ if (unlikely(anon_vma_prepare(vma))) {
+ ret = VM_FAULT_OOM;
+ goto backout_unlocked;
+ }
+ anon_rmap = 1;
+ }
+ } else {
+ /*
+ * If memory error occurs between mmap() and fault, some process
+ * don't have hwpoisoned swap entry for errored virtual address.
+ * So we need to block hugepage fault by PG_hwpoison bit check.
+ */
+ if (unlikely(PageHWPoison(page))) {
+ ret = VM_FAULT_HWPOISON |
+ VM_FAULT_SET_HINDEX(h - hstates);
+ goto backout_unlocked;
+ }
+ }
+
+ /*
+ * If we are going to COW a private mapping later, we examine the
+ * pending reservations for this page now. This will ensure that
+ * any allocations necessary to record that reservation occur outside
+ * the spinlock.
+ */
+ if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED))
+ if (vma_needs_reservation(h, vma, address) < 0) {
+ ret = VM_FAULT_OOM;
+ goto backout_unlocked;
+ }
+
+ spin_lock(&mm->page_table_lock);
+ size = i_size_read(mapping->host) >> huge_page_shift(h);
+ if (idx >= size)
+ goto backout;
+
+ ret = 0;
+ if (!huge_pte_none(huge_ptep_get(ptep)))
+ goto backout;
+
+ if (anon_rmap)
+ hugepage_add_new_anon_rmap(page, vma, address);
+ else
+ page_dup_rmap(page);
+ new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
+ && (vma->vm_flags & VM_SHARED)));
+ set_huge_pte_at(mm, address, ptep, new_pte);
+
+ if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
+ /* Optimization, do the COW without a second fault */
+ ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page);
+ }
+
+ spin_unlock(&mm->page_table_lock);
+ unlock_page(page);
+out:
+ return ret;
+
+backout:
+ spin_unlock(&mm->page_table_lock);
+backout_unlocked:
+ unlock_page(page);
+ put_page(page);
+ goto out;
+}
+
+int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, unsigned int flags)
+{
+ pte_t *ptep;
+ pte_t entry;
+ int ret;
+ struct page *page = NULL;
+ struct page *pagecache_page = NULL;
+ static DEFINE_MUTEX(hugetlb_instantiation_mutex);
+ struct hstate *h = hstate_vma(vma);
+ int need_wait_lock = 0;
+
+ address &= huge_page_mask(h);
+
+ ptep = huge_pte_offset(mm, address);
+ if (ptep) {
+ entry = huge_ptep_get(ptep);
+ if (unlikely(is_hugetlb_entry_migration(entry))) {
+ migration_entry_wait_huge(mm, ptep);
+ return 0;
+ } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
+ return VM_FAULT_HWPOISON_LARGE |
+ VM_FAULT_SET_HINDEX(h - hstates);
+ }
+
+ ptep = huge_pte_alloc(mm, address, huge_page_size(h));
+ if (!ptep)
+ return VM_FAULT_OOM;
+
+ /*
+ * Serialize hugepage allocation and instantiation, so that we don't
+ * get spurious allocation failures if two CPUs race to instantiate
+ * the same page in the page cache.
+ */
+ mutex_lock(&hugetlb_instantiation_mutex);
+ entry = huge_ptep_get(ptep);
+ if (huge_pte_none(entry)) {
+ ret = hugetlb_no_page(mm, vma, address, ptep, flags);
+ goto out_mutex;
+ }
+
+ ret = 0;
+
+ /*
+ * entry could be a migration/hwpoison entry at this point, so this
+ * check prevents the kernel from going below assuming that we have
+ * a active hugepage in pagecache. This goto expects the 2nd page fault,
+ * and is_hugetlb_entry_(migration|hwpoisoned) check will properly
+ * handle it.
+ */
+ if (!pte_present(entry))
+ goto out_mutex;
+
+ /*
+ * If we are going to COW the mapping later, we examine the pending
+ * reservations for this page now. This will ensure that any
+ * allocations necessary to record that reservation occur outside the
+ * spinlock. For private mappings, we also lookup the pagecache
+ * page now as it is used to determine if a reservation has been
+ * consumed.
+ */
+ if ((flags & FAULT_FLAG_WRITE) && !pte_write(entry)) {
+ if (vma_needs_reservation(h, vma, address) < 0) {
+ ret = VM_FAULT_OOM;
+ goto out_mutex;
+ }
+
+ if (!(vma->vm_flags & VM_MAYSHARE))
+ pagecache_page = hugetlbfs_pagecache_page(h,
+ vma, address);
+ }
+
+ spin_lock(&mm->page_table_lock);
+
+ /* Check for a racing update before calling hugetlb_cow */
+ if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
+ goto out_page_table_lock;
+
+ /*
+ * hugetlb_cow() requires page locks of pte_page(entry) and
+ * pagecache_page, so here we need take the former one
+ * when page != pagecache_page or !pagecache_page.
+ */
+ page = pte_page(entry);
+ if (page != pagecache_page)
+ if (!trylock_page(page)) {
+ need_wait_lock = 1;
+ goto out_page_table_lock;
+ }
+
+ get_page(page);
+
+
+ if (flags & FAULT_FLAG_WRITE) {
+ if (!pte_write(entry)) {
+ ret = hugetlb_cow(mm, vma, address, ptep, entry,
+ pagecache_page);
+ goto out_put_page;
+ }
+ entry = pte_mkdirty(entry);
+ }
+ entry = pte_mkyoung(entry);
+ if (huge_ptep_set_access_flags(vma, address, ptep, entry,
+ flags & FAULT_FLAG_WRITE))
+ update_mmu_cache(vma, address, ptep);
+
+out_put_page:
+ if (page != pagecache_page)
+ unlock_page(page);
+ put_page(page);
+out_page_table_lock:
+ spin_unlock(&mm->page_table_lock);
+
+ if (pagecache_page) {
+ unlock_page(pagecache_page);
+ put_page(pagecache_page);
+ }
+ if (page != pagecache_page)
+ unlock_page(page);
+ put_page(page);
+
+out_mutex:
+ mutex_unlock(&hugetlb_instantiation_mutex);
+
+ return ret;
+}
+
+/* Can be overriden by architectures */
+__attribute__((weak)) struct page *
+follow_huge_pud(struct mm_struct *mm, unsigned long address,
+ pud_t *pud, int write)
+{
+ BUG();
+ return NULL;
+}
+
+int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct page **pages, struct vm_area_struct **vmas,
+ unsigned long *position, int *length, int i,
+ unsigned int flags)
+{
+ unsigned long pfn_offset;
+ unsigned long vaddr = *position;
+ int remainder = *length;
+ struct hstate *h = hstate_vma(vma);
+
+ spin_lock(&mm->page_table_lock);
+ while (vaddr < vma->vm_end && remainder) {
+ pte_t *pte;
+ int absent;
+ struct page *page;
+
+ /*
+ * Some archs (sparc64, sh*) have multiple pte_ts to
+ * each hugepage. We have to make sure we get the
+ * first, for the page indexing below to work.
+ */
+ pte = huge_pte_offset(mm, vaddr & huge_page_mask(h));
+ absent = !pte || huge_pte_none(huge_ptep_get(pte));
+
+ /*
+ * When coredumping, it suits get_dump_page if we just return
+ * an error where there's an empty slot with no huge pagecache
+ * to back it. This way, we avoid allocating a hugepage, and
+ * the sparse dumpfile avoids allocating disk blocks, but its
+ * huge holes still show up with zeroes where they need to be.
+ */
+ if (absent && (flags & FOLL_DUMP) &&
+ !hugetlbfs_pagecache_present(h, vma, vaddr)) {
+ remainder = 0;
+ break;
+ }
+
+ /*
+ * We need call hugetlb_fault for both hugepages under migration
+ * (in which case hugetlb_fault waits for the migration,) and
+ * hwpoisoned hugepages (in which case we need to prevent the
+ * caller from accessing to them.) In order to do this, we use
+ * here is_swap_pte instead of is_hugetlb_entry_migration and
+ * is_hugetlb_entry_hwpoisoned. This is because it simply covers
+ * both cases, and because we can't follow correct pages
+ * directly from any kind of swap entries.
+ */
+ if (absent || is_swap_pte(huge_ptep_get(pte)) ||
+ ((flags & FOLL_WRITE) && !pte_write(huge_ptep_get(pte)))) {
+ int ret;
+
+ spin_unlock(&mm->page_table_lock);
+ ret = hugetlb_fault(mm, vma, vaddr,
+ (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0);
+ spin_lock(&mm->page_table_lock);
+ if (!(ret & VM_FAULT_ERROR))
+ continue;
+
+ remainder = 0;
+ break;
+ }
+
+ pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
+ page = pte_page(huge_ptep_get(pte));
+same_page:
+ if (pages) {
+ pages[i] = mem_map_offset(page, pfn_offset);
+ get_page(pages[i]);
+ }
+
+ if (vmas)
+ vmas[i] = vma;
+
+ vaddr += PAGE_SIZE;
+ ++pfn_offset;
+ --remainder;
+ ++i;
+ if (vaddr < vma->vm_end && remainder &&
+ pfn_offset < pages_per_huge_page(h)) {
+ /*
+ * We use pfn_offset to avoid touching the pageframes
+ * of this compound page.
+ */
+ goto same_page;
+ }
+ }
+ spin_unlock(&mm->page_table_lock);
+ *length = remainder;
+ *position = vaddr;
+
+ return i ? i : -EFAULT;
+}
+
+void hugetlb_change_protection(struct vm_area_struct *vma,
+ unsigned long address, unsigned long end, pgprot_t newprot)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long start = address;
+ pte_t *ptep;
+ pte_t pte;
+ struct hstate *h = hstate_vma(vma);
+
+ BUG_ON(address >= end);
+ flush_cache_range(vma, address, end);
+
+ mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
+ spin_lock(&mm->page_table_lock);
+ for (; address < end; address += huge_page_size(h)) {
+ ptep = huge_pte_offset(mm, address);
+ if (!ptep)
+ continue;
+ if (huge_pmd_unshare(mm, &address, ptep))
+ continue;
+ pte = huge_ptep_get(ptep);
+ if (unlikely(is_hugetlb_entry_hwpoisoned(pte)))
+ continue;
+ if (unlikely(is_hugetlb_entry_migration(pte))) {
+ swp_entry_t entry = pte_to_swp_entry(pte);
+
+ if (is_write_migration_entry(entry)) {
+ pte_t newpte;
+
+ make_migration_entry_read(&entry);
+ newpte = swp_entry_to_pte(entry);
+ set_huge_pte_at(mm, address, ptep, newpte);
+ }
+ continue;
+ }
+ if (!huge_pte_none(pte)) {
+ pte = huge_ptep_get_and_clear(mm, address, ptep);
+ pte = pte_mkhuge(pte_modify(pte, newprot));
+ set_huge_pte_at(mm, address, ptep, pte);
+ }
+ }
+ spin_unlock(&mm->page_table_lock);
+ /*
+ * Must flush TLB before releasing i_mmap_mutex: x86's huge_pmd_unshare
+ * may have cleared our pud entry and done put_page on the page table:
+ * once we release i_mmap_mutex, another task can do the final put_page
+ * and that page table be reused and filled with junk.
+ */
+ flush_tlb_range(vma, start, end);
+ mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
+}
+
+int hugetlb_reserve_pages(struct inode *inode,
+ long from, long to,
+ struct vm_area_struct *vma,
+ vm_flags_t vm_flags)
+{
+ long ret, chg;
+ struct hstate *h = hstate_inode(inode);
+ struct hugepage_subpool *spool = subpool_inode(inode);
+
+ /*
+ * Only apply hugepage reservation if asked. At fault time, an
+ * attempt will be made for VM_NORESERVE to allocate a page
+ * without using reserves
+ */
+ if (vm_flags & VM_NORESERVE)
+ return 0;
+
+ /*
+ * Shared mappings base their reservation on the number of pages that
+ * are already allocated on behalf of the file. Private mappings need
+ * to reserve the full area even if read-only as mprotect() may be
+ * called to make the mapping read-write. Assume !vma is a shm mapping
+ */
+ if (!vma || vma->vm_flags & VM_MAYSHARE)
+ chg = region_chg(&inode->i_mapping->private_list, from, to);
+ else {
+ struct resv_map *resv_map = resv_map_alloc();
+ if (!resv_map)
+ return -ENOMEM;
+
+ chg = to - from;
+
+ set_vma_resv_map(vma, resv_map);
+ set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
+ }
+
+ if (chg < 0) {
+ ret = chg;
+ goto out_err;
+ }
+
+ /* There must be enough pages in the subpool for the mapping */
+ if (hugepage_subpool_get_pages(spool, chg)) {
+ ret = -ENOSPC;
+ goto out_err;
+ }
+
+ /*
+ * Check enough hugepages are available for the reservation.
+ * Hand the pages back to the subpool if there are not
+ */
+ ret = hugetlb_acct_memory(h, chg);
+ if (ret < 0) {
+ hugepage_subpool_put_pages(spool, chg);
+ goto out_err;
+ }
+
+ /*
+ * Account for the reservations made. Shared mappings record regions
+ * that have reservations as they are shared by multiple VMAs.
+ * When the last VMA disappears, the region map says how much
+ * the reservation was and the page cache tells how much of
+ * the reservation was consumed. Private mappings are per-VMA and
+ * only the consumed reservations are tracked. When the VMA
+ * disappears, the original reservation is the VMA size and the
+ * consumed reservations are stored in the map. Hence, nothing
+ * else has to be done for private mappings here
+ */
+ if (!vma || vma->vm_flags & VM_MAYSHARE)
+ region_add(&inode->i_mapping->private_list, from, to);
+ return 0;
+out_err:
+ if (vma)
+ resv_map_put(vma);
+ return ret;
+}
+
+void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
+{
+ struct hstate *h = hstate_inode(inode);
+ long chg = region_truncate(&inode->i_mapping->private_list, offset);
+ struct hugepage_subpool *spool = subpool_inode(inode);
+
+ spin_lock(&inode->i_lock);
+ inode->i_blocks -= (blocks_per_huge_page(h) * freed);
+ spin_unlock(&inode->i_lock);
+
+ hugepage_subpool_put_pages(spool, (chg - freed));
+ hugetlb_acct_memory(h, -(chg - freed));
+}
+
+#ifdef CONFIG_MEMORY_FAILURE
+
+/* Should be called in hugetlb_lock */
+static int is_hugepage_on_freelist(struct page *hpage)
+{
+ struct page *page;
+ struct page *tmp;
+ struct hstate *h = page_hstate(hpage);
+ int nid = page_to_nid(hpage);
+
+ list_for_each_entry_safe(page, tmp, &h->hugepage_freelists[nid], lru)
+ if (page == hpage)
+ return 1;
+ return 0;
+}
+
+/*
+ * This function is called from memory failure code.
+ * Assume the caller holds page lock of the head page.
+ */
+int dequeue_hwpoisoned_huge_page(struct page *hpage)
+{
+ struct hstate *h = page_hstate(hpage);
+ int nid = page_to_nid(hpage);
+ int ret = -EBUSY;
+
+ spin_lock(&hugetlb_lock);
+ if (is_hugepage_on_freelist(hpage)) {
+ list_del(&hpage->lru);
+ set_page_refcounted(hpage);
+ h->free_huge_pages--;
+ h->free_huge_pages_node[nid]--;
+ ret = 0;
+ }
+ spin_unlock(&hugetlb_lock);
+ return ret;
+}
+#endif
diff --git a/ap/os/linux/linux-3.4.x/mm/hwpoison-inject.c b/ap/os/linux/linux-3.4.x/mm/hwpoison-inject.c
new file mode 100644
index 0000000..cc448bb
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/hwpoison-inject.c
@@ -0,0 +1,141 @@
+/* Inject a hwpoison memory failure on a arbitrary pfn */
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+#include <linux/hugetlb.h>
+#include "internal.h"
+
+static struct dentry *hwpoison_dir;
+
+static int hwpoison_inject(void *data, u64 val)
+{
+ unsigned long pfn = val;
+ struct page *p;
+ struct page *hpage;
+ int err;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (!hwpoison_filter_enable)
+ goto inject;
+ if (!pfn_valid(pfn))
+ return -ENXIO;
+
+ p = pfn_to_page(pfn);
+ hpage = compound_head(p);
+ /*
+ * This implies unable to support free buddy pages.
+ */
+ if (!get_page_unless_zero(hpage))
+ return 0;
+
+ if (!PageLRU(p) && !PageHuge(p))
+ shake_page(p, 0);
+ /*
+ * This implies unable to support non-LRU pages.
+ */
+ if (!PageLRU(p) && !PageHuge(p))
+ return 0;
+
+ /*
+ * do a racy check with elevated page count, to make sure PG_hwpoison
+ * will only be set for the targeted owner (or on a free page).
+ * We temporarily take page lock for try_get_mem_cgroup_from_page().
+ * memory_failure() will redo the check reliably inside page lock.
+ */
+ lock_page(hpage);
+ err = hwpoison_filter(hpage);
+ unlock_page(hpage);
+ if (err)
+ return 0;
+
+inject:
+ printk(KERN_INFO "Injecting memory failure at pfn %lx\n", pfn);
+ return memory_failure(pfn, 18, MF_COUNT_INCREASED);
+}
+
+static int hwpoison_unpoison(void *data, u64 val)
+{
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ return unpoison_memory(val);
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
+DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
+
+static void pfn_inject_exit(void)
+{
+ if (hwpoison_dir)
+ debugfs_remove_recursive(hwpoison_dir);
+}
+
+static int pfn_inject_init(void)
+{
+ struct dentry *dentry;
+
+ hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
+ if (hwpoison_dir == NULL)
+ return -ENOMEM;
+
+ /*
+ * Note that the below poison/unpoison interfaces do not involve
+ * hardware status change, hence do not require hardware support.
+ * They are mainly for testing hwpoison in software level.
+ */
+ dentry = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir,
+ NULL, &hwpoison_fops);
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_file("unpoison-pfn", 0600, hwpoison_dir,
+ NULL, &unpoison_fops);
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_u32("corrupt-filter-enable", 0600,
+ hwpoison_dir, &hwpoison_filter_enable);
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_u32("corrupt-filter-dev-major", 0600,
+ hwpoison_dir, &hwpoison_filter_dev_major);
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_u32("corrupt-filter-dev-minor", 0600,
+ hwpoison_dir, &hwpoison_filter_dev_minor);
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_u64("corrupt-filter-flags-mask", 0600,
+ hwpoison_dir, &hwpoison_filter_flags_mask);
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_u64("corrupt-filter-flags-value", 0600,
+ hwpoison_dir, &hwpoison_filter_flags_value);
+ if (!dentry)
+ goto fail;
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+ dentry = debugfs_create_u64("corrupt-filter-memcg", 0600,
+ hwpoison_dir, &hwpoison_filter_memcg);
+ if (!dentry)
+ goto fail;
+#endif
+
+ return 0;
+fail:
+ pfn_inject_exit();
+ return -ENOMEM;
+}
+
+module_init(pfn_inject_init);
+module_exit(pfn_inject_exit);
+MODULE_LICENSE("GPL");
diff --git a/ap/os/linux/linux-3.4.x/mm/init-mm.c b/ap/os/linux/linux-3.4.x/mm/init-mm.c
new file mode 100644
index 0000000..a56a851
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/init-mm.c
@@ -0,0 +1,25 @@
+#include <linux/mm_types.h>
+#include <linux/rbtree.h>
+#include <linux/rwsem.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/cpumask.h>
+
+#include <linux/atomic.h>
+#include <asm/pgtable.h>
+#include <asm/mmu.h>
+
+#ifndef INIT_MM_CONTEXT
+#define INIT_MM_CONTEXT(name)
+#endif
+
+struct mm_struct init_mm = {
+ .mm_rb = RB_ROOT,
+ .pgd = swapper_pg_dir,
+ .mm_users = ATOMIC_INIT(2),
+ .mm_count = ATOMIC_INIT(1),
+ .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem),
+ .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
+ .mmlist = LIST_HEAD_INIT(init_mm.mmlist),
+ INIT_MM_CONTEXT(init_mm)
+};
diff --git a/ap/os/linux/linux-3.4.x/mm/internal.h b/ap/os/linux/linux-3.4.x/mm/internal.h
new file mode 100644
index 0000000..0c26b5e
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/internal.h
@@ -0,0 +1,313 @@
+/* internal.h: mm/ internal definitions
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#ifndef __MM_INTERNAL_H
+#define __MM_INTERNAL_H
+
+#include <linux/mm.h>
+
+void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
+ unsigned long floor, unsigned long ceiling);
+
+static inline void set_page_count(struct page *page, int v)
+{
+ atomic_set(&page->_count, v);
+}
+
+/*
+ * Turn a non-refcounted page (->_count == 0) into refcounted with
+ * a count of one.
+ */
+static inline void set_page_refcounted(struct page *page)
+{
+ VM_BUG_ON(PageTail(page));
+ VM_BUG_ON(atomic_read(&page->_count));
+ set_page_count(page, 1);
+}
+
+static inline void __put_page(struct page *page)
+{
+ atomic_dec(&page->_count);
+}
+
+static inline void __get_page_tail_foll(struct page *page,
+ bool get_page_head)
+{
+ /*
+ * If we're getting a tail page, the elevated page->_count is
+ * required only in the head page and we will elevate the head
+ * page->_count and tail page->_mapcount.
+ *
+ * We elevate page_tail->_mapcount for tail pages to force
+ * page_tail->_count to be zero at all times to avoid getting
+ * false positives from get_page_unless_zero() with
+ * speculative page access (like in
+ * page_cache_get_speculative()) on tail pages.
+ */
+ VM_BUG_ON(atomic_read(&page->first_page->_count) <= 0);
+ VM_BUG_ON(atomic_read(&page->_count) != 0);
+ VM_BUG_ON(page_mapcount(page) < 0);
+ if (get_page_head)
+ atomic_inc(&page->first_page->_count);
+ atomic_inc(&page->_mapcount);
+}
+
+/*
+ * This is meant to be called as the FOLL_GET operation of
+ * follow_page() and it must be called while holding the proper PT
+ * lock while the pte (or pmd_trans_huge) is still mapping the page.
+ */
+static inline void get_page_foll(struct page *page)
+{
+ if (unlikely(PageTail(page)))
+ /*
+ * This is safe only because
+ * __split_huge_page_refcount() can't run under
+ * get_page_foll() because we hold the proper PT lock.
+ */
+ __get_page_tail_foll(page, true);
+ else {
+ /*
+ * Getting a normal page or the head of a compound page
+ * requires to already have an elevated page->_count.
+ */
+ VM_BUG_ON(atomic_read(&page->_count) <= 0);
+ atomic_inc(&page->_count);
+ }
+}
+
+extern unsigned long highest_memmap_pfn;
+
+/*
+ * in mm/vmscan.c:
+ */
+extern int isolate_lru_page(struct page *page);
+extern void putback_lru_page(struct page *page);
+
+/*
+ * in mm/page_alloc.c
+ */
+extern void __free_pages_bootmem(struct page *page, unsigned int order);
+extern void prep_compound_page(struct page *page, unsigned long order);
+#ifdef CONFIG_MEMORY_FAILURE
+extern bool is_free_buddy_page(struct page *page);
+#endif
+
+
+/*
+ * function for dealing with page's order in buddy system.
+ * zone->lock is already acquired when we use these.
+ * So, we don't need atomic page->flags operations here.
+ */
+static inline unsigned long page_order(struct page *page)
+{
+ /* PageBuddy() must be checked by the caller */
+ return page_private(page);
+}
+
+/* mm/util.c */
+void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct vm_area_struct *prev, struct rb_node *rb_parent);
+
+#ifdef CONFIG_MMU
+extern long mlock_vma_pages_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end);
+extern void munlock_vma_pages_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end);
+static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
+{
+ munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
+}
+
+/*
+ * Called only in fault path via page_evictable() for a new page
+ * to determine if it's being mapped into a LOCKED vma.
+ * If so, mark page as mlocked.
+ */
+static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
+{
+ VM_BUG_ON(PageLRU(page));
+
+ if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
+ return 0;
+
+ if (!TestSetPageMlocked(page)) {
+ inc_zone_page_state(page, NR_MLOCK);
+ count_vm_event(UNEVICTABLE_PGMLOCKED);
+ }
+ return 1;
+}
+
+/*
+ * must be called with vma's mmap_sem held for read or write, and page locked.
+ */
+extern void mlock_vma_page(struct page *page);
+extern void munlock_vma_page(struct page *page);
+
+/*
+ * Clear the page's PageMlocked(). This can be useful in a situation where
+ * we want to unconditionally remove a page from the pagecache -- e.g.,
+ * on truncation or freeing.
+ *
+ * It is legal to call this function for any page, mlocked or not.
+ * If called for a page that is still mapped by mlocked vmas, all we do
+ * is revert to lazy LRU behaviour -- semantics are not broken.
+ */
+extern void __clear_page_mlock(struct page *page);
+static inline void clear_page_mlock(struct page *page)
+{
+ if (unlikely(TestClearPageMlocked(page)))
+ __clear_page_mlock(page);
+}
+
+/*
+ * mlock_migrate_page - called only from migrate_page_copy() to
+ * migrate the Mlocked page flag; update statistics.
+ */
+static inline void mlock_migrate_page(struct page *newpage, struct page *page)
+{
+ if (TestClearPageMlocked(page)) {
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __dec_zone_page_state(page, NR_MLOCK);
+ SetPageMlocked(newpage);
+ __inc_zone_page_state(newpage, NR_MLOCK);
+ local_irq_restore(flags);
+ }
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+extern unsigned long vma_address(struct page *page,
+ struct vm_area_struct *vma);
+#endif
+#else /* !CONFIG_MMU */
+static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
+{
+ return 0;
+}
+static inline void clear_page_mlock(struct page *page) { }
+static inline void mlock_vma_page(struct page *page) { }
+static inline void mlock_migrate_page(struct page *new, struct page *old) { }
+
+#endif /* !CONFIG_MMU */
+
+/*
+ * Return the mem_map entry representing the 'offset' subpage within
+ * the maximally aligned gigantic page 'base'. Handle any discontiguity
+ * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
+ */
+static inline struct page *mem_map_offset(struct page *base, int offset)
+{
+ if (unlikely(offset >= MAX_ORDER_NR_PAGES))
+ return pfn_to_page(page_to_pfn(base) + offset);
+ return base + offset;
+}
+
+/*
+ * Iterator over all subpages within the maximally aligned gigantic
+ * page 'base'. Handle any discontiguity in the mem_map.
+ */
+static inline struct page *mem_map_next(struct page *iter,
+ struct page *base, int offset)
+{
+ if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
+ unsigned long pfn = page_to_pfn(base) + offset;
+ if (!pfn_valid(pfn))
+ return NULL;
+ return pfn_to_page(pfn);
+ }
+ return iter + 1;
+}
+
+/*
+ * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
+ * so all functions starting at paging_init should be marked __init
+ * in those cases. SPARSEMEM, however, allows for memory hotplug,
+ * and alloc_bootmem_node is not used.
+ */
+#ifdef CONFIG_SPARSEMEM
+#define __paginginit __meminit
+#else
+#define __paginginit __init
+#endif
+
+/* Memory initialisation debug and verification */
+enum mminit_level {
+ MMINIT_WARNING,
+ MMINIT_VERIFY,
+ MMINIT_TRACE
+};
+
+#ifdef CONFIG_DEBUG_MEMORY_INIT
+
+extern int mminit_loglevel;
+
+#define mminit_dprintk(level, prefix, fmt, arg...) \
+do { \
+ if (level < mminit_loglevel) { \
+ printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
+ printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
+ } \
+} while (0)
+
+extern void mminit_verify_pageflags_layout(void);
+extern void mminit_verify_page_links(struct page *page,
+ enum zone_type zone, unsigned long nid, unsigned long pfn);
+extern void mminit_verify_zonelist(void);
+
+#else
+
+static inline void mminit_dprintk(enum mminit_level level,
+ const char *prefix, const char *fmt, ...)
+{
+}
+
+static inline void mminit_verify_pageflags_layout(void)
+{
+}
+
+static inline void mminit_verify_page_links(struct page *page,
+ enum zone_type zone, unsigned long nid, unsigned long pfn)
+{
+}
+
+static inline void mminit_verify_zonelist(void)
+{
+}
+#endif /* CONFIG_DEBUG_MEMORY_INIT */
+
+/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
+#if defined(CONFIG_SPARSEMEM)
+extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
+ unsigned long *end_pfn);
+#else
+static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
+ unsigned long *end_pfn)
+{
+}
+#endif /* CONFIG_SPARSEMEM */
+
+#define ZONE_RECLAIM_NOSCAN -2
+#define ZONE_RECLAIM_FULL -1
+#define ZONE_RECLAIM_SOME 0
+#define ZONE_RECLAIM_SUCCESS 1
+#endif
+
+extern int hwpoison_filter(struct page *p);
+
+extern u32 hwpoison_filter_dev_major;
+extern u32 hwpoison_filter_dev_minor;
+extern u64 hwpoison_filter_flags_mask;
+extern u64 hwpoison_filter_flags_value;
+extern u64 hwpoison_filter_memcg;
+extern u32 hwpoison_filter_enable;
+
+extern void set_pageblock_order(void);
diff --git a/ap/os/linux/linux-3.4.x/mm/kmemcheck.c b/ap/os/linux/linux-3.4.x/mm/kmemcheck.c
new file mode 100644
index 0000000..fd814fd
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/kmemcheck.c
@@ -0,0 +1,122 @@
+#include <linux/gfp.h>
+#include <linux/mm_types.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/kmemcheck.h>
+
+void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node)
+{
+ struct page *shadow;
+ int pages;
+ int i;
+
+ pages = 1 << order;
+
+ /*
+ * With kmemcheck enabled, we need to allocate a memory area for the
+ * shadow bits as well.
+ */
+ shadow = alloc_pages_node(node, flags | __GFP_NOTRACK, order);
+ if (!shadow) {
+ if (printk_ratelimit())
+ printk(KERN_ERR "kmemcheck: failed to allocate "
+ "shadow bitmap\n");
+ return;
+ }
+
+ for(i = 0; i < pages; ++i)
+ page[i].shadow = page_address(&shadow[i]);
+
+ /*
+ * Mark it as non-present for the MMU so that our accesses to
+ * this memory will trigger a page fault and let us analyze
+ * the memory accesses.
+ */
+ kmemcheck_hide_pages(page, pages);
+}
+
+void kmemcheck_free_shadow(struct page *page, int order)
+{
+ struct page *shadow;
+ int pages;
+ int i;
+
+ if (!kmemcheck_page_is_tracked(page))
+ return;
+
+ pages = 1 << order;
+
+ kmemcheck_show_pages(page, pages);
+
+ shadow = virt_to_page(page[0].shadow);
+
+ for(i = 0; i < pages; ++i)
+ page[i].shadow = NULL;
+
+ __free_pages(shadow, order);
+}
+
+void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
+ size_t size)
+{
+ /*
+ * Has already been memset(), which initializes the shadow for us
+ * as well.
+ */
+ if (gfpflags & __GFP_ZERO)
+ return;
+
+ /* No need to initialize the shadow of a non-tracked slab. */
+ if (s->flags & SLAB_NOTRACK)
+ return;
+
+ if (!kmemcheck_enabled || gfpflags & __GFP_NOTRACK) {
+ /*
+ * Allow notracked objects to be allocated from
+ * tracked caches. Note however that these objects
+ * will still get page faults on access, they just
+ * won't ever be flagged as uninitialized. If page
+ * faults are not acceptable, the slab cache itself
+ * should be marked NOTRACK.
+ */
+ kmemcheck_mark_initialized(object, size);
+ } else if (!s->ctor) {
+ /*
+ * New objects should be marked uninitialized before
+ * they're returned to the called.
+ */
+ kmemcheck_mark_uninitialized(object, size);
+ }
+}
+
+void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size)
+{
+ /* TODO: RCU freeing is unsupported for now; hide false positives. */
+ if (!s->ctor && !(s->flags & SLAB_DESTROY_BY_RCU))
+ kmemcheck_mark_freed(object, size);
+}
+
+void kmemcheck_pagealloc_alloc(struct page *page, unsigned int order,
+ gfp_t gfpflags)
+{
+ int pages;
+
+ if (gfpflags & (__GFP_HIGHMEM | __GFP_NOTRACK))
+ return;
+
+ pages = 1 << order;
+
+ /*
+ * NOTE: We choose to track GFP_ZERO pages too; in fact, they
+ * can become uninitialized by copying uninitialized memory
+ * into them.
+ */
+
+ /* XXX: Can use zone->node for node? */
+ kmemcheck_alloc_shadow(page, order, gfpflags, -1);
+
+ if (gfpflags & __GFP_ZERO)
+ kmemcheck_mark_initialized_pages(page, pages);
+ else
+ kmemcheck_mark_uninitialized_pages(page, pages);
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/kmemleak-test.c b/ap/os/linux/linux-3.4.x/mm/kmemleak-test.c
new file mode 100644
index 0000000..ff0d977
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/kmemleak-test.c
@@ -0,0 +1,109 @@
+/*
+ * mm/kmemleak-test.c
+ *
+ * Copyright (C) 2008 ARM Limited
+ * Written by Catalin Marinas <catalin.marinas@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/list.h>
+#include <linux/percpu.h>
+#include <linux/fdtable.h>
+
+#include <linux/kmemleak.h>
+
+struct test_node {
+ long header[25];
+ struct list_head list;
+ long footer[25];
+};
+
+static LIST_HEAD(test_list);
+static DEFINE_PER_CPU(void *, kmemleak_test_pointer);
+
+/*
+ * Some very simple testing. This function needs to be extended for
+ * proper testing.
+ */
+static int __init kmemleak_test_init(void)
+{
+ struct test_node *elem;
+ int i;
+
+ printk(KERN_INFO "Kmemleak testing\n");
+
+ /* make some orphan objects */
+ pr_info("kmemleak: kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL));
+ pr_info("kmemleak: kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL));
+ pr_info("kmemleak: kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL));
+ pr_info("kmemleak: kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL));
+ pr_info("kmemleak: kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL));
+ pr_info("kmemleak: kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL));
+ pr_info("kmemleak: kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL));
+ pr_info("kmemleak: kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL));
+#ifndef CONFIG_MODULES
+ pr_info("kmemleak: kmem_cache_alloc(files_cachep) = %p\n",
+ kmem_cache_alloc(files_cachep, GFP_KERNEL));
+ pr_info("kmemleak: kmem_cache_alloc(files_cachep) = %p\n",
+ kmem_cache_alloc(files_cachep, GFP_KERNEL));
+#endif
+ pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64));
+ pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64));
+ pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64));
+ pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64));
+ pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64));
+
+ /*
+ * Add elements to a list. They should only appear as orphan
+ * after the module is removed.
+ */
+ for (i = 0; i < 10; i++) {
+ elem = kzalloc(sizeof(*elem), GFP_KERNEL);
+ pr_info("kmemleak: kzalloc(sizeof(*elem)) = %p\n", elem);
+ if (!elem)
+ return -ENOMEM;
+ INIT_LIST_HEAD(&elem->list);
+ list_add_tail(&elem->list, &test_list);
+ }
+
+ for_each_possible_cpu(i) {
+ per_cpu(kmemleak_test_pointer, i) = kmalloc(129, GFP_KERNEL);
+ pr_info("kmemleak: kmalloc(129) = %p\n",
+ per_cpu(kmemleak_test_pointer, i));
+ }
+
+ return 0;
+}
+module_init(kmemleak_test_init);
+
+static void __exit kmemleak_test_exit(void)
+{
+ struct test_node *elem, *tmp;
+
+ /*
+ * Remove the list elements without actually freeing the
+ * memory.
+ */
+ list_for_each_entry_safe(elem, tmp, &test_list, list)
+ list_del(&elem->list);
+}
+module_exit(kmemleak_test_exit);
+
+MODULE_LICENSE("GPL");
diff --git a/ap/os/linux/linux-3.4.x/mm/kmemleak.bak b/ap/os/linux/linux-3.4.x/mm/kmemleak.bak
new file mode 100755
index 0000000..c74827c
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/kmemleak.bak
@@ -0,0 +1,1882 @@
+/*
+ * mm/kmemleak.c
+ *
+ * Copyright (C) 2008 ARM Limited
+ * Written by Catalin Marinas <catalin.marinas@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ *
+ * For more information on the algorithm and kmemleak usage, please see
+ * Documentation/kmemleak.txt.
+ *
+ * Notes on locking
+ * ----------------
+ *
+ * The following locks and mutexes are used by kmemleak:
+ *
+ * - kmemleak_lock (rwlock): protects the object_list modifications and
+ * accesses to the object_tree_root. The object_list is the main list
+ * holding the metadata (struct kmemleak_object) for the allocated memory
+ * blocks. The object_tree_root is a priority search tree used to look-up
+ * metadata based on a pointer to the corresponding memory block. The
+ * kmemleak_object structures are added to the object_list and
+ * object_tree_root in the create_object() function called from the
+ * kmemleak_alloc() callback and removed in delete_object() called from the
+ * kmemleak_free() callback
+ * - kmemleak_object.lock (spinlock): protects a kmemleak_object. Accesses to
+ * the metadata (e.g. count) are protected by this lock. Note that some
+ * members of this structure may be protected by other means (atomic or
+ * kmemleak_lock). This lock is also held when scanning the corresponding
+ * memory block to avoid the kernel freeing it via the kmemleak_free()
+ * callback. This is less heavyweight than holding a global lock like
+ * kmemleak_lock during scanning
+ * - scan_mutex (mutex): ensures that only one thread may scan the memory for
+ * unreferenced objects at a time. The gray_list contains the objects which
+ * are already referenced or marked as false positives and need to be
+ * scanned. This list is only modified during a scanning episode when the
+ * scan_mutex is held. At the end of a scan, the gray_list is always empty.
+ * Note that the kmemleak_object.use_count is incremented when an object is
+ * added to the gray_list and therefore cannot be freed. This mutex also
+ * prevents multiple users of the "kmemleak" debugfs file together with
+ * modifications to the memory scanning parameters including the scan_thread
+ * pointer
+ *
+ * The kmemleak_object structures have a use_count incremented or decremented
+ * using the get_object()/put_object() functions. When the use_count becomes
+ * 0, this count can no longer be incremented and put_object() schedules the
+ * kmemleak_object freeing via an RCU callback. All calls to the get_object()
+ * function must be protected by rcu_read_lock() to avoid accessing a freed
+ * structure.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/sched.h>
+#include <linux/jiffies.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/kthread.h>
+#include <linux/prio_tree.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/cpumask.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/rcupdate.h>
+#include <linux/stacktrace.h>
+#include <linux/cache.h>
+#include <linux/percpu.h>
+#include <linux/hardirq.h>
+#include <linux/mmzone.h>
+#include <linux/slab.h>
+#include <linux/thread_info.h>
+#include <linux/err.h>
+#include <linux/uaccess.h>
+#include <linux/string.h>
+#include <linux/nodemask.h>
+#include <linux/mm.h>
+#include <linux/workqueue.h>
+#include <linux/crc32.h>
+
+#include <asm/sections.h>
+#include <asm/processor.h>
+#include <linux/atomic.h>
+
+#include <linux/kmemcheck.h>
+#include <linux/kmemleak.h>
+#include <linux/memory_hotplug.h>
+
+/*
+ * Kmemleak configuration and common defines.
+ */
+#define MAX_TRACE 16 /* stack trace length */
+#define MSECS_MIN_AGE 5000 /* minimum object age for reporting */
+#define SECS_FIRST_SCAN 60 /* delay before the first scan */
+#define SECS_SCAN_WAIT 600 /* subsequent auto scanning delay */
+#define MAX_SCAN_SIZE 4096 /* maximum size of a scanned block */
+
+#define BYTES_PER_POINTER sizeof(void *)
+
+/* GFP bitmask for kmemleak internal allocations */
+#define gfp_kmemleak_mask(gfp) (((gfp) & (GFP_KERNEL | GFP_ATOMIC)) | \
+ __GFP_NORETRY | __GFP_NOMEMALLOC | \
+ __GFP_NOWARN)
+
+/* scanning area inside a memory block */
+struct kmemleak_scan_area {
+ struct hlist_node node;
+ unsigned long start;
+ size_t size;
+};
+
+#define KMEMLEAK_GREY 0
+#define KMEMLEAK_BLACK -1
+
+/*
+ * Structure holding the metadata for each allocated memory block.
+ * Modifications to such objects should be made while holding the
+ * object->lock. Insertions or deletions from object_list, gray_list or
+ * tree_node are already protected by the corresponding locks or mutex (see
+ * the notes on locking above). These objects are reference-counted
+ * (use_count) and freed using the RCU mechanism.
+ */
+struct kmemleak_object {
+ spinlock_t lock;
+ unsigned long flags; /* object status flags */
+ struct list_head object_list;
+ struct list_head gray_list;
+ struct prio_tree_node tree_node;
+ struct rcu_head rcu; /* object_list lockless traversal */
+ /* object usage count; object freed when use_count == 0 */
+ atomic_t use_count;
+ unsigned long pointer;
+ size_t size;
+ /* minimum number of a pointers found before it is considered leak */
+ int min_count;
+ /* the total number of pointers found pointing to this object */
+ int count;
+ /* checksum for detecting modified objects */
+ u32 checksum;
+ /* memory ranges to be scanned inside an object (empty for all) */
+ struct hlist_head area_list;
+ unsigned long trace[MAX_TRACE];
+ unsigned int trace_len;
+ unsigned long jiffies; /* creation timestamp */
+ pid_t pid; /* pid of the current task */
+ char comm[TASK_COMM_LEN]; /* executable name */
+};
+
+/* flag representing the memory block allocation status */
+#define OBJECT_ALLOCATED (1 << 0)
+/* flag set after the first reporting of an unreference object */
+#define OBJECT_REPORTED (1 << 1)
+/* flag set to not scan the object */
+#define OBJECT_NO_SCAN (1 << 2)
+
+/* number of bytes to print per line; must be 16 or 32 */
+#define HEX_ROW_SIZE 16
+/* number of bytes to print at a time (1, 2, 4, 8) */
+#define HEX_GROUP_SIZE 1
+/* include ASCII after the hex output */
+#define HEX_ASCII 1
+/* max number of lines to be printed */
+#define HEX_MAX_LINES 2
+
+/* the list of all allocated objects */
+static LIST_HEAD(object_list);
+/* the list of gray-colored objects (see color_gray comment below) */
+static LIST_HEAD(gray_list);
+/* prio search tree for object boundaries */
+static struct prio_tree_root object_tree_root;
+/* rw_lock protecting the access to object_list and prio_tree_root */
+static DEFINE_RWLOCK(kmemleak_lock);
+
+/* allocation caches for kmemleak internal data */
+static struct kmem_cache *object_cache;
+static struct kmem_cache *scan_area_cache;
+
+/* set if tracing memory operations is enabled */
+static atomic_t kmemleak_enabled = ATOMIC_INIT(0);
+/* same as above but only for the kmemleak_free() callback */
+static int kmemleak_free_enabled;
+/* set in the late_initcall if there were no errors */
+static atomic_t kmemleak_initialized = ATOMIC_INIT(0);
+/* enables or disables early logging of the memory operations */
+static atomic_t kmemleak_early_log = ATOMIC_INIT(1);
+/* set if a kmemleak warning was issued */
+static atomic_t kmemleak_warning = ATOMIC_INIT(0);
+/* set if a fatal kmemleak error has occurred */
+static atomic_t kmemleak_error = ATOMIC_INIT(0);
+
+/* minimum and maximum address that may be valid pointers */
+static unsigned long min_addr = ULONG_MAX;
+static unsigned long max_addr;
+
+static struct task_struct *scan_thread;
+/* used to avoid reporting of recently allocated objects */
+static unsigned long jiffies_min_age;
+static unsigned long jiffies_last_scan;
+/* delay between automatic memory scannings */
+static signed long jiffies_scan_wait;
+/* enables or disables the task stacks scanning */
+static int kmemleak_stack_scan = 1;
+/* protects the memory scanning, parameters and debug/kmemleak file access */
+static DEFINE_MUTEX(scan_mutex);
+/* setting kmemleak=on, will set this var, skipping the disable */
+static int kmemleak_skip_disable;
+
+
+/*
+ * Early object allocation/freeing logging. Kmemleak is initialized after the
+ * kernel allocator. However, both the kernel allocator and kmemleak may
+ * allocate memory blocks which need to be tracked. Kmemleak defines an
+ * arbitrary buffer to hold the allocation/freeing information before it is
+ * fully initialized.
+ */
+
+/* kmemleak operation type for early logging */
+enum {
+ KMEMLEAK_ALLOC,
+ KMEMLEAK_ALLOC_PERCPU,
+ KMEMLEAK_FREE,
+ KMEMLEAK_FREE_PART,
+ KMEMLEAK_FREE_PERCPU,
+ KMEMLEAK_NOT_LEAK,
+ KMEMLEAK_IGNORE,
+ KMEMLEAK_SCAN_AREA,
+ KMEMLEAK_NO_SCAN
+};
+
+/*
+ * Structure holding the information passed to kmemleak callbacks during the
+ * early logging.
+ */
+struct early_log {
+ int op_type; /* kmemleak operation type */
+ const void *ptr; /* allocated/freed memory block */
+ size_t size; /* memory block size */
+ int min_count; /* minimum reference count */
+ unsigned long trace[MAX_TRACE]; /* stack trace */
+ unsigned int trace_len; /* stack trace length */
+};
+
+/* early logging buffer and current position */
+static struct early_log
+ early_log[CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE] __initdata;
+static int crt_early_log __initdata;
+
+static void kmemleak_disable(void);
+
+/*
+ * Print a warning and dump the stack trace.
+ */
+#define kmemleak_warn(x...) do { \
+ pr_warning(x); \
+ dump_stack(); \
+ atomic_set(&kmemleak_warning, 1); \
+} while (0)
+
+/*
+ * Macro invoked when a serious kmemleak condition occurred and cannot be
+ * recovered from. Kmemleak will be disabled and further allocation/freeing
+ * tracing no longer available.
+ */
+#define kmemleak_stop(x...) do { \
+ kmemleak_warn(x); \
+ kmemleak_disable(); \
+} while (0)
+
+/*
+ * Printing of the objects hex dump to the seq file. The number of lines to be
+ * printed is limited to HEX_MAX_LINES to prevent seq file spamming. The
+ * actual number of printed bytes depends on HEX_ROW_SIZE. It must be called
+ * with the object->lock held.
+ */
+static void hex_dump_object(struct seq_file *seq,
+ struct kmemleak_object *object)
+{
+ const u8 *ptr = (const u8 *)object->pointer;
+ int i, len, remaining;
+ unsigned char linebuf[HEX_ROW_SIZE * 5];
+
+ /* limit the number of lines to HEX_MAX_LINES */
+ remaining = len =
+ min(object->size, (size_t)(HEX_MAX_LINES * HEX_ROW_SIZE));
+
+ seq_printf(seq, " hex dump (first %d bytes):\n", len);
+ for (i = 0; i < len; i += HEX_ROW_SIZE) {
+ int linelen = min(remaining, HEX_ROW_SIZE);
+
+ remaining -= HEX_ROW_SIZE;
+ hex_dump_to_buffer(ptr + i, linelen, HEX_ROW_SIZE,
+ HEX_GROUP_SIZE, linebuf, sizeof(linebuf),
+ HEX_ASCII);
+ seq_printf(seq, " %s\n", linebuf);
+ }
+}
+
+/*
+ * Object colors, encoded with count and min_count:
+ * - white - orphan object, not enough references to it (count < min_count)
+ * - gray - not orphan, not marked as false positive (min_count == 0) or
+ * sufficient references to it (count >= min_count)
+ * - black - ignore, it doesn't contain references (e.g. text section)
+ * (min_count == -1). No function defined for this color.
+ * Newly created objects don't have any color assigned (object->count == -1)
+ * before the next memory scan when they become white.
+ */
+static bool color_white(const struct kmemleak_object *object)
+{
+ return object->count != KMEMLEAK_BLACK &&
+ object->count < object->min_count;
+}
+
+static bool color_gray(const struct kmemleak_object *object)
+{
+ return object->min_count != KMEMLEAK_BLACK &&
+ object->count >= object->min_count;
+}
+
+/*
+ * Objects are considered unreferenced only if their color is white, they have
+ * not be deleted and have a minimum age to avoid false positives caused by
+ * pointers temporarily stored in CPU registers.
+ */
+static bool unreferenced_object(struct kmemleak_object *object)
+{
+ return (color_white(object) && object->flags & OBJECT_ALLOCATED) &&
+ time_before_eq(object->jiffies + jiffies_min_age,
+ jiffies_last_scan);
+}
+
+/*
+ * Printing of the unreferenced objects information to the seq file. The
+ * print_unreferenced function must be called with the object->lock held.
+ */
+static void print_unreferenced(struct seq_file *seq,
+ struct kmemleak_object *object)
+{
+ int i;
+ unsigned int msecs_age = jiffies_to_msecs(jiffies - object->jiffies);
+
+ seq_printf(seq, "unreferenced object 0x%08lx (size %zu):\n",
+ object->pointer, object->size);
+ seq_printf(seq, " comm \"%s\", pid %d, jiffies %lu (age %d.%03ds)\n",
+ object->comm, object->pid, object->jiffies,
+ msecs_age / 1000, msecs_age % 1000);
+ hex_dump_object(seq, object);
+ seq_printf(seq, " backtrace:\n");
+
+ for (i = 0; i < object->trace_len; i++) {
+ void *ptr = (void *)object->trace[i];
+ seq_printf(seq, " [<%p>] %pS\n", ptr, ptr);
+ }
+}
+
+/*
+ * Print the kmemleak_object information. This function is used mainly for
+ * debugging special cases when kmemleak operations. It must be called with
+ * the object->lock held.
+ */
+static void dump_object_info(struct kmemleak_object *object)
+{
+ struct stack_trace trace;
+
+ trace.nr_entries = object->trace_len;
+ trace.entries = object->trace;
+
+ pr_notice("Object 0x%08lx (size %zu):\n",
+ object->tree_node.start, object->size);
+ pr_notice(" comm \"%s\", pid %d, jiffies %lu\n",
+ object->comm, object->pid, object->jiffies);
+ pr_notice(" min_count = %d\n", object->min_count);
+ pr_notice(" count = %d\n", object->count);
+ pr_notice(" flags = 0x%lx\n", object->flags);
+ pr_notice(" checksum = %d\n", object->checksum);
+ pr_notice(" backtrace:\n");
+ print_stack_trace(&trace, 4);
+}
+
+/*
+ * Look-up a memory block metadata (kmemleak_object) in the priority search
+ * tree based on a pointer value. If alias is 0, only values pointing to the
+ * beginning of the memory block are allowed. The kmemleak_lock must be held
+ * when calling this function.
+ */
+static struct kmemleak_object *lookup_object(unsigned long ptr, int alias)
+{
+ struct prio_tree_node *node;
+ struct prio_tree_iter iter;
+ struct kmemleak_object *object;
+
+ prio_tree_iter_init(&iter, &object_tree_root, ptr, ptr);
+ node = prio_tree_next(&iter);
+ if (node) {
+ object = prio_tree_entry(node, struct kmemleak_object,
+ tree_node);
+ if (!alias && object->pointer != ptr) {
+ kmemleak_warn("Found object by alias at 0x%08lx\n",
+ ptr);
+ dump_object_info(object);
+ object = NULL;
+ }
+ } else
+ object = NULL;
+
+ return object;
+}
+
+/*
+ * Increment the object use_count. Return 1 if successful or 0 otherwise. Note
+ * that once an object's use_count reached 0, the RCU freeing was already
+ * registered and the object should no longer be used. This function must be
+ * called under the protection of rcu_read_lock().
+ */
+static int get_object(struct kmemleak_object *object)
+{
+ return atomic_inc_not_zero(&object->use_count);
+}
+
+/*
+ * RCU callback to free a kmemleak_object.
+ */
+static void free_object_rcu(struct rcu_head *rcu)
+{
+ struct hlist_node *elem, *tmp;
+ struct kmemleak_scan_area *area;
+ struct kmemleak_object *object =
+ container_of(rcu, struct kmemleak_object, rcu);
+
+ /*
+ * Once use_count is 0 (guaranteed by put_object), there is no other
+ * code accessing this object, hence no need for locking.
+ */
+ hlist_for_each_entry_safe(area, elem, tmp, &object->area_list, node) {
+ hlist_del(elem);
+ kmem_cache_free(scan_area_cache, area);
+ }
+ kmem_cache_free(object_cache, object);
+}
+
+/*
+ * Decrement the object use_count. Once the count is 0, free the object using
+ * an RCU callback. Since put_object() may be called via the kmemleak_free() ->
+ * delete_object() path, the delayed RCU freeing ensures that there is no
+ * recursive call to the kernel allocator. Lock-less RCU object_list traversal
+ * is also possible.
+ */
+static void put_object(struct kmemleak_object *object)
+{
+ if (!atomic_dec_and_test(&object->use_count))
+ return;
+
+ /* should only get here after delete_object was called */
+ WARN_ON(object->flags & OBJECT_ALLOCATED);
+
+ call_rcu(&object->rcu, free_object_rcu);
+}
+
+/*
+ * Look up an object in the prio search tree and increase its use_count.
+ */
+static struct kmemleak_object *find_and_get_object(unsigned long ptr, int alias)
+{
+ unsigned long flags;
+ struct kmemleak_object *object = NULL;
+
+ rcu_read_lock();
+ read_lock_irqsave(&kmemleak_lock, flags);
+ if (ptr >= min_addr && ptr < max_addr)
+ object = lookup_object(ptr, alias);
+ read_unlock_irqrestore(&kmemleak_lock, flags);
+
+ /* check whether the object is still available */
+ if (object && !get_object(object))
+ object = NULL;
+ rcu_read_unlock();
+
+ return object;
+}
+
+/*
+ * Save stack trace to the given array of MAX_TRACE size.
+ */
+static int __save_stack_trace(unsigned long *trace)
+{
+ struct stack_trace stack_trace;
+
+ stack_trace.max_entries = MAX_TRACE;
+ stack_trace.nr_entries = 0;
+ stack_trace.entries = trace;
+ stack_trace.skip = 2;
+ save_stack_trace(&stack_trace);
+
+ return stack_trace.nr_entries;
+}
+
+/*
+ * Create the metadata (struct kmemleak_object) corresponding to an allocated
+ * memory block and add it to the object_list and object_tree_root.
+ */
+static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
+ int min_count, gfp_t gfp)
+{
+ unsigned long flags;
+ struct kmemleak_object *object;
+ struct prio_tree_node *node;
+
+ object = kmem_cache_alloc(object_cache, gfp_kmemleak_mask(gfp));
+ if (!object) {
+ pr_warning("Cannot allocate a kmemleak_object structure\n");
+ kmemleak_disable();
+ return NULL;
+ }
+
+ INIT_LIST_HEAD(&object->object_list);
+ INIT_LIST_HEAD(&object->gray_list);
+ INIT_HLIST_HEAD(&object->area_list);
+ spin_lock_init(&object->lock);
+ atomic_set(&object->use_count, 1);
+ object->flags = OBJECT_ALLOCATED;
+ object->pointer = ptr;
+ object->size = size;
+ object->min_count = min_count;
+ object->count = 0; /* white color initially */
+ object->jiffies = jiffies;
+ object->checksum = 0;
+
+ /* task information */
+ if (in_irq()) {
+ object->pid = 0;
+ strncpy(object->comm, "hardirq", sizeof(object->comm));
+ } else if (in_softirq()) {
+ object->pid = 0;
+ strncpy(object->comm, "softirq", sizeof(object->comm));
+ } else {
+ object->pid = current->pid;
+ /*
+ * There is a small chance of a race with set_task_comm(),
+ * however using get_task_comm() here may cause locking
+ * dependency issues with current->alloc_lock. In the worst
+ * case, the command line is not correct.
+ */
+ strncpy(object->comm, current->comm, sizeof(object->comm));
+ }
+
+ /* kernel backtrace */
+ object->trace_len = __save_stack_trace(object->trace);
+
+ INIT_PRIO_TREE_NODE(&object->tree_node);
+ object->tree_node.start = ptr;
+ object->tree_node.last = ptr + size - 1;
+
+ write_lock_irqsave(&kmemleak_lock, flags);
+
+ min_addr = min(min_addr, ptr);
+ max_addr = max(max_addr, ptr + size);
+ node = prio_tree_insert(&object_tree_root, &object->tree_node);
+ /*
+ * The code calling the kernel does not yet have the pointer to the
+ * memory block to be able to free it. However, we still hold the
+ * kmemleak_lock here in case parts of the kernel started freeing
+ * random memory blocks.
+ */
+ if (node != &object->tree_node) {
+ kmemleak_stop("Cannot insert 0x%lx into the object search tree "
+ "(already existing)\n", ptr);
+ object = lookup_object(ptr, 1);
+ spin_lock(&object->lock);
+ dump_object_info(object);
+ spin_unlock(&object->lock);
+
+ goto out;
+ }
+ list_add_tail_rcu(&object->object_list, &object_list);
+out:
+ write_unlock_irqrestore(&kmemleak_lock, flags);
+ return object;
+}
+
+/*
+ * Remove the metadata (struct kmemleak_object) for a memory block from the
+ * object_list and object_tree_root and decrement its use_count.
+ */
+static void __delete_object(struct kmemleak_object *object)
+{
+ unsigned long flags;
+
+ write_lock_irqsave(&kmemleak_lock, flags);
+ prio_tree_remove(&object_tree_root, &object->tree_node);
+ list_del_rcu(&object->object_list);
+ write_unlock_irqrestore(&kmemleak_lock, flags);
+
+ WARN_ON(!(object->flags & OBJECT_ALLOCATED));
+ WARN_ON(atomic_read(&object->use_count) < 2);
+
+ /*
+ * Locking here also ensures that the corresponding memory block
+ * cannot be freed when it is being scanned.
+ */
+ spin_lock_irqsave(&object->lock, flags);
+ object->flags &= ~OBJECT_ALLOCATED;
+ spin_unlock_irqrestore(&object->lock, flags);
+ put_object(object);
+}
+
+/*
+ * Look up the metadata (struct kmemleak_object) corresponding to ptr and
+ * delete it.
+ */
+static void delete_object_full(unsigned long ptr)
+{
+ struct kmemleak_object *object;
+
+ object = find_and_get_object(ptr, 0);
+ if (!object) {
+#ifdef DEBUG
+ kmemleak_warn("Freeing unknown object at 0x%08lx\n",
+ ptr);
+#endif
+ return;
+ }
+ __delete_object(object);
+ put_object(object);
+}
+
+/*
+ * Look up the metadata (struct kmemleak_object) corresponding to ptr and
+ * delete it. If the memory block is partially freed, the function may create
+ * additional metadata for the remaining parts of the block.
+ */
+static void delete_object_part(unsigned long ptr, size_t size)
+{
+ struct kmemleak_object *object;
+ unsigned long start, end;
+
+ object = find_and_get_object(ptr, 1);
+ if (!object) {
+#ifdef DEBUG
+ kmemleak_warn("Partially freeing unknown object at 0x%08lx "
+ "(size %zu)\n", ptr, size);
+#endif
+ return;
+ }
+ __delete_object(object);
+
+ /*
+ * Create one or two objects that may result from the memory block
+ * split. Note that partial freeing is only done by free_bootmem() and
+ * this happens before kmemleak_init() is called. The path below is
+ * only executed during early log recording in kmemleak_init(), so
+ * GFP_KERNEL is enough.
+ */
+ start = object->pointer;
+ end = object->pointer + object->size;
+ if (ptr > start)
+ create_object(start, ptr - start, object->min_count,
+ GFP_KERNEL);
+ if (ptr + size < end)
+ create_object(ptr + size, end - ptr - size, object->min_count,
+ GFP_KERNEL);
+
+ put_object(object);
+}
+
+static void __paint_it(struct kmemleak_object *object, int color)
+{
+ object->min_count = color;
+ if (color == KMEMLEAK_BLACK)
+ object->flags |= OBJECT_NO_SCAN;
+}
+
+static void paint_it(struct kmemleak_object *object, int color)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&object->lock, flags);
+ __paint_it(object, color);
+ spin_unlock_irqrestore(&object->lock, flags);
+}
+
+static void paint_ptr(unsigned long ptr, int color)
+{
+ struct kmemleak_object *object;
+
+ object = find_and_get_object(ptr, 0);
+ if (!object) {
+ kmemleak_warn("Trying to color unknown object "
+ "at 0x%08lx as %s\n", ptr,
+ (color == KMEMLEAK_GREY) ? "Grey" :
+ (color == KMEMLEAK_BLACK) ? "Black" : "Unknown");
+ return;
+ }
+ paint_it(object, color);
+ put_object(object);
+}
+
+/*
+ * Mark an object permanently as gray-colored so that it can no longer be
+ * reported as a leak. This is used in general to mark a false positive.
+ */
+static void make_gray_object(unsigned long ptr)
+{
+ paint_ptr(ptr, KMEMLEAK_GREY);
+}
+
+/*
+ * Mark the object as black-colored so that it is ignored from scans and
+ * reporting.
+ */
+static void make_black_object(unsigned long ptr)
+{
+ paint_ptr(ptr, KMEMLEAK_BLACK);
+}
+
+/*
+ * Add a scanning area to the object. If at least one such area is added,
+ * kmemleak will only scan these ranges rather than the whole memory block.
+ */
+static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp)
+{
+ unsigned long flags;
+ struct kmemleak_object *object;
+ struct kmemleak_scan_area *area;
+
+ object = find_and_get_object(ptr, 1);
+ if (!object) {
+ kmemleak_warn("Adding scan area to unknown object at 0x%08lx\n",
+ ptr);
+ return;
+ }
+
+ area = kmem_cache_alloc(scan_area_cache, gfp_kmemleak_mask(gfp));
+ if (!area) {
+ pr_warning("Cannot allocate a scan area\n");
+ goto out;
+ }
+
+ spin_lock_irqsave(&object->lock, flags);
+ if (size == SIZE_MAX) {
+ size = object->pointer + object->size - ptr;
+ } else if (ptr + size > object->pointer + object->size) {
+ kmemleak_warn("Scan area larger than object 0x%08lx\n", ptr);
+ dump_object_info(object);
+ kmem_cache_free(scan_area_cache, area);
+ goto out_unlock;
+ }
+
+ INIT_HLIST_NODE(&area->node);
+ area->start = ptr;
+ area->size = size;
+
+ hlist_add_head(&area->node, &object->area_list);
+out_unlock:
+ spin_unlock_irqrestore(&object->lock, flags);
+out:
+ put_object(object);
+}
+
+/*
+ * Set the OBJECT_NO_SCAN flag for the object corresponding to the give
+ * pointer. Such object will not be scanned by kmemleak but references to it
+ * are searched.
+ */
+static void object_no_scan(unsigned long ptr)
+{
+ unsigned long flags;
+ struct kmemleak_object *object;
+
+ object = find_and_get_object(ptr, 0);
+ if (!object) {
+ kmemleak_warn("Not scanning unknown object at 0x%08lx\n", ptr);
+ return;
+ }
+
+ spin_lock_irqsave(&object->lock, flags);
+ object->flags |= OBJECT_NO_SCAN;
+ spin_unlock_irqrestore(&object->lock, flags);
+ put_object(object);
+}
+
+/*
+ * Log an early kmemleak_* call to the early_log buffer. These calls will be
+ * processed later once kmemleak is fully initialized.
+ */
+static void __init log_early(int op_type, const void *ptr, size_t size,
+ int min_count)
+{
+ unsigned long flags;
+ struct early_log *log;
+
+ if (atomic_read(&kmemleak_error)) {
+ /* kmemleak stopped recording, just count the requests */
+ crt_early_log++;
+ return;
+ }
+
+ if (crt_early_log >= ARRAY_SIZE(early_log)) {
+ kmemleak_disable();
+ return;
+ }
+
+ /*
+ * There is no need for locking since the kernel is still in UP mode
+ * at this stage. Disabling the IRQs is enough.
+ */
+ local_irq_save(flags);
+ log = &early_log[crt_early_log];
+ log->op_type = op_type;
+ log->ptr = ptr;
+ log->size = size;
+ log->min_count = min_count;
+ log->trace_len = __save_stack_trace(log->trace);
+ crt_early_log++;
+ local_irq_restore(flags);
+}
+
+/*
+ * Log an early allocated block and populate the stack trace.
+ */
+static void early_alloc(struct early_log *log)
+{
+ struct kmemleak_object *object;
+ unsigned long flags;
+ int i;
+
+ if (!atomic_read(&kmemleak_enabled) || !log->ptr || IS_ERR(log->ptr))
+ return;
+
+ /*
+ * RCU locking needed to ensure object is not freed via put_object().
+ */
+ rcu_read_lock();
+ object = create_object((unsigned long)log->ptr, log->size,
+ log->min_count, GFP_ATOMIC);
+ if (!object)
+ goto out;
+ spin_lock_irqsave(&object->lock, flags);
+ for (i = 0; i < log->trace_len; i++)
+ object->trace[i] = log->trace[i];
+ object->trace_len = log->trace_len;
+ spin_unlock_irqrestore(&object->lock, flags);
+out:
+ rcu_read_unlock();
+}
+
+/*
+ * Log an early allocated block and populate the stack trace.
+ */
+static void early_alloc_percpu(struct early_log *log)
+{
+ unsigned int cpu;
+ const void __percpu *ptr = log->ptr;
+
+ for_each_possible_cpu(cpu) {
+ log->ptr = per_cpu_ptr(ptr, cpu);
+ early_alloc(log);
+ }
+}
+
+/**
+ * kmemleak_alloc - register a newly allocated object
+ * @ptr: pointer to beginning of the object
+ * @size: size of the object
+ * @min_count: minimum number of references to this object. If during memory
+ * scanning a number of references less than @min_count is found,
+ * the object is reported as a memory leak. If @min_count is 0,
+ * the object is never reported as a leak. If @min_count is -1,
+ * the object is ignored (not scanned and not reported as a leak)
+ * @gfp: kmalloc() flags used for kmemleak internal memory allocations
+ *
+ * This function is called from the kernel allocators when a new object
+ * (memory block) is allocated (kmem_cache_alloc, kmalloc, vmalloc etc.).
+ */
+void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count,
+ gfp_t gfp)
+{
+ pr_debug("%s(0x%p, %zu, %d)\n", __func__, ptr, size, min_count);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ create_object((unsigned long)ptr, size, min_count, gfp);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_ALLOC, ptr, size, min_count);
+}
+EXPORT_SYMBOL_GPL(kmemleak_alloc);
+
+/**
+ * kmemleak_alloc_percpu - register a newly allocated __percpu object
+ * @ptr: __percpu pointer to beginning of the object
+ * @size: size of the object
+ *
+ * This function is called from the kernel percpu allocator when a new object
+ * (memory block) is allocated (alloc_percpu). It assumes GFP_KERNEL
+ * allocation.
+ */
+void __ref kmemleak_alloc_percpu(const void __percpu *ptr, size_t size)
+{
+ unsigned int cpu;
+
+ pr_debug("%s(0x%p, %zu)\n", __func__, ptr, size);
+
+ /*
+ * Percpu allocations are only scanned and not reported as leaks
+ * (min_count is set to 0).
+ */
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ for_each_possible_cpu(cpu)
+ create_object((unsigned long)per_cpu_ptr(ptr, cpu),
+ size, 0, GFP_KERNEL);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_ALLOC_PERCPU, ptr, size, 0);
+}
+EXPORT_SYMBOL_GPL(kmemleak_alloc_percpu);
+
+/**
+ * kmemleak_free - unregister a previously registered object
+ * @ptr: pointer to beginning of the object
+ *
+ * This function is called from the kernel allocators when an object (memory
+ * block) is freed (kmem_cache_free, kfree, vfree etc.).
+ */
+void __ref kmemleak_free(const void *ptr)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (kmemleak_free_enabled && ptr && !IS_ERR(ptr))
+ delete_object_full((unsigned long)ptr);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_FREE, ptr, 0, 0);
+}
+EXPORT_SYMBOL_GPL(kmemleak_free);
+
+/**
+ * kmemleak_free_part - partially unregister a previously registered object
+ * @ptr: pointer to the beginning or inside the object. This also
+ * represents the start of the range to be freed
+ * @size: size to be unregistered
+ *
+ * This function is called when only a part of a memory block is freed
+ * (usually from the bootmem allocator).
+ */
+void __ref kmemleak_free_part(const void *ptr, size_t size)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ delete_object_part((unsigned long)ptr, size);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_FREE_PART, ptr, size, 0);
+}
+EXPORT_SYMBOL_GPL(kmemleak_free_part);
+
+/**
+ * kmemleak_free_percpu - unregister a previously registered __percpu object
+ * @ptr: __percpu pointer to beginning of the object
+ *
+ * This function is called from the kernel percpu allocator when an object
+ * (memory block) is freed (free_percpu).
+ */
+void __ref kmemleak_free_percpu(const void __percpu *ptr)
+{
+ unsigned int cpu;
+
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (kmemleak_free_enabled && ptr && !IS_ERR(ptr))
+ for_each_possible_cpu(cpu)
+ delete_object_full((unsigned long)per_cpu_ptr(ptr,
+ cpu));
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_FREE_PERCPU, ptr, 0, 0);
+}
+EXPORT_SYMBOL_GPL(kmemleak_free_percpu);
+
+/**
+ * kmemleak_not_leak - mark an allocated object as false positive
+ * @ptr: pointer to beginning of the object
+ *
+ * Calling this function on an object will cause the memory block to no longer
+ * be reported as leak and always be scanned.
+ */
+void __ref kmemleak_not_leak(const void *ptr)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ make_gray_object((unsigned long)ptr);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_NOT_LEAK, ptr, 0, 0);
+}
+EXPORT_SYMBOL(kmemleak_not_leak);
+
+/**
+ * kmemleak_ignore - ignore an allocated object
+ * @ptr: pointer to beginning of the object
+ *
+ * Calling this function on an object will cause the memory block to be
+ * ignored (not scanned and not reported as a leak). This is usually done when
+ * it is known that the corresponding block is not a leak and does not contain
+ * any references to other allocated memory blocks.
+ */
+void __ref kmemleak_ignore(const void *ptr)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ make_black_object((unsigned long)ptr);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_IGNORE, ptr, 0, 0);
+}
+EXPORT_SYMBOL(kmemleak_ignore);
+
+/**
+ * kmemleak_scan_area - limit the range to be scanned in an allocated object
+ * @ptr: pointer to beginning or inside the object. This also
+ * represents the start of the scan area
+ * @size: size of the scan area
+ * @gfp: kmalloc() flags used for kmemleak internal memory allocations
+ *
+ * This function is used when it is known that only certain parts of an object
+ * contain references to other objects. Kmemleak will only scan these areas
+ * reducing the number false negatives.
+ */
+void __ref kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && size && !IS_ERR(ptr))
+ add_scan_area((unsigned long)ptr, size, gfp);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_SCAN_AREA, ptr, size, 0);
+}
+EXPORT_SYMBOL(kmemleak_scan_area);
+
+/**
+ * kmemleak_no_scan - do not scan an allocated object
+ * @ptr: pointer to beginning of the object
+ *
+ * This function notifies kmemleak not to scan the given memory block. Useful
+ * in situations where it is known that the given object does not contain any
+ * references to other objects. Kmemleak will not scan such objects reducing
+ * the number of false negatives.
+ */
+void __ref kmemleak_no_scan(const void *ptr)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ object_no_scan((unsigned long)ptr);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_NO_SCAN, ptr, 0, 0);
+}
+EXPORT_SYMBOL(kmemleak_no_scan);
+
+/*
+ * Update an object's checksum and return true if it was modified.
+ */
+static bool update_checksum(struct kmemleak_object *object)
+{
+ u32 old_csum = object->checksum;
+
+ if (!kmemcheck_is_obj_initialized(object->pointer, object->size))
+ return false;
+
+ object->checksum = crc32(0, (void *)object->pointer, object->size);
+ return object->checksum != old_csum;
+}
+
+/*
+ * Memory scanning is a long process and it needs to be interruptable. This
+ * function checks whether such interrupt condition occurred.
+ */
+static int scan_should_stop(void)
+{
+ if (!atomic_read(&kmemleak_enabled))
+ return 1;
+
+ /*
+ * This function may be called from either process or kthread context,
+ * hence the need to check for both stop conditions.
+ */
+ if (current->mm)
+ return signal_pending(current);
+ else
+ return kthread_should_stop();
+
+ return 0;
+}
+
+/*
+ * Scan a memory block (exclusive range) for valid pointers and add those
+ * found to the gray list.
+ */
+static void scan_block(void *_start, void *_end,
+ struct kmemleak_object *scanned, int allow_resched)
+{
+ unsigned long *ptr;
+ unsigned long *start = PTR_ALIGN(_start, BYTES_PER_POINTER);
+ unsigned long *end = _end - (BYTES_PER_POINTER - 1);
+
+ for (ptr = start; ptr < end; ptr++) {
+ struct kmemleak_object *object;
+ unsigned long flags;
+ unsigned long pointer;
+
+ if (allow_resched)
+ cond_resched();
+ if (scan_should_stop())
+ break;
+
+ /* don't scan uninitialized memory */
+ if (!kmemcheck_is_obj_initialized((unsigned long)ptr,
+ BYTES_PER_POINTER))
+ continue;
+
+ pointer = *ptr;
+
+ object = find_and_get_object(pointer, 1);
+ if (!object)
+ continue;
+ if (object == scanned) {
+ /* self referenced, ignore */
+ put_object(object);
+ continue;
+ }
+
+ /*
+ * Avoid the lockdep recursive warning on object->lock being
+ * previously acquired in scan_object(). These locks are
+ * enclosed by scan_mutex.
+ */
+ spin_lock_irqsave_nested(&object->lock, flags,
+ SINGLE_DEPTH_NESTING);
+ if (!color_white(object)) {
+ /* non-orphan, ignored or new */
+ spin_unlock_irqrestore(&object->lock, flags);
+ put_object(object);
+ continue;
+ }
+
+ /*
+ * Increase the object's reference count (number of pointers
+ * to the memory block). If this count reaches the required
+ * minimum, the object's color will become gray and it will be
+ * added to the gray_list.
+ */
+ object->count++;
+ if (color_gray(object)) {
+ list_add_tail(&object->gray_list, &gray_list);
+ spin_unlock_irqrestore(&object->lock, flags);
+ continue;
+ }
+
+ spin_unlock_irqrestore(&object->lock, flags);
+ put_object(object);
+ }
+}
+
+/*
+ * Scan a memory block corresponding to a kmemleak_object. A condition is
+ * that object->use_count >= 1.
+ */
+static void scan_object(struct kmemleak_object *object)
+{
+ struct kmemleak_scan_area *area;
+ struct hlist_node *elem;
+ unsigned long flags;
+
+ /*
+ * Once the object->lock is acquired, the corresponding memory block
+ * cannot be freed (the same lock is acquired in delete_object).
+ */
+ spin_lock_irqsave(&object->lock, flags);
+ if (object->flags & OBJECT_NO_SCAN)
+ goto out;
+ if (!(object->flags & OBJECT_ALLOCATED))
+ /* already freed object */
+ goto out;
+ if (hlist_empty(&object->area_list)) {
+ void *start = (void *)object->pointer;
+ void *end = (void *)(object->pointer + object->size);
+
+ while (start < end && (object->flags & OBJECT_ALLOCATED) &&
+ !(object->flags & OBJECT_NO_SCAN)) {
+ scan_block(start, min(start + MAX_SCAN_SIZE, end),
+ object, 0);
+ start += MAX_SCAN_SIZE;
+
+ spin_unlock_irqrestore(&object->lock, flags);
+ cond_resched();
+ spin_lock_irqsave(&object->lock, flags);
+ }
+ } else
+ hlist_for_each_entry(area, elem, &object->area_list, node)
+ scan_block((void *)area->start,
+ (void *)(area->start + area->size),
+ object, 0);
+out:
+ spin_unlock_irqrestore(&object->lock, flags);
+}
+
+/*
+ * Scan the objects already referenced (gray objects). More objects will be
+ * referenced and, if there are no memory leaks, all the objects are scanned.
+ */
+static void scan_gray_list(void)
+{
+ struct kmemleak_object *object, *tmp;
+
+ /*
+ * The list traversal is safe for both tail additions and removals
+ * from inside the loop. The kmemleak objects cannot be freed from
+ * outside the loop because their use_count was incremented.
+ */
+ object = list_entry(gray_list.next, typeof(*object), gray_list);
+ while (&object->gray_list != &gray_list) {
+ cond_resched();
+
+ /* may add new objects to the list */
+ if (!scan_should_stop())
+ scan_object(object);
+
+ tmp = list_entry(object->gray_list.next, typeof(*object),
+ gray_list);
+
+ /* remove the object from the list and release it */
+ list_del(&object->gray_list);
+ put_object(object);
+
+ object = tmp;
+ }
+ WARN_ON(!list_empty(&gray_list));
+}
+
+/*
+ * Scan data sections and all the referenced memory blocks allocated via the
+ * kernel's standard allocators. This function must be called with the
+ * scan_mutex held.
+ */
+static void kmemleak_scan(void)
+{
+ unsigned long flags;
+ struct kmemleak_object *object;
+ int i;
+ int new_leaks = 0;
+
+ jiffies_last_scan = jiffies;
+
+ /* prepare the kmemleak_object's */
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ spin_lock_irqsave(&object->lock, flags);
+#ifdef DEBUG
+ /*
+ * With a few exceptions there should be a maximum of
+ * 1 reference to any object at this point.
+ */
+ if (atomic_read(&object->use_count) > 1) {
+ pr_debug("object->use_count = %d\n",
+ atomic_read(&object->use_count));
+ dump_object_info(object);
+ }
+#endif
+ /* reset the reference count (whiten the object) */
+ object->count = 0;
+ if (color_gray(object) && get_object(object))
+ list_add_tail(&object->gray_list, &gray_list);
+
+ spin_unlock_irqrestore(&object->lock, flags);
+ }
+ rcu_read_unlock();
+
+ /* data/bss scanning */
+ scan_block(_sdata, _edata, NULL, 1);
+ scan_block(__bss_start, __bss_stop, NULL, 1);
+
+#ifdef CONFIG_SMP
+ /* per-cpu sections scanning */
+ for_each_possible_cpu(i)
+ scan_block(__per_cpu_start + per_cpu_offset(i),
+ __per_cpu_end + per_cpu_offset(i), NULL, 1);
+#endif
+
+ /*
+ * Struct page scanning for each node.
+ */
+ lock_memory_hotplug();
+ for_each_online_node(i) {
+ pg_data_t *pgdat = NODE_DATA(i);
+ unsigned long start_pfn = pgdat->node_start_pfn;
+ unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
+ unsigned long pfn;
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn++) {
+ struct page *page;
+
+ if (!pfn_valid(pfn))
+ continue;
+ page = pfn_to_page(pfn);
+ /* only scan if page is in use */
+ if (page_count(page) == 0)
+ continue;
+ scan_block(page, page + 1, NULL, 1);
+ }
+ }
+ unlock_memory_hotplug();
+
+ /*
+ * Scanning the task stacks (may introduce false negatives).
+ */
+ if (kmemleak_stack_scan) {
+ struct task_struct *p, *g;
+
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ scan_block(task_stack_page(p), task_stack_page(p) +
+ THREAD_SIZE, NULL, 0);
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+ }
+
+ /*
+ * Scan the objects already referenced from the sections scanned
+ * above.
+ */
+ scan_gray_list();
+
+ /*
+ * Check for new or unreferenced objects modified since the previous
+ * scan and color them gray until the next scan.
+ */
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ spin_lock_irqsave(&object->lock, flags);
+ if (color_white(object) && (object->flags & OBJECT_ALLOCATED)
+ && update_checksum(object) && get_object(object)) {
+ /* color it gray temporarily */
+ object->count = object->min_count;
+ list_add_tail(&object->gray_list, &gray_list);
+ }
+ spin_unlock_irqrestore(&object->lock, flags);
+ }
+ rcu_read_unlock();
+
+ /*
+ * Re-scan the gray list for modified unreferenced objects.
+ */
+ scan_gray_list();
+
+ /*
+ * If scanning was stopped do not report any new unreferenced objects.
+ */
+ if (scan_should_stop())
+ return;
+
+ /*
+ * Scanning result reporting.
+ */
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ spin_lock_irqsave(&object->lock, flags);
+ if (unreferenced_object(object) &&
+ !(object->flags & OBJECT_REPORTED)) {
+ object->flags |= OBJECT_REPORTED;
+ new_leaks++;
+ }
+ spin_unlock_irqrestore(&object->lock, flags);
+ }
+ rcu_read_unlock();
+
+ if (new_leaks)
+ pr_info("%d new suspected memory leaks (see "
+ "/sys/kernel/debug/kmemleak)\n", new_leaks);
+
+}
+
+/*
+ * Thread function performing automatic memory scanning. Unreferenced objects
+ * at the end of a memory scan are reported but only the first time.
+ */
+static int kmemleak_scan_thread(void *arg)
+{
+ static int first_run = 1;
+
+ pr_info("Automatic memory scanning thread started\n");
+ set_user_nice(current, 10);
+
+ /*
+ * Wait before the first scan to allow the system to fully initialize.
+ */
+ if (first_run) {
+ first_run = 0;
+ ssleep(SECS_FIRST_SCAN);
+ }
+
+ while (!kthread_should_stop()) {
+ signed long timeout = jiffies_scan_wait;
+
+ mutex_lock(&scan_mutex);
+ kmemleak_scan();
+ mutex_unlock(&scan_mutex);
+
+ /* wait before the next scan */
+ while (timeout && !kthread_should_stop())
+ timeout = schedule_timeout_interruptible(timeout);
+ }
+
+ pr_info("Automatic memory scanning thread ended\n");
+
+ return 0;
+}
+
+/*
+ * Start the automatic memory scanning thread. This function must be called
+ * with the scan_mutex held.
+ */
+static void start_scan_thread(void)
+{
+ if (scan_thread)
+ return;
+ scan_thread = kthread_run(kmemleak_scan_thread, NULL, "kmemleak");
+ if (IS_ERR(scan_thread)) {
+ pr_warning("Failed to create the scan thread\n");
+ scan_thread = NULL;
+ }
+}
+
+/*
+ * Stop the automatic memory scanning thread. This function must be called
+ * with the scan_mutex held.
+ */
+static void stop_scan_thread(void)
+{
+ if (scan_thread) {
+ kthread_stop(scan_thread);
+ scan_thread = NULL;
+ }
+}
+
+/*
+ * Iterate over the object_list and return the first valid object at or after
+ * the required position with its use_count incremented. The function triggers
+ * a memory scanning when the pos argument points to the first position.
+ */
+static void *kmemleak_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ struct kmemleak_object *object;
+ loff_t n = *pos;
+ int err;
+
+ err = mutex_lock_interruptible(&scan_mutex);
+ if (err < 0)
+ return ERR_PTR(err);
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ if (n-- > 0)
+ continue;
+ if (get_object(object))
+ goto out;
+ }
+ object = NULL;
+out:
+ return object;
+}
+
+/*
+ * Return the next object in the object_list. The function decrements the
+ * use_count of the previous object and increases that of the next one.
+ */
+static void *kmemleak_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct kmemleak_object *prev_obj = v;
+ struct kmemleak_object *next_obj = NULL;
+ struct list_head *n = &prev_obj->object_list;
+
+ ++(*pos);
+
+ list_for_each_continue_rcu(n, &object_list) {
+ struct kmemleak_object *obj =
+ list_entry(n, struct kmemleak_object, object_list);
+ if (get_object(obj)) {
+ next_obj = obj;
+ break;
+ }
+ }
+
+ put_object(prev_obj);
+ return next_obj;
+}
+
+/*
+ * Decrement the use_count of the last object required, if any.
+ */
+static void kmemleak_seq_stop(struct seq_file *seq, void *v)
+{
+ if (!IS_ERR(v)) {
+ /*
+ * kmemleak_seq_start may return ERR_PTR if the scan_mutex
+ * waiting was interrupted, so only release it if !IS_ERR.
+ */
+ rcu_read_unlock();
+ mutex_unlock(&scan_mutex);
+ if (v)
+ put_object(v);
+ }
+}
+
+/*
+ * Print the information for an unreferenced object to the seq file.
+ */
+static int kmemleak_seq_show(struct seq_file *seq, void *v)
+{
+ struct kmemleak_object *object = v;
+ unsigned long flags;
+
+ spin_lock_irqsave(&object->lock, flags);
+ if ((object->flags & OBJECT_REPORTED) && unreferenced_object(object))
+ print_unreferenced(seq, object);
+ spin_unlock_irqrestore(&object->lock, flags);
+ return 0;
+}
+
+static const struct seq_operations kmemleak_seq_ops = {
+ .start = kmemleak_seq_start,
+ .next = kmemleak_seq_next,
+ .stop = kmemleak_seq_stop,
+ .show = kmemleak_seq_show,
+};
+
+static int kmemleak_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &kmemleak_seq_ops);
+}
+
+static int kmemleak_release(struct inode *inode, struct file *file)
+{
+ return seq_release(inode, file);
+}
+
+static int dump_str_object_info(const char *str)
+{
+ unsigned long flags;
+ struct kmemleak_object *object;
+ unsigned long addr;
+
+ addr= simple_strtoul(str, NULL, 0);
+ object = find_and_get_object(addr, 0);
+ if (!object) {
+ pr_info("Unknown object at 0x%08lx\n", addr);
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&object->lock, flags);
+ dump_object_info(object);
+ spin_unlock_irqrestore(&object->lock, flags);
+
+ put_object(object);
+ return 0;
+}
+
+/*
+ * We use grey instead of black to ensure we can do future scans on the same
+ * objects. If we did not do future scans these black objects could
+ * potentially contain references to newly allocated objects in the future and
+ * we'd end up with false positives.
+ */
+static void kmemleak_clear(void)
+{
+ struct kmemleak_object *object;
+ unsigned long flags;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ spin_lock_irqsave(&object->lock, flags);
+ if ((object->flags & OBJECT_REPORTED) &&
+ unreferenced_object(object))
+ __paint_it(object, KMEMLEAK_GREY);
+ spin_unlock_irqrestore(&object->lock, flags);
+ }
+ rcu_read_unlock();
+}
+
+/*
+ * File write operation to configure kmemleak at run-time. The following
+ * commands can be written to the /sys/kernel/debug/kmemleak file:
+ * off - disable kmemleak (irreversible)
+ * stack=on - enable the task stacks scanning
+ * stack=off - disable the tasks stacks scanning
+ * scan=on - start the automatic memory scanning thread
+ * scan=off - stop the automatic memory scanning thread
+ * scan=... - set the automatic memory scanning period in seconds (0 to
+ * disable it)
+ * scan - trigger a memory scan
+ * clear - mark all current reported unreferenced kmemleak objects as
+ * grey to ignore printing them
+ * dump=... - dump information about the object found at the given address
+ */
+static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
+ size_t size, loff_t *ppos)
+{
+ char buf[64];
+ int buf_size;
+ int ret;
+
+ if (!atomic_read(&kmemleak_enabled))
+ return -EBUSY;
+
+ buf_size = min(size, (sizeof(buf) - 1));
+ if (strncpy_from_user(buf, user_buf, buf_size) < 0)
+ return -EFAULT;
+ buf[buf_size] = 0;
+
+ ret = mutex_lock_interruptible(&scan_mutex);
+ if (ret < 0)
+ return ret;
+
+ if (strncmp(buf, "off", 3) == 0)
+ kmemleak_disable();
+ else if (strncmp(buf, "stack=on", 8) == 0)
+ kmemleak_stack_scan = 1;
+ else if (strncmp(buf, "stack=off", 9) == 0)
+ kmemleak_stack_scan = 0;
+ else if (strncmp(buf, "scan=on", 7) == 0)
+ start_scan_thread();
+ else if (strncmp(buf, "scan=off", 8) == 0)
+ stop_scan_thread();
+ else if (strncmp(buf, "scan=", 5) == 0) {
+ unsigned long secs;
+
+ ret = strict_strtoul(buf + 5, 0, &secs);
+ if (ret < 0)
+ goto out;
+ stop_scan_thread();
+ if (secs) {
+ jiffies_scan_wait = msecs_to_jiffies(secs * 1000);
+ start_scan_thread();
+ }
+ } else if (strncmp(buf, "scan", 4) == 0)
+ kmemleak_scan();
+ else if (strncmp(buf, "clear", 5) == 0)
+ kmemleak_clear();
+ else if (strncmp(buf, "dump=", 5) == 0)
+ ret = dump_str_object_info(buf + 5);
+ else
+ ret = -EINVAL;
+
+out:
+ mutex_unlock(&scan_mutex);
+ if (ret < 0)
+ return ret;
+
+ /* ignore the rest of the buffer, only one command at a time */
+ *ppos += size;
+ return size;
+}
+
+static const struct file_operations kmemleak_fops = {
+ .owner = THIS_MODULE,
+ .open = kmemleak_open,
+ .read = seq_read,
+ .write = kmemleak_write,
+ .llseek = seq_lseek,
+ .release = kmemleak_release,
+};
+
+/*
+ * Stop the memory scanning thread and free the kmemleak internal objects if
+ * no previous scan thread (otherwise, kmemleak may still have some useful
+ * information on memory leaks).
+ */
+static void kmemleak_do_cleanup(struct work_struct *work)
+{
+ struct kmemleak_object *object;
+ bool cleanup = scan_thread == NULL;
+
+ mutex_lock(&scan_mutex);
+ stop_scan_thread();
+
+ /*
+ * Once the scan thread has stopped, it is safe to no longer track
+ * object freeing. Ordering of the scan thread stopping and the memory
+ * accesses below is guaranteed by the kthread_stop() function.
+ */
+ kmemleak_free_enabled = 0;
+
+ if (cleanup) {
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list)
+ delete_object_full(object->pointer);
+ rcu_read_unlock();
+ }
+ mutex_unlock(&scan_mutex);
+}
+
+static DECLARE_WORK(cleanup_work, kmemleak_do_cleanup);
+
+/*
+ * Disable kmemleak. No memory allocation/freeing will be traced once this
+ * function is called. Disabling kmemleak is an irreversible operation.
+ */
+static void kmemleak_disable(void)
+{
+ /* atomically check whether it was already invoked */
+ if (atomic_cmpxchg(&kmemleak_error, 0, 1))
+ return;
+
+ /* stop any memory operation tracing */
+ atomic_set(&kmemleak_enabled, 0);
+
+ /* check whether it is too early for a kernel thread */
+ if (atomic_read(&kmemleak_initialized))
+ schedule_work(&cleanup_work);
+ else
+ kmemleak_free_enabled = 0;
+
+ pr_info("Kernel memory leak detector disabled\n");
+}
+
+/*
+ * Allow boot-time kmemleak disabling (enabled by default).
+ */
+static int kmemleak_boot_config(char *str)
+{
+ if (!str)
+ return -EINVAL;
+ if (strcmp(str, "off") == 0)
+ kmemleak_disable();
+ else if (strcmp(str, "on") == 0)
+ kmemleak_skip_disable = 1;
+ else
+ return -EINVAL;
+ return 0;
+}
+early_param("kmemleak", kmemleak_boot_config);
+
+static void __init print_log_trace(struct early_log *log)
+{
+ struct stack_trace trace;
+
+ trace.nr_entries = log->trace_len;
+ trace.entries = log->trace;
+
+ pr_notice("Early log backtrace:\n");
+ print_stack_trace(&trace, 2);
+}
+
+/*
+ * Kmemleak initialization.
+ */
+void __init kmemleak_init(void)
+{
+ int i;
+ unsigned long flags;
+
+#ifdef CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF
+ if (!kmemleak_skip_disable) {
+ atomic_set(&kmemleak_early_log, 0);
+ kmemleak_disable();
+ return;
+ }
+#endif
+
+ jiffies_min_age = msecs_to_jiffies(MSECS_MIN_AGE);
+ jiffies_scan_wait = msecs_to_jiffies(SECS_SCAN_WAIT * 1000);
+
+ object_cache = KMEM_CACHE(kmemleak_object, SLAB_NOLEAKTRACE);
+ scan_area_cache = KMEM_CACHE(kmemleak_scan_area, SLAB_NOLEAKTRACE);
+ INIT_PRIO_TREE_ROOT(&object_tree_root);
+
+ if (crt_early_log >= ARRAY_SIZE(early_log))
+ pr_warning("Early log buffer exceeded (%d), please increase "
+ "DEBUG_KMEMLEAK_EARLY_LOG_SIZE\n", crt_early_log);
+
+ /* the kernel is still in UP mode, so disabling the IRQs is enough */
+ local_irq_save(flags);
+ atomic_set(&kmemleak_early_log, 0);
+ if (atomic_read(&kmemleak_error)) {
+ local_irq_restore(flags);
+ return;
+ } else {
+ atomic_set(&kmemleak_enabled, 1);
+ kmemleak_free_enabled = 1;
+ }
+ local_irq_restore(flags);
+
+ /*
+ * This is the point where tracking allocations is safe. Automatic
+ * scanning is started during the late initcall. Add the early logged
+ * callbacks to the kmemleak infrastructure.
+ */
+ for (i = 0; i < crt_early_log; i++) {
+ struct early_log *log = &early_log[i];
+
+ switch (log->op_type) {
+ case KMEMLEAK_ALLOC:
+ early_alloc(log);
+ break;
+ case KMEMLEAK_ALLOC_PERCPU:
+ early_alloc_percpu(log);
+ break;
+ case KMEMLEAK_FREE:
+ kmemleak_free(log->ptr);
+ break;
+ case KMEMLEAK_FREE_PART:
+ kmemleak_free_part(log->ptr, log->size);
+ break;
+ case KMEMLEAK_FREE_PERCPU:
+ kmemleak_free_percpu(log->ptr);
+ break;
+ case KMEMLEAK_NOT_LEAK:
+ kmemleak_not_leak(log->ptr);
+ break;
+ case KMEMLEAK_IGNORE:
+ kmemleak_ignore(log->ptr);
+ break;
+ case KMEMLEAK_SCAN_AREA:
+ kmemleak_scan_area(log->ptr, log->size, GFP_KERNEL);
+ break;
+ case KMEMLEAK_NO_SCAN:
+ kmemleak_no_scan(log->ptr);
+ break;
+ default:
+ kmemleak_warn("Unknown early log operation: %d\n",
+ log->op_type);
+ }
+
+ if (atomic_read(&kmemleak_warning)) {
+ print_log_trace(log);
+ atomic_set(&kmemleak_warning, 0);
+ }
+ }
+}
+
+/*
+ * Late initialization function.
+ */
+static int __init kmemleak_late_init(void)
+{
+ struct dentry *dentry;
+
+ atomic_set(&kmemleak_initialized, 1);
+
+ if (atomic_read(&kmemleak_error)) {
+ /*
+ * Some error occurred and kmemleak was disabled. There is a
+ * small chance that kmemleak_disable() was called immediately
+ * after setting kmemleak_initialized and we may end up with
+ * two clean-up threads but serialized by scan_mutex.
+ */
+ schedule_work(&cleanup_work);
+ return -ENOMEM;
+ }
+
+ dentry = debugfs_create_file("kmemleak", S_IRUGO, NULL, NULL,
+ &kmemleak_fops);
+ if (!dentry)
+ pr_warning("Failed to create the debugfs kmemleak file\n");
+ mutex_lock(&scan_mutex);
+ start_scan_thread();
+ mutex_unlock(&scan_mutex);
+
+ pr_info("Kernel memory leak detector initialized\n");
+
+ return 0;
+}
+late_initcall(kmemleak_late_init);
diff --git a/ap/os/linux/linux-3.4.x/mm/kmemleak.c b/ap/os/linux/linux-3.4.x/mm/kmemleak.c
new file mode 100644
index 0000000..1136030
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/kmemleak.c
@@ -0,0 +1,1989 @@
+/*
+ * mm/kmemleak.c
+ *
+ * Copyright (C) 2008 ARM Limited
+ * Written by Catalin Marinas <catalin.marinas@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ *
+ * For more information on the algorithm and kmemleak usage, please see
+ * Documentation/kmemleak.txt.
+ *
+ * Notes on locking
+ * ----------------
+ *
+ * The following locks and mutexes are used by kmemleak:
+ *
+ * - kmemleak_lock (rwlock): protects the object_list modifications and
+ * accesses to the object_tree_root. The object_list is the main list
+ * holding the metadata (struct kmemleak_object) for the allocated memory
+ * blocks. The object_tree_root is a priority search tree used to look-up
+ * metadata based on a pointer to the corresponding memory block. The
+ * kmemleak_object structures are added to the object_list and
+ * object_tree_root in the create_object() function called from the
+ * kmemleak_alloc() callback and removed in delete_object() called from the
+ * kmemleak_free() callback
+ * - kmemleak_object.lock (spinlock): protects a kmemleak_object. Accesses to
+ * the metadata (e.g. count) are protected by this lock. Note that some
+ * members of this structure may be protected by other means (atomic or
+ * kmemleak_lock). This lock is also held when scanning the corresponding
+ * memory block to avoid the kernel freeing it via the kmemleak_free()
+ * callback. This is less heavyweight than holding a global lock like
+ * kmemleak_lock during scanning
+ * - scan_mutex (mutex): ensures that only one thread may scan the memory for
+ * unreferenced objects at a time. The gray_list contains the objects which
+ * are already referenced or marked as false positives and need to be
+ * scanned. This list is only modified during a scanning episode when the
+ * scan_mutex is held. At the end of a scan, the gray_list is always empty.
+ * Note that the kmemleak_object.use_count is incremented when an object is
+ * added to the gray_list and therefore cannot be freed. This mutex also
+ * prevents multiple users of the "kmemleak" debugfs file together with
+ * modifications to the memory scanning parameters including the scan_thread
+ * pointer
+ *
+ * The kmemleak_object structures have a use_count incremented or decremented
+ * using the get_object()/put_object() functions. When the use_count becomes
+ * 0, this count can no longer be incremented and put_object() schedules the
+ * kmemleak_object freeing via an RCU callback. All calls to the get_object()
+ * function must be protected by rcu_read_lock() to avoid accessing a freed
+ * structure.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/sched.h>
+#include <linux/jiffies.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/kthread.h>
+#include <linux/prio_tree.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/cpumask.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/rcupdate.h>
+#include <linux/stacktrace.h>
+#include <linux/cache.h>
+#include <linux/percpu.h>
+#include <linux/hardirq.h>
+#include <linux/mmzone.h>
+#include <linux/slab.h>
+#include <linux/thread_info.h>
+#include <linux/err.h>
+#include <linux/uaccess.h>
+#include <linux/string.h>
+#include <linux/nodemask.h>
+#include <linux/mm.h>
+#include <linux/workqueue.h>
+#include <linux/crc32.h>
+
+#include <asm/sections.h>
+#include <asm/processor.h>
+#include <linux/atomic.h>
+
+#include <linux/kmemcheck.h>
+#include <linux/kmemleak.h>
+#include <linux/memory_hotplug.h>
+
+/*
+ * Kmemleak configuration and common defines.
+ * Add KMEMLEAK_FULL for full function version( By zhu di)
+ */
+ #ifdef KMEMLEAK_FULL
+#define MAX_TRACE 16 /* stack trace length */
+#else
+#define MAX_TRACE 2 /* minimum the footprint */
+#endif
+#define MSECS_MIN_AGE 5000 /* minimum object age for reporting */
+#define SECS_FIRST_SCAN 60 /* delay before the first scan */
+#define SECS_SCAN_WAIT 600 /* subsequent auto scanning delay */
+#define MAX_SCAN_SIZE 4096 /* maximum size of a scanned block */
+
+#define BYTES_PER_POINTER sizeof(void *)
+
+/* GFP bitmask for kmemleak internal allocations */
+#define gfp_kmemleak_mask(gfp) (((gfp) & (GFP_KERNEL | GFP_ATOMIC)) | \
+ __GFP_NORETRY | __GFP_NOMEMALLOC | \
+ __GFP_NOWARN)
+
+/* scanning area inside a memory block */
+struct kmemleak_scan_area {
+ struct hlist_node node;
+ unsigned long start;
+ size_t size;
+};
+
+#define KMEMLEAK_GREY 0
+#define KMEMLEAK_BLACK -1
+
+/*
+ * Structure holding the metadata for each allocated memory block.
+ * Modifications to such objects should be made while holding the
+ * object->lock. Insertions or deletions from object_list, gray_list or
+ * tree_node are already protected by the corresponding locks or mutex (see
+ * the notes on locking above). These objects are reference-counted
+ * (use_count) and freed using the RCU mechanism.
+ */
+struct kmemleak_object {
+#ifdef KMEMLEAK_FULL
+ spinlock_t lock;
+ unsigned long flags; /* object status flags */
+ struct list_head gray_list;
+
+ /* object usage count; object freed when use_count == 0 */
+ atomic_t use_count;
+ unsigned long pointer;
+ /* minimum number of a pointers found before it is considered leak */
+ int min_count;
+ /* the total number of pointers found pointing to this object */
+ int count;
+ /* checksum for detecting modified objects */
+ u32 checksum;
+ /* memory ranges to be scanned inside an object (empty for all) */
+ struct hlist_head area_list;
+ unsigned int trace_len;
+#endif
+ size_t size;
+ unsigned long trace[MAX_TRACE];
+ struct list_head object_list;
+ struct prio_tree_node tree_node;
+ struct rcu_head rcu; /* object_list lockless traversal */
+ unsigned long jiffies; /* creation timestamp */
+ pid_t pid; /* pid of the current task */
+ char comm[TASK_COMM_LEN]; /* executable name */
+};
+
+/* flag representing the memory block allocation status */
+#define OBJECT_ALLOCATED (1 << 0)
+/* flag set after the first reporting of an unreference object */
+#define OBJECT_REPORTED (1 << 1)
+/* flag set to not scan the object */
+#define OBJECT_NO_SCAN (1 << 2)
+
+/* number of bytes to print per line; must be 16 or 32 */
+#define HEX_ROW_SIZE 16
+/* number of bytes to print at a time (1, 2, 4, 8) */
+#define HEX_GROUP_SIZE 1
+/* include ASCII after the hex output */
+#define HEX_ASCII 1
+/* max number of lines to be printed */
+#define HEX_MAX_LINES 2
+
+/* the list of all allocated objects */
+static LIST_HEAD(object_list);
+/* the list of gray-colored objects (see color_gray comment below) */
+static LIST_HEAD(gray_list);
+/* prio search tree for object boundaries */
+static struct prio_tree_root object_tree_root;
+/* rw_lock protecting the access to object_list and prio_tree_root */
+static DEFINE_RWLOCK(kmemleak_lock);
+
+/* allocation caches for kmemleak internal data */
+static struct kmem_cache *object_cache;
+static struct kmem_cache *scan_area_cache;
+
+/* set if tracing memory operations is enabled */
+static atomic_t kmemleak_enabled = ATOMIC_INIT(0);
+/* same as above but only for the kmemleak_free() callback */
+static int kmemleak_free_enabled;
+/* set in the late_initcall if there were no errors */
+static atomic_t kmemleak_initialized = ATOMIC_INIT(0);
+/* enables or disables early logging of the memory operations */
+static atomic_t kmemleak_early_log = ATOMIC_INIT(1);
+/* set if a kmemleak warning was issued */
+static atomic_t kmemleak_warning = ATOMIC_INIT(0);
+/* set if a fatal kmemleak error has occurred */
+static atomic_t kmemleak_error = ATOMIC_INIT(0);
+
+/* minimum and maximum address that may be valid pointers */
+static unsigned long min_addr = ULONG_MAX;
+static unsigned long max_addr;
+
+static struct task_struct *scan_thread;
+/* used to avoid reporting of recently allocated objects */
+static unsigned long jiffies_min_age;
+static unsigned long jiffies_last_scan;
+/* delay between automatic memory scannings */
+static signed long jiffies_scan_wait;
+/* enables or disables the task stacks scanning */
+static int kmemleak_stack_scan = 1;
+/* protects the memory scanning, parameters and debug/kmemleak file access */
+static DEFINE_MUTEX(scan_mutex);
+/* setting kmemleak=on, will set this var, skipping the disable */
+static int kmemleak_skip_disable;
+
+
+/*
+ * Early object allocation/freeing logging. Kmemleak is initialized after the
+ * kernel allocator. However, both the kernel allocator and kmemleak may
+ * allocate memory blocks which need to be tracked. Kmemleak defines an
+ * arbitrary buffer to hold the allocation/freeing information before it is
+ * fully initialized.
+ */
+
+/* kmemleak operation type for early logging */
+enum {
+ KMEMLEAK_ALLOC,
+ KMEMLEAK_ALLOC_PERCPU,
+ KMEMLEAK_FREE,
+ KMEMLEAK_FREE_PART,
+ KMEMLEAK_FREE_PERCPU,
+ KMEMLEAK_NOT_LEAK,
+ KMEMLEAK_IGNORE,
+ KMEMLEAK_SCAN_AREA,
+ KMEMLEAK_NO_SCAN
+};
+
+/*
+ * Structure holding the information passed to kmemleak callbacks during the
+ * early logging.
+ */
+struct early_log {
+ int op_type; /* kmemleak operation type */
+ const void *ptr; /* allocated/freed memory block */
+ size_t size; /* memory block size */
+ int min_count; /* minimum reference count */
+ unsigned long trace[MAX_TRACE]; /* stack trace */
+ unsigned int trace_len; /* stack trace length */
+};
+
+/* early logging buffer and current position */
+static struct early_log
+ early_log[CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE] __initdata;
+static int crt_early_log __initdata;
+
+static void kmemleak_disable(void);
+
+/*
+ * Print a warning and dump the stack trace.
+ */
+#define kmemleak_warn(x...) do { \
+ pr_warning(x); \
+ dump_stack(); \
+ atomic_set(&kmemleak_warning, 1); \
+} while (0)
+
+/*
+ * Macro invoked when a serious kmemleak condition occurred and cannot be
+ * recovered from. Kmemleak will be disabled and further allocation/freeing
+ * tracing no longer available.
+ */
+#define kmemleak_stop(x...) do { \
+ kmemleak_warn(x); \
+ kmemleak_disable(); \
+} while (0)
+
+/*
+ * Printing of the objects hex dump to the seq file. The number of lines to be
+ * printed is limited to HEX_MAX_LINES to prevent seq file spamming. The
+ * actual number of printed bytes depends on HEX_ROW_SIZE. It must be called
+ * with the object->lock held.
+ */
+ #ifdef KMEMLEAK_FULL
+static void hex_dump_object(struct seq_file *seq,
+ struct kmemleak_object *object)
+{
+ const u8 *ptr = (const u8 *)object->pointer;
+ int i, len, remaining;
+ unsigned char linebuf[HEX_ROW_SIZE * 5];
+
+ /* limit the number of lines to HEX_MAX_LINES */
+ remaining = len =
+ min(object->size, (size_t)(HEX_MAX_LINES * HEX_ROW_SIZE));
+
+ seq_printf(seq, " hex dump (first %d bytes):\n", len);
+ for (i = 0; i < len; i += HEX_ROW_SIZE) {
+ int linelen = min(remaining, HEX_ROW_SIZE);
+
+ remaining -= HEX_ROW_SIZE;
+ hex_dump_to_buffer(ptr + i, linelen, HEX_ROW_SIZE,
+ HEX_GROUP_SIZE, linebuf, sizeof(linebuf),
+ HEX_ASCII);
+ seq_printf(seq, " %s\n", linebuf);
+ }
+}
+
+/*
+ * Object colors, encoded with count and min_count:
+ * - white - orphan object, not enough references to it (count < min_count)
+ * - gray - not orphan, not marked as false positive (min_count == 0) or
+ * sufficient references to it (count >= min_count)
+ * - black - ignore, it doesn't contain references (e.g. text section)
+ * (min_count == -1). No function defined for this color.
+ * Newly created objects don't have any color assigned (object->count == -1)
+ * before the next memory scan when they become white.
+ */
+static bool color_white(const struct kmemleak_object *object)
+{
+ return object->count != KMEMLEAK_BLACK &&
+ object->count < object->min_count;
+}
+
+static bool color_gray(const struct kmemleak_object *object)
+{
+ return object->min_count != KMEMLEAK_BLACK &&
+ object->count >= object->min_count;
+}
+
+/*
+ * Objects are considered unreferenced only if their color is white, they have
+ * not be deleted and have a minimum age to avoid false positives caused by
+ * pointers temporarily stored in CPU registers.
+ */
+static bool unreferenced_object(struct kmemleak_object *object)
+{
+ return (color_white(object) && object->flags & OBJECT_ALLOCATED) &&
+ time_before_eq(object->jiffies + jiffies_min_age,
+ jiffies_last_scan);
+}
+
+
+/*
+ * Printing of the unreferenced objects information to the seq file. The
+ * print_unreferenced function must be called with the object->lock held.
+ */
+static void print_unreferenced(struct seq_file *seq,
+ struct kmemleak_object *object)
+{
+ int i;
+ unsigned int msecs_age = jiffies_to_msecs(jiffies - object->jiffies);
+
+ seq_printf(seq, "unreferenced object 0x%08lx (size %zu):\n",
+ object->pointer, object->size);
+ seq_printf(seq, " comm \"%s\", pid %d, jiffies %lu (age %d.%03ds)\n",
+ object->comm, object->pid, object->jiffies,
+ msecs_age / 1000, msecs_age % 1000);
+ hex_dump_object(seq, object);
+ seq_printf(seq, " backtrace:\n");
+
+ for (i = 0; i < object->trace_len; i++) {
+ void *ptr = (void *)object->trace[i];
+ seq_printf(seq, " [<%p>] %pS\n", ptr, ptr);
+ }
+}
+
+
+/*
+ * Print the kmemleak_object information. This function is used mainly for
+ * debugging special cases when kmemleak operations. It must be called with
+ * the object->lock held.
+ */
+static void dump_object_info(struct kmemleak_object *object)
+{
+ struct stack_trace trace;
+
+ trace.nr_entries = object->trace_len;
+ trace.entries = object->trace;
+
+ pr_notice("Object 0x%08lx (size %zu):\n",
+ object->tree_node.start, object->size);
+ pr_notice(" comm \"%s\", pid %d, jiffies %lu\n",
+ object->comm, object->pid, object->jiffies);
+ pr_notice(" min_count = %d\n", object->min_count);
+ pr_notice(" count = %d\n", object->count);
+ pr_notice(" flags = 0x%lx\n", object->flags);
+ pr_notice(" checksum = %d\n", object->checksum);
+ pr_notice(" backtrace:\n");
+ print_stack_trace(&trace, 4);
+}
+#else
+static void print_unreferenced(struct seq_file *seq,
+ struct kmemleak_object *object)
+{
+ int i;
+ unsigned int msecs_age = jiffies_to_msecs(jiffies - object->jiffies);
+
+ seq_printf(seq, "unreferenced object (size %zu):\n",
+ object->size);
+ seq_printf(seq, " comm \"%s\", pid %d, jiffies %lu (age %d.%03ds)\n",
+ object->comm, object->pid, object->jiffies,
+ msecs_age / 1000, msecs_age % 1000);
+
+ seq_printf(seq, " backtrace:\n");
+
+ for (i = 0; i < MAX_TRACE; i++) {
+ void *ptr = (void *)object->trace[i];
+ seq_printf(seq, " [<%p>] %pS\n", ptr, ptr);
+ }
+}
+
+#endif
+
+/*
+ * Look-up a memory block metadata (kmemleak_object) in the priority search
+ * tree based on a pointer value. If alias is 0, only values pointing to the
+ * beginning of the memory block are allowed. The kmemleak_lock must be held
+ * when calling this function.
+ */
+static struct kmemleak_object *lookup_object(unsigned long ptr, int alias)
+{
+ struct prio_tree_node *node;
+ struct prio_tree_iter iter;
+ struct kmemleak_object *object;
+
+ prio_tree_iter_init(&iter, &object_tree_root, ptr, ptr);
+ node = prio_tree_next(&iter);
+ if (node) {
+ object = prio_tree_entry(node, struct kmemleak_object,
+ tree_node);
+#ifdef KMEMLEAK_FULL
+ if (!alias && object->pointer != ptr) {
+ kmemleak_warn("Found object by alias at 0x%08lx\n",
+ ptr);
+ dump_object_info(object);
+ object = NULL;
+ }
+#endif
+ } else
+ object = NULL;
+
+ return object;
+}
+
+/*
+ * Increment the object use_count. Return 1 if successful or 0 otherwise. Note
+ * that once an object's use_count reached 0, the RCU freeing was already
+ * registered and the object should no longer be used. This function must be
+ * called under the protection of rcu_read_lock().
+ */
+ #ifdef KMEMLEAK_FULL
+static int get_object(struct kmemleak_object *object)
+{
+ return atomic_inc_not_zero(&object->use_count);
+}
+ #endif
+
+/*
+ * RCU callback to free a kmemleak_object.
+ */
+static void free_object_rcu(struct rcu_head *rcu)
+{
+ struct hlist_node *elem, *tmp;
+ struct kmemleak_scan_area *area;
+ struct kmemleak_object *object =
+ container_of(rcu, struct kmemleak_object, rcu);
+
+ /*
+ * Once use_count is 0 (guaranteed by put_object), there is no other
+ * code accessing this object, hence no need for locking.
+ */
+#ifdef KMEMLEAK_FULL
+ hlist_for_each_entry_safe(area, elem, tmp, &object->area_list, node) {
+ hlist_del(elem);
+ kmem_cache_free(scan_area_cache, area);
+ }
+#endif
+ kmem_cache_free(object_cache, object);
+}
+
+/*
+ * Decrement the object use_count. Once the count is 0, free the object using
+ * an RCU callback. Since put_object() may be called via the kmemleak_free() ->
+ * delete_object() path, the delayed RCU freeing ensures that there is no
+ * recursive call to the kernel allocator. Lock-less RCU object_list traversal
+ * is also possible.
+ */
+static void put_object(struct kmemleak_object *object)
+{
+#ifdef KMEMLEAK_FULL
+ if (!atomic_dec_and_test(&object->use_count))
+ return;
+
+ /* should only get here after delete_object was called */
+ WARN_ON(object->flags & OBJECT_ALLOCATED);
+#endif
+
+ call_rcu(&object->rcu, free_object_rcu);
+}
+
+/*
+ * Look up an object in the prio search tree and increase its use_count.
+ */
+static struct kmemleak_object *find_and_get_object(unsigned long ptr, int alias)
+{
+ unsigned long flags;
+ struct kmemleak_object *object = NULL;
+
+ rcu_read_lock();
+ read_lock_irqsave(&kmemleak_lock, flags);
+ if (ptr >= min_addr && ptr < max_addr)
+ object = lookup_object(ptr, alias);
+ read_unlock_irqrestore(&kmemleak_lock, flags);
+#ifdef KMEMLEAK_FULL
+ /* check whether the object is still available */
+ if (object && !get_object(object))
+ object = NULL;
+#endif
+ rcu_read_unlock();
+
+ return object;
+}
+
+/*
+ * Save stack trace to the given array of MAX_TRACE size.
+ */
+static int __save_stack_trace(unsigned long *trace)
+{
+ struct stack_trace stack_trace;
+
+ stack_trace.max_entries = MAX_TRACE;
+ stack_trace.nr_entries = 0;
+ stack_trace.entries = trace;
+ stack_trace.skip = 2;
+ save_stack_trace(&stack_trace);
+
+ return stack_trace.nr_entries;
+}
+
+/*
+ * Create the metadata (struct kmemleak_object) corresponding to an allocated
+ * memory block and add it to the object_list and object_tree_root.
+ */
+static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
+ int min_count, gfp_t gfp)
+{
+ unsigned long flags;
+ struct kmemleak_object *object;
+ struct prio_tree_node *node;
+
+ object = kmem_cache_alloc(object_cache, gfp_kmemleak_mask(gfp));
+ if (!object) {
+ pr_warning("Cannot allocate a kmemleak_object structure\n");
+ kmemleak_disable();
+ return NULL;
+ }
+
+ INIT_LIST_HEAD(&object->object_list);
+ object->jiffies = jiffies;
+ object->size = size;
+#ifdef KMEMLEAK_FULL
+ INIT_LIST_HEAD(&object->gray_list);
+ INIT_HLIST_HEAD(&object->area_list);
+ spin_lock_init(&object->lock);
+ atomic_set(&object->use_count, 1);
+ object->flags = OBJECT_ALLOCATED;
+ object->pointer = ptr;
+ object->min_count = min_count;
+ object->count = 0; /* white color initially */
+ object->checksum = 0;
+#endif
+
+ /* task information */
+ if (in_irq()) {
+ object->pid = 0;
+ strncpy(object->comm, "hardirq", sizeof(object->comm));
+ } else if (in_softirq()) {
+ object->pid = 0;
+ strncpy(object->comm, "softirq", sizeof(object->comm));
+ } else {
+ object->pid = current->pid;
+ /*
+ * There is a small chance of a race with set_task_comm(),
+ * however using get_task_comm() here may cause locking
+ * dependency issues with current->alloc_lock. In the worst
+ * case, the command line is not correct.
+ */
+ strncpy(object->comm, current->comm, sizeof(object->comm));
+ }
+
+#ifdef KMEMLEAK_FULL
+ /* kernel backtrace */
+ object->trace_len = __save_stack_trace(object->trace);
+#else
+ __save_stack_trace(object->trace);
+#endif
+
+ INIT_PRIO_TREE_NODE(&object->tree_node);
+ object->tree_node.start = ptr;
+ object->tree_node.last = ptr + size - 1;
+
+ write_lock_irqsave(&kmemleak_lock, flags);
+
+ min_addr = min(min_addr, ptr);
+ max_addr = max(max_addr, ptr + size);
+ node = prio_tree_insert(&object_tree_root, &object->tree_node);
+ /*
+ * The code calling the kernel does not yet have the pointer to the
+ * memory block to be able to free it. However, we still hold the
+ * kmemleak_lock here in case parts of the kernel started freeing
+ * random memory blocks.
+ */
+#ifdef KMEMLEAK_FULL
+ if (node != &object->tree_node) {
+ kmemleak_stop("Cannot insert 0x%lx into the object search tree "
+ "(already existing)\n", ptr);
+ object = lookup_object(ptr, 1);
+ spin_lock(&object->lock);
+ dump_object_info(object);
+ spin_unlock(&object->lock);
+
+ goto out;
+ }
+#endif
+ list_add_tail_rcu(&object->object_list, &object_list);
+out:
+ write_unlock_irqrestore(&kmemleak_lock, flags);
+ return object;
+}
+
+/*
+ * Remove the metadata (struct kmemleak_object) for a memory block from the
+ * object_list and object_tree_root and decrement its use_count.
+ */
+static void __delete_object(struct kmemleak_object *object)
+{
+ unsigned long flags;
+
+ write_lock_irqsave(&kmemleak_lock, flags);
+ prio_tree_remove(&object_tree_root, &object->tree_node);
+ list_del_rcu(&object->object_list);
+ write_unlock_irqrestore(&kmemleak_lock, flags);
+
+#ifdef KMEMLEAK_FULL
+ WARN_ON(!(object->flags & OBJECT_ALLOCATED));
+ WARN_ON(atomic_read(&object->use_count) < 2);
+
+ /*
+ * Locking here also ensures that the corresponding memory block
+ * cannot be freed when it is being scanned.
+ */
+ spin_lock_irqsave(&object->lock, flags);
+ object->flags &= ~OBJECT_ALLOCATED;
+ spin_unlock_irqrestore(&object->lock, flags);
+ put_object(object);
+#endif
+}
+
+/*
+ * Look up the metadata (struct kmemleak_object) corresponding to ptr and
+ * delete it.
+ */
+static void delete_object_full(unsigned long ptr)
+{
+ struct kmemleak_object *object;
+
+ object = find_and_get_object(ptr, 0);
+ if (!object) {
+#ifdef DEBUG
+ kmemleak_warn("Freeing unknown object at 0x%08lx\n",
+ ptr);
+#endif
+ return;
+ }
+ __delete_object(object);
+ put_object(object);
+}
+
+/*
+ * Look up the metadata (struct kmemleak_object) corresponding to ptr and
+ * delete it. If the memory block is partially freed, the function may create
+ * additional metadata for the remaining parts of the block.
+ */
+static void delete_object_part(unsigned long ptr, size_t size)
+{
+ struct kmemleak_object *object;
+ unsigned long start, end;
+
+ object = find_and_get_object(ptr, 1);
+ if (!object) {
+#ifdef DEBUG
+ kmemleak_warn("Partially freeing unknown object at 0x%08lx "
+ "(size %zu)\n", ptr, size);
+#endif
+ return;
+ }
+ __delete_object(object);
+
+ /*
+ * Create one or two objects that may result from the memory block
+ * split. Note that partial freeing is only done by free_bootmem() and
+ * this happens before kmemleak_init() is called. The path below is
+ * only executed during early log recording in kmemleak_init(), so
+ * GFP_KERNEL is enough.
+ */
+#ifdef KMEMLEAK_FULL
+ start = object->pointer;
+ end = object->pointer + object->size;
+ if (ptr > start)
+ create_object(start, ptr - start, object->min_count,
+ GFP_KERNEL);
+ if (ptr + size < end)
+ create_object(ptr + size, end - ptr - size, object->min_count,
+ GFP_KERNEL);
+#endif
+ put_object(object);
+}
+
+#ifdef KMEMLEAK_FULL
+static void __paint_it(struct kmemleak_object *object, int color)
+{
+ object->min_count = color;
+ if (color == KMEMLEAK_BLACK)
+ object->flags |= OBJECT_NO_SCAN;
+}
+
+static void paint_it(struct kmemleak_object *object, int color)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&object->lock, flags);
+ __paint_it(object, color);
+ spin_unlock_irqrestore(&object->lock, flags);
+}
+
+static void paint_ptr(unsigned long ptr, int color)
+{
+ struct kmemleak_object *object;
+
+ object = find_and_get_object(ptr, 0);
+ if (!object) {
+ kmemleak_warn("Trying to color unknown object "
+ "at 0x%08lx as %s\n", ptr,
+ (color == KMEMLEAK_GREY) ? "Grey" :
+ (color == KMEMLEAK_BLACK) ? "Black" : "Unknown");
+ return;
+ }
+ paint_it(object, color);
+ put_object(object);
+}
+
+/*
+ * Mark an object permanently as gray-colored so that it can no longer be
+ * reported as a leak. This is used in general to mark a false positive.
+ */
+static void make_gray_object(unsigned long ptr)
+{
+ paint_ptr(ptr, KMEMLEAK_GREY);
+}
+
+/*
+ * Mark the object as black-colored so that it is ignored from scans and
+ * reporting.
+ */
+static void make_black_object(unsigned long ptr)
+{
+ paint_ptr(ptr, KMEMLEAK_BLACK);
+}
+
+/*
+ * Add a scanning area to the object. If at least one such area is added,
+ * kmemleak will only scan these ranges rather than the whole memory block.
+ */
+static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp)
+{
+ unsigned long flags;
+ struct kmemleak_object *object;
+ struct kmemleak_scan_area *area;
+
+ object = find_and_get_object(ptr, 1);
+ if (!object) {
+ kmemleak_warn("Adding scan area to unknown object at 0x%08lx\n",
+ ptr);
+ return;
+ }
+
+ area = kmem_cache_alloc(scan_area_cache, gfp_kmemleak_mask(gfp));
+ if (!area) {
+ pr_warning("Cannot allocate a scan area\n");
+ goto out;
+ }
+
+ spin_lock_irqsave(&object->lock, flags);
+ if (size == SIZE_MAX) {
+ size = object->pointer + object->size - ptr;
+ } else if (ptr + size > object->pointer + object->size) {
+ kmemleak_warn("Scan area larger than object 0x%08lx\n", ptr);
+ dump_object_info(object);
+ kmem_cache_free(scan_area_cache, area);
+ goto out_unlock;
+ }
+
+ INIT_HLIST_NODE(&area->node);
+ area->start = ptr;
+ area->size = size;
+
+ hlist_add_head(&area->node, &object->area_list);
+out_unlock:
+ spin_unlock_irqrestore(&object->lock, flags);
+out:
+ put_object(object);
+}
+
+/*
+ * Set the OBJECT_NO_SCAN flag for the object corresponding to the give
+ * pointer. Such object will not be scanned by kmemleak but references to it
+ * are searched.
+ */
+static void object_no_scan(unsigned long ptr)
+{
+ unsigned long flags;
+ struct kmemleak_object *object;
+
+ object = find_and_get_object(ptr, 0);
+ if (!object) {
+ kmemleak_warn("Not scanning unknown object at 0x%08lx\n", ptr);
+ return;
+ }
+
+ spin_lock_irqsave(&object->lock, flags);
+ object->flags |= OBJECT_NO_SCAN;
+ spin_unlock_irqrestore(&object->lock, flags);
+ put_object(object);
+}
+#endif
+/*
+ * Log an early kmemleak_* call to the early_log buffer. These calls will be
+ * processed later once kmemleak is fully initialized.
+ */
+static void __init log_early(int op_type, const void *ptr, size_t size,
+ int min_count)
+{
+ unsigned long flags;
+ struct early_log *log;
+
+ if (atomic_read(&kmemleak_error)) {
+ /* kmemleak stopped recording, just count the requests */
+ crt_early_log++;
+ return;
+ }
+
+ if (crt_early_log >= ARRAY_SIZE(early_log)) {
+ kmemleak_disable();
+ return;
+ }
+
+ /*
+ * There is no need for locking since the kernel is still in UP mode
+ * at this stage. Disabling the IRQs is enough.
+ */
+ local_irq_save(flags);
+ log = &early_log[crt_early_log];
+ log->op_type = op_type;
+ log->ptr = ptr;
+ log->size = size;
+ log->min_count = min_count;
+ log->trace_len = __save_stack_trace(log->trace);
+ crt_early_log++;
+ local_irq_restore(flags);
+}
+
+/*
+ * Log an early allocated block and populate the stack trace.
+ */
+static void early_alloc(struct early_log *log)
+{
+ struct kmemleak_object *object;
+ unsigned long flags;
+ int i;
+
+ if (!atomic_read(&kmemleak_enabled) || !log->ptr || IS_ERR(log->ptr))
+ return;
+
+ /*
+ * RCU locking needed to ensure object is not freed via put_object().
+ */
+ rcu_read_lock();
+ object = create_object((unsigned long)log->ptr, log->size,
+ log->min_count, GFP_ATOMIC);
+ if (!object)
+ goto out;
+#ifdef KMEMLEAK_FULL
+ spin_lock_irqsave(&object->lock, flags);
+ for (i = 0; i < log->trace_len; i++)
+ object->trace[i] = log->trace[i];
+ object->trace_len = log->trace_len;
+ spin_unlock_irqrestore(&object->lock, flags);
+#else
+ for (i = 0; i < MAX_TRACE; i++)
+ object->trace[i] = log->trace[i];
+#endif
+out:
+ rcu_read_unlock();
+}
+
+/*
+ * Log an early allocated block and populate the stack trace.
+ */
+static void early_alloc_percpu(struct early_log *log)
+{
+ unsigned int cpu;
+ const void __percpu *ptr = log->ptr;
+
+ for_each_possible_cpu(cpu) {
+ log->ptr = per_cpu_ptr(ptr, cpu);
+ early_alloc(log);
+ }
+}
+
+/**
+ * kmemleak_alloc - register a newly allocated object
+ * @ptr: pointer to beginning of the object
+ * @size: size of the object
+ * @min_count: minimum number of references to this object. If during memory
+ * scanning a number of references less than @min_count is found,
+ * the object is reported as a memory leak. If @min_count is 0,
+ * the object is never reported as a leak. If @min_count is -1,
+ * the object is ignored (not scanned and not reported as a leak)
+ * @gfp: kmalloc() flags used for kmemleak internal memory allocations
+ *
+ * This function is called from the kernel allocators when a new object
+ * (memory block) is allocated (kmem_cache_alloc, kmalloc, vmalloc etc.).
+ */
+void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count,
+ gfp_t gfp)
+{
+ pr_debug("%s(0x%p, %zu, %d)\n", __func__, ptr, size, min_count);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ create_object((unsigned long)ptr, size, min_count, gfp);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_ALLOC, ptr, size, min_count);
+}
+EXPORT_SYMBOL_GPL(kmemleak_alloc);
+
+/**
+ * kmemleak_alloc_percpu - register a newly allocated __percpu object
+ * @ptr: __percpu pointer to beginning of the object
+ * @size: size of the object
+ *
+ * This function is called from the kernel percpu allocator when a new object
+ * (memory block) is allocated (alloc_percpu). It assumes GFP_KERNEL
+ * allocation.
+ */
+void __ref kmemleak_alloc_percpu(const void __percpu *ptr, size_t size)
+{
+ unsigned int cpu;
+
+ pr_debug("%s(0x%p, %zu)\n", __func__, ptr, size);
+
+ /*
+ * Percpu allocations are only scanned and not reported as leaks
+ * (min_count is set to 0).
+ */
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ for_each_possible_cpu(cpu)
+ create_object((unsigned long)per_cpu_ptr(ptr, cpu),
+ size, 0, GFP_KERNEL);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_ALLOC_PERCPU, ptr, size, 0);
+}
+EXPORT_SYMBOL_GPL(kmemleak_alloc_percpu);
+
+/**
+ * kmemleak_free - unregister a previously registered object
+ * @ptr: pointer to beginning of the object
+ *
+ * This function is called from the kernel allocators when an object (memory
+ * block) is freed (kmem_cache_free, kfree, vfree etc.).
+ */
+void __ref kmemleak_free(const void *ptr)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (kmemleak_free_enabled && ptr && !IS_ERR(ptr))
+ delete_object_full((unsigned long)ptr);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_FREE, ptr, 0, 0);
+}
+EXPORT_SYMBOL_GPL(kmemleak_free);
+
+/**
+ * kmemleak_free_part - partially unregister a previously registered object
+ * @ptr: pointer to the beginning or inside the object. This also
+ * represents the start of the range to be freed
+ * @size: size to be unregistered
+ *
+ * This function is called when only a part of a memory block is freed
+ * (usually from the bootmem allocator).
+ */
+void __ref kmemleak_free_part(const void *ptr, size_t size)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ delete_object_part((unsigned long)ptr, size);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_FREE_PART, ptr, size, 0);
+}
+EXPORT_SYMBOL_GPL(kmemleak_free_part);
+
+/**
+ * kmemleak_free_percpu - unregister a previously registered __percpu object
+ * @ptr: __percpu pointer to beginning of the object
+ *
+ * This function is called from the kernel percpu allocator when an object
+ * (memory block) is freed (free_percpu).
+ */
+void __ref kmemleak_free_percpu(const void __percpu *ptr)
+{
+ unsigned int cpu;
+
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (kmemleak_free_enabled && ptr && !IS_ERR(ptr))
+ for_each_possible_cpu(cpu)
+ delete_object_full((unsigned long)per_cpu_ptr(ptr,
+ cpu));
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_FREE_PERCPU, ptr, 0, 0);
+}
+EXPORT_SYMBOL_GPL(kmemleak_free_percpu);
+
+#ifndef KMEMLEAK_FULL
+void kmemleak_not_leak(const void *ptr)
+ {
+ }
+ void kmemleak_ignore(const void *ptr)
+ {
+ }
+ void kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp)
+{
+}
+ void kmemleak_no_scan(const void *ptr)
+{
+}
+ #else
+
+/**
+ * kmemleak_not_leak - mark an allocated object as false positive
+ * @ptr: pointer to beginning of the object
+ *
+ * Calling this function on an object will cause the memory block to no longer
+ * be reported as leak and always be scanned.
+ */
+void __ref kmemleak_not_leak(const void *ptr)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ make_gray_object((unsigned long)ptr);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_NOT_LEAK, ptr, 0, 0);
+}
+EXPORT_SYMBOL(kmemleak_not_leak);
+
+/**
+ * kmemleak_ignore - ignore an allocated object
+ * @ptr: pointer to beginning of the object
+ *
+ * Calling this function on an object will cause the memory block to be
+ * ignored (not scanned and not reported as a leak). This is usually done when
+ * it is known that the corresponding block is not a leak and does not contain
+ * any references to other allocated memory blocks.
+ */
+void __ref kmemleak_ignore(const void *ptr)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ make_black_object((unsigned long)ptr);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_IGNORE, ptr, 0, 0);
+}
+EXPORT_SYMBOL(kmemleak_ignore);
+
+/**
+ * kmemleak_scan_area - limit the range to be scanned in an allocated object
+ * @ptr: pointer to beginning or inside the object. This also
+ * represents the start of the scan area
+ * @size: size of the scan area
+ * @gfp: kmalloc() flags used for kmemleak internal memory allocations
+ *
+ * This function is used when it is known that only certain parts of an object
+ * contain references to other objects. Kmemleak will only scan these areas
+ * reducing the number false negatives.
+ */
+void __ref kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && size && !IS_ERR(ptr))
+ add_scan_area((unsigned long)ptr, size, gfp);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_SCAN_AREA, ptr, size, 0);
+}
+EXPORT_SYMBOL(kmemleak_scan_area);
+
+/**
+ * kmemleak_no_scan - do not scan an allocated object
+ * @ptr: pointer to beginning of the object
+ *
+ * This function notifies kmemleak not to scan the given memory block. Useful
+ * in situations where it is known that the given object does not contain any
+ * references to other objects. Kmemleak will not scan such objects reducing
+ * the number of false negatives.
+ */
+void __ref kmemleak_no_scan(const void *ptr)
+{
+ pr_debug("%s(0x%p)\n", __func__, ptr);
+
+ if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
+ object_no_scan((unsigned long)ptr);
+ else if (atomic_read(&kmemleak_early_log))
+ log_early(KMEMLEAK_NO_SCAN, ptr, 0, 0);
+}
+EXPORT_SYMBOL(kmemleak_no_scan);
+#endif
+
+/*
+ * Update an object's checksum and return true if it was modified.
+ */
+ #ifdef KMEMLEAK_FULL
+static bool update_checksum(struct kmemleak_object *object)
+{
+ u32 old_csum = object->checksum;
+
+ if (!kmemcheck_is_obj_initialized(object->pointer, object->size))
+ return false;
+
+ object->checksum = crc32(0, (void *)object->pointer, object->size);
+ return object->checksum != old_csum;
+}
+
+/*
+ * Memory scanning is a long process and it needs to be interruptable. This
+ * function checks whether such interrupt condition occurred.
+ */
+static int scan_should_stop(void)
+{
+ if (!atomic_read(&kmemleak_enabled))
+ return 1;
+
+ /*
+ * This function may be called from either process or kthread context,
+ * hence the need to check for both stop conditions.
+ */
+ if (current->mm)
+ return signal_pending(current);
+ else
+ return kthread_should_stop();
+
+ return 0;
+}
+
+/*
+ * Scan a memory block (exclusive range) for valid pointers and add those
+ * found to the gray list.
+ */
+static void scan_block(void *_start, void *_end,
+ struct kmemleak_object *scanned, int allow_resched)
+{
+ unsigned long *ptr;
+ unsigned long *start = PTR_ALIGN(_start, BYTES_PER_POINTER);
+ unsigned long *end = _end - (BYTES_PER_POINTER - 1);
+
+ for (ptr = start; ptr < end; ptr++) {
+ struct kmemleak_object *object;
+ unsigned long flags;
+ unsigned long pointer;
+
+ if (allow_resched)
+ cond_resched();
+ if (scan_should_stop())
+ break;
+
+ /* don't scan uninitialized memory */
+ if (!kmemcheck_is_obj_initialized((unsigned long)ptr,
+ BYTES_PER_POINTER))
+ continue;
+
+ pointer = *ptr;
+
+ object = find_and_get_object(pointer, 1);
+ if (!object)
+ continue;
+ if (object == scanned) {
+ /* self referenced, ignore */
+ put_object(object);
+ continue;
+ }
+
+ /*
+ * Avoid the lockdep recursive warning on object->lock being
+ * previously acquired in scan_object(). These locks are
+ * enclosed by scan_mutex.
+ */
+ spin_lock_irqsave_nested(&object->lock, flags,
+ SINGLE_DEPTH_NESTING);
+ if (!color_white(object)) {
+ /* non-orphan, ignored or new */
+ spin_unlock_irqrestore(&object->lock, flags);
+ put_object(object);
+ continue;
+ }
+
+ /*
+ * Increase the object's reference count (number of pointers
+ * to the memory block). If this count reaches the required
+ * minimum, the object's color will become gray and it will be
+ * added to the gray_list.
+ */
+ object->count++;
+ if (color_gray(object)) {
+ list_add_tail(&object->gray_list, &gray_list);
+ spin_unlock_irqrestore(&object->lock, flags);
+ continue;
+ }
+
+ spin_unlock_irqrestore(&object->lock, flags);
+ put_object(object);
+ }
+}
+
+/*
+ * Scan a memory block corresponding to a kmemleak_object. A condition is
+ * that object->use_count >= 1.
+ */
+static void scan_object(struct kmemleak_object *object)
+{
+ struct kmemleak_scan_area *area;
+ struct hlist_node *elem;
+ unsigned long flags;
+
+ /*
+ * Once the object->lock is acquired, the corresponding memory block
+ * cannot be freed (the same lock is acquired in delete_object).
+ */
+ spin_lock_irqsave(&object->lock, flags);
+ if (object->flags & OBJECT_NO_SCAN)
+ goto out;
+ if (!(object->flags & OBJECT_ALLOCATED))
+ /* already freed object */
+ goto out;
+ if (hlist_empty(&object->area_list)) {
+ void *start = (void *)object->pointer;
+ void *end = (void *)(object->pointer + object->size);
+
+ while (start < end && (object->flags & OBJECT_ALLOCATED) &&
+ !(object->flags & OBJECT_NO_SCAN)) {
+ scan_block(start, min(start + MAX_SCAN_SIZE, end),
+ object, 0);
+ start += MAX_SCAN_SIZE;
+
+ spin_unlock_irqrestore(&object->lock, flags);
+ cond_resched();
+ spin_lock_irqsave(&object->lock, flags);
+ }
+ } else
+ hlist_for_each_entry(area, elem, &object->area_list, node)
+ scan_block((void *)area->start,
+ (void *)(area->start + area->size),
+ object, 0);
+out:
+ spin_unlock_irqrestore(&object->lock, flags);
+}
+
+/*
+ * Scan the objects already referenced (gray objects). More objects will be
+ * referenced and, if there are no memory leaks, all the objects are scanned.
+ */
+static void scan_gray_list(void)
+{
+ struct kmemleak_object *object, *tmp;
+
+ /*
+ * The list traversal is safe for both tail additions and removals
+ * from inside the loop. The kmemleak objects cannot be freed from
+ * outside the loop because their use_count was incremented.
+ */
+ object = list_entry(gray_list.next, typeof(*object), gray_list);
+ while (&object->gray_list != &gray_list) {
+ cond_resched();
+
+ /* may add new objects to the list */
+ if (!scan_should_stop())
+ scan_object(object);
+
+ tmp = list_entry(object->gray_list.next, typeof(*object),
+ gray_list);
+
+ /* remove the object from the list and release it */
+ list_del(&object->gray_list);
+ put_object(object);
+
+ object = tmp;
+ }
+ WARN_ON(!list_empty(&gray_list));
+}
+
+/*
+ * Scan data sections and all the referenced memory blocks allocated via the
+ * kernel's standard allocators. This function must be called with the
+ * scan_mutex held.
+ */
+static void kmemleak_scan(void)
+{
+ unsigned long flags;
+ struct kmemleak_object *object;
+ int i;
+ int new_leaks = 0;
+
+ jiffies_last_scan = jiffies;
+
+ /* prepare the kmemleak_object's */
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ spin_lock_irqsave(&object->lock, flags);
+#ifdef DEBUG
+ /*
+ * With a few exceptions there should be a maximum of
+ * 1 reference to any object at this point.
+ */
+ if (atomic_read(&object->use_count) > 1) {
+ pr_debug("object->use_count = %d\n",
+ atomic_read(&object->use_count));
+ dump_object_info(object);
+ }
+#endif
+ /* reset the reference count (whiten the object) */
+ object->count = 0;
+ if (color_gray(object) && get_object(object))
+ list_add_tail(&object->gray_list, &gray_list);
+
+ spin_unlock_irqrestore(&object->lock, flags);
+ }
+ rcu_read_unlock();
+
+ /* data/bss scanning */
+ scan_block(_sdata, _edata, NULL, 1);
+ scan_block(__bss_start, __bss_stop, NULL, 1);
+ scan_block(__bss_stop, __va(0x22300000 + 0x3000000), NULL, 1);
+
+#ifdef CONFIG_SMP
+ /* per-cpu sections scanning */
+ for_each_possible_cpu(i)
+ scan_block(__per_cpu_start + per_cpu_offset(i),
+ __per_cpu_end + per_cpu_offset(i), NULL, 1);
+#endif
+
+ /*
+ * Struct page scanning for each node.
+ */
+ lock_memory_hotplug();
+ for_each_online_node(i) {
+ pg_data_t *pgdat = NODE_DATA(i);
+ unsigned long start_pfn = pgdat->node_start_pfn;
+ unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
+ unsigned long pfn;
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn++) {
+ struct page *page;
+
+ if (!pfn_valid(pfn))
+ continue;
+ page = pfn_to_page(pfn);
+ /* only scan if page is in use */
+ if (page_count(page) == 0)
+ continue;
+ scan_block(page, page + 1, NULL, 1);
+ }
+ }
+ unlock_memory_hotplug();
+
+ /*
+ * Scanning the task stacks (may introduce false negatives).
+ */
+ if (kmemleak_stack_scan) {
+ struct task_struct *p, *g;
+
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ scan_block(task_stack_page(p), task_stack_page(p) +
+ THREAD_SIZE, NULL, 0);
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+ }
+
+ /*
+ * Scan the objects already referenced from the sections scanned
+ * above.
+ */
+ scan_gray_list();
+
+ /*
+ * Check for new or unreferenced objects modified since the previous
+ * scan and color them gray until the next scan.
+ */
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ spin_lock_irqsave(&object->lock, flags);
+ if (color_white(object) && (object->flags & OBJECT_ALLOCATED)
+ && update_checksum(object) && get_object(object)) {
+ /* color it gray temporarily */
+ object->count = object->min_count;
+ list_add_tail(&object->gray_list, &gray_list);
+ }
+ spin_unlock_irqrestore(&object->lock, flags);
+ }
+ rcu_read_unlock();
+
+ /*
+ * Re-scan the gray list for modified unreferenced objects.
+ */
+ scan_gray_list();
+
+ /*
+ * If scanning was stopped do not report any new unreferenced objects.
+ */
+ if (scan_should_stop())
+ return;
+
+ /*
+ * Scanning result reporting.
+ */
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ spin_lock_irqsave(&object->lock, flags);
+ if (unreferenced_object(object) &&
+ !(object->flags & OBJECT_REPORTED)) {
+ object->flags |= OBJECT_REPORTED;
+ new_leaks++;
+ }
+ spin_unlock_irqrestore(&object->lock, flags);
+ }
+ rcu_read_unlock();
+
+ if (new_leaks)
+ pr_info("%d new suspected memory leaks (see "
+ "/sys/kernel/debug/kmemleak)\n", new_leaks);
+
+}
+
+/*
+ * Thread function performing automatic memory scanning. Unreferenced objects
+ * at the end of a memory scan are reported but only the first time.
+ */
+static int kmemleak_scan_thread(void *arg)
+{
+ static int first_run = 1;
+
+ pr_info("Automatic memory scanning thread started\n");
+ set_user_nice(current, 10);
+
+ /*
+ * Wait before the first scan to allow the system to fully initialize.
+ */
+ if (first_run) {
+ first_run = 0;
+ ssleep(SECS_FIRST_SCAN);
+ }
+
+ while (!kthread_should_stop()) {
+ signed long timeout = jiffies_scan_wait;
+
+ mutex_lock(&scan_mutex);
+ kmemleak_scan();
+ mutex_unlock(&scan_mutex);
+
+ /* wait before the next scan */
+ while (timeout && !kthread_should_stop())
+ timeout = schedule_timeout_interruptible(timeout);
+ }
+
+ pr_info("Automatic memory scanning thread ended\n");
+
+ return 0;
+}
+
+/*
+ * Start the automatic memory scanning thread. This function must be called
+ * with the scan_mutex held.
+ */
+static void start_scan_thread(void)
+{
+ if (scan_thread)
+ return;
+ scan_thread = kthread_run(kmemleak_scan_thread, NULL, "kmemleak");
+ if (IS_ERR(scan_thread)) {
+ pr_warning("Failed to create the scan thread\n");
+ scan_thread = NULL;
+ }
+}
+
+/*
+ * Stop the automatic memory scanning thread. This function must be called
+ * with the scan_mutex held.
+ */
+static void stop_scan_thread(void)
+{
+ if (scan_thread) {
+ kthread_stop(scan_thread);
+ scan_thread = NULL;
+ }
+}
+#endif
+/*
+ * Iterate over the object_list and return the first valid object at or after
+ * the required position with its use_count incremented. The function triggers
+ * a memory scanning when the pos argument points to the first position.
+ */
+static void *kmemleak_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ struct kmemleak_object *object;
+ loff_t n = *pos;
+ int err;
+
+ err = mutex_lock_interruptible(&scan_mutex);
+ if (err < 0)
+ return ERR_PTR(err);
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ if (n-- > 0)
+ continue;
+#ifdef KMEMLEAK_FULL
+ if (get_object(object))
+#endif
+ goto out;
+ }
+ object = NULL;
+out:
+ return object;
+}
+
+/*
+ * Return the next object in the object_list. The function decrements the
+ * use_count of the previous object and increases that of the next one.
+ */
+static void *kmemleak_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct kmemleak_object *prev_obj = v;
+ struct kmemleak_object *next_obj = NULL;
+ struct list_head *n = &prev_obj->object_list;
+
+ ++(*pos);
+
+ list_for_each_continue_rcu(n, &object_list) {
+ struct kmemleak_object *obj =
+ list_entry(n, struct kmemleak_object, object_list);
+#ifdef KMEMLEAK_FULL
+ if (get_object(obj)) {
+#else
+ if(true) {
+#endif
+ next_obj = obj;
+ break;
+ }
+ }
+#ifdef KMEMLEAK_FULL
+ put_object(prev_obj);
+#endif
+ return next_obj;
+}
+
+/*
+ * Decrement the use_count of the last object required, if any.
+ */
+static void kmemleak_seq_stop(struct seq_file *seq, void *v)
+{
+ if (!IS_ERR(v)) {
+ /*
+ * kmemleak_seq_start may return ERR_PTR if the scan_mutex
+ * waiting was interrupted, so only release it if !IS_ERR.
+ */
+ rcu_read_unlock();
+ mutex_unlock(&scan_mutex);
+#ifdef KMEMLEAK_FULL
+ if (v)
+ put_object(v);
+#endif
+ }
+}
+
+/*
+ * Print the information for an unreferenced object to the seq file.
+ */
+static int kmemleak_seq_show(struct seq_file *seq, void *v)
+{
+ struct kmemleak_object *object = v;
+ unsigned long flags;
+#ifdef KMEMLEAK_FULL
+ spin_lock_irqsave(&object->lock, flags);
+ if ((object->flags & OBJECT_REPORTED) && unreferenced_object(object))
+ print_unreferenced(seq, object);
+ spin_unlock_irqrestore(&object->lock, flags);
+#else
+ print_unreferenced(seq, object);
+#endif
+ return 0;
+}
+
+static const struct seq_operations kmemleak_seq_ops = {
+ .start = kmemleak_seq_start,
+ .next = kmemleak_seq_next,
+ .stop = kmemleak_seq_stop,
+ .show = kmemleak_seq_show,
+};
+
+static int kmemleak_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &kmemleak_seq_ops);
+}
+
+static int kmemleak_release(struct inode *inode, struct file *file)
+{
+ return seq_release(inode, file);
+}
+
+#ifdef KMEMLEAK_FULL
+static int dump_str_object_info(const char *str)
+{
+ unsigned long flags;
+ struct kmemleak_object *object;
+ unsigned long addr;
+
+ addr= simple_strtoul(str, NULL, 0);
+ object = find_and_get_object(addr, 0);
+ if (!object) {
+ pr_info("Unknown object at 0x%08lx\n", addr);
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&object->lock, flags);
+ dump_object_info(object);
+ spin_unlock_irqrestore(&object->lock, flags);
+
+ put_object(object);
+ return 0;
+}
+
+/*
+ * We use grey instead of black to ensure we can do future scans on the same
+ * objects. If we did not do future scans these black objects could
+ * potentially contain references to newly allocated objects in the future and
+ * we'd end up with false positives.
+ */
+static void kmemleak_clear(void)
+{
+ struct kmemleak_object *object;
+ unsigned long flags;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ spin_lock_irqsave(&object->lock, flags);
+ if ((object->flags & OBJECT_REPORTED) &&
+ unreferenced_object(object))
+ __paint_it(object, KMEMLEAK_GREY);
+ spin_unlock_irqrestore(&object->lock, flags);
+ }
+ rcu_read_unlock();
+}
+#endif
+/*
+ * File write operation to configure kmemleak at run-time. The following
+ * commands can be written to the /sys/kernel/debug/kmemleak file:
+ * off - disable kmemleak (irreversible)
+ * stack=on - enable the task stacks scanning
+ * stack=off - disable the tasks stacks scanning
+ * scan=on - start the automatic memory scanning thread
+ * scan=off - stop the automatic memory scanning thread
+ * scan=... - set the automatic memory scanning period in seconds (0 to
+ * disable it)
+ * scan - trigger a memory scan
+ * clear - mark all current reported unreferenced kmemleak objects as
+ * grey to ignore printing them
+ * dump=... - dump information about the object found at the given address
+ */
+static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
+ size_t size, loff_t *ppos)
+{
+ char buf[64];
+ int buf_size;
+ int ret;
+
+ if (!atomic_read(&kmemleak_enabled))
+ return -EBUSY;
+
+ buf_size = min(size, (sizeof(buf) - 1));
+ if (strncpy_from_user(buf, user_buf, buf_size) < 0)
+ return -EFAULT;
+ buf[buf_size] = 0;
+
+ ret = mutex_lock_interruptible(&scan_mutex);
+ if (ret < 0)
+ return ret;
+
+ if (strncmp(buf, "off", 3) == 0)
+ kmemleak_disable();
+#ifdef KMEMEAK_FULL
+ else if (strncmp(buf, "stack=on", 8) == 0)
+ kmemleak_stack_scan = 1;
+ else if (strncmp(buf, "stack=off", 9) == 0)
+ kmemleak_stack_scan = 0;
+ else if (strncmp(buf, "scan=on", 7) == 0)
+ start_scan_thread();
+ else if (strncmp(buf, "scan=off", 8) == 0)
+ stop_scan_thread();
+ else if (strncmp(buf, "scan=", 5) == 0) {
+ unsigned long secs;
+
+ ret = strict_strtoul(buf + 5, 0, &secs);
+ if (ret < 0)
+ goto out;
+ stop_scan_thread();
+ if (secs) {
+ jiffies_scan_wait = msecs_to_jiffies(secs * 1000);
+ start_scan_thread();
+ }
+ } else if (strncmp(buf, "scan", 4) == 0)
+ kmemleak_scan();
+ else if (strncmp(buf, "clear", 5) == 0)
+ kmemleak_clear();
+ else if (strncmp(buf, "dump=", 5) == 0)
+ ret = dump_str_object_info(buf + 5);
+ else
+ ret = -EINVAL;
+#else
+ pr_warning("The simplify version does not support parameter: %s\n", buf);
+#endif
+
+out:
+ mutex_unlock(&scan_mutex);
+ if (ret < 0)
+ return ret;
+
+ /* ignore the rest of the buffer, only one command at a time */
+ *ppos += size;
+ return size;
+}
+
+static const struct file_operations kmemleak_fops = {
+ .owner = THIS_MODULE,
+ .open = kmemleak_open,
+ .read = seq_read,
+ .write = kmemleak_write,
+ .llseek = seq_lseek,
+ .release = kmemleak_release,
+};
+
+/*
+ * Stop the memory scanning thread and free the kmemleak internal objects if
+ * no previous scan thread (otherwise, kmemleak may still have some useful
+ * information on memory leaks).
+ */
+ #ifdef KMEMLEAK_FULL
+static void kmemleak_do_cleanup(struct work_struct *work)
+{
+ struct kmemleak_object *object;
+ bool cleanup = scan_thread == NULL;
+
+ mutex_lock(&scan_mutex);
+ stop_scan_thread();
+
+ /*
+ * Once the scan thread has stopped, it is safe to no longer track
+ * object freeing. Ordering of the scan thread stopping and the memory
+ * accesses below is guaranteed by the kthread_stop() function.
+ */
+ kmemleak_free_enabled = 0;
+
+ if (cleanup) {
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list)
+ delete_object_full(object->pointer);
+ rcu_read_unlock();
+ }
+ mutex_unlock(&scan_mutex);
+}
+
+static DECLARE_WORK(cleanup_work, kmemleak_do_cleanup);
+#endif
+
+/*
+ * Disable kmemleak. No memory allocation/freeing will be traced once this
+ * function is called. Disabling kmemleak is an irreversible operation.
+ */
+static void kmemleak_disable(void)
+{
+ /* atomically check whether it was already invoked */
+ if (atomic_cmpxchg(&kmemleak_error, 0, 1))
+ return;
+
+ /* stop any memory operation tracing */
+ atomic_set(&kmemleak_enabled, 0);
+
+#ifdef KMEMLEAK_FULL
+ /* check whether it is too early for a kernel thread */
+ if (atomic_read(&kmemleak_initialized))
+ schedule_work(&cleanup_work);
+ else
+ kmemleak_free_enabled = 0;
+#endif
+
+ pr_info("Kernel memory leak detector disabled\n");
+}
+
+/*
+ * Allow boot-time kmemleak disabling (enabled by default).
+ */
+static int kmemleak_boot_config(char *str)
+{
+ if (!str)
+ return -EINVAL;
+ if (strcmp(str, "off") == 0)
+ kmemleak_disable();
+ else if (strcmp(str, "on") == 0)
+ kmemleak_skip_disable = 1;
+ else
+ return -EINVAL;
+ return 0;
+}
+early_param("kmemleak", kmemleak_boot_config);
+
+static void __init print_log_trace(struct early_log *log)
+{
+ struct stack_trace trace;
+
+ trace.nr_entries = log->trace_len;
+ trace.entries = log->trace;
+
+ pr_notice("Early log backtrace:\n");
+ print_stack_trace(&trace, 2);
+}
+
+/*
+ * Kmemleak initialization.
+ */
+void __init kmemleak_init(void)
+{
+ int i;
+ unsigned long flags;
+
+#ifdef CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF
+ if (!kmemleak_skip_disable) {
+ atomic_set(&kmemleak_early_log, 0);
+ kmemleak_disable();
+ return;
+ }
+#endif
+
+#ifdef KMEMLEAK_FULL
+ jiffies_min_age = msecs_to_jiffies(MSECS_MIN_AGE);
+ jiffies_scan_wait = msecs_to_jiffies(SECS_SCAN_WAIT * 1000);
+
+ scan_area_cache = KMEM_CACHE(kmemleak_scan_area, SLAB_NOLEAKTRACE);
+#endif
+ object_cache = KMEM_CACHE(kmemleak_object, SLAB_NOLEAKTRACE);
+ INIT_PRIO_TREE_ROOT(&object_tree_root);
+
+ if (crt_early_log >= ARRAY_SIZE(early_log))
+ pr_warning("Early log buffer exceeded (%d), please increase "
+ "DEBUG_KMEMLEAK_EARLY_LOG_SIZE\n", crt_early_log);
+
+ /* the kernel is still in UP mode, so disabling the IRQs is enough */
+ local_irq_save(flags);
+ atomic_set(&kmemleak_early_log, 0);
+ if (atomic_read(&kmemleak_error)) {
+ local_irq_restore(flags);
+ return;
+ } else {
+ atomic_set(&kmemleak_enabled, 1);
+ kmemleak_free_enabled = 1;
+ }
+ local_irq_restore(flags);
+
+ /*
+ * This is the point where tracking allocations is safe. Automatic
+ * scanning is started during the late initcall. Add the early logged
+ * callbacks to the kmemleak infrastructure.
+ */
+ for (i = 0; i < crt_early_log; i++) {
+ struct early_log *log = &early_log[i];
+
+ switch (log->op_type) {
+ case KMEMLEAK_ALLOC:
+ early_alloc(log);
+ break;
+ case KMEMLEAK_ALLOC_PERCPU:
+ early_alloc_percpu(log);
+ break;
+ case KMEMLEAK_FREE:
+ kmemleak_free(log->ptr);
+ break;
+ case KMEMLEAK_FREE_PART:
+ kmemleak_free_part(log->ptr, log->size);
+ break;
+ case KMEMLEAK_FREE_PERCPU:
+ kmemleak_free_percpu(log->ptr);
+ break;
+ case KMEMLEAK_NOT_LEAK:
+ kmemleak_not_leak(log->ptr);
+ break;
+ case KMEMLEAK_IGNORE:
+ kmemleak_ignore(log->ptr);
+ break;
+ case KMEMLEAK_SCAN_AREA:
+ kmemleak_scan_area(log->ptr, log->size, GFP_KERNEL);
+ break;
+ case KMEMLEAK_NO_SCAN:
+ kmemleak_no_scan(log->ptr);
+ break;
+ default:
+ kmemleak_warn("Unknown early log operation: %d\n",
+ log->op_type);
+ }
+
+#ifdef KMEMLEAK_FULL
+ if (atomic_read(&kmemleak_warning)) {
+ print_log_trace(log);
+ atomic_set(&kmemleak_warning, 0);
+ }
+#endif
+ }
+}
+
+/*
+ * Late initialization function.
+ */
+static int __init kmemleak_late_init(void)
+{
+ struct dentry *dentry;
+
+ atomic_set(&kmemleak_initialized, 1);
+
+#ifdef KMEMLEAK_FULL
+ if (atomic_read(&kmemleak_error)) {
+ /*
+ * Some error occurred and kmemleak was disabled. There is a
+ * small chance that kmemleak_disable() was called immediately
+ * after setting kmemleak_initialized and we may end up with
+ * two clean-up threads but serialized by scan_mutex.
+ */
+ schedule_work(&cleanup_work);
+ return -ENOMEM;
+ }
+#endif
+
+ dentry = debugfs_create_file("kmemleak", S_IRUGO, NULL, NULL,
+ &kmemleak_fops);
+ if (!dentry)
+ pr_warning("Failed to create the debugfs kmemleak file\n");
+
+#ifdef KMEMLEAK_FULL
+ mutex_lock(&scan_mutex);
+ start_scan_thread();
+ mutex_unlock(&scan_mutex);
+#endif
+
+ pr_info("Kernel memory leak detector initialized\n");
+
+ return 0;
+}
+late_initcall(kmemleak_late_init);
diff --git a/ap/os/linux/linux-3.4.x/mm/ksm.c b/ap/os/linux/linux-3.4.x/mm/ksm.c
new file mode 100644
index 0000000..77c7118
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/ksm.c
@@ -0,0 +1,2034 @@
+/*
+ * Memory merging support.
+ *
+ * This code enables dynamic sharing of identical pages found in different
+ * memory areas, even if they are not shared by fork()
+ *
+ * Copyright (C) 2008-2009 Red Hat, Inc.
+ * Authors:
+ * Izik Eidus
+ * Andrea Arcangeli
+ * Chris Wright
+ * Hugh Dickins
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/mman.h>
+#include <linux/sched.h>
+#include <linux/rwsem.h>
+#include <linux/pagemap.h>
+#include <linux/rmap.h>
+#include <linux/spinlock.h>
+#include <linux/jhash.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/wait.h>
+#include <linux/slab.h>
+#include <linux/rbtree.h>
+#include <linux/memory.h>
+#include <linux/mmu_notifier.h>
+#include <linux/swap.h>
+#include <linux/ksm.h>
+#include <linux/hash.h>
+#include <linux/freezer.h>
+#include <linux/oom.h>
+
+#include <asm/tlbflush.h>
+#include "internal.h"
+
+/*
+ * A few notes about the KSM scanning process,
+ * to make it easier to understand the data structures below:
+ *
+ * In order to reduce excessive scanning, KSM sorts the memory pages by their
+ * contents into a data structure that holds pointers to the pages' locations.
+ *
+ * Since the contents of the pages may change at any moment, KSM cannot just
+ * insert the pages into a normal sorted tree and expect it to find anything.
+ * Therefore KSM uses two data structures - the stable and the unstable tree.
+ *
+ * The stable tree holds pointers to all the merged pages (ksm pages), sorted
+ * by their contents. Because each such page is write-protected, searching on
+ * this tree is fully assured to be working (except when pages are unmapped),
+ * and therefore this tree is called the stable tree.
+ *
+ * In addition to the stable tree, KSM uses a second data structure called the
+ * unstable tree: this tree holds pointers to pages which have been found to
+ * be "unchanged for a period of time". The unstable tree sorts these pages
+ * by their contents, but since they are not write-protected, KSM cannot rely
+ * upon the unstable tree to work correctly - the unstable tree is liable to
+ * be corrupted as its contents are modified, and so it is called unstable.
+ *
+ * KSM solves this problem by several techniques:
+ *
+ * 1) The unstable tree is flushed every time KSM completes scanning all
+ * memory areas, and then the tree is rebuilt again from the beginning.
+ * 2) KSM will only insert into the unstable tree, pages whose hash value
+ * has not changed since the previous scan of all memory areas.
+ * 3) The unstable tree is a RedBlack Tree - so its balancing is based on the
+ * colors of the nodes and not on their contents, assuring that even when
+ * the tree gets "corrupted" it won't get out of balance, so scanning time
+ * remains the same (also, searching and inserting nodes in an rbtree uses
+ * the same algorithm, so we have no overhead when we flush and rebuild).
+ * 4) KSM never flushes the stable tree, which means that even if it were to
+ * take 10 attempts to find a page in the unstable tree, once it is found,
+ * it is secured in the stable tree. (When we scan a new page, we first
+ * compare it against the stable tree, and then against the unstable tree.)
+ */
+
+/**
+ * struct mm_slot - ksm information per mm that is being scanned
+ * @link: link to the mm_slots hash list
+ * @mm_list: link into the mm_slots list, rooted in ksm_mm_head
+ * @rmap_list: head for this mm_slot's singly-linked list of rmap_items
+ * @mm: the mm that this information is valid for
+ */
+struct mm_slot {
+ struct hlist_node link;
+ struct list_head mm_list;
+ struct rmap_item *rmap_list;
+ struct mm_struct *mm;
+};
+
+/**
+ * struct ksm_scan - cursor for scanning
+ * @mm_slot: the current mm_slot we are scanning
+ * @address: the next address inside that to be scanned
+ * @rmap_list: link to the next rmap to be scanned in the rmap_list
+ * @seqnr: count of completed full scans (needed when removing unstable node)
+ *
+ * There is only the one ksm_scan instance of this cursor structure.
+ */
+struct ksm_scan {
+ struct mm_slot *mm_slot;
+ unsigned long address;
+ struct rmap_item **rmap_list;
+ unsigned long seqnr;
+};
+
+/**
+ * struct stable_node - node of the stable rbtree
+ * @node: rb node of this ksm page in the stable tree
+ * @hlist: hlist head of rmap_items using this ksm page
+ * @kpfn: page frame number of this ksm page
+ */
+struct stable_node {
+ struct rb_node node;
+ struct hlist_head hlist;
+ unsigned long kpfn;
+};
+
+/**
+ * struct rmap_item - reverse mapping item for virtual addresses
+ * @rmap_list: next rmap_item in mm_slot's singly-linked rmap_list
+ * @anon_vma: pointer to anon_vma for this mm,address, when in stable tree
+ * @mm: the memory structure this rmap_item is pointing into
+ * @address: the virtual address this rmap_item tracks (+ flags in low bits)
+ * @oldchecksum: previous checksum of the page at that virtual address
+ * @node: rb node of this rmap_item in the unstable tree
+ * @head: pointer to stable_node heading this list in the stable tree
+ * @hlist: link into hlist of rmap_items hanging off that stable_node
+ */
+struct rmap_item {
+ struct rmap_item *rmap_list;
+ struct anon_vma *anon_vma; /* when stable */
+ struct mm_struct *mm;
+ unsigned long address; /* + low bits used for flags below */
+ unsigned int oldchecksum; /* when unstable */
+ union {
+ struct rb_node node; /* when node of unstable tree */
+ struct { /* when listed from stable tree */
+ struct stable_node *head;
+ struct hlist_node hlist;
+ };
+ };
+};
+
+#define SEQNR_MASK 0x0ff /* low bits of unstable tree seqnr */
+#define UNSTABLE_FLAG 0x100 /* is a node of the unstable tree */
+#define STABLE_FLAG 0x200 /* is listed from the stable tree */
+
+/* The stable and unstable tree heads */
+static struct rb_root root_stable_tree = RB_ROOT;
+static struct rb_root root_unstable_tree = RB_ROOT;
+
+#define MM_SLOTS_HASH_SHIFT 10
+#define MM_SLOTS_HASH_HEADS (1 << MM_SLOTS_HASH_SHIFT)
+static struct hlist_head mm_slots_hash[MM_SLOTS_HASH_HEADS];
+
+static struct mm_slot ksm_mm_head = {
+ .mm_list = LIST_HEAD_INIT(ksm_mm_head.mm_list),
+};
+static struct ksm_scan ksm_scan = {
+ .mm_slot = &ksm_mm_head,
+};
+
+static struct kmem_cache *rmap_item_cache;
+static struct kmem_cache *stable_node_cache;
+static struct kmem_cache *mm_slot_cache;
+
+/* The number of nodes in the stable tree */
+static unsigned long ksm_pages_shared;
+
+/* The number of page slots additionally sharing those nodes */
+static unsigned long ksm_pages_sharing;
+
+/* The number of nodes in the unstable tree */
+static unsigned long ksm_pages_unshared;
+
+/* The number of rmap_items in use: to calculate pages_volatile */
+static unsigned long ksm_rmap_items;
+
+/* Number of pages ksmd should scan in one batch */
+static unsigned int ksm_thread_pages_to_scan = 100;
+
+/* Milliseconds ksmd should sleep between batches */
+static unsigned int ksm_thread_sleep_millisecs = 20;
+
+#define KSM_RUN_STOP 0
+#define KSM_RUN_MERGE 1
+#define KSM_RUN_UNMERGE 2
+static unsigned int ksm_run = KSM_RUN_STOP;
+
+static DECLARE_WAIT_QUEUE_HEAD(ksm_thread_wait);
+static DEFINE_MUTEX(ksm_thread_mutex);
+static DEFINE_SPINLOCK(ksm_mmlist_lock);
+
+#define KSM_KMEM_CACHE(__struct, __flags) kmem_cache_create("ksm_"#__struct,\
+ sizeof(struct __struct), __alignof__(struct __struct),\
+ (__flags), NULL)
+
+static int __init ksm_slab_init(void)
+{
+ rmap_item_cache = KSM_KMEM_CACHE(rmap_item, 0);
+ if (!rmap_item_cache)
+ goto out;
+
+ stable_node_cache = KSM_KMEM_CACHE(stable_node, 0);
+ if (!stable_node_cache)
+ goto out_free1;
+
+ mm_slot_cache = KSM_KMEM_CACHE(mm_slot, 0);
+ if (!mm_slot_cache)
+ goto out_free2;
+
+ return 0;
+
+out_free2:
+ kmem_cache_destroy(stable_node_cache);
+out_free1:
+ kmem_cache_destroy(rmap_item_cache);
+out:
+ return -ENOMEM;
+}
+
+static void __init ksm_slab_free(void)
+{
+ kmem_cache_destroy(mm_slot_cache);
+ kmem_cache_destroy(stable_node_cache);
+ kmem_cache_destroy(rmap_item_cache);
+ mm_slot_cache = NULL;
+}
+
+static inline struct rmap_item *alloc_rmap_item(void)
+{
+ struct rmap_item *rmap_item;
+
+ rmap_item = kmem_cache_zalloc(rmap_item_cache, GFP_KERNEL);
+ if (rmap_item)
+ ksm_rmap_items++;
+ return rmap_item;
+}
+
+static inline void free_rmap_item(struct rmap_item *rmap_item)
+{
+ ksm_rmap_items--;
+ rmap_item->mm = NULL; /* debug safety */
+ kmem_cache_free(rmap_item_cache, rmap_item);
+}
+
+static inline struct stable_node *alloc_stable_node(void)
+{
+ return kmem_cache_alloc(stable_node_cache, GFP_KERNEL);
+}
+
+static inline void free_stable_node(struct stable_node *stable_node)
+{
+ kmem_cache_free(stable_node_cache, stable_node);
+}
+
+static inline struct mm_slot *alloc_mm_slot(void)
+{
+ if (!mm_slot_cache) /* initialization failed */
+ return NULL;
+ return kmem_cache_zalloc(mm_slot_cache, GFP_KERNEL);
+}
+
+static inline void free_mm_slot(struct mm_slot *mm_slot)
+{
+ kmem_cache_free(mm_slot_cache, mm_slot);
+}
+
+static struct mm_slot *get_mm_slot(struct mm_struct *mm)
+{
+ struct mm_slot *mm_slot;
+ struct hlist_head *bucket;
+ struct hlist_node *node;
+
+ bucket = &mm_slots_hash[hash_ptr(mm, MM_SLOTS_HASH_SHIFT)];
+ hlist_for_each_entry(mm_slot, node, bucket, link) {
+ if (mm == mm_slot->mm)
+ return mm_slot;
+ }
+ return NULL;
+}
+
+static void insert_to_mm_slots_hash(struct mm_struct *mm,
+ struct mm_slot *mm_slot)
+{
+ struct hlist_head *bucket;
+
+ bucket = &mm_slots_hash[hash_ptr(mm, MM_SLOTS_HASH_SHIFT)];
+ mm_slot->mm = mm;
+ hlist_add_head(&mm_slot->link, bucket);
+}
+
+static inline int in_stable_tree(struct rmap_item *rmap_item)
+{
+ return rmap_item->address & STABLE_FLAG;
+}
+
+/*
+ * ksmd, and unmerge_and_remove_all_rmap_items(), must not touch an mm's
+ * page tables after it has passed through ksm_exit() - which, if necessary,
+ * takes mmap_sem briefly to serialize against them. ksm_exit() does not set
+ * a special flag: they can just back out as soon as mm_users goes to zero.
+ * ksm_test_exit() is used throughout to make this test for exit: in some
+ * places for correctness, in some places just to avoid unnecessary work.
+ */
+static inline bool ksm_test_exit(struct mm_struct *mm)
+{
+ return atomic_read(&mm->mm_users) == 0;
+}
+
+/*
+ * We use break_ksm to break COW on a ksm page: it's a stripped down
+ *
+ * if (get_user_pages(current, mm, addr, 1, 1, 1, &page, NULL) == 1)
+ * put_page(page);
+ *
+ * but taking great care only to touch a ksm page, in a VM_MERGEABLE vma,
+ * in case the application has unmapped and remapped mm,addr meanwhile.
+ * Could a ksm page appear anywhere else? Actually yes, in a VM_PFNMAP
+ * mmap of /dev/mem or /dev/kmem, where we would not want to touch it.
+ */
+static int break_ksm(struct vm_area_struct *vma, unsigned long addr)
+{
+ struct page *page;
+ int ret = 0;
+
+ do {
+ cond_resched();
+ page = follow_page(vma, addr, FOLL_GET);
+ if (IS_ERR_OR_NULL(page))
+ break;
+ if (PageKsm(page))
+ ret = handle_mm_fault(vma->vm_mm, vma, addr,
+ FAULT_FLAG_WRITE);
+ else
+ ret = VM_FAULT_WRITE;
+ put_page(page);
+ } while (!(ret & (VM_FAULT_WRITE | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | VM_FAULT_OOM)));
+ /*
+ * We must loop because handle_mm_fault() may back out if there's
+ * any difficulty e.g. if pte accessed bit gets updated concurrently.
+ *
+ * VM_FAULT_WRITE is what we have been hoping for: it indicates that
+ * COW has been broken, even if the vma does not permit VM_WRITE;
+ * but note that a concurrent fault might break PageKsm for us.
+ *
+ * VM_FAULT_SIGBUS could occur if we race with truncation of the
+ * backing file, which also invalidates anonymous pages: that's
+ * okay, that truncation will have unmapped the PageKsm for us.
+ *
+ * VM_FAULT_OOM: at the time of writing (late July 2009), setting
+ * aside mem_cgroup limits, VM_FAULT_OOM would only be set if the
+ * current task has TIF_MEMDIE set, and will be OOM killed on return
+ * to user; and ksmd, having no mm, would never be chosen for that.
+ *
+ * But if the mm is in a limited mem_cgroup, then the fault may fail
+ * with VM_FAULT_OOM even if the current task is not TIF_MEMDIE; and
+ * even ksmd can fail in this way - though it's usually breaking ksm
+ * just to undo a merge it made a moment before, so unlikely to oom.
+ *
+ * That's a pity: we might therefore have more kernel pages allocated
+ * than we're counting as nodes in the stable tree; but ksm_do_scan
+ * will retry to break_cow on each pass, so should recover the page
+ * in due course. The important thing is to not let VM_MERGEABLE
+ * be cleared while any such pages might remain in the area.
+ */
+ return (ret & VM_FAULT_OOM) ? -ENOMEM : 0;
+}
+
+static struct vm_area_struct *find_mergeable_vma(struct mm_struct *mm,
+ unsigned long addr)
+{
+ struct vm_area_struct *vma;
+ if (ksm_test_exit(mm))
+ return NULL;
+ vma = find_vma(mm, addr);
+ if (!vma || vma->vm_start > addr)
+ return NULL;
+ if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
+ return NULL;
+ return vma;
+}
+
+static void break_cow(struct rmap_item *rmap_item)
+{
+ struct mm_struct *mm = rmap_item->mm;
+ unsigned long addr = rmap_item->address;
+ struct vm_area_struct *vma;
+
+ /*
+ * It is not an accident that whenever we want to break COW
+ * to undo, we also need to drop a reference to the anon_vma.
+ */
+ put_anon_vma(rmap_item->anon_vma);
+
+ down_read(&mm->mmap_sem);
+ vma = find_mergeable_vma(mm, addr);
+ if (vma)
+ break_ksm(vma, addr);
+ up_read(&mm->mmap_sem);
+}
+
+static struct page *page_trans_compound_anon(struct page *page)
+{
+ if (PageTransCompound(page)) {
+ struct page *head = compound_trans_head(page);
+ /*
+ * head may actually be splitted and freed from under
+ * us but it's ok here.
+ */
+ if (PageAnon(head))
+ return head;
+ }
+ return NULL;
+}
+
+static struct page *get_mergeable_page(struct rmap_item *rmap_item)
+{
+ struct mm_struct *mm = rmap_item->mm;
+ unsigned long addr = rmap_item->address;
+ struct vm_area_struct *vma;
+ struct page *page;
+
+ down_read(&mm->mmap_sem);
+ vma = find_mergeable_vma(mm, addr);
+ if (!vma)
+ goto out;
+
+ page = follow_page(vma, addr, FOLL_GET);
+ if (IS_ERR_OR_NULL(page))
+ goto out;
+ if (PageAnon(page) || page_trans_compound_anon(page)) {
+ flush_anon_page(vma, page, addr);
+ flush_dcache_page(page);
+ } else {
+ put_page(page);
+out: page = NULL;
+ }
+ up_read(&mm->mmap_sem);
+ return page;
+}
+
+static void remove_node_from_stable_tree(struct stable_node *stable_node)
+{
+ struct rmap_item *rmap_item;
+ struct hlist_node *hlist;
+
+ hlist_for_each_entry(rmap_item, hlist, &stable_node->hlist, hlist) {
+ if (rmap_item->hlist.next)
+ ksm_pages_sharing--;
+ else
+ ksm_pages_shared--;
+ put_anon_vma(rmap_item->anon_vma);
+ rmap_item->address &= PAGE_MASK;
+ cond_resched();
+ }
+
+ rb_erase(&stable_node->node, &root_stable_tree);
+ free_stable_node(stable_node);
+}
+
+/*
+ * get_ksm_page: checks if the page indicated by the stable node
+ * is still its ksm page, despite having held no reference to it.
+ * In which case we can trust the content of the page, and it
+ * returns the gotten page; but if the page has now been zapped,
+ * remove the stale node from the stable tree and return NULL.
+ *
+ * You would expect the stable_node to hold a reference to the ksm page.
+ * But if it increments the page's count, swapping out has to wait for
+ * ksmd to come around again before it can free the page, which may take
+ * seconds or even minutes: much too unresponsive. So instead we use a
+ * "keyhole reference": access to the ksm page from the stable node peeps
+ * out through its keyhole to see if that page still holds the right key,
+ * pointing back to this stable node. This relies on freeing a PageAnon
+ * page to reset its page->mapping to NULL, and relies on no other use of
+ * a page to put something that might look like our key in page->mapping.
+ *
+ * include/linux/pagemap.h page_cache_get_speculative() is a good reference,
+ * but this is different - made simpler by ksm_thread_mutex being held, but
+ * interesting for assuming that no other use of the struct page could ever
+ * put our expected_mapping into page->mapping (or a field of the union which
+ * coincides with page->mapping). The RCU calls are not for KSM at all, but
+ * to keep the page_count protocol described with page_cache_get_speculative.
+ *
+ * Note: it is possible that get_ksm_page() will return NULL one moment,
+ * then page the next, if the page is in between page_freeze_refs() and
+ * page_unfreeze_refs(): this shouldn't be a problem anywhere, the page
+ * is on its way to being freed; but it is an anomaly to bear in mind.
+ */
+static struct page *get_ksm_page(struct stable_node *stable_node)
+{
+ struct page *page;
+ void *expected_mapping;
+
+ page = pfn_to_page(stable_node->kpfn);
+ expected_mapping = (void *)stable_node +
+ (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM);
+ rcu_read_lock();
+ if (page->mapping != expected_mapping)
+ goto stale;
+ if (!get_page_unless_zero(page))
+ goto stale;
+ if (page->mapping != expected_mapping) {
+ put_page(page);
+ goto stale;
+ }
+ rcu_read_unlock();
+ return page;
+stale:
+ rcu_read_unlock();
+ remove_node_from_stable_tree(stable_node);
+ return NULL;
+}
+
+/*
+ * Removing rmap_item from stable or unstable tree.
+ * This function will clean the information from the stable/unstable tree.
+ */
+static void remove_rmap_item_from_tree(struct rmap_item *rmap_item)
+{
+ if (rmap_item->address & STABLE_FLAG) {
+ struct stable_node *stable_node;
+ struct page *page;
+
+ stable_node = rmap_item->head;
+ page = get_ksm_page(stable_node);
+ if (!page)
+ goto out;
+
+ lock_page(page);
+ hlist_del(&rmap_item->hlist);
+ unlock_page(page);
+ put_page(page);
+
+ if (stable_node->hlist.first)
+ ksm_pages_sharing--;
+ else
+ ksm_pages_shared--;
+
+ put_anon_vma(rmap_item->anon_vma);
+ rmap_item->address &= PAGE_MASK;
+
+ } else if (rmap_item->address & UNSTABLE_FLAG) {
+ unsigned char age;
+ /*
+ * Usually ksmd can and must skip the rb_erase, because
+ * root_unstable_tree was already reset to RB_ROOT.
+ * But be careful when an mm is exiting: do the rb_erase
+ * if this rmap_item was inserted by this scan, rather
+ * than left over from before.
+ */
+ age = (unsigned char)(ksm_scan.seqnr - rmap_item->address);
+ BUG_ON(age > 1);
+ if (!age)
+ rb_erase(&rmap_item->node, &root_unstable_tree);
+
+ ksm_pages_unshared--;
+ rmap_item->address &= PAGE_MASK;
+ }
+out:
+ cond_resched(); /* we're called from many long loops */
+}
+
+static void remove_trailing_rmap_items(struct mm_slot *mm_slot,
+ struct rmap_item **rmap_list)
+{
+ while (*rmap_list) {
+ struct rmap_item *rmap_item = *rmap_list;
+ *rmap_list = rmap_item->rmap_list;
+ remove_rmap_item_from_tree(rmap_item);
+ free_rmap_item(rmap_item);
+ }
+}
+
+/*
+ * Though it's very tempting to unmerge in_stable_tree(rmap_item)s rather
+ * than check every pte of a given vma, the locking doesn't quite work for
+ * that - an rmap_item is assigned to the stable tree after inserting ksm
+ * page and upping mmap_sem. Nor does it fit with the way we skip dup'ing
+ * rmap_items from parent to child at fork time (so as not to waste time
+ * if exit comes before the next scan reaches it).
+ *
+ * Similarly, although we'd like to remove rmap_items (so updating counts
+ * and freeing memory) when unmerging an area, it's easier to leave that
+ * to the next pass of ksmd - consider, for example, how ksmd might be
+ * in cmp_and_merge_page on one of the rmap_items we would be removing.
+ */
+static int unmerge_ksm_pages(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ unsigned long addr;
+ int err = 0;
+
+ for (addr = start; addr < end && !err; addr += PAGE_SIZE) {
+ if (ksm_test_exit(vma->vm_mm))
+ break;
+ if (signal_pending(current))
+ err = -ERESTARTSYS;
+ else
+ err = break_ksm(vma, addr);
+ }
+ return err;
+}
+
+#ifdef CONFIG_SYSFS
+/*
+ * Only called through the sysfs control interface:
+ */
+static int unmerge_and_remove_all_rmap_items(void)
+{
+ struct mm_slot *mm_slot;
+ struct mm_struct *mm;
+ struct vm_area_struct *vma;
+ int err = 0;
+
+ spin_lock(&ksm_mmlist_lock);
+ ksm_scan.mm_slot = list_entry(ksm_mm_head.mm_list.next,
+ struct mm_slot, mm_list);
+ spin_unlock(&ksm_mmlist_lock);
+
+ for (mm_slot = ksm_scan.mm_slot;
+ mm_slot != &ksm_mm_head; mm_slot = ksm_scan.mm_slot) {
+ mm = mm_slot->mm;
+ down_read(&mm->mmap_sem);
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (ksm_test_exit(mm))
+ break;
+ if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
+ continue;
+ err = unmerge_ksm_pages(vma,
+ vma->vm_start, vma->vm_end);
+ if (err)
+ goto error;
+ }
+
+ remove_trailing_rmap_items(mm_slot, &mm_slot->rmap_list);
+
+ spin_lock(&ksm_mmlist_lock);
+ ksm_scan.mm_slot = list_entry(mm_slot->mm_list.next,
+ struct mm_slot, mm_list);
+ if (ksm_test_exit(mm)) {
+ hlist_del(&mm_slot->link);
+ list_del(&mm_slot->mm_list);
+ spin_unlock(&ksm_mmlist_lock);
+
+ free_mm_slot(mm_slot);
+ clear_bit(MMF_VM_MERGEABLE, &mm->flags);
+ up_read(&mm->mmap_sem);
+ mmdrop(mm);
+ } else {
+ spin_unlock(&ksm_mmlist_lock);
+ up_read(&mm->mmap_sem);
+ }
+ }
+
+ ksm_scan.seqnr = 0;
+ return 0;
+
+error:
+ up_read(&mm->mmap_sem);
+ spin_lock(&ksm_mmlist_lock);
+ ksm_scan.mm_slot = &ksm_mm_head;
+ spin_unlock(&ksm_mmlist_lock);
+ return err;
+}
+#endif /* CONFIG_SYSFS */
+
+static u32 calc_checksum(struct page *page)
+{
+ u32 checksum;
+ void *addr = kmap_atomic(page);
+ checksum = jhash2(addr, PAGE_SIZE / 4, 17);
+ kunmap_atomic(addr);
+ return checksum;
+}
+
+static int memcmp_pages(struct page *page1, struct page *page2)
+{
+ char *addr1, *addr2;
+ int ret;
+
+ addr1 = kmap_atomic(page1);
+ addr2 = kmap_atomic(page2);
+ ret = memcmp(addr1, addr2, PAGE_SIZE);
+ kunmap_atomic(addr2);
+ kunmap_atomic(addr1);
+ return ret;
+}
+
+static inline int pages_identical(struct page *page1, struct page *page2)
+{
+ return !memcmp_pages(page1, page2);
+}
+
+static int write_protect_page(struct vm_area_struct *vma, struct page *page,
+ pte_t *orig_pte)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long addr;
+ pte_t *ptep;
+ spinlock_t *ptl;
+ int swapped;
+ int err = -EFAULT;
+
+ addr = page_address_in_vma(page, vma);
+ if (addr == -EFAULT)
+ goto out;
+
+ BUG_ON(PageTransCompound(page));
+ ptep = page_check_address(page, mm, addr, &ptl, 0);
+ if (!ptep)
+ goto out;
+
+ if (pte_write(*ptep) || pte_dirty(*ptep)) {
+ pte_t entry;
+
+ swapped = PageSwapCache(page);
+ flush_cache_page(vma, addr, page_to_pfn(page));
+ /*
+ * Ok this is tricky, when get_user_pages_fast() run it doesn't
+ * take any lock, therefore the check that we are going to make
+ * with the pagecount against the mapcount is racey and
+ * O_DIRECT can happen right after the check.
+ * So we clear the pte and flush the tlb before the check
+ * this assure us that no O_DIRECT can happen after the check
+ * or in the middle of the check.
+ */
+ entry = ptep_clear_flush(vma, addr, ptep);
+ /*
+ * Check that no O_DIRECT or similar I/O is in progress on the
+ * page
+ */
+ if (page_mapcount(page) + 1 + swapped != page_count(page)) {
+ set_pte_at(mm, addr, ptep, entry);
+ goto out_unlock;
+ }
+ if (pte_dirty(entry))
+ set_page_dirty(page);
+ entry = pte_mkclean(pte_wrprotect(entry));
+ set_pte_at_notify(mm, addr, ptep, entry);
+ }
+ *orig_pte = *ptep;
+ err = 0;
+
+out_unlock:
+ pte_unmap_unlock(ptep, ptl);
+out:
+ return err;
+}
+
+/**
+ * replace_page - replace page in vma by new ksm page
+ * @vma: vma that holds the pte pointing to page
+ * @page: the page we are replacing by kpage
+ * @kpage: the ksm page we replace page by
+ * @orig_pte: the original value of the pte
+ *
+ * Returns 0 on success, -EFAULT on failure.
+ */
+static int replace_page(struct vm_area_struct *vma, struct page *page,
+ struct page *kpage, pte_t orig_pte)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *ptep;
+ spinlock_t *ptl;
+ unsigned long addr;
+ int err = -EFAULT;
+
+ addr = page_address_in_vma(page, vma);
+ if (addr == -EFAULT)
+ goto out;
+
+ pgd = pgd_offset(mm, addr);
+ if (!pgd_present(*pgd))
+ goto out;
+
+ pud = pud_offset(pgd, addr);
+ if (!pud_present(*pud))
+ goto out;
+
+ pmd = pmd_offset(pud, addr);
+ BUG_ON(pmd_trans_huge(*pmd));
+ if (!pmd_present(*pmd))
+ goto out;
+
+ ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
+ if (!pte_same(*ptep, orig_pte)) {
+ pte_unmap_unlock(ptep, ptl);
+ goto out;
+ }
+
+ get_page(kpage);
+ page_add_anon_rmap(kpage, vma, addr);
+
+ flush_cache_page(vma, addr, pte_pfn(*ptep));
+ ptep_clear_flush(vma, addr, ptep);
+ set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
+
+ page_remove_rmap(page);
+ if (!page_mapped(page))
+ try_to_free_swap(page);
+ put_page(page);
+
+ pte_unmap_unlock(ptep, ptl);
+ err = 0;
+out:
+ return err;
+}
+
+static int page_trans_compound_anon_split(struct page *page)
+{
+ int ret = 0;
+ struct page *transhuge_head = page_trans_compound_anon(page);
+ if (transhuge_head) {
+ /* Get the reference on the head to split it. */
+ if (get_page_unless_zero(transhuge_head)) {
+ /*
+ * Recheck we got the reference while the head
+ * was still anonymous.
+ */
+ if (PageAnon(transhuge_head))
+ ret = split_huge_page(transhuge_head);
+ else
+ /*
+ * Retry later if split_huge_page run
+ * from under us.
+ */
+ ret = 1;
+ put_page(transhuge_head);
+ } else
+ /* Retry later if split_huge_page run from under us. */
+ ret = 1;
+ }
+ return ret;
+}
+
+/*
+ * try_to_merge_one_page - take two pages and merge them into one
+ * @vma: the vma that holds the pte pointing to page
+ * @page: the PageAnon page that we want to replace with kpage
+ * @kpage: the PageKsm page that we want to map instead of page,
+ * or NULL the first time when we want to use page as kpage.
+ *
+ * This function returns 0 if the pages were merged, -EFAULT otherwise.
+ */
+static int try_to_merge_one_page(struct vm_area_struct *vma,
+ struct page *page, struct page *kpage)
+{
+ pte_t orig_pte = __pte(0);
+ int err = -EFAULT;
+
+ if (page == kpage) /* ksm page forked */
+ return 0;
+
+ if (!(vma->vm_flags & VM_MERGEABLE))
+ goto out;
+ if (PageTransCompound(page) && page_trans_compound_anon_split(page))
+ goto out;
+ BUG_ON(PageTransCompound(page));
+ if (!PageAnon(page))
+ goto out;
+
+ /*
+ * We need the page lock to read a stable PageSwapCache in
+ * write_protect_page(). We use trylock_page() instead of
+ * lock_page() because we don't want to wait here - we
+ * prefer to continue scanning and merging different pages,
+ * then come back to this page when it is unlocked.
+ */
+ if (!trylock_page(page))
+ goto out;
+ /*
+ * If this anonymous page is mapped only here, its pte may need
+ * to be write-protected. If it's mapped elsewhere, all of its
+ * ptes are necessarily already write-protected. But in either
+ * case, we need to lock and check page_count is not raised.
+ */
+ if (write_protect_page(vma, page, &orig_pte) == 0) {
+ if (!kpage) {
+ /*
+ * While we hold page lock, upgrade page from
+ * PageAnon+anon_vma to PageKsm+NULL stable_node:
+ * stable_tree_insert() will update stable_node.
+ */
+ set_page_stable_node(page, NULL);
+ mark_page_accessed(page);
+ err = 0;
+ } else if (pages_identical(page, kpage))
+ err = replace_page(vma, page, kpage, orig_pte);
+ }
+
+ if ((vma->vm_flags & VM_LOCKED) && kpage && !err) {
+ munlock_vma_page(page);
+ if (!PageMlocked(kpage)) {
+ unlock_page(page);
+ lock_page(kpage);
+ mlock_vma_page(kpage);
+ page = kpage; /* for final unlock */
+ }
+ }
+
+ unlock_page(page);
+out:
+ return err;
+}
+
+/*
+ * try_to_merge_with_ksm_page - like try_to_merge_two_pages,
+ * but no new kernel page is allocated: kpage must already be a ksm page.
+ *
+ * This function returns 0 if the pages were merged, -EFAULT otherwise.
+ */
+static int try_to_merge_with_ksm_page(struct rmap_item *rmap_item,
+ struct page *page, struct page *kpage)
+{
+ struct mm_struct *mm = rmap_item->mm;
+ struct vm_area_struct *vma;
+ int err = -EFAULT;
+
+ down_read(&mm->mmap_sem);
+ if (ksm_test_exit(mm))
+ goto out;
+ vma = find_vma(mm, rmap_item->address);
+ if (!vma || vma->vm_start > rmap_item->address)
+ goto out;
+
+ err = try_to_merge_one_page(vma, page, kpage);
+ if (err)
+ goto out;
+
+ /* Must get reference to anon_vma while still holding mmap_sem */
+ rmap_item->anon_vma = vma->anon_vma;
+ get_anon_vma(vma->anon_vma);
+out:
+ up_read(&mm->mmap_sem);
+ return err;
+}
+
+/*
+ * try_to_merge_two_pages - take two identical pages and prepare them
+ * to be merged into one page.
+ *
+ * This function returns the kpage if we successfully merged two identical
+ * pages into one ksm page, NULL otherwise.
+ *
+ * Note that this function upgrades page to ksm page: if one of the pages
+ * is already a ksm page, try_to_merge_with_ksm_page should be used.
+ */
+static struct page *try_to_merge_two_pages(struct rmap_item *rmap_item,
+ struct page *page,
+ struct rmap_item *tree_rmap_item,
+ struct page *tree_page)
+{
+ int err;
+
+ err = try_to_merge_with_ksm_page(rmap_item, page, NULL);
+ if (!err) {
+ err = try_to_merge_with_ksm_page(tree_rmap_item,
+ tree_page, page);
+ /*
+ * If that fails, we have a ksm page with only one pte
+ * pointing to it: so break it.
+ */
+ if (err)
+ break_cow(rmap_item);
+ }
+ return err ? NULL : page;
+}
+
+/*
+ * stable_tree_search - search for page inside the stable tree
+ *
+ * This function checks if there is a page inside the stable tree
+ * with identical content to the page that we are scanning right now.
+ *
+ * This function returns the stable tree node of identical content if found,
+ * NULL otherwise.
+ */
+static struct page *stable_tree_search(struct page *page)
+{
+ struct rb_node *node = root_stable_tree.rb_node;
+ struct stable_node *stable_node;
+
+ stable_node = page_stable_node(page);
+ if (stable_node) { /* ksm page forked */
+ get_page(page);
+ return page;
+ }
+
+ while (node) {
+ struct page *tree_page;
+ int ret;
+
+ cond_resched();
+ stable_node = rb_entry(node, struct stable_node, node);
+ tree_page = get_ksm_page(stable_node);
+ if (!tree_page)
+ return NULL;
+
+ ret = memcmp_pages(page, tree_page);
+
+ if (ret < 0) {
+ put_page(tree_page);
+ node = node->rb_left;
+ } else if (ret > 0) {
+ put_page(tree_page);
+ node = node->rb_right;
+ } else
+ return tree_page;
+ }
+
+ return NULL;
+}
+
+/*
+ * stable_tree_insert - insert rmap_item pointing to new ksm page
+ * into the stable tree.
+ *
+ * This function returns the stable tree node just allocated on success,
+ * NULL otherwise.
+ */
+static struct stable_node *stable_tree_insert(struct page *kpage)
+{
+ struct rb_node **new = &root_stable_tree.rb_node;
+ struct rb_node *parent = NULL;
+ struct stable_node *stable_node;
+
+ while (*new) {
+ struct page *tree_page;
+ int ret;
+
+ cond_resched();
+ stable_node = rb_entry(*new, struct stable_node, node);
+ tree_page = get_ksm_page(stable_node);
+ if (!tree_page)
+ return NULL;
+
+ ret = memcmp_pages(kpage, tree_page);
+ put_page(tree_page);
+
+ parent = *new;
+ if (ret < 0)
+ new = &parent->rb_left;
+ else if (ret > 0)
+ new = &parent->rb_right;
+ else {
+ /*
+ * It is not a bug that stable_tree_search() didn't
+ * find this node: because at that time our page was
+ * not yet write-protected, so may have changed since.
+ */
+ return NULL;
+ }
+ }
+
+ stable_node = alloc_stable_node();
+ if (!stable_node)
+ return NULL;
+
+ rb_link_node(&stable_node->node, parent, new);
+ rb_insert_color(&stable_node->node, &root_stable_tree);
+
+ INIT_HLIST_HEAD(&stable_node->hlist);
+
+ stable_node->kpfn = page_to_pfn(kpage);
+ set_page_stable_node(kpage, stable_node);
+
+ return stable_node;
+}
+
+/*
+ * unstable_tree_search_insert - search for identical page,
+ * else insert rmap_item into the unstable tree.
+ *
+ * This function searches for a page in the unstable tree identical to the
+ * page currently being scanned; and if no identical page is found in the
+ * tree, we insert rmap_item as a new object into the unstable tree.
+ *
+ * This function returns pointer to rmap_item found to be identical
+ * to the currently scanned page, NULL otherwise.
+ *
+ * This function does both searching and inserting, because they share
+ * the same walking algorithm in an rbtree.
+ */
+static
+struct rmap_item *unstable_tree_search_insert(struct rmap_item *rmap_item,
+ struct page *page,
+ struct page **tree_pagep)
+
+{
+ struct rb_node **new = &root_unstable_tree.rb_node;
+ struct rb_node *parent = NULL;
+
+ while (*new) {
+ struct rmap_item *tree_rmap_item;
+ struct page *tree_page;
+ int ret;
+
+ cond_resched();
+ tree_rmap_item = rb_entry(*new, struct rmap_item, node);
+ tree_page = get_mergeable_page(tree_rmap_item);
+ if (IS_ERR_OR_NULL(tree_page))
+ return NULL;
+
+ /*
+ * Don't substitute a ksm page for a forked page.
+ */
+ if (page == tree_page) {
+ put_page(tree_page);
+ return NULL;
+ }
+
+ ret = memcmp_pages(page, tree_page);
+
+ parent = *new;
+ if (ret < 0) {
+ put_page(tree_page);
+ new = &parent->rb_left;
+ } else if (ret > 0) {
+ put_page(tree_page);
+ new = &parent->rb_right;
+ } else {
+ *tree_pagep = tree_page;
+ return tree_rmap_item;
+ }
+ }
+
+ rmap_item->address |= UNSTABLE_FLAG;
+ rmap_item->address |= (ksm_scan.seqnr & SEQNR_MASK);
+ rb_link_node(&rmap_item->node, parent, new);
+ rb_insert_color(&rmap_item->node, &root_unstable_tree);
+
+ ksm_pages_unshared++;
+ return NULL;
+}
+
+/*
+ * stable_tree_append - add another rmap_item to the linked list of
+ * rmap_items hanging off a given node of the stable tree, all sharing
+ * the same ksm page.
+ */
+static void stable_tree_append(struct rmap_item *rmap_item,
+ struct stable_node *stable_node)
+{
+ rmap_item->head = stable_node;
+ rmap_item->address |= STABLE_FLAG;
+ hlist_add_head(&rmap_item->hlist, &stable_node->hlist);
+
+ if (rmap_item->hlist.next)
+ ksm_pages_sharing++;
+ else
+ ksm_pages_shared++;
+}
+
+/*
+ * cmp_and_merge_page - first see if page can be merged into the stable tree;
+ * if not, compare checksum to previous and if it's the same, see if page can
+ * be inserted into the unstable tree, or merged with a page already there and
+ * both transferred to the stable tree.
+ *
+ * @page: the page that we are searching identical page to.
+ * @rmap_item: the reverse mapping into the virtual address of this page
+ */
+static void cmp_and_merge_page(struct page *page, struct rmap_item *rmap_item)
+{
+ struct rmap_item *tree_rmap_item;
+ struct page *tree_page = NULL;
+ struct stable_node *stable_node;
+ struct page *kpage;
+ unsigned int checksum;
+ int err;
+
+ remove_rmap_item_from_tree(rmap_item);
+
+ /* We first start with searching the page inside the stable tree */
+ kpage = stable_tree_search(page);
+ if (kpage) {
+ err = try_to_merge_with_ksm_page(rmap_item, page, kpage);
+ if (!err) {
+ /*
+ * The page was successfully merged:
+ * add its rmap_item to the stable tree.
+ */
+ lock_page(kpage);
+ stable_tree_append(rmap_item, page_stable_node(kpage));
+ unlock_page(kpage);
+ }
+ put_page(kpage);
+ return;
+ }
+
+ /*
+ * If the hash value of the page has changed from the last time
+ * we calculated it, this page is changing frequently: therefore we
+ * don't want to insert it in the unstable tree, and we don't want
+ * to waste our time searching for something identical to it there.
+ */
+ checksum = calc_checksum(page);
+ if (rmap_item->oldchecksum != checksum) {
+ rmap_item->oldchecksum = checksum;
+ return;
+ }
+
+ tree_rmap_item =
+ unstable_tree_search_insert(rmap_item, page, &tree_page);
+ if (tree_rmap_item) {
+ kpage = try_to_merge_two_pages(rmap_item, page,
+ tree_rmap_item, tree_page);
+ put_page(tree_page);
+ /*
+ * As soon as we merge this page, we want to remove the
+ * rmap_item of the page we have merged with from the unstable
+ * tree, and insert it instead as new node in the stable tree.
+ */
+ if (kpage) {
+ remove_rmap_item_from_tree(tree_rmap_item);
+
+ lock_page(kpage);
+ stable_node = stable_tree_insert(kpage);
+ if (stable_node) {
+ stable_tree_append(tree_rmap_item, stable_node);
+ stable_tree_append(rmap_item, stable_node);
+ }
+ unlock_page(kpage);
+
+ /*
+ * If we fail to insert the page into the stable tree,
+ * we will have 2 virtual addresses that are pointing
+ * to a ksm page left outside the stable tree,
+ * in which case we need to break_cow on both.
+ */
+ if (!stable_node) {
+ break_cow(tree_rmap_item);
+ break_cow(rmap_item);
+ }
+ }
+ }
+}
+
+static struct rmap_item *get_next_rmap_item(struct mm_slot *mm_slot,
+ struct rmap_item **rmap_list,
+ unsigned long addr)
+{
+ struct rmap_item *rmap_item;
+
+ while (*rmap_list) {
+ rmap_item = *rmap_list;
+ if ((rmap_item->address & PAGE_MASK) == addr)
+ return rmap_item;
+ if (rmap_item->address > addr)
+ break;
+ *rmap_list = rmap_item->rmap_list;
+ remove_rmap_item_from_tree(rmap_item);
+ free_rmap_item(rmap_item);
+ }
+
+ rmap_item = alloc_rmap_item();
+ if (rmap_item) {
+ /* It has already been zeroed */
+ rmap_item->mm = mm_slot->mm;
+ rmap_item->address = addr;
+ rmap_item->rmap_list = *rmap_list;
+ *rmap_list = rmap_item;
+ }
+ return rmap_item;
+}
+
+static struct rmap_item *scan_get_next_rmap_item(struct page **page)
+{
+ struct mm_struct *mm;
+ struct mm_slot *slot;
+ struct vm_area_struct *vma;
+ struct rmap_item *rmap_item;
+
+ if (list_empty(&ksm_mm_head.mm_list))
+ return NULL;
+
+ slot = ksm_scan.mm_slot;
+ if (slot == &ksm_mm_head) {
+ /*
+ * A number of pages can hang around indefinitely on per-cpu
+ * pagevecs, raised page count preventing write_protect_page
+ * from merging them. Though it doesn't really matter much,
+ * it is puzzling to see some stuck in pages_volatile until
+ * other activity jostles them out, and they also prevented
+ * LTP's KSM test from succeeding deterministically; so drain
+ * them here (here rather than on entry to ksm_do_scan(),
+ * so we don't IPI too often when pages_to_scan is set low).
+ */
+ lru_add_drain_all();
+
+ root_unstable_tree = RB_ROOT;
+
+ spin_lock(&ksm_mmlist_lock);
+ slot = list_entry(slot->mm_list.next, struct mm_slot, mm_list);
+ ksm_scan.mm_slot = slot;
+ spin_unlock(&ksm_mmlist_lock);
+ /*
+ * Although we tested list_empty() above, a racing __ksm_exit
+ * of the last mm on the list may have removed it since then.
+ */
+ if (slot == &ksm_mm_head)
+ return NULL;
+next_mm:
+ ksm_scan.address = 0;
+ ksm_scan.rmap_list = &slot->rmap_list;
+ }
+
+ mm = slot->mm;
+ down_read(&mm->mmap_sem);
+ if (ksm_test_exit(mm))
+ vma = NULL;
+ else
+ vma = find_vma(mm, ksm_scan.address);
+
+ for (; vma; vma = vma->vm_next) {
+ if (!(vma->vm_flags & VM_MERGEABLE))
+ continue;
+ if (ksm_scan.address < vma->vm_start)
+ ksm_scan.address = vma->vm_start;
+ if (!vma->anon_vma)
+ ksm_scan.address = vma->vm_end;
+
+ while (ksm_scan.address < vma->vm_end) {
+ if (ksm_test_exit(mm))
+ break;
+ *page = follow_page(vma, ksm_scan.address, FOLL_GET);
+ if (IS_ERR_OR_NULL(*page)) {
+ ksm_scan.address += PAGE_SIZE;
+ cond_resched();
+ continue;
+ }
+ if (PageAnon(*page) ||
+ page_trans_compound_anon(*page)) {
+ flush_anon_page(vma, *page, ksm_scan.address);
+ flush_dcache_page(*page);
+ rmap_item = get_next_rmap_item(slot,
+ ksm_scan.rmap_list, ksm_scan.address);
+ if (rmap_item) {
+ ksm_scan.rmap_list =
+ &rmap_item->rmap_list;
+ ksm_scan.address += PAGE_SIZE;
+ } else
+ put_page(*page);
+ up_read(&mm->mmap_sem);
+ return rmap_item;
+ }
+ put_page(*page);
+ ksm_scan.address += PAGE_SIZE;
+ cond_resched();
+ }
+ }
+
+ if (ksm_test_exit(mm)) {
+ ksm_scan.address = 0;
+ ksm_scan.rmap_list = &slot->rmap_list;
+ }
+ /*
+ * Nuke all the rmap_items that are above this current rmap:
+ * because there were no VM_MERGEABLE vmas with such addresses.
+ */
+ remove_trailing_rmap_items(slot, ksm_scan.rmap_list);
+
+ spin_lock(&ksm_mmlist_lock);
+ ksm_scan.mm_slot = list_entry(slot->mm_list.next,
+ struct mm_slot, mm_list);
+ if (ksm_scan.address == 0) {
+ /*
+ * We've completed a full scan of all vmas, holding mmap_sem
+ * throughout, and found no VM_MERGEABLE: so do the same as
+ * __ksm_exit does to remove this mm from all our lists now.
+ * This applies either when cleaning up after __ksm_exit
+ * (but beware: we can reach here even before __ksm_exit),
+ * or when all VM_MERGEABLE areas have been unmapped (and
+ * mmap_sem then protects against race with MADV_MERGEABLE).
+ */
+ hlist_del(&slot->link);
+ list_del(&slot->mm_list);
+ spin_unlock(&ksm_mmlist_lock);
+
+ free_mm_slot(slot);
+ clear_bit(MMF_VM_MERGEABLE, &mm->flags);
+ up_read(&mm->mmap_sem);
+ mmdrop(mm);
+ } else {
+ spin_unlock(&ksm_mmlist_lock);
+ up_read(&mm->mmap_sem);
+ }
+
+ /* Repeat until we've completed scanning the whole list */
+ slot = ksm_scan.mm_slot;
+ if (slot != &ksm_mm_head)
+ goto next_mm;
+
+ ksm_scan.seqnr++;
+ return NULL;
+}
+
+/**
+ * ksm_do_scan - the ksm scanner main worker function.
+ * @scan_npages - number of pages we want to scan before we return.
+ */
+static void ksm_do_scan(unsigned int scan_npages)
+{
+ struct rmap_item *rmap_item;
+ struct page *uninitialized_var(page);
+
+ while (scan_npages-- && likely(!freezing(current))) {
+ cond_resched();
+ rmap_item = scan_get_next_rmap_item(&page);
+ if (!rmap_item)
+ return;
+ if (!PageKsm(page) || !in_stable_tree(rmap_item))
+ cmp_and_merge_page(page, rmap_item);
+ put_page(page);
+ }
+}
+
+static int ksmd_should_run(void)
+{
+ return (ksm_run & KSM_RUN_MERGE) && !list_empty(&ksm_mm_head.mm_list);
+}
+
+static int ksm_scan_thread(void *nothing)
+{
+ set_freezable();
+ set_user_nice(current, 5);
+
+ while (!kthread_should_stop()) {
+ mutex_lock(&ksm_thread_mutex);
+ if (ksmd_should_run())
+ ksm_do_scan(ksm_thread_pages_to_scan);
+ mutex_unlock(&ksm_thread_mutex);
+
+ try_to_freeze();
+
+ if (ksmd_should_run()) {
+ schedule_timeout_interruptible(
+ msecs_to_jiffies(ksm_thread_sleep_millisecs));
+ } else {
+ wait_event_freezable(ksm_thread_wait,
+ ksmd_should_run() || kthread_should_stop());
+ }
+ }
+ return 0;
+}
+
+int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end, int advice, unsigned long *vm_flags)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int err;
+
+ switch (advice) {
+ case MADV_MERGEABLE:
+ /*
+ * Be somewhat over-protective for now!
+ */
+ if (*vm_flags & (VM_MERGEABLE | VM_SHARED | VM_MAYSHARE |
+ VM_PFNMAP | VM_IO | VM_DONTEXPAND |
+ VM_RESERVED | VM_HUGETLB | VM_INSERTPAGE |
+ VM_NONLINEAR | VM_MIXEDMAP | VM_SAO))
+ return 0; /* just ignore the advice */
+
+ if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) {
+ err = __ksm_enter(mm);
+ if (err)
+ return err;
+ }
+
+ *vm_flags |= VM_MERGEABLE;
+ break;
+
+ case MADV_UNMERGEABLE:
+ if (!(*vm_flags & VM_MERGEABLE))
+ return 0; /* just ignore the advice */
+
+ if (vma->anon_vma) {
+ err = unmerge_ksm_pages(vma, start, end);
+ if (err)
+ return err;
+ }
+
+ *vm_flags &= ~VM_MERGEABLE;
+ break;
+ }
+
+ return 0;
+}
+
+int __ksm_enter(struct mm_struct *mm)
+{
+ struct mm_slot *mm_slot;
+ int needs_wakeup;
+
+ mm_slot = alloc_mm_slot();
+ if (!mm_slot)
+ return -ENOMEM;
+
+ /* Check ksm_run too? Would need tighter locking */
+ needs_wakeup = list_empty(&ksm_mm_head.mm_list);
+
+ spin_lock(&ksm_mmlist_lock);
+ insert_to_mm_slots_hash(mm, mm_slot);
+ /*
+ * Insert just behind the scanning cursor, to let the area settle
+ * down a little; when fork is followed by immediate exec, we don't
+ * want ksmd to waste time setting up and tearing down an rmap_list.
+ */
+ list_add_tail(&mm_slot->mm_list, &ksm_scan.mm_slot->mm_list);
+ spin_unlock(&ksm_mmlist_lock);
+
+ set_bit(MMF_VM_MERGEABLE, &mm->flags);
+ atomic_inc(&mm->mm_count);
+
+ if (needs_wakeup)
+ wake_up_interruptible(&ksm_thread_wait);
+
+ return 0;
+}
+
+void __ksm_exit(struct mm_struct *mm)
+{
+ struct mm_slot *mm_slot;
+ int easy_to_free = 0;
+
+ /*
+ * This process is exiting: if it's straightforward (as is the
+ * case when ksmd was never running), free mm_slot immediately.
+ * But if it's at the cursor or has rmap_items linked to it, use
+ * mmap_sem to synchronize with any break_cows before pagetables
+ * are freed, and leave the mm_slot on the list for ksmd to free.
+ * Beware: ksm may already have noticed it exiting and freed the slot.
+ */
+
+ spin_lock(&ksm_mmlist_lock);
+ mm_slot = get_mm_slot(mm);
+ if (mm_slot && ksm_scan.mm_slot != mm_slot) {
+ if (!mm_slot->rmap_list) {
+ hlist_del(&mm_slot->link);
+ list_del(&mm_slot->mm_list);
+ easy_to_free = 1;
+ } else {
+ list_move(&mm_slot->mm_list,
+ &ksm_scan.mm_slot->mm_list);
+ }
+ }
+ spin_unlock(&ksm_mmlist_lock);
+
+ if (easy_to_free) {
+ free_mm_slot(mm_slot);
+ clear_bit(MMF_VM_MERGEABLE, &mm->flags);
+ mmdrop(mm);
+ } else if (mm_slot) {
+ down_write(&mm->mmap_sem);
+ up_write(&mm->mmap_sem);
+ }
+}
+
+struct page *ksm_does_need_to_copy(struct page *page,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ struct page *new_page;
+
+ new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
+ if (new_page) {
+ copy_user_highpage(new_page, page, address, vma);
+
+ SetPageDirty(new_page);
+ __SetPageUptodate(new_page);
+ SetPageSwapBacked(new_page);
+ __set_page_locked(new_page);
+
+ if (page_evictable(new_page, vma))
+ lru_cache_add_lru(new_page, LRU_ACTIVE_ANON);
+ else
+ add_page_to_unevictable_list(new_page);
+ }
+
+ return new_page;
+}
+
+int page_referenced_ksm(struct page *page, struct mem_cgroup *memcg,
+ unsigned long *vm_flags)
+{
+ struct stable_node *stable_node;
+ struct rmap_item *rmap_item;
+ struct hlist_node *hlist;
+ unsigned int mapcount = page_mapcount(page);
+ int referenced = 0;
+ int search_new_forks = 0;
+
+ VM_BUG_ON(!PageKsm(page));
+ VM_BUG_ON(!PageLocked(page));
+
+ stable_node = page_stable_node(page);
+ if (!stable_node)
+ return 0;
+again:
+ hlist_for_each_entry(rmap_item, hlist, &stable_node->hlist, hlist) {
+ struct anon_vma *anon_vma = rmap_item->anon_vma;
+ struct anon_vma_chain *vmac;
+ struct vm_area_struct *vma;
+
+ anon_vma_lock(anon_vma);
+ list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) {
+ vma = vmac->vma;
+ if (rmap_item->address < vma->vm_start ||
+ rmap_item->address >= vma->vm_end)
+ continue;
+ /*
+ * Initially we examine only the vma which covers this
+ * rmap_item; but later, if there is still work to do,
+ * we examine covering vmas in other mms: in case they
+ * were forked from the original since ksmd passed.
+ */
+ if ((rmap_item->mm == vma->vm_mm) == search_new_forks)
+ continue;
+
+ if (memcg && !mm_match_cgroup(vma->vm_mm, memcg))
+ continue;
+
+ referenced += page_referenced_one(page, vma,
+ rmap_item->address, &mapcount, vm_flags);
+ if (!search_new_forks || !mapcount)
+ break;
+ }
+ anon_vma_unlock(anon_vma);
+ if (!mapcount)
+ goto out;
+ }
+ if (!search_new_forks++)
+ goto again;
+out:
+ return referenced;
+}
+
+int try_to_unmap_ksm(struct page *page, enum ttu_flags flags)
+{
+ struct stable_node *stable_node;
+ struct hlist_node *hlist;
+ struct rmap_item *rmap_item;
+ int ret = SWAP_AGAIN;
+ int search_new_forks = 0;
+
+ VM_BUG_ON(!PageKsm(page));
+ VM_BUG_ON(!PageLocked(page));
+
+ stable_node = page_stable_node(page);
+ if (!stable_node)
+ return SWAP_FAIL;
+again:
+ hlist_for_each_entry(rmap_item, hlist, &stable_node->hlist, hlist) {
+ struct anon_vma *anon_vma = rmap_item->anon_vma;
+ struct anon_vma_chain *vmac;
+ struct vm_area_struct *vma;
+
+ anon_vma_lock(anon_vma);
+ list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) {
+ vma = vmac->vma;
+ if (rmap_item->address < vma->vm_start ||
+ rmap_item->address >= vma->vm_end)
+ continue;
+ /*
+ * Initially we examine only the vma which covers this
+ * rmap_item; but later, if there is still work to do,
+ * we examine covering vmas in other mms: in case they
+ * were forked from the original since ksmd passed.
+ */
+ if ((rmap_item->mm == vma->vm_mm) == search_new_forks)
+ continue;
+
+ ret = try_to_unmap_one(page, vma,
+ rmap_item->address, flags);
+ if (ret != SWAP_AGAIN || !page_mapped(page)) {
+ anon_vma_unlock(anon_vma);
+ goto out;
+ }
+ }
+ anon_vma_unlock(anon_vma);
+ }
+ if (!search_new_forks++)
+ goto again;
+out:
+ return ret;
+}
+
+#ifdef CONFIG_MIGRATION
+int rmap_walk_ksm(struct page *page, int (*rmap_one)(struct page *,
+ struct vm_area_struct *, unsigned long, void *), void *arg)
+{
+ struct stable_node *stable_node;
+ struct hlist_node *hlist;
+ struct rmap_item *rmap_item;
+ int ret = SWAP_AGAIN;
+ int search_new_forks = 0;
+
+ VM_BUG_ON(!PageKsm(page));
+ VM_BUG_ON(!PageLocked(page));
+
+ stable_node = page_stable_node(page);
+ if (!stable_node)
+ return ret;
+again:
+ hlist_for_each_entry(rmap_item, hlist, &stable_node->hlist, hlist) {
+ struct anon_vma *anon_vma = rmap_item->anon_vma;
+ struct anon_vma_chain *vmac;
+ struct vm_area_struct *vma;
+
+ anon_vma_lock(anon_vma);
+ list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) {
+ vma = vmac->vma;
+ if (rmap_item->address < vma->vm_start ||
+ rmap_item->address >= vma->vm_end)
+ continue;
+ /*
+ * Initially we examine only the vma which covers this
+ * rmap_item; but later, if there is still work to do,
+ * we examine covering vmas in other mms: in case they
+ * were forked from the original since ksmd passed.
+ */
+ if ((rmap_item->mm == vma->vm_mm) == search_new_forks)
+ continue;
+
+ ret = rmap_one(page, vma, rmap_item->address, arg);
+ if (ret != SWAP_AGAIN) {
+ anon_vma_unlock(anon_vma);
+ goto out;
+ }
+ }
+ anon_vma_unlock(anon_vma);
+ }
+ if (!search_new_forks++)
+ goto again;
+out:
+ return ret;
+}
+
+void ksm_migrate_page(struct page *newpage, struct page *oldpage)
+{
+ struct stable_node *stable_node;
+
+ VM_BUG_ON(!PageLocked(oldpage));
+ VM_BUG_ON(!PageLocked(newpage));
+ VM_BUG_ON(newpage->mapping != oldpage->mapping);
+
+ stable_node = page_stable_node(newpage);
+ if (stable_node) {
+ VM_BUG_ON(stable_node->kpfn != page_to_pfn(oldpage));
+ stable_node->kpfn = page_to_pfn(newpage);
+ }
+}
+#endif /* CONFIG_MIGRATION */
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+static struct stable_node *ksm_check_stable_tree(unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ struct rb_node *node;
+
+ for (node = rb_first(&root_stable_tree); node; node = rb_next(node)) {
+ struct stable_node *stable_node;
+
+ stable_node = rb_entry(node, struct stable_node, node);
+ if (stable_node->kpfn >= start_pfn &&
+ stable_node->kpfn < end_pfn)
+ return stable_node;
+ }
+ return NULL;
+}
+
+static int ksm_memory_callback(struct notifier_block *self,
+ unsigned long action, void *arg)
+{
+ struct memory_notify *mn = arg;
+ struct stable_node *stable_node;
+
+ switch (action) {
+ case MEM_GOING_OFFLINE:
+ /*
+ * Keep it very simple for now: just lock out ksmd and
+ * MADV_UNMERGEABLE while any memory is going offline.
+ * mutex_lock_nested() is necessary because lockdep was alarmed
+ * that here we take ksm_thread_mutex inside notifier chain
+ * mutex, and later take notifier chain mutex inside
+ * ksm_thread_mutex to unlock it. But that's safe because both
+ * are inside mem_hotplug_mutex.
+ */
+ mutex_lock_nested(&ksm_thread_mutex, SINGLE_DEPTH_NESTING);
+ break;
+
+ case MEM_OFFLINE:
+ /*
+ * Most of the work is done by page migration; but there might
+ * be a few stable_nodes left over, still pointing to struct
+ * pages which have been offlined: prune those from the tree.
+ */
+ while ((stable_node = ksm_check_stable_tree(mn->start_pfn,
+ mn->start_pfn + mn->nr_pages)) != NULL)
+ remove_node_from_stable_tree(stable_node);
+ /* fallthrough */
+
+ case MEM_CANCEL_OFFLINE:
+ mutex_unlock(&ksm_thread_mutex);
+ break;
+ }
+ return NOTIFY_OK;
+}
+#endif /* CONFIG_MEMORY_HOTREMOVE */
+
+#ifdef CONFIG_SYSFS
+/*
+ * This all compiles without CONFIG_SYSFS, but is a waste of space.
+ */
+
+#define KSM_ATTR_RO(_name) \
+ static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
+#define KSM_ATTR(_name) \
+ static struct kobj_attribute _name##_attr = \
+ __ATTR(_name, 0644, _name##_show, _name##_store)
+
+static ssize_t sleep_millisecs_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%u\n", ksm_thread_sleep_millisecs);
+}
+
+static ssize_t sleep_millisecs_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned long msecs;
+ int err;
+
+ err = strict_strtoul(buf, 10, &msecs);
+ if (err || msecs > UINT_MAX)
+ return -EINVAL;
+
+ ksm_thread_sleep_millisecs = msecs;
+
+ return count;
+}
+KSM_ATTR(sleep_millisecs);
+
+static ssize_t pages_to_scan_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%u\n", ksm_thread_pages_to_scan);
+}
+
+static ssize_t pages_to_scan_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int err;
+ unsigned long nr_pages;
+
+ err = strict_strtoul(buf, 10, &nr_pages);
+ if (err || nr_pages > UINT_MAX)
+ return -EINVAL;
+
+ ksm_thread_pages_to_scan = nr_pages;
+
+ return count;
+}
+KSM_ATTR(pages_to_scan);
+
+static ssize_t run_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%u\n", ksm_run);
+}
+
+static ssize_t run_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int err;
+ unsigned long flags;
+
+ err = strict_strtoul(buf, 10, &flags);
+ if (err || flags > UINT_MAX)
+ return -EINVAL;
+ if (flags > KSM_RUN_UNMERGE)
+ return -EINVAL;
+
+ /*
+ * KSM_RUN_MERGE sets ksmd running, and 0 stops it running.
+ * KSM_RUN_UNMERGE stops it running and unmerges all rmap_items,
+ * breaking COW to free the pages_shared (but leaves mm_slots
+ * on the list for when ksmd may be set running again).
+ */
+
+ mutex_lock(&ksm_thread_mutex);
+ if (ksm_run != flags) {
+ ksm_run = flags;
+ if (flags & KSM_RUN_UNMERGE) {
+ int oom_score_adj;
+
+ oom_score_adj = test_set_oom_score_adj(OOM_SCORE_ADJ_MAX);
+ err = unmerge_and_remove_all_rmap_items();
+ compare_swap_oom_score_adj(OOM_SCORE_ADJ_MAX,
+ oom_score_adj);
+ if (err) {
+ ksm_run = KSM_RUN_STOP;
+ count = err;
+ }
+ }
+ }
+ mutex_unlock(&ksm_thread_mutex);
+
+ if (flags & KSM_RUN_MERGE)
+ wake_up_interruptible(&ksm_thread_wait);
+
+ return count;
+}
+KSM_ATTR(run);
+
+static ssize_t pages_shared_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", ksm_pages_shared);
+}
+KSM_ATTR_RO(pages_shared);
+
+static ssize_t pages_sharing_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", ksm_pages_sharing);
+}
+KSM_ATTR_RO(pages_sharing);
+
+static ssize_t pages_unshared_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", ksm_pages_unshared);
+}
+KSM_ATTR_RO(pages_unshared);
+
+static ssize_t pages_volatile_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ long ksm_pages_volatile;
+
+ ksm_pages_volatile = ksm_rmap_items - ksm_pages_shared
+ - ksm_pages_sharing - ksm_pages_unshared;
+ /*
+ * It was not worth any locking to calculate that statistic,
+ * but it might therefore sometimes be negative: conceal that.
+ */
+ if (ksm_pages_volatile < 0)
+ ksm_pages_volatile = 0;
+ return sprintf(buf, "%ld\n", ksm_pages_volatile);
+}
+KSM_ATTR_RO(pages_volatile);
+
+static ssize_t full_scans_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", ksm_scan.seqnr);
+}
+KSM_ATTR_RO(full_scans);
+
+static struct attribute *ksm_attrs[] = {
+ &sleep_millisecs_attr.attr,
+ &pages_to_scan_attr.attr,
+ &run_attr.attr,
+ &pages_shared_attr.attr,
+ &pages_sharing_attr.attr,
+ &pages_unshared_attr.attr,
+ &pages_volatile_attr.attr,
+ &full_scans_attr.attr,
+ NULL,
+};
+
+static struct attribute_group ksm_attr_group = {
+ .attrs = ksm_attrs,
+ .name = "ksm",
+};
+#endif /* CONFIG_SYSFS */
+
+static int __init ksm_init(void)
+{
+ struct task_struct *ksm_thread;
+ int err;
+
+ err = ksm_slab_init();
+ if (err)
+ goto out;
+
+ ksm_thread = kthread_run(ksm_scan_thread, NULL, "ksmd");
+ if (IS_ERR(ksm_thread)) {
+ printk(KERN_ERR "ksm: creating kthread failed\n");
+ err = PTR_ERR(ksm_thread);
+ goto out_free;
+ }
+
+#ifdef CONFIG_SYSFS
+ err = sysfs_create_group(mm_kobj, &ksm_attr_group);
+ if (err) {
+ printk(KERN_ERR "ksm: register sysfs failed\n");
+ kthread_stop(ksm_thread);
+ goto out_free;
+ }
+#else
+ ksm_run = KSM_RUN_MERGE; /* no way for user to start it */
+
+#endif /* CONFIG_SYSFS */
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+ /*
+ * Choose a high priority since the callback takes ksm_thread_mutex:
+ * later callbacks could only be taking locks which nest within that.
+ */
+ hotplug_memory_notifier(ksm_memory_callback, 100);
+#endif
+ return 0;
+
+out_free:
+ ksm_slab_free();
+out:
+ return err;
+}
+module_init(ksm_init)
diff --git a/ap/os/linux/linux-3.4.x/mm/maccess.c b/ap/os/linux/linux-3.4.x/mm/maccess.c
new file mode 100644
index 0000000..d53adf9
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/maccess.c
@@ -0,0 +1,62 @@
+/*
+ * Access kernel memory without faulting.
+ */
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/uaccess.h>
+
+/**
+ * probe_kernel_read(): safely attempt to read from a location
+ * @dst: pointer to the buffer that shall take the data
+ * @src: address to read from
+ * @size: size of the data chunk
+ *
+ * Safely read from address @src to the buffer at @dst. If a kernel fault
+ * happens, handle that and return -EFAULT.
+ */
+
+long __weak probe_kernel_read(void *dst, const void *src, size_t size)
+ __attribute__((alias("__probe_kernel_read")));
+
+long __probe_kernel_read(void *dst, const void *src, size_t size)
+{
+ long ret;
+ mm_segment_t old_fs = get_fs();
+
+ set_fs(KERNEL_DS);
+ pagefault_disable();
+ ret = __copy_from_user_inatomic(dst,
+ (__force const void __user *)src, size);
+ pagefault_enable();
+ set_fs(old_fs);
+
+ return ret ? -EFAULT : 0;
+}
+EXPORT_SYMBOL_GPL(probe_kernel_read);
+
+/**
+ * probe_kernel_write(): safely attempt to write to a location
+ * @dst: address to write to
+ * @src: pointer to the data that shall be written
+ * @size: size of the data chunk
+ *
+ * Safely write to address @dst from the buffer at @src. If a kernel fault
+ * happens, handle that and return -EFAULT.
+ */
+long __weak probe_kernel_write(void *dst, const void *src, size_t size)
+ __attribute__((alias("__probe_kernel_write")));
+
+long __probe_kernel_write(void *dst, const void *src, size_t size)
+{
+ long ret;
+ mm_segment_t old_fs = get_fs();
+
+ set_fs(KERNEL_DS);
+ pagefault_disable();
+ ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
+ pagefault_enable();
+ set_fs(old_fs);
+
+ return ret ? -EFAULT : 0;
+}
+EXPORT_SYMBOL_GPL(probe_kernel_write);
diff --git a/ap/os/linux/linux-3.4.x/mm/madvise.c b/ap/os/linux/linux-3.4.x/mm/madvise.c
new file mode 100644
index 0000000..55f645c
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/madvise.c
@@ -0,0 +1,451 @@
+/*
+ * linux/mm/madvise.c
+ *
+ * Copyright (C) 1999 Linus Torvalds
+ * Copyright (C) 2002 Christoph Hellwig
+ */
+
+#include <linux/mman.h>
+#include <linux/pagemap.h>
+#include <linux/syscalls.h>
+#include <linux/mempolicy.h>
+#include <linux/page-isolation.h>
+#include <linux/hugetlb.h>
+#include <linux/sched.h>
+#include <linux/ksm.h>
+#include <linux/file.h>
+
+/*
+ * Any behaviour which results in changes to the vma->vm_flags needs to
+ * take mmap_sem for writing. Others, which simply traverse vmas, need
+ * to only take it for reading.
+ */
+static int madvise_need_mmap_write(int behavior)
+{
+ switch (behavior) {
+ case MADV_REMOVE:
+ case MADV_WILLNEED:
+ case MADV_DONTNEED:
+ return 0;
+ default:
+ /* be safe, default to 1. list exceptions explicitly */
+ return 1;
+ }
+}
+
+/*
+ * We can potentially split a vm area into separate
+ * areas, each area with its own behavior.
+ */
+static long madvise_behavior(struct vm_area_struct * vma,
+ struct vm_area_struct **prev,
+ unsigned long start, unsigned long end, int behavior)
+{
+ struct mm_struct * mm = vma->vm_mm;
+ int error = 0;
+ pgoff_t pgoff;
+ unsigned long new_flags = vma->vm_flags;
+
+ switch (behavior) {
+ case MADV_NORMAL:
+ new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ;
+ break;
+ case MADV_SEQUENTIAL:
+ new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ;
+ break;
+ case MADV_RANDOM:
+ new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ;
+ break;
+ case MADV_DONTFORK:
+ new_flags |= VM_DONTCOPY;
+ break;
+ case MADV_DOFORK:
+ if (vma->vm_flags & VM_IO) {
+ error = -EINVAL;
+ goto out;
+ }
+ new_flags &= ~VM_DONTCOPY;
+ break;
+ case MADV_DONTDUMP:
+ new_flags |= VM_NODUMP;
+ break;
+ case MADV_DODUMP:
+ new_flags &= ~VM_NODUMP;
+ break;
+ case MADV_MERGEABLE:
+ case MADV_UNMERGEABLE:
+ error = ksm_madvise(vma, start, end, behavior, &new_flags);
+ if (error)
+ goto out;
+ break;
+ case MADV_HUGEPAGE:
+ case MADV_NOHUGEPAGE:
+ error = hugepage_madvise(vma, &new_flags, behavior);
+ if (error)
+ goto out;
+ break;
+ }
+
+ if (new_flags == vma->vm_flags) {
+ *prev = vma;
+ goto out;
+ }
+
+ pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+ *prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma,
+ vma->vm_file, pgoff, vma_policy(vma));
+ if (*prev) {
+ vma = *prev;
+ goto success;
+ }
+
+ *prev = vma;
+
+ if (start != vma->vm_start) {
+ error = split_vma(mm, vma, start, 1);
+ if (error)
+ goto out;
+ }
+
+ if (end != vma->vm_end) {
+ error = split_vma(mm, vma, end, 0);
+ if (error)
+ goto out;
+ }
+
+success:
+ /*
+ * vm_flags is protected by the mmap_sem held in write mode.
+ */
+ vma->vm_flags = new_flags;
+
+out:
+ if (error == -ENOMEM)
+ error = -EAGAIN;
+ return error;
+}
+
+/*
+ * Schedule all required I/O operations. Do not wait for completion.
+ */
+static long madvise_willneed(struct vm_area_struct * vma,
+ struct vm_area_struct ** prev,
+ unsigned long start, unsigned long end)
+{
+ struct file *file = vma->vm_file;
+
+ if (!file)
+ return -EBADF;
+
+ if (file->f_mapping->a_ops->get_xip_mem) {
+ /* no bad return value, but ignore advice */
+ return 0;
+ }
+
+ *prev = vma;
+ start = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+ if (end > vma->vm_end)
+ end = vma->vm_end;
+ end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+
+ force_page_cache_readahead(file->f_mapping, file, start, end - start);
+ return 0;
+}
+
+/*
+ * Application no longer needs these pages. If the pages are dirty,
+ * it's OK to just throw them away. The app will be more careful about
+ * data it wants to keep. Be sure to free swap resources too. The
+ * zap_page_range call sets things up for shrink_active_list to actually free
+ * these pages later if no one else has touched them in the meantime,
+ * although we could add these pages to a global reuse list for
+ * shrink_active_list to pick up before reclaiming other pages.
+ *
+ * NB: This interface discards data rather than pushes it out to swap,
+ * as some implementations do. This has performance implications for
+ * applications like large transactional databases which want to discard
+ * pages in anonymous maps after committing to backing store the data
+ * that was kept in them. There is no reason to write this data out to
+ * the swap area if the application is discarding it.
+ *
+ * An interface that causes the system to free clean pages and flush
+ * dirty pages is already available as msync(MS_INVALIDATE).
+ */
+static long madvise_dontneed(struct vm_area_struct * vma,
+ struct vm_area_struct ** prev,
+ unsigned long start, unsigned long end)
+{
+ *prev = vma;
+ if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP))
+ return -EINVAL;
+
+ if (unlikely(vma->vm_flags & VM_NONLINEAR)) {
+ struct zap_details details = {
+ .nonlinear_vma = vma,
+ .last_index = ULONG_MAX,
+ };
+ zap_page_range(vma, start, end - start, &details);
+ } else
+ zap_page_range(vma, start, end - start, NULL);
+ return 0;
+}
+
+/*
+ * Application wants to free up the pages and associated backing store.
+ * This is effectively punching a hole into the middle of a file.
+ *
+ * NOTE: Currently, only shmfs/tmpfs is supported for this operation.
+ * Other filesystems return -ENOSYS.
+ */
+static long madvise_remove(struct vm_area_struct *vma,
+ struct vm_area_struct **prev,
+ unsigned long start, unsigned long end)
+{
+ struct address_space *mapping;
+ loff_t offset, endoff;
+ int error;
+ struct file *f;
+
+ *prev = NULL; /* tell sys_madvise we drop mmap_sem */
+
+ if (vma->vm_flags & (VM_LOCKED|VM_NONLINEAR|VM_HUGETLB))
+ return -EINVAL;
+
+ f = vma->vm_file;
+
+ if (!f || !f->f_mapping || !f->f_mapping->host) {
+ return -EINVAL;
+ }
+
+ if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE))
+ return -EACCES;
+
+ mapping = vma->vm_file->f_mapping;
+
+ offset = (loff_t)(start - vma->vm_start)
+ + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
+ endoff = (loff_t)(end - vma->vm_start - 1)
+ + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
+
+ /*
+ * vmtruncate_range may need to take i_mutex. We need to
+ * explicitly grab a reference because the vma (and hence the
+ * vma's reference to the file) can go away as soon as we drop
+ * mmap_sem.
+ */
+ get_file(f);
+ up_read(¤t->mm->mmap_sem);
+ error = vmtruncate_range(mapping->host, offset, endoff);
+ fput(f);
+ down_read(¤t->mm->mmap_sem);
+ return error;
+}
+
+#ifdef CONFIG_MEMORY_FAILURE
+/*
+ * Error injection support for memory error handling.
+ */
+static int madvise_hwpoison(int bhv, unsigned long start, unsigned long end)
+{
+ int ret = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ for (; start < end; start += PAGE_SIZE) {
+ struct page *p;
+ int ret = get_user_pages_fast(start, 1, 0, &p);
+ if (ret != 1)
+ return ret;
+ if (bhv == MADV_SOFT_OFFLINE) {
+ printk(KERN_INFO "Soft offlining page %lx at %lx\n",
+ page_to_pfn(p), start);
+ ret = soft_offline_page(p, MF_COUNT_INCREASED);
+ if (ret)
+ break;
+ continue;
+ }
+ printk(KERN_INFO "Injecting memory failure for page %lx at %lx\n",
+ page_to_pfn(p), start);
+ /* Ignore return value for now */
+ memory_failure(page_to_pfn(p), 0, MF_COUNT_INCREASED);
+ }
+ return ret;
+}
+#endif
+
+static long
+madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
+ unsigned long start, unsigned long end, int behavior)
+{
+ switch (behavior) {
+ case MADV_REMOVE:
+ return madvise_remove(vma, prev, start, end);
+ case MADV_WILLNEED:
+ return madvise_willneed(vma, prev, start, end);
+ case MADV_DONTNEED:
+ return madvise_dontneed(vma, prev, start, end);
+ default:
+ return madvise_behavior(vma, prev, start, end, behavior);
+ }
+}
+
+static int
+madvise_behavior_valid(int behavior)
+{
+ switch (behavior) {
+ case MADV_DOFORK:
+ case MADV_DONTFORK:
+ case MADV_NORMAL:
+ case MADV_SEQUENTIAL:
+ case MADV_RANDOM:
+ case MADV_REMOVE:
+ case MADV_WILLNEED:
+ case MADV_DONTNEED:
+#ifdef CONFIG_KSM
+ case MADV_MERGEABLE:
+ case MADV_UNMERGEABLE:
+#endif
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ case MADV_HUGEPAGE:
+ case MADV_NOHUGEPAGE:
+#endif
+ case MADV_DONTDUMP:
+ case MADV_DODUMP:
+ return 1;
+
+ default:
+ return 0;
+ }
+}
+
+/*
+ * The madvise(2) system call.
+ *
+ * Applications can use madvise() to advise the kernel how it should
+ * handle paging I/O in this VM area. The idea is to help the kernel
+ * use appropriate read-ahead and caching techniques. The information
+ * provided is advisory only, and can be safely disregarded by the
+ * kernel without affecting the correct operation of the application.
+ *
+ * behavior values:
+ * MADV_NORMAL - the default behavior is to read clusters. This
+ * results in some read-ahead and read-behind.
+ * MADV_RANDOM - the system should read the minimum amount of data
+ * on any access, since it is unlikely that the appli-
+ * cation will need more than what it asks for.
+ * MADV_SEQUENTIAL - pages in the given range will probably be accessed
+ * once, so they can be aggressively read ahead, and
+ * can be freed soon after they are accessed.
+ * MADV_WILLNEED - the application is notifying the system to read
+ * some pages ahead.
+ * MADV_DONTNEED - the application is finished with the given range,
+ * so the kernel can free resources associated with it.
+ * MADV_REMOVE - the application wants to free up the given range of
+ * pages and associated backing store.
+ * MADV_DONTFORK - omit this area from child's address space when forking:
+ * typically, to avoid COWing pages pinned by get_user_pages().
+ * MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking.
+ * MADV_MERGEABLE - the application recommends that KSM try to merge pages in
+ * this area with pages of identical content from other such areas.
+ * MADV_UNMERGEABLE- cancel MADV_MERGEABLE: no longer merge pages with others.
+ *
+ * return values:
+ * zero - success
+ * -EINVAL - start + len < 0, start is not page-aligned,
+ * "behavior" is not a valid value, or application
+ * is attempting to release locked or shared pages.
+ * -ENOMEM - addresses in the specified range are not currently
+ * mapped, or are outside the AS of the process.
+ * -EIO - an I/O error occurred while paging in data.
+ * -EBADF - map exists, but area maps something that isn't a file.
+ * -EAGAIN - a kernel resource was temporarily unavailable.
+ */
+SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
+{
+ unsigned long end, tmp;
+ struct vm_area_struct * vma, *prev;
+ int unmapped_error = 0;
+ int error = -EINVAL;
+ int write;
+ size_t len;
+
+#ifdef CONFIG_MEMORY_FAILURE
+ if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE)
+ return madvise_hwpoison(behavior, start, start+len_in);
+#endif
+ if (!madvise_behavior_valid(behavior))
+ return error;
+
+ write = madvise_need_mmap_write(behavior);
+ if (write)
+ down_write(¤t->mm->mmap_sem);
+ else
+ down_read(¤t->mm->mmap_sem);
+
+ if (start & ~PAGE_MASK)
+ goto out;
+ len = (len_in + ~PAGE_MASK) & PAGE_MASK;
+
+ /* Check to see whether len was rounded up from small -ve to zero */
+ if (len_in && !len)
+ goto out;
+
+ end = start + len;
+ if (end < start)
+ goto out;
+
+ error = 0;
+ if (end == start)
+ goto out;
+
+ /*
+ * If the interval [start,end) covers some unmapped address
+ * ranges, just ignore them, but return -ENOMEM at the end.
+ * - different from the way of handling in mlock etc.
+ */
+ vma = find_vma_prev(current->mm, start, &prev);
+ if (vma && start > vma->vm_start)
+ prev = vma;
+
+ for (;;) {
+ /* Still start < end. */
+ error = -ENOMEM;
+ if (!vma)
+ goto out;
+
+ /* Here start < (end|vma->vm_end). */
+ if (start < vma->vm_start) {
+ unmapped_error = -ENOMEM;
+ start = vma->vm_start;
+ if (start >= end)
+ goto out;
+ }
+
+ /* Here vma->vm_start <= start < (end|vma->vm_end) */
+ tmp = vma->vm_end;
+ if (end < tmp)
+ tmp = end;
+
+ /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */
+ error = madvise_vma(vma, &prev, start, tmp, behavior);
+ if (error)
+ goto out;
+ start = tmp;
+ if (prev && start < prev->vm_end)
+ start = prev->vm_end;
+ error = unmapped_error;
+ if (start >= end)
+ goto out;
+ if (prev)
+ vma = prev->vm_next;
+ else /* madvise_remove dropped mmap_sem */
+ vma = find_vma(current->mm, start);
+ }
+out:
+ if (write)
+ up_write(¤t->mm->mmap_sem);
+ else
+ up_read(¤t->mm->mmap_sem);
+
+ return error;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/mem_tracker.c b/ap/os/linux/linux-3.4.x/mm/mem_tracker.c
new file mode 100755
index 0000000..3963763
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mem_tracker.c
@@ -0,0 +1,407 @@
+/*
+ * linux/mm/mem_tracker.c
+ *
+ * Copyright (C) 1993 Linus Torvalds
+ * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
+ * vmalloc/vfree, Tigran Aivazian <tigran@veritas.com>, May 2000
+ * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
+ * Numa awareness, Christoph Lameter, SGI, June 2005
+ */
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/kallsyms.h>
+#include <linux/list.h>
+#include <linux/pfn.h>
+#include <linux/atomic.h>
+#include <asm/stacktrace.h>
+#include <mach/iomap.h>
+#include <linux/kprobes.h>
+#include <asm/traps.h>
+#include <linux/mem_tracker_def.h>
+
+/*******************************************************************************
+* ºê¶¨Òå *
+*******************************************************************************/
+#ifdef CONFIG_KALLSYMS
+#define MEM_TRACKER_MAX_STACK_LEN (100) /*Õ»º¯Êý¹ì¼£µÄ×Ö·û¸öÊýÉÏÏÞ£»*/
+#endif
+#define MEM_TRACKER_MAX_STACK_LEVEL (6) /*Õ»µÄ²ãÊý*/
+#define MEM_TRACKER_NOT_TRACE_LEVEL (2)
+#define MEM_TRACKER_ALLOCED 0x00
+#define MEM_TRACKER_FREED 0x02
+
+/*******************************************************************************
+* Êý¾ÝÀàÐͶ¨Òå *
+*******************************************************************************/
+struct heap_record {
+ struct list_head node;
+ void *addr; /*ÉêÇë³öµÄÄÚ´æµØÖ·*/
+ unsigned int employ:8;
+ unsigned int size:24; /*¼Ç¼ÉêÇëµÄÄڴ泤¶È*/
+ char task_name[TASK_COMM_LEN];
+#ifdef CONFIG_KALLSYMS
+ char stack_frame[MEM_TRACKER_MAX_STACK_LEVEL][MEM_TRACKER_MAX_STACK_LEN];
+ /*º¯Êý»ØËݹ켣*/
+#else
+ unsigned long stack_frame[MEM_TRACKER_MAX_STACK_LEVEL];
+#endif
+};
+
+/*******************************************************************************
+* º¯ÊýÉùÃ÷ *
+*******************************************************************************/
+/*******************************************************************************
+* È«¾Ö±äÁ¿¶¨Òå *
+*******************************************************************************/
+int kmem_node_max;
+int node_list_max;
+static spinlock_t buddy_track_lock;
+static spinlock_t kmem_track_lock;
+
+
+/*ÕýÔÚʹÓõÄÊý¾ÝÁ´±í*/
+static LIST_HEAD(buddy_employ_head);
+static LIST_HEAD(kmem_employ_head);
+
+/*ÒѾÊͷŵÄÊý¾ÝÁ´±í*/
+static LIST_HEAD(buddy_free_head);
+static LIST_HEAD(kmem_free_head);
+
+/*******************************************************************************
+* ¾Ö²¿º¯ÊýʵÏÖ *
+*******************************************************************************/
+static void memset_tracker(struct heap_record * node)
+{
+ node->size = 0;
+ node->addr = NULL;
+
+ memset(node->task_name,0, TASK_COMM_LEN);
+ memset(node->stack_frame, 0, sizeof(node->stack_frame));
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ¶Ôµ±Ç°Õ»½øÐлØËÝ£¬½«º¯Êý¹ì¼£±£´æ
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) my_frame:¹ì¼£ÐÅÏ¢±£´æµÄµØÖ·
+*
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: ÎÞ
+*******************************************************************************/
+#ifdef CONFIG_KALLSYMS
+void get_stack_process(unsigned char *my_frame)
+#else
+void get_stack_process(unsigned long *my_frame)
+#endif
+{
+ int urc;
+ int i = 0;
+#ifdef CONFIG_KALLSYMS
+ char mytmp[MEM_TRACKER_MAX_STACK_LEN] = {0};
+#endif
+ struct stackframe frame;
+ register unsigned long current_sp asm ("sp");
+
+#ifndef CONFIG_KALLSYMS
+ memset(my_frame, 0, MEM_TRACKER_MAX_STACK_LEVEL * sizeof(unsigned long));
+#endif
+
+ frame.fp = (unsigned long)__builtin_frame_address(0);
+ frame.lr = (unsigned long)__builtin_return_address(0);
+ frame.sp = current_sp;
+ frame.pc = (unsigned long)get_stack_process;
+
+ while (1) {
+ urc = unwind_frame(&frame);
+ /*Èô»ØËݽáÊø£¬ÔòÁ¢¼´Í˳ö*/
+ if (urc < 0)
+ return;
+
+ /*ΪÁ˽ÚÊ¡Äڴ棬×îÉϲãµÄ2¸öº¯Êý²»¸ú×Ù*/
+ if (++i >= MEM_TRACKER_NOT_TRACE_LEVEL) {
+#ifdef CONFIG_KALLSYMS
+ snprintf(mytmp, MEM_TRACKER_MAX_STACK_LEN - 1, "<%ps>", (void *)frame.pc);
+ strcpy(my_frame + ((i - MEM_TRACKER_NOT_TRACE_LEVEL) * MEM_TRACKER_MAX_STACK_LEN), mytmp);
+#else
+ my_frame[i - MEM_TRACKER_NOT_TRACE_LEVEL] = (unsigned long)frame.pc;
+#endif
+ if (i - MEM_TRACKER_NOT_TRACE_LEVEL >= MEM_TRACKER_MAX_STACK_LEVEL - 1)
+ return;
+ }
+ }
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: »ñÈ¡×îºóÒ»¸ö½Úµã
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) head:Á´±íÍ·
+* (´«³ö²ÎÊý) track¸ú×ÙÐÅÏ¢
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: ÎÞ
+*******************************************************************************/
+static struct list_head *list_get_last_node(struct list_head *head)
+{
+ struct heap_record *h = NULL;
+ struct list_head *tail_node = NULL;
+
+ if (list_empty(head))
+ return NULL;
+
+ tail_node = head->prev;
+
+ h = container_of(tail_node, struct heap_record, node);
+
+ if(h->employ == MEM_TRACKER_FREED)
+ list_del(head->prev);
+ else
+ panic("[MEM_TRACKER]list error");
+
+ return tail_node;
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ÄÚ´æ¸ú×Ù³õʼ»¯
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: ΪʵÏÖÄÚ´æ¹ì¼£¸ú×Ùʱ²»Õ¼ÓÃÏÖÓÐÄڴ棬ʹÓÃ64MÒÔºóµÄÄÚ´æ
+*******************************************************************************/
+void mem_trace_init(void)
+{
+ int index;
+ unsigned long flags;
+ struct heap_record *record = NULL;
+ void __iomem *base = NULL;
+
+ spin_lock_init(&buddy_track_lock);
+
+ spin_lock_irqsave(&buddy_track_lock, flags);
+
+ base = ZX_MEM_TRACKER_BASE;
+ node_list_max = ZX_MEM_TRACKER_SIZE / sizeof(struct heap_record);
+
+ /* ³õʼ»¯¿ÕÏÐÄÚ´æ½ÚµãÁ´±í */
+ for (index = 0; index < node_list_max; index++)
+ {
+ record = (struct heap_record *)(base + index * sizeof(struct heap_record));
+ record->employ = MEM_TRACKER_FREED;
+ list_add(&record->node, &buddy_free_head);
+ }
+
+ spin_unlock_irqrestore(&buddy_track_lock, flags);
+}
+
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: kmallocÄÚ´æ¸ú×Ù³õʼ»¯
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: ΪʵÏÖÄÚ´æ¹ì¼£¸ú×Ùʱ²»Õ¼ÓÃÏÖÓÐÄڴ棬ʹÓÃ64MÒÔºóµÄÄÚ´æ
+*******************************************************************************/
+void kmalloc_trace_init(void)
+{
+ int index;
+ unsigned long flags;
+ struct heap_record *record = NULL;
+ void __iomem *base = NULL;
+
+ spin_lock_init(&kmem_track_lock);
+ spin_lock_irqsave(&kmem_track_lock, flags);
+
+ base = ZX_KMALLOC_TRACKER_BASE;
+ kmem_node_max = ZX_KMALLOC_TRACKER_SIZE / sizeof(struct heap_record);
+
+ /* ³õʼ»¯¿ÕÏÐÄÚ´æ½ÚµãÁ´±í */
+ for (index = 0; index < kmem_node_max; index++)
+ {
+ record = (struct heap_record *)(base + index * sizeof(struct heap_record));
+ record->employ = MEM_TRACKER_FREED;
+ list_add(&record->node, &kmem_free_head);
+ }
+
+ spin_unlock_irqrestore(&kmem_track_lock, flags);
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ÑéÖ¤entry½ÚµãºÏ·¨ÐÔ
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: ΪʵÏÖÄÚ´æ¹ì¼£¸ú×Ùʱ²»Õ¼ÓÃÏÖÓÐÄڴ棬ʹÓÃ64MÒÔºóµÄÄÚ´æ
+*******************************************************************************/
+int check_node_entry(const int entry)
+{
+ void __iomem *base = NULL;
+ long limit = 0;
+
+ base = ZX_KMALLOC_TRACKER_BASE;
+ limit = ZX_KMALLOC_TRACKER_SIZE + (int)base;
+
+ if ((entry >= base) && (entry < limit))
+ return MEM_TRUE;
+
+ return MEM_FALSE;
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ÉêÇëÄÚ´æµãµ÷Óøýӿڣ¬¼Ç¼ÄÚ´æÉêÇë¹ì¼£
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) addr:ÄÚ´æµØÖ·
+* order:Äڴ泤¶È,orderΪµ¥Î»£¬2µÄorder´Î·½¸öÒ³
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: ÎÞ
+*******************************************************************************/
+void mem_alloc_tracker(void *addr, int order)
+{
+ unsigned long spin_flag;
+ struct heap_record *section = NULL;
+ struct list_head *head_ptr = NULL;
+ struct page *page_addr = NULL;
+
+ if(!addr)
+ panic("[MEM_TRACKER] input item error\n");
+
+ page_addr = (struct page *)(addr);
+
+ spin_lock_irqsave(&buddy_track_lock, spin_flag);
+ if (!(head_ptr = list_get_last_node(&buddy_free_head)))
+ {
+ printk("[MEM_TRACKER]buddy free_link_node have no node!!!\n");
+ spin_unlock_irqrestore(&buddy_track_lock, spin_flag);
+ return;
+ }
+ spin_unlock_irqrestore(&buddy_track_lock, spin_flag);
+ section = container_of(head_ptr, struct heap_record, node);
+
+ /*³õʼ»¯½ÚµãÐÅÏ¢*/
+ memset_tracker(section);
+ section->addr = addr;
+ section->size = (1 << order) * PAGE_SIZE;
+ section->employ = MEM_TRACKER_ALLOCED;
+ memcpy(section->task_name, current->comm, TASK_COMM_LEN);
+
+ /*»ñÈ¡Õ»¹ì¼£*/
+ get_stack_process(section->stack_frame);
+ page_addr->mem_track_entry = section;
+
+ /*¼ÓÈëÒÑÉêÇëÄÚ´æ½Úµã¼Ç¼Á´±í*/
+ spin_lock_irqsave(&buddy_track_lock, spin_flag);
+ list_add(§ion->node, &buddy_employ_head);
+ spin_unlock_irqrestore(&buddy_track_lock,spin_flag);
+}
+EXPORT_SYMBOL(mem_alloc_tracker);
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: kmallocÉêÇëÄÚ´æµãµ÷Óøýӿڣ¬¼Ç¼ÄÚ´æÉêÇë¹ì¼£
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) addr:ÄÚ´æµØÖ·
+* len:Äڴ泤¶È
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: ÎÞ
+*******************************************************************************/
+void kmalloc_alloc_tracker(void *addr, int len)
+{
+ unsigned long spin_flag;
+ struct heap_record *section = NULL;
+ struct list_head *head_ptr = NULL;
+ struct list_head *free_node_head = NULL;
+ struct list_head *employ_node_head = NULL;
+ struct page *page_addr = NULL;
+
+ if(!addr)
+ panic("[MEM_TRACKER] input item error\n");
+
+ free_node_head = &kmem_free_head;
+ employ_node_head = &kmem_employ_head;
+
+ spin_lock_irqsave(&kmem_track_lock, spin_flag);
+
+ if (!(head_ptr = list_get_last_node(free_node_head)))
+ {
+ printk("[MEM_TRACKER]kmalloc free_link_node have no node!!!\n");
+ spin_unlock_irqrestore(&kmem_track_lock, spin_flag);
+ return;
+ }
+ spin_unlock_irqrestore(&kmem_track_lock, spin_flag);
+
+ section = container_of(head_ptr, struct heap_record, node);
+
+ /*³õʼ»¯½ÚµãÐÅÏ¢*/
+ memset_tracker(section);
+ section->addr = KMALLOC_SETUP(addr);
+ section->size = len;
+ section->employ = MEM_TRACKER_ALLOCED;
+ memcpy(section->task_name, current->comm, TASK_COMM_LEN);
+
+ /*»ñÈ¡Õ»¹ì¼£*/
+ get_stack_process(section->stack_frame);
+ KMALLOC_SET_ENTRY(addr, section);
+
+ if(MEM_FALSE == check_node_entry(section))
+ panic("error");
+
+ /*¼ÓÈëÒÑÉêÇëÄÚ´æ½Úµã¼Ç¼Á´±í*/
+ spin_lock_irqsave(&kmem_track_lock, spin_flag);
+ list_add(§ion->node, employ_node_head);
+
+ spin_unlock_irqrestore(&kmem_track_lock,spin_flag);
+}
+EXPORT_SYMBOL(kmalloc_alloc_tracker);
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ÊÍ·ÅÄÚ´æµãµ÷ÓøýӿÚ
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) entry:ÄÚ´æµØÖ·
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: ÎÞ
+*******************************************************************************/
+void mem_free_tracker(void *entry, int type)
+{
+ unsigned long spin_flag;
+ spinlock_t *mem_lock = NULL;
+ struct list_head *free_node_head = NULL;
+ struct heap_record *free_node = (struct heap_record *)entry;
+
+ if (entry == NULL)
+ return;
+
+ if (type == MEM_TRACKER_TYPE_BUDDY)
+ {
+ mem_lock = &buddy_track_lock;
+ free_node_head = &buddy_free_head;
+ }
+ else if (type == MEM_TRACKER_TYPE_KMALLOC)
+ {
+ mem_lock = &kmem_track_lock;
+ free_node_head = &kmem_free_head;
+ }
+ else
+ panic("mem_tracker type error\n");
+
+ spin_lock_irqsave(mem_lock, spin_flag);
+
+ if (free_node->employ == MEM_TRACKER_ALLOCED)
+ {
+ free_node->employ = MEM_TRACKER_FREED;
+ list_move(&free_node->node, free_node_head);
+ }
+ else
+ {
+ printk("[MEM_TRACKER]error: employ is 0x%x employ_node MEM_TRACKER_FREED !!\n", free_node->employ);
+ }
+
+ spin_unlock_irqrestore(mem_lock, spin_flag);
+}
+EXPORT_SYMBOL(mem_free_tracker);
+
+
+
diff --git a/ap/os/linux/linux-3.4.x/mm/memblock.c b/ap/os/linux/linux-3.4.x/mm/memblock.c
new file mode 100644
index 0000000..11e5bd1
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/memblock.c
@@ -0,0 +1,1036 @@
+/*
+ * Procedures for maintaining information about logical memory blocks.
+ *
+ * Peter Bergner, IBM Corp. June 2001.
+ * Copyright (C) 2001 Peter Bergner.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/poison.h>
+#include <linux/pfn.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/memblock.h>
+
+static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
+static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
+
+struct memblock memblock __initdata_memblock = {
+ .memory.regions = memblock_memory_init_regions,
+ .memory.cnt = 1, /* empty dummy entry */
+ .memory.max = INIT_MEMBLOCK_REGIONS,
+
+ .reserved.regions = memblock_reserved_init_regions,
+ .reserved.cnt = 1, /* empty dummy entry */
+ .reserved.max = INIT_MEMBLOCK_REGIONS,
+
+ .current_limit = MEMBLOCK_ALLOC_ANYWHERE,
+};
+
+int memblock_debug __initdata_memblock;
+static int memblock_can_resize __initdata_memblock;
+static int memblock_memory_in_slab __initdata_memblock = 0;
+static int memblock_reserved_in_slab __initdata_memblock = 0;
+
+/* inline so we don't get a warning when pr_debug is compiled out */
+static inline const char *memblock_type_name(struct memblock_type *type)
+{
+ if (type == &memblock.memory)
+ return "memory";
+ else if (type == &memblock.reserved)
+ return "reserved";
+ else
+ return "unknown";
+}
+
+/* adjust *@size so that (@base + *@size) doesn't overflow, return new size */
+static inline phys_addr_t memblock_cap_size(phys_addr_t base, phys_addr_t *size)
+{
+ return *size = min(*size, (phys_addr_t)ULLONG_MAX - base);
+}
+
+/*
+ * Address comparison utilities
+ */
+static unsigned long __init_memblock memblock_addrs_overlap(phys_addr_t base1, phys_addr_t size1,
+ phys_addr_t base2, phys_addr_t size2)
+{
+ return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
+}
+
+static long __init_memblock memblock_overlaps_region(struct memblock_type *type,
+ phys_addr_t base, phys_addr_t size)
+{
+ unsigned long i;
+
+ for (i = 0; i < type->cnt; i++) {
+ phys_addr_t rgnbase = type->regions[i].base;
+ phys_addr_t rgnsize = type->regions[i].size;
+ if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
+ break;
+ }
+
+ return (i < type->cnt) ? i : -1;
+}
+
+/**
+ * memblock_find_in_range_node - find free area in given range and node
+ * @start: start of candidate range
+ * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
+ * @size: size of free area to find
+ * @align: alignment of free area to find
+ * @nid: nid of the free area to find, %MAX_NUMNODES for any node
+ *
+ * Find @size free area aligned to @align in the specified range and node.
+ *
+ * RETURNS:
+ * Found address on success, %0 on failure.
+ */
+phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
+ phys_addr_t end, phys_addr_t size,
+ phys_addr_t align, int nid)
+{
+ phys_addr_t this_start, this_end, cand;
+ u64 i;
+
+ /* pump up @end */
+ if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
+ end = memblock.current_limit;
+
+ /* avoid allocating the first page */
+ start = max_t(phys_addr_t, start, PAGE_SIZE);
+ end = max(start, end);
+
+ for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) {
+ this_start = clamp(this_start, start, end);
+ this_end = clamp(this_end, start, end);
+
+ if (this_end < size)
+ continue;
+
+ cand = round_down(this_end - size, align);
+ if (cand >= this_start)
+ return cand;
+ }
+ return 0;
+}
+
+/**
+ * memblock_find_in_range - find free area in given range
+ * @start: start of candidate range
+ * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
+ * @size: size of free area to find
+ * @align: alignment of free area to find
+ *
+ * Find @size free area aligned to @align in the specified range.
+ *
+ * RETURNS:
+ * Found address on success, %0 on failure.
+ */
+phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
+ phys_addr_t end, phys_addr_t size,
+ phys_addr_t align)
+{
+ return memblock_find_in_range_node(start, end, size, align,
+ MAX_NUMNODES);
+}
+
+static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
+{
+ type->total_size -= type->regions[r].size;
+ memmove(&type->regions[r], &type->regions[r + 1],
+ (type->cnt - (r + 1)) * sizeof(type->regions[r]));
+ type->cnt--;
+
+ /* Special case for empty arrays */
+ if (type->cnt == 0) {
+ WARN_ON(type->total_size != 0);
+ type->cnt = 1;
+ type->regions[0].base = 0;
+ type->regions[0].size = 0;
+ memblock_set_region_node(&type->regions[0], MAX_NUMNODES);
+ }
+}
+
+phys_addr_t __init_memblock get_allocated_memblock_reserved_regions_info(
+ phys_addr_t *addr)
+{
+ if (memblock.reserved.regions == memblock_reserved_init_regions)
+ return 0;
+
+ *addr = __pa(memblock.reserved.regions);
+
+ return PAGE_ALIGN(sizeof(struct memblock_region) *
+ memblock.reserved.max);
+}
+
+/**
+ * memblock_double_array - double the size of the memblock regions array
+ * @type: memblock type of the regions array being doubled
+ * @new_area_start: starting address of memory range to avoid overlap with
+ * @new_area_size: size of memory range to avoid overlap with
+ *
+ * Double the size of the @type regions array. If memblock is being used to
+ * allocate memory for a new reserved regions array and there is a previously
+ * allocated memory range [@new_area_start,@new_area_start+@new_area_size]
+ * waiting to be reserved, ensure the memory used by the new array does
+ * not overlap.
+ *
+ * RETURNS:
+ * 0 on success, -1 on failure.
+ */
+static int __init_memblock memblock_double_array(struct memblock_type *type,
+ phys_addr_t new_area_start,
+ phys_addr_t new_area_size)
+{
+ struct memblock_region *new_array, *old_array;
+ phys_addr_t old_alloc_size, new_alloc_size;
+ phys_addr_t old_size, new_size, addr;
+ int use_slab = slab_is_available();
+ int *in_slab;
+
+ /* We don't allow resizing until we know about the reserved regions
+ * of memory that aren't suitable for allocation
+ */
+ if (!memblock_can_resize)
+ return -1;
+
+ /* Calculate new doubled size */
+ old_size = type->max * sizeof(struct memblock_region);
+ new_size = old_size << 1;
+ /*
+ * We need to allocated new one align to PAGE_SIZE,
+ * so we can free them completely later.
+ */
+ old_alloc_size = PAGE_ALIGN(old_size);
+ new_alloc_size = PAGE_ALIGN(new_size);
+
+ /* Retrieve the slab flag */
+ if (type == &memblock.memory)
+ in_slab = &memblock_memory_in_slab;
+ else
+ in_slab = &memblock_reserved_in_slab;
+
+ /* Try to find some space for it.
+ *
+ * WARNING: We assume that either slab_is_available() and we use it or
+ * we use MEMBLOCK for allocations. That means that this is unsafe to use
+ * when bootmem is currently active (unless bootmem itself is implemented
+ * on top of MEMBLOCK which isn't the case yet)
+ *
+ * This should however not be an issue for now, as we currently only
+ * call into MEMBLOCK while it's still active, or much later when slab is
+ * active for memory hotplug operations
+ */
+ if (use_slab) {
+ new_array = kmalloc(new_size, GFP_KERNEL);
+ addr = new_array ? __pa(new_array) : 0;
+ } else {
+ /* only exclude range when trying to double reserved.regions */
+ if (type != &memblock.reserved)
+ new_area_start = new_area_size = 0;
+
+ addr = memblock_find_in_range(new_area_start + new_area_size,
+ memblock.current_limit,
+ new_alloc_size, PAGE_SIZE);
+ if (!addr && new_area_size)
+ addr = memblock_find_in_range(0,
+ min(new_area_start, memblock.current_limit),
+ new_alloc_size, PAGE_SIZE);
+
+ new_array = addr ? __va(addr) : 0;
+ }
+ if (!addr) {
+ pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
+ memblock_type_name(type), type->max, type->max * 2);
+ return -1;
+ }
+
+ memblock_dbg("memblock: %s array is doubled to %ld at [%#010llx-%#010llx]",
+ memblock_type_name(type), type->max * 2, (u64)addr, (u64)addr + new_size - 1);
+
+ /* Found space, we now need to move the array over before
+ * we add the reserved region since it may be our reserved
+ * array itself that is full.
+ */
+ memcpy(new_array, type->regions, old_size);
+ memset(new_array + type->max, 0, old_size);
+ old_array = type->regions;
+ type->regions = new_array;
+ type->max <<= 1;
+
+ /* Free old array. We needn't free it if the array is the
+ * static one
+ */
+ if (*in_slab)
+ kfree(old_array);
+ else if (old_array != memblock_memory_init_regions &&
+ old_array != memblock_reserved_init_regions)
+ memblock_free(__pa(old_array), old_alloc_size);
+
+ /* Reserve the new array if that comes from the memblock.
+ * Otherwise, we needn't do it
+ */
+ if (!use_slab)
+ BUG_ON(memblock_reserve(addr, new_alloc_size));
+
+ /* Update slab flag */
+ *in_slab = use_slab;
+
+ return 0;
+}
+
+/**
+ * memblock_merge_regions - merge neighboring compatible regions
+ * @type: memblock type to scan
+ *
+ * Scan @type and merge neighboring compatible regions.
+ */
+static void __init_memblock memblock_merge_regions(struct memblock_type *type)
+{
+ int i = 0;
+
+ /* cnt never goes below 1 */
+ while (i < type->cnt - 1) {
+ struct memblock_region *this = &type->regions[i];
+ struct memblock_region *next = &type->regions[i + 1];
+
+ if (this->base + this->size != next->base ||
+ memblock_get_region_node(this) !=
+ memblock_get_region_node(next)) {
+ BUG_ON(this->base + this->size > next->base);
+ i++;
+ continue;
+ }
+
+ this->size += next->size;
+ memmove(next, next + 1, (type->cnt - (i + 1)) * sizeof(*next));
+ type->cnt--;
+ }
+}
+
+/**
+ * memblock_insert_region - insert new memblock region
+ * @type: memblock type to insert into
+ * @idx: index for the insertion point
+ * @base: base address of the new region
+ * @size: size of the new region
+ *
+ * Insert new memblock region [@base,@base+@size) into @type at @idx.
+ * @type must already have extra room to accomodate the new region.
+ */
+static void __init_memblock memblock_insert_region(struct memblock_type *type,
+ int idx, phys_addr_t base,
+ phys_addr_t size, int nid)
+{
+ struct memblock_region *rgn = &type->regions[idx];
+
+ BUG_ON(type->cnt >= type->max);
+ memmove(rgn + 1, rgn, (type->cnt - idx) * sizeof(*rgn));
+ rgn->base = base;
+ rgn->size = size;
+ memblock_set_region_node(rgn, nid);
+ type->cnt++;
+ type->total_size += size;
+}
+
+/**
+ * memblock_add_region - add new memblock region
+ * @type: memblock type to add new region into
+ * @base: base address of the new region
+ * @size: size of the new region
+ * @nid: nid of the new region
+ *
+ * Add new memblock region [@base,@base+@size) into @type. The new region
+ * is allowed to overlap with existing ones - overlaps don't affect already
+ * existing regions. @type is guaranteed to be minimal (all neighbouring
+ * compatible regions are merged) after the addition.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+static int __init_memblock memblock_add_region(struct memblock_type *type,
+ phys_addr_t base, phys_addr_t size, int nid)
+{
+ bool insert = false;
+ phys_addr_t obase = base;
+ phys_addr_t end = base + memblock_cap_size(base, &size);
+ int i, nr_new;
+
+ if (!size)
+ return 0;
+
+ /* special case for empty array */
+ if (type->regions[0].size == 0) {
+ WARN_ON(type->cnt != 1 || type->total_size);
+ type->regions[0].base = base;
+ type->regions[0].size = size;
+ memblock_set_region_node(&type->regions[0], nid);
+ type->total_size = size;
+ return 0;
+ }
+repeat:
+ /*
+ * The following is executed twice. Once with %false @insert and
+ * then with %true. The first counts the number of regions needed
+ * to accomodate the new area. The second actually inserts them.
+ */
+ base = obase;
+ nr_new = 0;
+
+ for (i = 0; i < type->cnt; i++) {
+ struct memblock_region *rgn = &type->regions[i];
+ phys_addr_t rbase = rgn->base;
+ phys_addr_t rend = rbase + rgn->size;
+
+ if (rbase >= end)
+ break;
+ if (rend <= base)
+ continue;
+ /*
+ * @rgn overlaps. If it separates the lower part of new
+ * area, insert that portion.
+ */
+ if (rbase > base) {
+ nr_new++;
+ if (insert)
+ memblock_insert_region(type, i++, base,
+ rbase - base, nid);
+ }
+ /* area below @rend is dealt with, forget about it */
+ base = min(rend, end);
+ }
+
+ /* insert the remaining portion */
+ if (base < end) {
+ nr_new++;
+ if (insert)
+ memblock_insert_region(type, i, base, end - base, nid);
+ }
+
+ /*
+ * If this was the first round, resize array and repeat for actual
+ * insertions; otherwise, merge and return.
+ */
+ if (!insert) {
+ while (type->cnt + nr_new > type->max)
+ if (memblock_double_array(type, obase, size) < 0)
+ return -ENOMEM;
+ insert = true;
+ goto repeat;
+ } else {
+ memblock_merge_regions(type);
+ return 0;
+ }
+}
+
+int __init_memblock memblock_add_node(phys_addr_t base, phys_addr_t size,
+ int nid)
+{
+ return memblock_add_region(&memblock.memory, base, size, nid);
+}
+
+int __init_memblock memblock_add(phys_addr_t base, phys_addr_t size)
+{
+ return memblock_add_region(&memblock.memory, base, size, MAX_NUMNODES);
+}
+
+/**
+ * memblock_isolate_range - isolate given range into disjoint memblocks
+ * @type: memblock type to isolate range for
+ * @base: base of range to isolate
+ * @size: size of range to isolate
+ * @start_rgn: out parameter for the start of isolated region
+ * @end_rgn: out parameter for the end of isolated region
+ *
+ * Walk @type and ensure that regions don't cross the boundaries defined by
+ * [@base,@base+@size). Crossing regions are split at the boundaries,
+ * which may create at most two more regions. The index of the first
+ * region inside the range is returned in *@start_rgn and end in *@end_rgn.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+static int __init_memblock memblock_isolate_range(struct memblock_type *type,
+ phys_addr_t base, phys_addr_t size,
+ int *start_rgn, int *end_rgn)
+{
+ phys_addr_t end = base + memblock_cap_size(base, &size);
+ int i;
+
+ *start_rgn = *end_rgn = 0;
+
+ if (!size)
+ return 0;
+
+ /* we'll create at most two more regions */
+ while (type->cnt + 2 > type->max)
+ if (memblock_double_array(type, base, size) < 0)
+ return -ENOMEM;
+
+ for (i = 0; i < type->cnt; i++) {
+ struct memblock_region *rgn = &type->regions[i];
+ phys_addr_t rbase = rgn->base;
+ phys_addr_t rend = rbase + rgn->size;
+
+ if (rbase >= end)
+ break;
+ if (rend <= base)
+ continue;
+
+ if (rbase < base) {
+ /*
+ * @rgn intersects from below. Split and continue
+ * to process the next region - the new top half.
+ */
+ rgn->base = base;
+ rgn->size -= base - rbase;
+ type->total_size -= base - rbase;
+ memblock_insert_region(type, i, rbase, base - rbase,
+ memblock_get_region_node(rgn));
+ } else if (rend > end) {
+ /*
+ * @rgn intersects from above. Split and redo the
+ * current region - the new bottom half.
+ */
+ rgn->base = end;
+ rgn->size -= end - rbase;
+ type->total_size -= end - rbase;
+ memblock_insert_region(type, i--, rbase, end - rbase,
+ memblock_get_region_node(rgn));
+ } else {
+ /* @rgn is fully contained, record it */
+ if (!*end_rgn)
+ *start_rgn = i;
+ *end_rgn = i + 1;
+ }
+ }
+
+ return 0;
+}
+
+static int __init_memblock __memblock_remove(struct memblock_type *type,
+ phys_addr_t base, phys_addr_t size)
+{
+ int start_rgn, end_rgn;
+ int i, ret;
+
+ ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
+ if (ret)
+ return ret;
+
+ for (i = end_rgn - 1; i >= start_rgn; i--)
+ memblock_remove_region(type, i);
+ return 0;
+}
+
+int __init_memblock memblock_remove(phys_addr_t base, phys_addr_t size)
+{
+ return __memblock_remove(&memblock.memory, base, size);
+}
+
+int __init_memblock memblock_free(phys_addr_t base, phys_addr_t size)
+{
+ memblock_dbg(" memblock_free: [%#016llx-%#016llx] %pF\n",
+ (unsigned long long)base,
+ (unsigned long long)base + size,
+ (void *)_RET_IP_);
+
+ return __memblock_remove(&memblock.reserved, base, size);
+}
+
+int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
+{
+ struct memblock_type *_rgn = &memblock.reserved;
+
+ memblock_dbg("memblock_reserve: [%#016llx-%#016llx] %pF\n",
+ (unsigned long long)base,
+ (unsigned long long)base + size,
+ (void *)_RET_IP_);
+
+ return memblock_add_region(_rgn, base, size, MAX_NUMNODES);
+}
+
+/**
+ * __next_free_mem_range - next function for for_each_free_mem_range()
+ * @idx: pointer to u64 loop variable
+ * @nid: nid: node selector, %MAX_NUMNODES for all nodes
+ * @p_start: ptr to phys_addr_t for start address of the range, can be %NULL
+ * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL
+ * @p_nid: ptr to int for nid of the range, can be %NULL
+ *
+ * Find the first free area from *@idx which matches @nid, fill the out
+ * parameters, and update *@idx for the next iteration. The lower 32bit of
+ * *@idx contains index into memory region and the upper 32bit indexes the
+ * areas before each reserved region. For example, if reserved regions
+ * look like the following,
+ *
+ * 0:[0-16), 1:[32-48), 2:[128-130)
+ *
+ * The upper 32bit indexes the following regions.
+ *
+ * 0:[0-0), 1:[16-32), 2:[48-128), 3:[130-MAX)
+ *
+ * As both region arrays are sorted, the function advances the two indices
+ * in lockstep and returns each intersection.
+ */
+void __init_memblock __next_free_mem_range(u64 *idx, int nid,
+ phys_addr_t *out_start,
+ phys_addr_t *out_end, int *out_nid)
+{
+ struct memblock_type *mem = &memblock.memory;
+ struct memblock_type *rsv = &memblock.reserved;
+ int mi = *idx & 0xffffffff;
+ int ri = *idx >> 32;
+
+ for ( ; mi < mem->cnt; mi++) {
+ struct memblock_region *m = &mem->regions[mi];
+ phys_addr_t m_start = m->base;
+ phys_addr_t m_end = m->base + m->size;
+
+ /* only memory regions are associated with nodes, check it */
+ if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m))
+ continue;
+
+ /* scan areas before each reservation for intersection */
+ for ( ; ri < rsv->cnt + 1; ri++) {
+ struct memblock_region *r = &rsv->regions[ri];
+ phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0;
+ phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX;
+
+ /* if ri advanced past mi, break out to advance mi */
+ if (r_start >= m_end)
+ break;
+ /* if the two regions intersect, we're done */
+ if (m_start < r_end) {
+ if (out_start)
+ *out_start = max(m_start, r_start);
+ if (out_end)
+ *out_end = min(m_end, r_end);
+ if (out_nid)
+ *out_nid = memblock_get_region_node(m);
+ /*
+ * The region which ends first is advanced
+ * for the next iteration.
+ */
+ if (m_end <= r_end)
+ mi++;
+ else
+ ri++;
+ *idx = (u32)mi | (u64)ri << 32;
+ return;
+ }
+ }
+ }
+
+ /* signal end of iteration */
+ *idx = ULLONG_MAX;
+}
+
+/**
+ * __next_free_mem_range_rev - next function for for_each_free_mem_range_reverse()
+ * @idx: pointer to u64 loop variable
+ * @nid: nid: node selector, %MAX_NUMNODES for all nodes
+ * @p_start: ptr to phys_addr_t for start address of the range, can be %NULL
+ * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL
+ * @p_nid: ptr to int for nid of the range, can be %NULL
+ *
+ * Reverse of __next_free_mem_range().
+ */
+void __init_memblock __next_free_mem_range_rev(u64 *idx, int nid,
+ phys_addr_t *out_start,
+ phys_addr_t *out_end, int *out_nid)
+{
+ struct memblock_type *mem = &memblock.memory;
+ struct memblock_type *rsv = &memblock.reserved;
+ int mi = *idx & 0xffffffff;
+ int ri = *idx >> 32;
+
+ if (*idx == (u64)ULLONG_MAX) {
+ mi = mem->cnt - 1;
+ ri = rsv->cnt;
+ }
+
+ for ( ; mi >= 0; mi--) {
+ struct memblock_region *m = &mem->regions[mi];
+ phys_addr_t m_start = m->base;
+ phys_addr_t m_end = m->base + m->size;
+
+ /* only memory regions are associated with nodes, check it */
+ if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m))
+ continue;
+
+ /* scan areas before each reservation for intersection */
+ for ( ; ri >= 0; ri--) {
+ struct memblock_region *r = &rsv->regions[ri];
+ phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0;
+ phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX;
+
+ /* if ri advanced past mi, break out to advance mi */
+ if (r_end <= m_start)
+ break;
+ /* if the two regions intersect, we're done */
+ if (m_end > r_start) {
+ if (out_start)
+ *out_start = max(m_start, r_start);
+ if (out_end)
+ *out_end = min(m_end, r_end);
+ if (out_nid)
+ *out_nid = memblock_get_region_node(m);
+
+ if (m_start >= r_start)
+ mi--;
+ else
+ ri--;
+ *idx = (u32)mi | (u64)ri << 32;
+ return;
+ }
+ }
+ }
+
+ *idx = ULLONG_MAX;
+}
+
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+/*
+ * Common iterator interface used to define for_each_mem_range().
+ */
+void __init_memblock __next_mem_pfn_range(int *idx, int nid,
+ unsigned long *out_start_pfn,
+ unsigned long *out_end_pfn, int *out_nid)
+{
+ struct memblock_type *type = &memblock.memory;
+ struct memblock_region *r;
+
+ while (++*idx < type->cnt) {
+ r = &type->regions[*idx];
+
+ if (PFN_UP(r->base) >= PFN_DOWN(r->base + r->size))
+ continue;
+ if (nid == MAX_NUMNODES || nid == r->nid)
+ break;
+ }
+ if (*idx >= type->cnt) {
+ *idx = -1;
+ return;
+ }
+
+ if (out_start_pfn)
+ *out_start_pfn = PFN_UP(r->base);
+ if (out_end_pfn)
+ *out_end_pfn = PFN_DOWN(r->base + r->size);
+ if (out_nid)
+ *out_nid = r->nid;
+}
+
+/**
+ * memblock_set_node - set node ID on memblock regions
+ * @base: base of area to set node ID for
+ * @size: size of area to set node ID for
+ * @nid: node ID to set
+ *
+ * Set the nid of memblock memory regions in [@base,@base+@size) to @nid.
+ * Regions which cross the area boundaries are split as necessary.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
+ int nid)
+{
+ struct memblock_type *type = &memblock.memory;
+ int start_rgn, end_rgn;
+ int i, ret;
+
+ ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
+ if (ret)
+ return ret;
+
+ for (i = start_rgn; i < end_rgn; i++)
+ type->regions[i].nid = nid;
+
+ memblock_merge_regions(type);
+ return 0;
+}
+#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
+
+static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size,
+ phys_addr_t align, phys_addr_t max_addr,
+ int nid)
+{
+ phys_addr_t found;
+
+ /* align @size to avoid excessive fragmentation on reserved array */
+ size = round_up(size, align);
+
+ found = memblock_find_in_range_node(0, max_addr, size, align, nid);
+ if (found && !memblock_reserve(found, size))
+ return found;
+
+ return 0;
+}
+
+phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid)
+{
+ return memblock_alloc_base_nid(size, align, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
+}
+
+phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
+{
+ return memblock_alloc_base_nid(size, align, max_addr, MAX_NUMNODES);
+}
+
+phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
+{
+ phys_addr_t alloc;
+
+ alloc = __memblock_alloc_base(size, align, max_addr);
+
+ if (alloc == 0)
+ panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
+ (unsigned long long) size, (unsigned long long) max_addr);
+
+ return alloc;
+}
+
+phys_addr_t __init memblock_alloc(phys_addr_t size, phys_addr_t align)
+{
+ return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
+}
+
+phys_addr_t __init memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
+{
+ phys_addr_t res = memblock_alloc_nid(size, align, nid);
+
+ if (res)
+ return res;
+ return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
+}
+
+
+/*
+ * Remaining API functions
+ */
+
+phys_addr_t __init memblock_phys_mem_size(void)
+{
+ return memblock.memory.total_size;
+}
+
+/* lowest address */
+phys_addr_t __init_memblock memblock_start_of_DRAM(void)
+{
+ return memblock.memory.regions[0].base;
+}
+
+phys_addr_t __init_memblock memblock_end_of_DRAM(void)
+{
+ int idx = memblock.memory.cnt - 1;
+
+ return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
+}
+
+void __init memblock_enforce_memory_limit(phys_addr_t limit)
+{
+ unsigned long i;
+ phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX;
+
+ if (!limit)
+ return;
+
+ /* find out max address */
+ for (i = 0; i < memblock.memory.cnt; i++) {
+ struct memblock_region *r = &memblock.memory.regions[i];
+
+ if (limit <= r->size) {
+ max_addr = r->base + limit;
+ break;
+ }
+ limit -= r->size;
+ }
+
+ /* truncate both memory and reserved regions */
+ __memblock_remove(&memblock.memory, max_addr, (phys_addr_t)ULLONG_MAX);
+ __memblock_remove(&memblock.reserved, max_addr, (phys_addr_t)ULLONG_MAX);
+}
+
+static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)
+{
+ unsigned int left = 0, right = type->cnt;
+
+ do {
+ unsigned int mid = (right + left) / 2;
+
+ if (addr < type->regions[mid].base)
+ right = mid;
+ else if (addr >= (type->regions[mid].base +
+ type->regions[mid].size))
+ left = mid + 1;
+ else
+ return mid;
+ } while (left < right);
+ return -1;
+}
+
+int __init memblock_is_reserved(phys_addr_t addr)
+{
+ return memblock_search(&memblock.reserved, addr) != -1;
+}
+
+int __init_memblock memblock_is_memory(phys_addr_t addr)
+{
+ return memblock_search(&memblock.memory, addr) != -1;
+}
+
+int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size)
+{
+ int idx = memblock_search(&memblock.memory, base);
+ phys_addr_t end = base + memblock_cap_size(base, &size);
+
+ if (idx == -1)
+ return 0;
+ return memblock.memory.regions[idx].base <= base &&
+ (memblock.memory.regions[idx].base +
+ memblock.memory.regions[idx].size) >= end;
+}
+
+int __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
+{
+ memblock_cap_size(base, &size);
+ return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
+}
+
+void __init_memblock memblock_trim_memory(phys_addr_t align)
+{
+ int i;
+ phys_addr_t start, end, orig_start, orig_end;
+ struct memblock_type *mem = &memblock.memory;
+
+ for (i = 0; i < mem->cnt; i++) {
+ orig_start = mem->regions[i].base;
+ orig_end = mem->regions[i].base + mem->regions[i].size;
+ start = round_up(orig_start, align);
+ end = round_down(orig_end, align);
+
+ if (start == orig_start && end == orig_end)
+ continue;
+
+ if (start < end) {
+ mem->regions[i].base = start;
+ mem->regions[i].size = end - start;
+ } else {
+ memblock_remove_region(mem, i);
+ i--;
+ }
+ }
+}
+
+void __init_memblock memblock_set_current_limit(phys_addr_t limit)
+{
+ memblock.current_limit = limit;
+}
+
+static void __init_memblock memblock_dump(struct memblock_type *type, char *name)
+{
+ unsigned long long base, size;
+ int i;
+
+ pr_info(" %s.cnt = 0x%lx\n", name, type->cnt);
+
+ for (i = 0; i < type->cnt; i++) {
+ struct memblock_region *rgn = &type->regions[i];
+ char nid_buf[32] = "";
+
+ base = rgn->base;
+ size = rgn->size;
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+ if (memblock_get_region_node(rgn) != MAX_NUMNODES)
+ snprintf(nid_buf, sizeof(nid_buf), " on node %d",
+ memblock_get_region_node(rgn));
+#endif
+ pr_info(" %s[%#x]\t[%#016llx-%#016llx], %#llx bytes%s\n",
+ name, i, base, base + size - 1, size, nid_buf);
+ }
+}
+
+void __init_memblock __memblock_dump_all(void)
+{
+ pr_info("MEMBLOCK configuration:\n");
+ pr_info(" memory size = %#llx reserved size = %#llx\n",
+ (unsigned long long)memblock.memory.total_size,
+ (unsigned long long)memblock.reserved.total_size);
+
+ memblock_dump(&memblock.memory, "memory");
+ memblock_dump(&memblock.reserved, "reserved");
+}
+
+void __init memblock_allow_resize(void)
+{
+ memblock_can_resize = 1;
+}
+
+static int __init early_memblock(char *p)
+{
+ if (p && strstr(p, "debug"))
+ memblock_debug = 1;
+ return 0;
+}
+early_param("memblock", early_memblock);
+
+#if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK)
+
+static int memblock_debug_show(struct seq_file *m, void *private)
+{
+ struct memblock_type *type = m->private;
+ struct memblock_region *reg;
+ int i;
+
+ for (i = 0; i < type->cnt; i++) {
+ reg = &type->regions[i];
+ seq_printf(m, "%4d: ", i);
+ if (sizeof(phys_addr_t) == 4)
+ seq_printf(m, "0x%08lx..0x%08lx\n",
+ (unsigned long)reg->base,
+ (unsigned long)(reg->base + reg->size - 1));
+ else
+ seq_printf(m, "0x%016llx..0x%016llx\n",
+ (unsigned long long)reg->base,
+ (unsigned long long)(reg->base + reg->size - 1));
+
+ }
+ return 0;
+}
+
+static int memblock_debug_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, memblock_debug_show, inode->i_private);
+}
+
+static const struct file_operations memblock_debug_fops = {
+ .open = memblock_debug_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init memblock_init_debugfs(void)
+{
+ struct dentry *root = debugfs_create_dir("memblock", NULL);
+ if (!root)
+ return -ENXIO;
+ debugfs_create_file("memory", S_IRUGO, root, &memblock.memory, &memblock_debug_fops);
+ debugfs_create_file("reserved", S_IRUGO, root, &memblock.reserved, &memblock_debug_fops);
+
+ return 0;
+}
+__initcall(memblock_init_debugfs);
+
+#endif /* CONFIG_DEBUG_FS */
diff --git a/ap/os/linux/linux-3.4.x/mm/memcontrol.c b/ap/os/linux/linux-3.4.x/mm/memcontrol.c
new file mode 100644
index 0000000..8c3dd64
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/memcontrol.c
@@ -0,0 +1,5679 @@
+/* memcontrol.c - Memory Controller
+ *
+ * Copyright IBM Corporation, 2007
+ * Author Balbir Singh <balbir@linux.vnet.ibm.com>
+ *
+ * Copyright 2007 OpenVZ SWsoft Inc
+ * Author: Pavel Emelianov <xemul@openvz.org>
+ *
+ * Memory thresholds
+ * Copyright (C) 2009 Nokia Corporation
+ * Author: Kirill A. Shutemov
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/res_counter.h>
+#include <linux/memcontrol.h>
+#include <linux/cgroup.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/pagemap.h>
+#include <linux/smp.h>
+#include <linux/page-flags.h>
+#include <linux/backing-dev.h>
+#include <linux/bit_spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/limits.h>
+#include <linux/export.h>
+#include <linux/mutex.h>
+#include <linux/rbtree.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/spinlock.h>
+#include <linux/eventfd.h>
+#include <linux/sort.h>
+#include <linux/fs.h>
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
+#include <linux/mm_inline.h>
+#include <linux/page_cgroup.h>
+#include <linux/cpu.h>
+#include <linux/oom.h>
+#include "internal.h"
+#include <net/sock.h>
+#include <net/tcp_memcontrol.h>
+
+#include <asm/uaccess.h>
+
+#include <trace/events/vmscan.h>
+
+struct cgroup_subsys mem_cgroup_subsys __read_mostly;
+#define MEM_CGROUP_RECLAIM_RETRIES 5
+struct mem_cgroup *root_mem_cgroup __read_mostly;
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+/* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
+int do_swap_account __read_mostly;
+
+/* for remember boot option*/
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED
+static int really_do_swap_account __initdata = 1;
+#else
+static int really_do_swap_account __initdata = 0;
+#endif
+
+#else
+#define do_swap_account (0)
+#endif
+
+
+/*
+ * Statistics for memory cgroup.
+ */
+enum mem_cgroup_stat_index {
+ /*
+ * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
+ */
+ MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
+ MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
+ MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */
+ MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
+ MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */
+ MEM_CGROUP_STAT_NSTATS,
+};
+
+enum mem_cgroup_events_index {
+ MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */
+ MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */
+ MEM_CGROUP_EVENTS_COUNT, /* # of pages paged in/out */
+ MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */
+ MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */
+ MEM_CGROUP_EVENTS_NSTATS,
+};
+/*
+ * Per memcg event counter is incremented at every pagein/pageout. With THP,
+ * it will be incremated by the number of pages. This counter is used for
+ * for trigger some periodic events. This is straightforward and better
+ * than using jiffies etc. to handle periodic memcg event.
+ */
+enum mem_cgroup_events_target {
+ MEM_CGROUP_TARGET_THRESH,
+ MEM_CGROUP_TARGET_SOFTLIMIT,
+ MEM_CGROUP_TARGET_NUMAINFO,
+ MEM_CGROUP_NTARGETS,
+};
+#define THRESHOLDS_EVENTS_TARGET (128)
+#define SOFTLIMIT_EVENTS_TARGET (1024)
+#define NUMAINFO_EVENTS_TARGET (1024)
+
+struct mem_cgroup_stat_cpu {
+ long count[MEM_CGROUP_STAT_NSTATS];
+ unsigned long events[MEM_CGROUP_EVENTS_NSTATS];
+ unsigned long targets[MEM_CGROUP_NTARGETS];
+};
+
+struct mem_cgroup_reclaim_iter {
+ /* css_id of the last scanned hierarchy member */
+ int position;
+ /* scan generation, increased every round-trip */
+ unsigned int generation;
+};
+
+/*
+ * per-zone information in memory controller.
+ */
+struct mem_cgroup_per_zone {
+ struct lruvec lruvec;
+ unsigned long lru_size[NR_LRU_LISTS];
+
+ struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
+
+ struct zone_reclaim_stat reclaim_stat;
+ struct rb_node tree_node; /* RB tree node */
+ unsigned long long usage_in_excess;/* Set to the value by which */
+ /* the soft limit is exceeded*/
+ bool on_tree;
+ struct mem_cgroup *memcg; /* Back pointer, we cannot */
+ /* use container_of */
+};
+
+struct mem_cgroup_per_node {
+ struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
+};
+
+struct mem_cgroup_lru_info {
+ struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
+};
+
+/*
+ * Cgroups above their limits are maintained in a RB-Tree, independent of
+ * their hierarchy representation
+ */
+
+struct mem_cgroup_tree_per_zone {
+ struct rb_root rb_root;
+ spinlock_t lock;
+};
+
+struct mem_cgroup_tree_per_node {
+ struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
+};
+
+struct mem_cgroup_tree {
+ struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
+};
+
+static struct mem_cgroup_tree soft_limit_tree __read_mostly;
+
+struct mem_cgroup_threshold {
+ struct eventfd_ctx *eventfd;
+ u64 threshold;
+};
+
+/* For threshold */
+struct mem_cgroup_threshold_ary {
+ /* An array index points to threshold just below usage. */
+ int current_threshold;
+ /* Size of entries[] */
+ unsigned int size;
+ /* Array of thresholds */
+ struct mem_cgroup_threshold entries[0];
+};
+
+struct mem_cgroup_thresholds {
+ /* Primary thresholds array */
+ struct mem_cgroup_threshold_ary *primary;
+ /*
+ * Spare threshold array.
+ * This is needed to make mem_cgroup_unregister_event() "never fail".
+ * It must be able to store at least primary->size - 1 entries.
+ */
+ struct mem_cgroup_threshold_ary *spare;
+};
+
+/* for OOM */
+struct mem_cgroup_eventfd_list {
+ struct list_head list;
+ struct eventfd_ctx *eventfd;
+};
+
+static void mem_cgroup_threshold(struct mem_cgroup *memcg);
+static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
+
+/*
+ * The memory controller data structure. The memory controller controls both
+ * page cache and RSS per cgroup. We would eventually like to provide
+ * statistics based on the statistics developed by Rik Van Riel for clock-pro,
+ * to help the administrator determine what knobs to tune.
+ *
+ * TODO: Add a water mark for the memory controller. Reclaim will begin when
+ * we hit the water mark. May be even add a low water mark, such that
+ * no reclaim occurs from a cgroup at it's low water mark, this is
+ * a feature that will be implemented much later in the future.
+ */
+struct mem_cgroup {
+ struct cgroup_subsys_state css;
+ /*
+ * the counter to account for memory usage
+ */
+ struct res_counter res;
+
+ union {
+ /*
+ * the counter to account for mem+swap usage.
+ */
+ struct res_counter memsw;
+
+ /*
+ * rcu_freeing is used only when freeing struct mem_cgroup,
+ * so put it into a union to avoid wasting more memory.
+ * It must be disjoint from the css field. It could be
+ * in a union with the res field, but res plays a much
+ * larger part in mem_cgroup life than memsw, and might
+ * be of interest, even at time of free, when debugging.
+ * So share rcu_head with the less interesting memsw.
+ */
+ struct rcu_head rcu_freeing;
+ /*
+ * But when using vfree(), that cannot be done at
+ * interrupt time, so we must then queue the work.
+ */
+ struct work_struct work_freeing;
+ };
+
+ /*
+ * Per cgroup active and inactive list, similar to the
+ * per zone LRU lists.
+ */
+ struct mem_cgroup_lru_info info;
+ int last_scanned_node;
+#if MAX_NUMNODES > 1
+ nodemask_t scan_nodes;
+ atomic_t numainfo_events;
+ atomic_t numainfo_updating;
+#endif
+ /*
+ * Should the accounting and control be hierarchical, per subtree?
+ */
+ bool use_hierarchy;
+
+ bool oom_lock;
+ atomic_t under_oom;
+
+ atomic_t refcnt;
+
+ int swappiness;
+ /* OOM-Killer disable */
+ int oom_kill_disable;
+
+ /* set when res.limit == memsw.limit */
+ bool memsw_is_minimum;
+
+ /* protect arrays of thresholds */
+ struct mutex thresholds_lock;
+
+ /* thresholds for memory usage. RCU-protected */
+ struct mem_cgroup_thresholds thresholds;
+
+ /* thresholds for mem+swap usage. RCU-protected */
+ struct mem_cgroup_thresholds memsw_thresholds;
+
+ /* For oom notifier event fd */
+ struct list_head oom_notify;
+
+ /*
+ * Should we move charges of a task when a task is moved into this
+ * mem_cgroup ? And what type of charges should we move ?
+ */
+ unsigned long move_charge_at_immigrate;
+ /*
+ * set > 0 if pages under this cgroup are moving to other cgroup.
+ */
+ atomic_t moving_account;
+ /* taken only while moving_account > 0 */
+ spinlock_t move_lock;
+ /*
+ * percpu counter.
+ */
+ struct mem_cgroup_stat_cpu *stat;
+ /*
+ * used when a cpu is offlined or other synchronizations
+ * See mem_cgroup_read_stat().
+ */
+ struct mem_cgroup_stat_cpu nocpu_base;
+ spinlock_t pcp_counter_lock;
+
+#ifdef CONFIG_INET
+ struct tcp_memcontrol tcp_mem;
+#endif
+};
+
+/* Stuffs for move charges at task migration. */
+/*
+ * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
+ * left-shifted bitmap of these types.
+ */
+enum move_type {
+ MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
+ MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */
+ NR_MOVE_TYPE,
+};
+
+/* "mc" and its members are protected by cgroup_mutex */
+static struct move_charge_struct {
+ spinlock_t lock; /* for from, to */
+ struct mem_cgroup *from;
+ struct mem_cgroup *to;
+ unsigned long precharge;
+ unsigned long moved_charge;
+ unsigned long moved_swap;
+ struct task_struct *moving_task; /* a task moving charges */
+ wait_queue_head_t waitq; /* a waitq for other context */
+} mc = {
+ .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
+ .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
+};
+
+static bool move_anon(void)
+{
+ return test_bit(MOVE_CHARGE_TYPE_ANON,
+ &mc.to->move_charge_at_immigrate);
+}
+
+static bool move_file(void)
+{
+ return test_bit(MOVE_CHARGE_TYPE_FILE,
+ &mc.to->move_charge_at_immigrate);
+}
+
+/*
+ * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
+ * limit reclaim to prevent infinite loops, if they ever occur.
+ */
+#define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
+#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
+
+enum charge_type {
+ MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
+ MEM_CGROUP_CHARGE_TYPE_MAPPED,
+ MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
+ MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
+ MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
+ MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
+ NR_CHARGE_TYPE,
+};
+
+/* for encoding cft->private value on file */
+#define _MEM (0)
+#define _MEMSWAP (1)
+#define _OOM_TYPE (2)
+#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
+#define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff)
+#define MEMFILE_ATTR(val) ((val) & 0xffff)
+/* Used for OOM nofiier */
+#define OOM_CONTROL (0)
+
+/*
+ * Reclaim flags for mem_cgroup_hierarchical_reclaim
+ */
+#define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
+#define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
+#define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
+#define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
+
+static void mem_cgroup_get(struct mem_cgroup *memcg);
+static void mem_cgroup_put(struct mem_cgroup *memcg);
+
+/* Writing them here to avoid exposing memcg's inner layout */
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+#include <net/sock.h>
+#include <net/ip.h>
+
+static bool mem_cgroup_is_root(struct mem_cgroup *memcg);
+void sock_update_memcg(struct sock *sk)
+{
+ if (mem_cgroup_sockets_enabled) {
+ struct mem_cgroup *memcg;
+
+ BUG_ON(!sk->sk_prot->proto_cgroup);
+
+ /* Socket cloning can throw us here with sk_cgrp already
+ * filled. It won't however, necessarily happen from
+ * process context. So the test for root memcg given
+ * the current task's memcg won't help us in this case.
+ *
+ * Respecting the original socket's memcg is a better
+ * decision in this case.
+ */
+ if (sk->sk_cgrp) {
+ BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg));
+ mem_cgroup_get(sk->sk_cgrp->memcg);
+ return;
+ }
+
+ rcu_read_lock();
+ memcg = mem_cgroup_from_task(current);
+ if (!mem_cgroup_is_root(memcg)) {
+ mem_cgroup_get(memcg);
+ sk->sk_cgrp = sk->sk_prot->proto_cgroup(memcg);
+ }
+ rcu_read_unlock();
+ }
+}
+EXPORT_SYMBOL(sock_update_memcg);
+
+void sock_release_memcg(struct sock *sk)
+{
+ if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
+ struct mem_cgroup *memcg;
+ WARN_ON(!sk->sk_cgrp->memcg);
+ memcg = sk->sk_cgrp->memcg;
+ mem_cgroup_put(memcg);
+ }
+}
+
+#ifdef CONFIG_INET
+struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
+{
+ if (!memcg || mem_cgroup_is_root(memcg))
+ return NULL;
+
+ return &memcg->tcp_mem.cg_proto;
+}
+EXPORT_SYMBOL(tcp_proto_cgroup);
+#endif /* CONFIG_INET */
+#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+
+static void drain_all_stock_async(struct mem_cgroup *memcg);
+
+static struct mem_cgroup_per_zone *
+mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid)
+{
+ return &memcg->info.nodeinfo[nid]->zoneinfo[zid];
+}
+
+struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg)
+{
+ return &memcg->css;
+}
+
+static struct mem_cgroup_per_zone *
+page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page)
+{
+ int nid = page_to_nid(page);
+ int zid = page_zonenum(page);
+
+ return mem_cgroup_zoneinfo(memcg, nid, zid);
+}
+
+static struct mem_cgroup_tree_per_zone *
+soft_limit_tree_node_zone(int nid, int zid)
+{
+ return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
+}
+
+static struct mem_cgroup_tree_per_zone *
+soft_limit_tree_from_page(struct page *page)
+{
+ int nid = page_to_nid(page);
+ int zid = page_zonenum(page);
+
+ return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
+}
+
+static void
+__mem_cgroup_insert_exceeded(struct mem_cgroup *memcg,
+ struct mem_cgroup_per_zone *mz,
+ struct mem_cgroup_tree_per_zone *mctz,
+ unsigned long long new_usage_in_excess)
+{
+ struct rb_node **p = &mctz->rb_root.rb_node;
+ struct rb_node *parent = NULL;
+ struct mem_cgroup_per_zone *mz_node;
+
+ if (mz->on_tree)
+ return;
+
+ mz->usage_in_excess = new_usage_in_excess;
+ if (!mz->usage_in_excess)
+ return;
+ while (*p) {
+ parent = *p;
+ mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
+ tree_node);
+ if (mz->usage_in_excess < mz_node->usage_in_excess)
+ p = &(*p)->rb_left;
+ /*
+ * We can't avoid mem cgroups that are over their soft
+ * limit by the same amount
+ */
+ else if (mz->usage_in_excess >= mz_node->usage_in_excess)
+ p = &(*p)->rb_right;
+ }
+ rb_link_node(&mz->tree_node, parent, p);
+ rb_insert_color(&mz->tree_node, &mctz->rb_root);
+ mz->on_tree = true;
+}
+
+static void
+__mem_cgroup_remove_exceeded(struct mem_cgroup *memcg,
+ struct mem_cgroup_per_zone *mz,
+ struct mem_cgroup_tree_per_zone *mctz)
+{
+ if (!mz->on_tree)
+ return;
+ rb_erase(&mz->tree_node, &mctz->rb_root);
+ mz->on_tree = false;
+}
+
+static void
+mem_cgroup_remove_exceeded(struct mem_cgroup *memcg,
+ struct mem_cgroup_per_zone *mz,
+ struct mem_cgroup_tree_per_zone *mctz)
+{
+ spin_lock(&mctz->lock);
+ __mem_cgroup_remove_exceeded(memcg, mz, mctz);
+ spin_unlock(&mctz->lock);
+}
+
+
+static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
+{
+ unsigned long long excess;
+ struct mem_cgroup_per_zone *mz;
+ struct mem_cgroup_tree_per_zone *mctz;
+ int nid = page_to_nid(page);
+ int zid = page_zonenum(page);
+ mctz = soft_limit_tree_from_page(page);
+
+ /*
+ * Necessary to update all ancestors when hierarchy is used.
+ * because their event counter is not touched.
+ */
+ for (; memcg; memcg = parent_mem_cgroup(memcg)) {
+ mz = mem_cgroup_zoneinfo(memcg, nid, zid);
+ excess = res_counter_soft_limit_excess(&memcg->res);
+ /*
+ * We have to update the tree if mz is on RB-tree or
+ * mem is over its softlimit.
+ */
+ if (excess || mz->on_tree) {
+ spin_lock(&mctz->lock);
+ /* if on-tree, remove it */
+ if (mz->on_tree)
+ __mem_cgroup_remove_exceeded(memcg, mz, mctz);
+ /*
+ * Insert again. mz->usage_in_excess will be updated.
+ * If excess is 0, no tree ops.
+ */
+ __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess);
+ spin_unlock(&mctz->lock);
+ }
+ }
+}
+
+static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
+{
+ int node, zone;
+ struct mem_cgroup_per_zone *mz;
+ struct mem_cgroup_tree_per_zone *mctz;
+
+ for_each_node(node) {
+ for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+ mz = mem_cgroup_zoneinfo(memcg, node, zone);
+ mctz = soft_limit_tree_node_zone(node, zone);
+ mem_cgroup_remove_exceeded(memcg, mz, mctz);
+ }
+ }
+}
+
+static struct mem_cgroup_per_zone *
+__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
+{
+ struct rb_node *rightmost = NULL;
+ struct mem_cgroup_per_zone *mz;
+
+retry:
+ mz = NULL;
+ rightmost = rb_last(&mctz->rb_root);
+ if (!rightmost)
+ goto done; /* Nothing to reclaim from */
+
+ mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
+ /*
+ * Remove the node now but someone else can add it back,
+ * we will to add it back at the end of reclaim to its correct
+ * position in the tree.
+ */
+ __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz);
+ if (!res_counter_soft_limit_excess(&mz->memcg->res) ||
+ !css_tryget(&mz->memcg->css))
+ goto retry;
+done:
+ return mz;
+}
+
+static struct mem_cgroup_per_zone *
+mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
+{
+ struct mem_cgroup_per_zone *mz;
+
+ spin_lock(&mctz->lock);
+ mz = __mem_cgroup_largest_soft_limit_node(mctz);
+ spin_unlock(&mctz->lock);
+ return mz;
+}
+
+/*
+ * Implementation Note: reading percpu statistics for memcg.
+ *
+ * Both of vmstat[] and percpu_counter has threshold and do periodic
+ * synchronization to implement "quick" read. There are trade-off between
+ * reading cost and precision of value. Then, we may have a chance to implement
+ * a periodic synchronizion of counter in memcg's counter.
+ *
+ * But this _read() function is used for user interface now. The user accounts
+ * memory usage by memory cgroup and he _always_ requires exact value because
+ * he accounts memory. Even if we provide quick-and-fuzzy read, we always
+ * have to visit all online cpus and make sum. So, for now, unnecessary
+ * synchronization is not implemented. (just implemented for cpu hotplug)
+ *
+ * If there are kernel internal actions which can make use of some not-exact
+ * value, and reading all cpu value can be performance bottleneck in some
+ * common workload, threashold and synchonization as vmstat[] should be
+ * implemented.
+ */
+static long mem_cgroup_read_stat(struct mem_cgroup *memcg,
+ enum mem_cgroup_stat_index idx)
+{
+ long val = 0;
+ int cpu;
+
+ get_online_cpus();
+ for_each_online_cpu(cpu)
+ val += per_cpu(memcg->stat->count[idx], cpu);
+#ifdef CONFIG_HOTPLUG_CPU
+ spin_lock(&memcg->pcp_counter_lock);
+ val += memcg->nocpu_base.count[idx];
+ spin_unlock(&memcg->pcp_counter_lock);
+#endif
+ put_online_cpus();
+ return val;
+}
+
+static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
+ bool charge)
+{
+ int val = (charge) ? 1 : -1;
+ this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
+}
+
+static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
+ enum mem_cgroup_events_index idx)
+{
+ unsigned long val = 0;
+ int cpu;
+
+ for_each_online_cpu(cpu)
+ val += per_cpu(memcg->stat->events[idx], cpu);
+#ifdef CONFIG_HOTPLUG_CPU
+ spin_lock(&memcg->pcp_counter_lock);
+ val += memcg->nocpu_base.events[idx];
+ spin_unlock(&memcg->pcp_counter_lock);
+#endif
+ return val;
+}
+
+static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
+ bool anon, int nr_pages)
+{
+ preempt_disable();
+
+ /*
+ * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
+ * counted as CACHE even if it's on ANON LRU.
+ */
+ if (anon)
+ __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS],
+ nr_pages);
+ else
+ __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE],
+ nr_pages);
+
+ /* pagein of a big page is an event. So, ignore page size */
+ if (nr_pages > 0)
+ __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]);
+ else {
+ __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]);
+ nr_pages = -nr_pages; /* for event */
+ }
+
+ __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT], nr_pages);
+
+ preempt_enable();
+}
+
+unsigned long
+mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid,
+ unsigned int lru_mask)
+{
+ struct mem_cgroup_per_zone *mz;
+ enum lru_list lru;
+ unsigned long ret = 0;
+
+ mz = mem_cgroup_zoneinfo(memcg, nid, zid);
+
+ for_each_lru(lru) {
+ if (BIT(lru) & lru_mask)
+ ret += mz->lru_size[lru];
+ }
+ return ret;
+}
+
+static unsigned long
+mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
+ int nid, unsigned int lru_mask)
+{
+ u64 total = 0;
+ int zid;
+
+ for (zid = 0; zid < MAX_NR_ZONES; zid++)
+ total += mem_cgroup_zone_nr_lru_pages(memcg,
+ nid, zid, lru_mask);
+
+ return total;
+}
+
+static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
+ unsigned int lru_mask)
+{
+ int nid;
+ u64 total = 0;
+
+ for_each_node_state(nid, N_HIGH_MEMORY)
+ total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask);
+ return total;
+}
+
+static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
+ enum mem_cgroup_events_target target)
+{
+ unsigned long val, next;
+
+ val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
+ next = __this_cpu_read(memcg->stat->targets[target]);
+ /* from time_after() in jiffies.h */
+ if ((long)next - (long)val < 0) {
+ switch (target) {
+ case MEM_CGROUP_TARGET_THRESH:
+ next = val + THRESHOLDS_EVENTS_TARGET;
+ break;
+ case MEM_CGROUP_TARGET_SOFTLIMIT:
+ next = val + SOFTLIMIT_EVENTS_TARGET;
+ break;
+ case MEM_CGROUP_TARGET_NUMAINFO:
+ next = val + NUMAINFO_EVENTS_TARGET;
+ break;
+ default:
+ break;
+ }
+ __this_cpu_write(memcg->stat->targets[target], next);
+ return true;
+ }
+ return false;
+}
+
+/*
+ * Check events in order.
+ *
+ */
+static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
+{
+ preempt_disable();
+ /* threshold event is triggered in finer grain than soft limit */
+ if (unlikely(mem_cgroup_event_ratelimit(memcg,
+ MEM_CGROUP_TARGET_THRESH))) {
+ bool do_softlimit;
+ bool do_numainfo __maybe_unused;
+
+ do_softlimit = mem_cgroup_event_ratelimit(memcg,
+ MEM_CGROUP_TARGET_SOFTLIMIT);
+#if MAX_NUMNODES > 1
+ do_numainfo = mem_cgroup_event_ratelimit(memcg,
+ MEM_CGROUP_TARGET_NUMAINFO);
+#endif
+ preempt_enable();
+
+ mem_cgroup_threshold(memcg);
+ if (unlikely(do_softlimit))
+ mem_cgroup_update_tree(memcg, page);
+#if MAX_NUMNODES > 1
+ if (unlikely(do_numainfo))
+ atomic_inc(&memcg->numainfo_events);
+#endif
+ } else
+ preempt_enable();
+}
+
+struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
+{
+ return container_of(cgroup_subsys_state(cont,
+ mem_cgroup_subsys_id), struct mem_cgroup,
+ css);
+}
+
+struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
+{
+ /*
+ * mm_update_next_owner() may clear mm->owner to NULL
+ * if it races with swapoff, page migration, etc.
+ * So this can be called with p == NULL.
+ */
+ if (unlikely(!p))
+ return NULL;
+
+ return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
+ struct mem_cgroup, css);
+}
+
+struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
+{
+ struct mem_cgroup *memcg = NULL;
+
+ if (!mm)
+ return NULL;
+ /*
+ * Because we have no locks, mm->owner's may be being moved to other
+ * cgroup. We use css_tryget() here even if this looks
+ * pessimistic (rather than adding locks here).
+ */
+ rcu_read_lock();
+ do {
+ memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
+ if (unlikely(!memcg))
+ break;
+ } while (!css_tryget(&memcg->css));
+ rcu_read_unlock();
+ return memcg;
+}
+
+/**
+ * mem_cgroup_iter - iterate over memory cgroup hierarchy
+ * @root: hierarchy root
+ * @prev: previously returned memcg, NULL on first invocation
+ * @reclaim: cookie for shared reclaim walks, NULL for full walks
+ *
+ * Returns references to children of the hierarchy below @root, or
+ * @root itself, or %NULL after a full round-trip.
+ *
+ * Caller must pass the return value in @prev on subsequent
+ * invocations for reference counting, or use mem_cgroup_iter_break()
+ * to cancel a hierarchy walk before the round-trip is complete.
+ *
+ * Reclaimers can specify a zone and a priority level in @reclaim to
+ * divide up the memcgs in the hierarchy among all concurrent
+ * reclaimers operating on the same zone and priority.
+ */
+struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
+ struct mem_cgroup *prev,
+ struct mem_cgroup_reclaim_cookie *reclaim)
+{
+ struct mem_cgroup *memcg = NULL;
+ int id = 0;
+
+ if (mem_cgroup_disabled())
+ return NULL;
+
+ if (!root)
+ root = root_mem_cgroup;
+
+ if (prev && !reclaim)
+ id = css_id(&prev->css);
+
+ if (prev && prev != root)
+ css_put(&prev->css);
+
+ if (!root->use_hierarchy && root != root_mem_cgroup) {
+ if (prev)
+ return NULL;
+ return root;
+ }
+
+ while (!memcg) {
+ struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
+ struct cgroup_subsys_state *css;
+
+ if (reclaim) {
+ int nid = zone_to_nid(reclaim->zone);
+ int zid = zone_idx(reclaim->zone);
+ struct mem_cgroup_per_zone *mz;
+
+ mz = mem_cgroup_zoneinfo(root, nid, zid);
+ iter = &mz->reclaim_iter[reclaim->priority];
+ if (prev && reclaim->generation != iter->generation)
+ return NULL;
+ id = iter->position;
+ }
+
+ rcu_read_lock();
+ css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id);
+ if (css) {
+ if (css == &root->css || css_tryget(css))
+ memcg = container_of(css,
+ struct mem_cgroup, css);
+ } else
+ id = 0;
+ rcu_read_unlock();
+
+ if (reclaim) {
+ iter->position = id;
+ if (!css)
+ iter->generation++;
+ else if (!prev && memcg)
+ reclaim->generation = iter->generation;
+ }
+
+ if (prev && !css)
+ return NULL;
+ }
+ return memcg;
+}
+
+/**
+ * mem_cgroup_iter_break - abort a hierarchy walk prematurely
+ * @root: hierarchy root
+ * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
+ */
+void mem_cgroup_iter_break(struct mem_cgroup *root,
+ struct mem_cgroup *prev)
+{
+ if (!root)
+ root = root_mem_cgroup;
+ if (prev && prev != root)
+ css_put(&prev->css);
+}
+
+/*
+ * Iteration constructs for visiting all cgroups (under a tree). If
+ * loops are exited prematurely (break), mem_cgroup_iter_break() must
+ * be used for reference counting.
+ */
+#define for_each_mem_cgroup_tree(iter, root) \
+ for (iter = mem_cgroup_iter(root, NULL, NULL); \
+ iter != NULL; \
+ iter = mem_cgroup_iter(root, iter, NULL))
+
+#define for_each_mem_cgroup(iter) \
+ for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
+ iter != NULL; \
+ iter = mem_cgroup_iter(NULL, iter, NULL))
+
+static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
+{
+ return (memcg == root_mem_cgroup);
+}
+
+void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
+{
+ struct mem_cgroup *memcg;
+
+ if (!mm)
+ return;
+
+ rcu_read_lock();
+ memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
+ if (unlikely(!memcg))
+ goto out;
+
+ switch (idx) {
+ case PGFAULT:
+ this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
+ break;
+ case PGMAJFAULT:
+ this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
+ break;
+ default:
+ BUG();
+ }
+out:
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL(mem_cgroup_count_vm_event);
+
+/**
+ * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
+ * @zone: zone of the wanted lruvec
+ * @mem: memcg of the wanted lruvec
+ *
+ * Returns the lru list vector holding pages for the given @zone and
+ * @mem. This can be the global zone lruvec, if the memory controller
+ * is disabled.
+ */
+struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
+ struct mem_cgroup *memcg)
+{
+ struct mem_cgroup_per_zone *mz;
+
+ if (mem_cgroup_disabled())
+ return &zone->lruvec;
+
+ mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone));
+ return &mz->lruvec;
+}
+
+/*
+ * Following LRU functions are allowed to be used without PCG_LOCK.
+ * Operations are called by routine of global LRU independently from memcg.
+ * What we have to take care of here is validness of pc->mem_cgroup.
+ *
+ * Changes to pc->mem_cgroup happens when
+ * 1. charge
+ * 2. moving account
+ * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
+ * It is added to LRU before charge.
+ * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
+ * When moving account, the page is not on LRU. It's isolated.
+ */
+
+/**
+ * mem_cgroup_lru_add_list - account for adding an lru page and return lruvec
+ * @zone: zone of the page
+ * @page: the page
+ * @lru: current lru
+ *
+ * This function accounts for @page being added to @lru, and returns
+ * the lruvec for the given @zone and the memcg @page is charged to.
+ *
+ * The callsite is then responsible for physically linking the page to
+ * the returned lruvec->lists[@lru].
+ */
+struct lruvec *mem_cgroup_lru_add_list(struct zone *zone, struct page *page,
+ enum lru_list lru)
+{
+ struct mem_cgroup_per_zone *mz;
+ struct mem_cgroup *memcg;
+ struct page_cgroup *pc;
+
+ if (mem_cgroup_disabled())
+ return &zone->lruvec;
+
+ pc = lookup_page_cgroup(page);
+ memcg = pc->mem_cgroup;
+
+ /*
+ * Surreptitiously switch any uncharged page to root:
+ * an uncharged page off lru does nothing to secure
+ * its former mem_cgroup from sudden removal.
+ *
+ * Our caller holds lru_lock, and PageCgroupUsed is updated
+ * under page_cgroup lock: between them, they make all uses
+ * of pc->mem_cgroup safe.
+ */
+ if (!PageCgroupUsed(pc) && memcg != root_mem_cgroup)
+ pc->mem_cgroup = memcg = root_mem_cgroup;
+
+ mz = page_cgroup_zoneinfo(memcg, page);
+ /* compound_order() is stabilized through lru_lock */
+ mz->lru_size[lru] += 1 << compound_order(page);
+ return &mz->lruvec;
+}
+
+/**
+ * mem_cgroup_lru_del_list - account for removing an lru page
+ * @page: the page
+ * @lru: target lru
+ *
+ * This function accounts for @page being removed from @lru.
+ *
+ * The callsite is then responsible for physically unlinking
+ * @page->lru.
+ */
+void mem_cgroup_lru_del_list(struct page *page, enum lru_list lru)
+{
+ struct mem_cgroup_per_zone *mz;
+ struct mem_cgroup *memcg;
+ struct page_cgroup *pc;
+
+ if (mem_cgroup_disabled())
+ return;
+
+ pc = lookup_page_cgroup(page);
+ memcg = pc->mem_cgroup;
+ VM_BUG_ON(!memcg);
+ mz = page_cgroup_zoneinfo(memcg, page);
+ /* huge page split is done under lru_lock. so, we have no races. */
+ VM_BUG_ON(mz->lru_size[lru] < (1 << compound_order(page)));
+ mz->lru_size[lru] -= 1 << compound_order(page);
+}
+
+void mem_cgroup_lru_del(struct page *page)
+{
+ mem_cgroup_lru_del_list(page, page_lru(page));
+}
+
+/**
+ * mem_cgroup_lru_move_lists - account for moving a page between lrus
+ * @zone: zone of the page
+ * @page: the page
+ * @from: current lru
+ * @to: target lru
+ *
+ * This function accounts for @page being moved between the lrus @from
+ * and @to, and returns the lruvec for the given @zone and the memcg
+ * @page is charged to.
+ *
+ * The callsite is then responsible for physically relinking
+ * @page->lru to the returned lruvec->lists[@to].
+ */
+struct lruvec *mem_cgroup_lru_move_lists(struct zone *zone,
+ struct page *page,
+ enum lru_list from,
+ enum lru_list to)
+{
+ /* XXX: Optimize this, especially for @from == @to */
+ mem_cgroup_lru_del_list(page, from);
+ return mem_cgroup_lru_add_list(zone, page, to);
+}
+
+/*
+ * Checks whether given mem is same or in the root_mem_cgroup's
+ * hierarchy subtree
+ */
+static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
+ struct mem_cgroup *memcg)
+{
+ if (root_memcg != memcg) {
+ return (root_memcg->use_hierarchy &&
+ css_is_ancestor(&memcg->css, &root_memcg->css));
+ }
+
+ return true;
+}
+
+int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg)
+{
+ int ret;
+ struct mem_cgroup *curr = NULL;
+ struct task_struct *p;
+
+ p = find_lock_task_mm(task);
+ if (p) {
+ curr = try_get_mem_cgroup_from_mm(p->mm);
+ task_unlock(p);
+ } else {
+ /*
+ * All threads may have already detached their mm's, but the oom
+ * killer still needs to detect if they have already been oom
+ * killed to prevent needlessly killing additional tasks.
+ */
+ task_lock(task);
+ curr = mem_cgroup_from_task(task);
+ if (curr)
+ css_get(&curr->css);
+ task_unlock(task);
+ }
+ if (!curr)
+ return 0;
+ /*
+ * We should check use_hierarchy of "memcg" not "curr". Because checking
+ * use_hierarchy of "curr" here make this function true if hierarchy is
+ * enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
+ * hierarchy(even if use_hierarchy is disabled in "memcg").
+ */
+ ret = mem_cgroup_same_or_subtree(memcg, curr);
+ css_put(&curr->css);
+ return ret;
+}
+
+int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg, struct zone *zone)
+{
+ unsigned long inactive_ratio;
+ int nid = zone_to_nid(zone);
+ int zid = zone_idx(zone);
+ unsigned long inactive;
+ unsigned long active;
+ unsigned long gb;
+
+ inactive = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
+ BIT(LRU_INACTIVE_ANON));
+ active = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
+ BIT(LRU_ACTIVE_ANON));
+
+ gb = (inactive + active) >> (30 - PAGE_SHIFT);
+ if (gb)
+ inactive_ratio = int_sqrt(10 * gb);
+ else
+ inactive_ratio = 1;
+
+ return inactive * inactive_ratio < active;
+}
+
+int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg, struct zone *zone)
+{
+ unsigned long active;
+ unsigned long inactive;
+ int zid = zone_idx(zone);
+ int nid = zone_to_nid(zone);
+
+ inactive = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
+ BIT(LRU_INACTIVE_FILE));
+ active = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
+ BIT(LRU_ACTIVE_FILE));
+
+ return (active > inactive);
+}
+
+struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
+ struct zone *zone)
+{
+ int nid = zone_to_nid(zone);
+ int zid = zone_idx(zone);
+ struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
+
+ return &mz->reclaim_stat;
+}
+
+struct zone_reclaim_stat *
+mem_cgroup_get_reclaim_stat_from_page(struct page *page)
+{
+ struct page_cgroup *pc;
+ struct mem_cgroup_per_zone *mz;
+
+ if (mem_cgroup_disabled())
+ return NULL;
+
+ pc = lookup_page_cgroup(page);
+ if (!PageCgroupUsed(pc))
+ return NULL;
+ /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
+ smp_rmb();
+ mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
+ return &mz->reclaim_stat;
+}
+
+#define mem_cgroup_from_res_counter(counter, member) \
+ container_of(counter, struct mem_cgroup, member)
+
+/**
+ * mem_cgroup_margin - calculate chargeable space of a memory cgroup
+ * @mem: the memory cgroup
+ *
+ * Returns the maximum amount of memory @mem can be charged with, in
+ * pages.
+ */
+static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
+{
+ unsigned long long margin;
+
+ margin = res_counter_margin(&memcg->res);
+ if (do_swap_account)
+ margin = min(margin, res_counter_margin(&memcg->memsw));
+ return margin >> PAGE_SHIFT;
+}
+
+int mem_cgroup_swappiness(struct mem_cgroup *memcg)
+{
+ struct cgroup *cgrp = memcg->css.cgroup;
+
+ /* root ? */
+ if (cgrp->parent == NULL)
+ return vm_swappiness;
+
+ return memcg->swappiness;
+}
+
+/*
+ * memcg->moving_account is used for checking possibility that some thread is
+ * calling move_account(). When a thread on CPU-A starts moving pages under
+ * a memcg, other threads should check memcg->moving_account under
+ * rcu_read_lock(), like this:
+ *
+ * CPU-A CPU-B
+ * rcu_read_lock()
+ * memcg->moving_account+1 if (memcg->mocing_account)
+ * take heavy locks.
+ * synchronize_rcu() update something.
+ * rcu_read_unlock()
+ * start move here.
+ */
+
+/* for quick checking without looking up memcg */
+atomic_t memcg_moving __read_mostly;
+
+static void mem_cgroup_start_move(struct mem_cgroup *memcg)
+{
+ atomic_inc(&memcg_moving);
+ atomic_inc(&memcg->moving_account);
+ synchronize_rcu();
+}
+
+static void mem_cgroup_end_move(struct mem_cgroup *memcg)
+{
+ /*
+ * Now, mem_cgroup_clear_mc() may call this function with NULL.
+ * We check NULL in callee rather than caller.
+ */
+ if (memcg) {
+ atomic_dec(&memcg_moving);
+ atomic_dec(&memcg->moving_account);
+ }
+}
+
+/*
+ * 2 routines for checking "mem" is under move_account() or not.
+ *
+ * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
+ * is used for avoiding races in accounting. If true,
+ * pc->mem_cgroup may be overwritten.
+ *
+ * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
+ * under hierarchy of moving cgroups. This is for
+ * waiting at hith-memory prressure caused by "move".
+ */
+
+static bool mem_cgroup_stolen(struct mem_cgroup *memcg)
+{
+ VM_BUG_ON(!rcu_read_lock_held());
+ return atomic_read(&memcg->moving_account) > 0;
+}
+
+static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *from;
+ struct mem_cgroup *to;
+ bool ret = false;
+ /*
+ * Unlike task_move routines, we access mc.to, mc.from not under
+ * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
+ */
+ spin_lock(&mc.lock);
+ from = mc.from;
+ to = mc.to;
+ if (!from)
+ goto unlock;
+
+ ret = mem_cgroup_same_or_subtree(memcg, from)
+ || mem_cgroup_same_or_subtree(memcg, to);
+unlock:
+ spin_unlock(&mc.lock);
+ return ret;
+}
+
+static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
+{
+ if (mc.moving_task && current != mc.moving_task) {
+ if (mem_cgroup_under_move(memcg)) {
+ DEFINE_WAIT(wait);
+ prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
+ /* moving charge context might have finished. */
+ if (mc.moving_task)
+ schedule();
+ finish_wait(&mc.waitq, &wait);
+ return true;
+ }
+ }
+ return false;
+}
+
+/*
+ * Take this lock when
+ * - a code tries to modify page's memcg while it's USED.
+ * - a code tries to modify page state accounting in a memcg.
+ * see mem_cgroup_stolen(), too.
+ */
+static void move_lock_mem_cgroup(struct mem_cgroup *memcg,
+ unsigned long *flags)
+{
+ spin_lock_irqsave(&memcg->move_lock, *flags);
+}
+
+static void move_unlock_mem_cgroup(struct mem_cgroup *memcg,
+ unsigned long *flags)
+{
+ spin_unlock_irqrestore(&memcg->move_lock, *flags);
+}
+
+/**
+ * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
+ * @memcg: The memory cgroup that went over limit
+ * @p: Task that is going to be killed
+ *
+ * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
+ * enabled
+ */
+void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
+{
+ struct cgroup *task_cgrp;
+ struct cgroup *mem_cgrp;
+ /*
+ * Need a buffer in BSS, can't rely on allocations. The code relies
+ * on the assumption that OOM is serialized for memory controller.
+ * If this assumption is broken, revisit this code.
+ */
+ static char memcg_name[PATH_MAX];
+ int ret;
+
+ if (!memcg || !p)
+ return;
+
+ rcu_read_lock();
+
+ mem_cgrp = memcg->css.cgroup;
+ task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
+
+ ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
+ if (ret < 0) {
+ /*
+ * Unfortunately, we are unable to convert to a useful name
+ * But we'll still print out the usage information
+ */
+ rcu_read_unlock();
+ goto done;
+ }
+ rcu_read_unlock();
+
+ printk(KERN_INFO "Task in %s killed", memcg_name);
+
+ rcu_read_lock();
+ ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
+ if (ret < 0) {
+ rcu_read_unlock();
+ goto done;
+ }
+ rcu_read_unlock();
+
+ /*
+ * Continues from above, so we don't need an KERN_ level
+ */
+ printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
+done:
+
+ printk(KERN_INFO "memory: usage %llukB, limit %llukB, failcnt %llu\n",
+ res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
+ res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
+ res_counter_read_u64(&memcg->res, RES_FAILCNT));
+ printk(KERN_INFO "memory+swap: usage %llukB, limit %llukB, "
+ "failcnt %llu\n",
+ res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
+ res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
+ res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
+}
+
+/*
+ * This function returns the number of memcg under hierarchy tree. Returns
+ * 1(self count) if no children.
+ */
+static int mem_cgroup_count_children(struct mem_cgroup *memcg)
+{
+ int num = 0;
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg)
+ num++;
+ return num;
+}
+
+/*
+ * Return the memory (and swap, if configured) limit for a memcg.
+ */
+u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
+{
+ u64 limit;
+
+ limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
+
+ /*
+ * Do not consider swap space if we cannot swap due to swappiness
+ */
+ if (mem_cgroup_swappiness(memcg)) {
+ u64 memsw;
+
+ limit += total_swap_pages << PAGE_SHIFT;
+ memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+
+ /*
+ * If memsw is finite and limits the amount of swap space
+ * available to this memcg, return that limit.
+ */
+ limit = min(limit, memsw);
+ }
+
+ return limit;
+}
+
+static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg,
+ gfp_t gfp_mask,
+ unsigned long flags)
+{
+ unsigned long total = 0;
+ bool noswap = false;
+ int loop;
+
+ if (flags & MEM_CGROUP_RECLAIM_NOSWAP)
+ noswap = true;
+ if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum)
+ noswap = true;
+
+ for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) {
+ if (loop)
+ drain_all_stock_async(memcg);
+ total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap);
+ /*
+ * Allow limit shrinkers, which are triggered directly
+ * by userspace, to catch signals and stop reclaim
+ * after minimal progress, regardless of the margin.
+ */
+ if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK))
+ break;
+ if (mem_cgroup_margin(memcg))
+ break;
+ /*
+ * If nothing was reclaimed after two attempts, there
+ * may be no reclaimable pages in this hierarchy.
+ */
+ if (loop && !total)
+ break;
+ }
+ return total;
+}
+
+/**
+ * test_mem_cgroup_node_reclaimable
+ * @mem: the target memcg
+ * @nid: the node ID to be checked.
+ * @noswap : specify true here if the user wants flle only information.
+ *
+ * This function returns whether the specified memcg contains any
+ * reclaimable pages on a node. Returns true if there are any reclaimable
+ * pages in the node.
+ */
+static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg,
+ int nid, bool noswap)
+{
+ if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE))
+ return true;
+ if (noswap || !total_swap_pages)
+ return false;
+ if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON))
+ return true;
+ return false;
+
+}
+#if MAX_NUMNODES > 1
+
+/*
+ * Always updating the nodemask is not very good - even if we have an empty
+ * list or the wrong list here, we can start from some node and traverse all
+ * nodes based on the zonelist. So update the list loosely once per 10 secs.
+ *
+ */
+static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg)
+{
+ int nid;
+ /*
+ * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
+ * pagein/pageout changes since the last update.
+ */
+ if (!atomic_read(&memcg->numainfo_events))
+ return;
+ if (atomic_inc_return(&memcg->numainfo_updating) > 1)
+ return;
+
+ /* make a nodemask where this memcg uses memory from */
+ memcg->scan_nodes = node_states[N_HIGH_MEMORY];
+
+ for_each_node_mask(nid, node_states[N_HIGH_MEMORY]) {
+
+ if (!test_mem_cgroup_node_reclaimable(memcg, nid, false))
+ node_clear(nid, memcg->scan_nodes);
+ }
+
+ atomic_set(&memcg->numainfo_events, 0);
+ atomic_set(&memcg->numainfo_updating, 0);
+}
+
+/*
+ * Selecting a node where we start reclaim from. Because what we need is just
+ * reducing usage counter, start from anywhere is O,K. Considering
+ * memory reclaim from current node, there are pros. and cons.
+ *
+ * Freeing memory from current node means freeing memory from a node which
+ * we'll use or we've used. So, it may make LRU bad. And if several threads
+ * hit limits, it will see a contention on a node. But freeing from remote
+ * node means more costs for memory reclaim because of memory latency.
+ *
+ * Now, we use round-robin. Better algorithm is welcomed.
+ */
+int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
+{
+ int node;
+
+ mem_cgroup_may_update_nodemask(memcg);
+ node = memcg->last_scanned_node;
+
+ node = next_node(node, memcg->scan_nodes);
+ if (node == MAX_NUMNODES)
+ node = first_node(memcg->scan_nodes);
+ /*
+ * We call this when we hit limit, not when pages are added to LRU.
+ * No LRU may hold pages because all pages are UNEVICTABLE or
+ * memcg is too small and all pages are not on LRU. In that case,
+ * we use curret node.
+ */
+ if (unlikely(node == MAX_NUMNODES))
+ node = numa_node_id();
+
+ memcg->last_scanned_node = node;
+ return node;
+}
+
+/*
+ * Check all nodes whether it contains reclaimable pages or not.
+ * For quick scan, we make use of scan_nodes. This will allow us to skip
+ * unused nodes. But scan_nodes is lazily updated and may not cotain
+ * enough new information. We need to do double check.
+ */
+bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
+{
+ int nid;
+
+ /*
+ * quick check...making use of scan_node.
+ * We can skip unused nodes.
+ */
+ if (!nodes_empty(memcg->scan_nodes)) {
+ for (nid = first_node(memcg->scan_nodes);
+ nid < MAX_NUMNODES;
+ nid = next_node(nid, memcg->scan_nodes)) {
+
+ if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap))
+ return true;
+ }
+ }
+ /*
+ * Check rest of nodes.
+ */
+ for_each_node_state(nid, N_HIGH_MEMORY) {
+ if (node_isset(nid, memcg->scan_nodes))
+ continue;
+ if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap))
+ return true;
+ }
+ return false;
+}
+
+#else
+int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
+{
+ return 0;
+}
+
+bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
+{
+ return test_mem_cgroup_node_reclaimable(memcg, 0, noswap);
+}
+#endif
+
+static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
+ struct zone *zone,
+ gfp_t gfp_mask,
+ unsigned long *total_scanned)
+{
+ struct mem_cgroup *victim = NULL;
+ int total = 0;
+ int loop = 0;
+ unsigned long excess;
+ unsigned long nr_scanned;
+ struct mem_cgroup_reclaim_cookie reclaim = {
+ .zone = zone,
+ .priority = 0,
+ };
+
+ excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
+
+ while (1) {
+ victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
+ if (!victim) {
+ loop++;
+ if (loop >= 2) {
+ /*
+ * If we have not been able to reclaim
+ * anything, it might because there are
+ * no reclaimable pages under this hierarchy
+ */
+ if (!total)
+ break;
+ /*
+ * We want to do more targeted reclaim.
+ * excess >> 2 is not to excessive so as to
+ * reclaim too much, nor too less that we keep
+ * coming back to reclaim from this cgroup
+ */
+ if (total >= (excess >> 2) ||
+ (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
+ break;
+ }
+ continue;
+ }
+ if (!mem_cgroup_reclaimable(victim, false))
+ continue;
+ total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
+ zone, &nr_scanned);
+ *total_scanned += nr_scanned;
+ if (!res_counter_soft_limit_excess(&root_memcg->res))
+ break;
+ }
+ mem_cgroup_iter_break(root_memcg, victim);
+ return total;
+}
+
+/*
+ * Check OOM-Killer is already running under our hierarchy.
+ * If someone is running, return false.
+ * Has to be called with memcg_oom_lock
+ */
+static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter, *failed = NULL;
+
+ for_each_mem_cgroup_tree(iter, memcg) {
+ if (iter->oom_lock) {
+ /*
+ * this subtree of our hierarchy is already locked
+ * so we cannot give a lock.
+ */
+ failed = iter;
+ mem_cgroup_iter_break(memcg, iter);
+ break;
+ } else
+ iter->oom_lock = true;
+ }
+
+ if (!failed)
+ return true;
+
+ /*
+ * OK, we failed to lock the whole subtree so we have to clean up
+ * what we set up to the failing subtree
+ */
+ for_each_mem_cgroup_tree(iter, memcg) {
+ if (iter == failed) {
+ mem_cgroup_iter_break(memcg, iter);
+ break;
+ }
+ iter->oom_lock = false;
+ }
+ return false;
+}
+
+/*
+ * Has to be called with memcg_oom_lock
+ */
+static int mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg)
+ iter->oom_lock = false;
+ return 0;
+}
+
+static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg)
+ atomic_inc(&iter->under_oom);
+}
+
+static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ /*
+ * When a new child is created while the hierarchy is under oom,
+ * mem_cgroup_oom_lock() may not be called. We have to use
+ * atomic_add_unless() here.
+ */
+ for_each_mem_cgroup_tree(iter, memcg)
+ atomic_add_unless(&iter->under_oom, -1, 0);
+}
+
+static DEFINE_SPINLOCK(memcg_oom_lock);
+static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
+
+struct oom_wait_info {
+ struct mem_cgroup *memcg;
+ wait_queue_t wait;
+};
+
+static int memcg_oom_wake_function(wait_queue_t *wait,
+ unsigned mode, int sync, void *arg)
+{
+ struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg;
+ struct mem_cgroup *oom_wait_memcg;
+ struct oom_wait_info *oom_wait_info;
+
+ oom_wait_info = container_of(wait, struct oom_wait_info, wait);
+ oom_wait_memcg = oom_wait_info->memcg;
+
+ /*
+ * Both of oom_wait_info->memcg and wake_memcg are stable under us.
+ * Then we can use css_is_ancestor without taking care of RCU.
+ */
+ if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg)
+ && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg))
+ return 0;
+ return autoremove_wake_function(wait, mode, sync, arg);
+}
+
+static void memcg_wakeup_oom(struct mem_cgroup *memcg)
+{
+ /* for filtering, pass "memcg" as argument. */
+ __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
+}
+
+static void memcg_oom_recover(struct mem_cgroup *memcg)
+{
+ if (memcg && atomic_read(&memcg->under_oom))
+ memcg_wakeup_oom(memcg);
+}
+
+/*
+ * try to call OOM killer. returns false if we should exit memory-reclaim loop.
+ */
+bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
+{
+ struct oom_wait_info owait;
+ bool locked, need_to_kill;
+
+ owait.memcg = memcg;
+ owait.wait.flags = 0;
+ owait.wait.func = memcg_oom_wake_function;
+ owait.wait.private = current;
+ INIT_LIST_HEAD(&owait.wait.task_list);
+ need_to_kill = true;
+ mem_cgroup_mark_under_oom(memcg);
+
+ /* At first, try to OOM lock hierarchy under memcg.*/
+ spin_lock(&memcg_oom_lock);
+ locked = mem_cgroup_oom_lock(memcg);
+ /*
+ * Even if signal_pending(), we can't quit charge() loop without
+ * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
+ * under OOM is always welcomed, use TASK_KILLABLE here.
+ */
+ prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
+ if (!locked || memcg->oom_kill_disable)
+ need_to_kill = false;
+ if (locked)
+ mem_cgroup_oom_notify(memcg);
+ spin_unlock(&memcg_oom_lock);
+
+ if (need_to_kill) {
+ finish_wait(&memcg_oom_waitq, &owait.wait);
+ mem_cgroup_out_of_memory(memcg, mask, order);
+ } else {
+ schedule();
+ finish_wait(&memcg_oom_waitq, &owait.wait);
+ }
+ spin_lock(&memcg_oom_lock);
+ if (locked)
+ mem_cgroup_oom_unlock(memcg);
+ memcg_wakeup_oom(memcg);
+ spin_unlock(&memcg_oom_lock);
+
+ mem_cgroup_unmark_under_oom(memcg);
+
+ if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
+ return false;
+ /* Give chance to dying process */
+ schedule_timeout_uninterruptible(1);
+ return true;
+}
+
+/*
+ * Currently used to update mapped file statistics, but the routine can be
+ * generalized to update other statistics as well.
+ *
+ * Notes: Race condition
+ *
+ * We usually use page_cgroup_lock() for accessing page_cgroup member but
+ * it tends to be costly. But considering some conditions, we doesn't need
+ * to do so _always_.
+ *
+ * Considering "charge", lock_page_cgroup() is not required because all
+ * file-stat operations happen after a page is attached to radix-tree. There
+ * are no race with "charge".
+ *
+ * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
+ * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
+ * if there are race with "uncharge". Statistics itself is properly handled
+ * by flags.
+ *
+ * Considering "move", this is an only case we see a race. To make the race
+ * small, we check mm->moving_account and detect there are possibility of race
+ * If there is, we take a lock.
+ */
+
+void __mem_cgroup_begin_update_page_stat(struct page *page,
+ bool *locked, unsigned long *flags)
+{
+ struct mem_cgroup *memcg;
+ struct page_cgroup *pc;
+
+ pc = lookup_page_cgroup(page);
+again:
+ memcg = pc->mem_cgroup;
+ if (unlikely(!memcg || !PageCgroupUsed(pc)))
+ return;
+ /*
+ * If this memory cgroup is not under account moving, we don't
+ * need to take move_lock_page_cgroup(). Because we already hold
+ * rcu_read_lock(), any calls to move_account will be delayed until
+ * rcu_read_unlock() if mem_cgroup_stolen() == true.
+ */
+ if (!mem_cgroup_stolen(memcg))
+ return;
+
+ move_lock_mem_cgroup(memcg, flags);
+ if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) {
+ move_unlock_mem_cgroup(memcg, flags);
+ goto again;
+ }
+ *locked = true;
+}
+
+void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags)
+{
+ struct page_cgroup *pc = lookup_page_cgroup(page);
+
+ /*
+ * It's guaranteed that pc->mem_cgroup never changes while
+ * lock is held because a routine modifies pc->mem_cgroup
+ * should take move_lock_page_cgroup().
+ */
+ move_unlock_mem_cgroup(pc->mem_cgroup, flags);
+}
+
+void mem_cgroup_update_page_stat(struct page *page,
+ enum mem_cgroup_page_stat_item idx, int val)
+{
+ struct mem_cgroup *memcg;
+ struct page_cgroup *pc = lookup_page_cgroup(page);
+ unsigned long uninitialized_var(flags);
+
+ if (mem_cgroup_disabled())
+ return;
+
+ memcg = pc->mem_cgroup;
+ if (unlikely(!memcg || !PageCgroupUsed(pc)))
+ return;
+
+ switch (idx) {
+ case MEMCG_NR_FILE_MAPPED:
+ idx = MEM_CGROUP_STAT_FILE_MAPPED;
+ break;
+ default:
+ BUG();
+ }
+
+ this_cpu_add(memcg->stat->count[idx], val);
+}
+
+/*
+ * size of first charge trial. "32" comes from vmscan.c's magic value.
+ * TODO: maybe necessary to use big numbers in big irons.
+ */
+#define CHARGE_BATCH 32U
+struct memcg_stock_pcp {
+ struct mem_cgroup *cached; /* this never be root cgroup */
+ unsigned int nr_pages;
+ struct work_struct work;
+ unsigned long flags;
+#define FLUSHING_CACHED_CHARGE (0)
+};
+static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
+static DEFINE_MUTEX(percpu_charge_mutex);
+
+/*
+ * Try to consume stocked charge on this cpu. If success, one page is consumed
+ * from local stock and true is returned. If the stock is 0 or charges from a
+ * cgroup which is not current target, returns false. This stock will be
+ * refilled.
+ */
+static bool consume_stock(struct mem_cgroup *memcg)
+{
+ struct memcg_stock_pcp *stock;
+ bool ret = true;
+
+ stock = &get_cpu_var(memcg_stock);
+ if (memcg == stock->cached && stock->nr_pages)
+ stock->nr_pages--;
+ else /* need to call res_counter_charge */
+ ret = false;
+ put_cpu_var(memcg_stock);
+ return ret;
+}
+
+/*
+ * Returns stocks cached in percpu to res_counter and reset cached information.
+ */
+static void drain_stock(struct memcg_stock_pcp *stock)
+{
+ struct mem_cgroup *old = stock->cached;
+
+ if (stock->nr_pages) {
+ unsigned long bytes = stock->nr_pages * PAGE_SIZE;
+
+ res_counter_uncharge(&old->res, bytes);
+ if (do_swap_account)
+ res_counter_uncharge(&old->memsw, bytes);
+ stock->nr_pages = 0;
+ }
+ stock->cached = NULL;
+}
+
+/*
+ * This must be called under preempt disabled or must be called by
+ * a thread which is pinned to local cpu.
+ */
+static void drain_local_stock(struct work_struct *dummy)
+{
+ struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
+ drain_stock(stock);
+ clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
+}
+
+/*
+ * Cache charges(val) which is from res_counter, to local per_cpu area.
+ * This will be consumed by consume_stock() function, later.
+ */
+static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
+{
+ struct memcg_stock_pcp *stock;
+ int cpu = get_cpu_light();
+
+ stock = &per_cpu(memcg_stock, cpu);
+
+ if (stock->cached != memcg) { /* reset if necessary */
+ drain_stock(stock);
+ stock->cached = memcg;
+ }
+ stock->nr_pages += nr_pages;
+ put_cpu_light();
+}
+
+/*
+ * Drains all per-CPU charge caches for given root_memcg resp. subtree
+ * of the hierarchy under it. sync flag says whether we should block
+ * until the work is done.
+ */
+static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync)
+{
+ int cpu, curcpu;
+
+ /* Notify other cpus that system-wide "drain" is running */
+ get_online_cpus();
+ curcpu = get_cpu_light();
+ for_each_online_cpu(cpu) {
+ struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
+ struct mem_cgroup *memcg;
+
+ memcg = stock->cached;
+ if (!memcg || !stock->nr_pages)
+ continue;
+ if (!mem_cgroup_same_or_subtree(root_memcg, memcg))
+ continue;
+ if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {
+ if (cpu == curcpu)
+ drain_local_stock(&stock->work);
+ else
+ schedule_work_on(cpu, &stock->work);
+ }
+ }
+ put_cpu_light();
+
+ if (!sync)
+ goto out;
+
+ for_each_online_cpu(cpu) {
+ struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
+ if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags))
+ flush_work(&stock->work);
+ }
+out:
+ put_online_cpus();
+}
+
+/*
+ * Tries to drain stocked charges in other cpus. This function is asynchronous
+ * and just put a work per cpu for draining localy on each cpu. Caller can
+ * expects some charges will be back to res_counter later but cannot wait for
+ * it.
+ */
+static void drain_all_stock_async(struct mem_cgroup *root_memcg)
+{
+ /*
+ * If someone calls draining, avoid adding more kworker runs.
+ */
+ if (!mutex_trylock(&percpu_charge_mutex))
+ return;
+ drain_all_stock(root_memcg, false);
+ mutex_unlock(&percpu_charge_mutex);
+}
+
+/* This is a synchronous drain interface. */
+static void drain_all_stock_sync(struct mem_cgroup *root_memcg)
+{
+ /* called when force_empty is called */
+ mutex_lock(&percpu_charge_mutex);
+ drain_all_stock(root_memcg, true);
+ mutex_unlock(&percpu_charge_mutex);
+}
+
+/*
+ * This function drains percpu counter value from DEAD cpu and
+ * move it to local cpu. Note that this function can be preempted.
+ */
+static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu)
+{
+ int i;
+
+ spin_lock(&memcg->pcp_counter_lock);
+ for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) {
+ long x = per_cpu(memcg->stat->count[i], cpu);
+
+ per_cpu(memcg->stat->count[i], cpu) = 0;
+ memcg->nocpu_base.count[i] += x;
+ }
+ for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
+ unsigned long x = per_cpu(memcg->stat->events[i], cpu);
+
+ per_cpu(memcg->stat->events[i], cpu) = 0;
+ memcg->nocpu_base.events[i] += x;
+ }
+ spin_unlock(&memcg->pcp_counter_lock);
+}
+
+static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
+ unsigned long action,
+ void *hcpu)
+{
+ int cpu = (unsigned long)hcpu;
+ struct memcg_stock_pcp *stock;
+ struct mem_cgroup *iter;
+
+ if (action == CPU_ONLINE)
+ return NOTIFY_OK;
+
+ if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
+ return NOTIFY_OK;
+
+ for_each_mem_cgroup(iter)
+ mem_cgroup_drain_pcp_counter(iter, cpu);
+
+ stock = &per_cpu(memcg_stock, cpu);
+ drain_stock(stock);
+ return NOTIFY_OK;
+}
+
+
+/* See __mem_cgroup_try_charge() for details */
+enum {
+ CHARGE_OK, /* success */
+ CHARGE_RETRY, /* need to retry but retry is not bad */
+ CHARGE_NOMEM, /* we can't do more. return -ENOMEM */
+ CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */
+ CHARGE_OOM_DIE, /* the current is killed because of OOM */
+};
+
+static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
+ unsigned int nr_pages, bool oom_check)
+{
+ unsigned long csize = nr_pages * PAGE_SIZE;
+ struct mem_cgroup *mem_over_limit;
+ struct res_counter *fail_res;
+ unsigned long flags = 0;
+ int ret;
+
+ ret = res_counter_charge(&memcg->res, csize, &fail_res);
+
+ if (likely(!ret)) {
+ if (!do_swap_account)
+ return CHARGE_OK;
+ ret = res_counter_charge(&memcg->memsw, csize, &fail_res);
+ if (likely(!ret))
+ return CHARGE_OK;
+
+ res_counter_uncharge(&memcg->res, csize);
+ mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
+ flags |= MEM_CGROUP_RECLAIM_NOSWAP;
+ } else
+ mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
+ /*
+ * nr_pages can be either a huge page (HPAGE_PMD_NR), a batch
+ * of regular pages (CHARGE_BATCH), or a single regular page (1).
+ *
+ * Never reclaim on behalf of optional batching, retry with a
+ * single page instead.
+ */
+ if (nr_pages == CHARGE_BATCH)
+ return CHARGE_RETRY;
+
+ if (!(gfp_mask & __GFP_WAIT))
+ return CHARGE_WOULDBLOCK;
+
+ ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags);
+ if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
+ return CHARGE_RETRY;
+ /*
+ * Even though the limit is exceeded at this point, reclaim
+ * may have been able to free some pages. Retry the charge
+ * before killing the task.
+ *
+ * Only for regular pages, though: huge pages are rather
+ * unlikely to succeed so close to the limit, and we fall back
+ * to regular pages anyway in case of failure.
+ */
+ if (nr_pages == 1 && ret)
+ return CHARGE_RETRY;
+
+ /*
+ * At task move, charge accounts can be doubly counted. So, it's
+ * better to wait until the end of task_move if something is going on.
+ */
+ if (mem_cgroup_wait_acct_move(mem_over_limit))
+ return CHARGE_RETRY;
+
+ /* If we don't need to call oom-killer at el, return immediately */
+ if (!oom_check)
+ return CHARGE_NOMEM;
+ /* check OOM */
+ if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask, get_order(csize)))
+ return CHARGE_OOM_DIE;
+
+ return CHARGE_RETRY;
+}
+
+/*
+ * __mem_cgroup_try_charge() does
+ * 1. detect memcg to be charged against from passed *mm and *ptr,
+ * 2. update res_counter
+ * 3. call memory reclaim if necessary.
+ *
+ * In some special case, if the task is fatal, fatal_signal_pending() or
+ * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
+ * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
+ * as possible without any hazards. 2: all pages should have a valid
+ * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
+ * pointer, that is treated as a charge to root_mem_cgroup.
+ *
+ * So __mem_cgroup_try_charge() will return
+ * 0 ... on success, filling *ptr with a valid memcg pointer.
+ * -ENOMEM ... charge failure because of resource limits.
+ * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
+ *
+ * Unlike the exported interface, an "oom" parameter is added. if oom==true,
+ * the oom-killer can be invoked.
+ */
+static int __mem_cgroup_try_charge(struct mm_struct *mm,
+ gfp_t gfp_mask,
+ unsigned int nr_pages,
+ struct mem_cgroup **ptr,
+ bool oom)
+{
+ unsigned int batch = max(CHARGE_BATCH, nr_pages);
+ int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
+ struct mem_cgroup *memcg = NULL;
+ int ret;
+
+ /*
+ * Unlike gloval-vm's OOM-kill, we're not in memory shortage
+ * in system level. So, allow to go ahead dying process in addition to
+ * MEMDIE process.
+ */
+ if (unlikely(test_thread_flag(TIF_MEMDIE)
+ || fatal_signal_pending(current)))
+ goto bypass;
+
+ /*
+ * We always charge the cgroup the mm_struct belongs to.
+ * The mm_struct's mem_cgroup changes on task migration if the
+ * thread group leader migrates. It's possible that mm is not
+ * set, if so charge the init_mm (happens for pagecache usage).
+ */
+ if (!*ptr && !mm)
+ *ptr = root_mem_cgroup;
+again:
+ if (*ptr) { /* css should be a valid one */
+ memcg = *ptr;
+ VM_BUG_ON(css_is_removed(&memcg->css));
+ if (mem_cgroup_is_root(memcg))
+ goto done;
+ if (nr_pages == 1 && consume_stock(memcg))
+ goto done;
+ css_get(&memcg->css);
+ } else {
+ struct task_struct *p;
+
+ rcu_read_lock();
+ p = rcu_dereference(mm->owner);
+ /*
+ * Because we don't have task_lock(), "p" can exit.
+ * In that case, "memcg" can point to root or p can be NULL with
+ * race with swapoff. Then, we have small risk of mis-accouning.
+ * But such kind of mis-account by race always happens because
+ * we don't have cgroup_mutex(). It's overkill and we allo that
+ * small race, here.
+ * (*) swapoff at el will charge against mm-struct not against
+ * task-struct. So, mm->owner can be NULL.
+ */
+ memcg = mem_cgroup_from_task(p);
+ if (!memcg)
+ memcg = root_mem_cgroup;
+ if (mem_cgroup_is_root(memcg)) {
+ rcu_read_unlock();
+ goto done;
+ }
+ if (nr_pages == 1 && consume_stock(memcg)) {
+ /*
+ * It seems dagerous to access memcg without css_get().
+ * But considering how consume_stok works, it's not
+ * necessary. If consume_stock success, some charges
+ * from this memcg are cached on this cpu. So, we
+ * don't need to call css_get()/css_tryget() before
+ * calling consume_stock().
+ */
+ rcu_read_unlock();
+ goto done;
+ }
+ /* after here, we may be blocked. we need to get refcnt */
+ if (!css_tryget(&memcg->css)) {
+ rcu_read_unlock();
+ goto again;
+ }
+ rcu_read_unlock();
+ }
+
+ do {
+ bool oom_check;
+
+ /* If killed, bypass charge */
+ if (fatal_signal_pending(current)) {
+ css_put(&memcg->css);
+ goto bypass;
+ }
+
+ oom_check = false;
+ if (oom && !nr_oom_retries) {
+ oom_check = true;
+ nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
+ }
+
+ ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, oom_check);
+ switch (ret) {
+ case CHARGE_OK:
+ break;
+ case CHARGE_RETRY: /* not in OOM situation but retry */
+ batch = nr_pages;
+ css_put(&memcg->css);
+ memcg = NULL;
+ goto again;
+ case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
+ css_put(&memcg->css);
+ goto nomem;
+ case CHARGE_NOMEM: /* OOM routine works */
+ if (!oom) {
+ css_put(&memcg->css);
+ goto nomem;
+ }
+ /* If oom, we never return -ENOMEM */
+ nr_oom_retries--;
+ break;
+ case CHARGE_OOM_DIE: /* Killed by OOM Killer */
+ css_put(&memcg->css);
+ goto bypass;
+ }
+ } while (ret != CHARGE_OK);
+
+ if (batch > nr_pages)
+ refill_stock(memcg, batch - nr_pages);
+ css_put(&memcg->css);
+done:
+ *ptr = memcg;
+ return 0;
+nomem:
+ *ptr = NULL;
+ return -ENOMEM;
+bypass:
+ *ptr = root_mem_cgroup;
+ return -EINTR;
+}
+
+/*
+ * Somemtimes we have to undo a charge we got by try_charge().
+ * This function is for that and do uncharge, put css's refcnt.
+ * gotten by try_charge().
+ */
+static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg,
+ unsigned int nr_pages)
+{
+ if (!mem_cgroup_is_root(memcg)) {
+ unsigned long bytes = nr_pages * PAGE_SIZE;
+
+ res_counter_uncharge(&memcg->res, bytes);
+ if (do_swap_account)
+ res_counter_uncharge(&memcg->memsw, bytes);
+ }
+}
+
+/*
+ * A helper function to get mem_cgroup from ID. must be called under
+ * rcu_read_lock(). The caller must check css_is_removed() or some if
+ * it's concern. (dropping refcnt from swap can be called against removed
+ * memcg.)
+ */
+static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
+{
+ struct cgroup_subsys_state *css;
+
+ /* ID 0 is unused ID */
+ if (!id)
+ return NULL;
+ css = css_lookup(&mem_cgroup_subsys, id);
+ if (!css)
+ return NULL;
+ return container_of(css, struct mem_cgroup, css);
+}
+
+struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
+{
+ struct mem_cgroup *memcg = NULL;
+ struct page_cgroup *pc;
+ unsigned short id;
+ swp_entry_t ent;
+
+ VM_BUG_ON(!PageLocked(page));
+
+ pc = lookup_page_cgroup(page);
+ lock_page_cgroup(pc);
+ if (PageCgroupUsed(pc)) {
+ memcg = pc->mem_cgroup;
+ if (memcg && !css_tryget(&memcg->css))
+ memcg = NULL;
+ } else if (PageSwapCache(page)) {
+ ent.val = page_private(page);
+ id = lookup_swap_cgroup_id(ent);
+ rcu_read_lock();
+ memcg = mem_cgroup_lookup(id);
+ if (memcg && !css_tryget(&memcg->css))
+ memcg = NULL;
+ rcu_read_unlock();
+ }
+ unlock_page_cgroup(pc);
+ return memcg;
+}
+
+static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
+ struct page *page,
+ unsigned int nr_pages,
+ enum charge_type ctype,
+ bool lrucare)
+{
+ struct page_cgroup *pc = lookup_page_cgroup(page);
+ struct zone *uninitialized_var(zone);
+ bool was_on_lru = false;
+ bool anon;
+
+ lock_page_cgroup(pc);
+ if (unlikely(PageCgroupUsed(pc))) {
+ unlock_page_cgroup(pc);
+ __mem_cgroup_cancel_charge(memcg, nr_pages);
+ return;
+ }
+ /*
+ * we don't need page_cgroup_lock about tail pages, becase they are not
+ * accessed by any other context at this point.
+ */
+
+ /*
+ * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
+ * may already be on some other mem_cgroup's LRU. Take care of it.
+ */
+ if (lrucare) {
+ zone = page_zone(page);
+ spin_lock_irq(&zone->lru_lock);
+ if (PageLRU(page)) {
+ ClearPageLRU(page);
+ del_page_from_lru_list(zone, page, page_lru(page));
+ was_on_lru = true;
+ }
+ }
+
+ pc->mem_cgroup = memcg;
+ /*
+ * We access a page_cgroup asynchronously without lock_page_cgroup().
+ * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
+ * is accessed after testing USED bit. To make pc->mem_cgroup visible
+ * before USED bit, we need memory barrier here.
+ * See mem_cgroup_add_lru_list(), etc.
+ */
+ smp_wmb();
+ SetPageCgroupUsed(pc);
+
+ if (lrucare) {
+ if (was_on_lru) {
+ VM_BUG_ON(PageLRU(page));
+ SetPageLRU(page);
+ add_page_to_lru_list(zone, page, page_lru(page));
+ }
+ spin_unlock_irq(&zone->lru_lock);
+ }
+
+ if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
+ anon = true;
+ else
+ anon = false;
+
+ mem_cgroup_charge_statistics(memcg, anon, nr_pages);
+ unlock_page_cgroup(pc);
+
+ /*
+ * "charge_statistics" updated event counter. Then, check it.
+ * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
+ * if they exceeds softlimit.
+ */
+ memcg_check_events(memcg, page);
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+#define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MIGRATION))
+/*
+ * Because tail pages are not marked as "used", set it. We're under
+ * zone->lru_lock, 'splitting on pmd' and compound_lock.
+ * charge/uncharge will be never happen and move_account() is done under
+ * compound_lock(), so we don't have to take care of races.
+ */
+void mem_cgroup_split_huge_fixup(struct page *head)
+{
+ struct page_cgroup *head_pc = lookup_page_cgroup(head);
+ struct page_cgroup *pc;
+ int i;
+
+ if (mem_cgroup_disabled())
+ return;
+ for (i = 1; i < HPAGE_PMD_NR; i++) {
+ pc = head_pc + i;
+ pc->mem_cgroup = head_pc->mem_cgroup;
+ smp_wmb();/* see __commit_charge() */
+ pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
+ }
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+/**
+ * mem_cgroup_move_account - move account of the page
+ * @page: the page
+ * @nr_pages: number of regular pages (>1 for huge pages)
+ * @pc: page_cgroup of the page.
+ * @from: mem_cgroup which the page is moved from.
+ * @to: mem_cgroup which the page is moved to. @from != @to.
+ * @uncharge: whether we should call uncharge and css_put against @from.
+ *
+ * The caller must confirm following.
+ * - page is not on LRU (isolate_page() is useful.)
+ * - compound_lock is held when nr_pages > 1
+ *
+ * This function doesn't do "charge" nor css_get to new cgroup. It should be
+ * done by a caller(__mem_cgroup_try_charge would be useful). If @uncharge is
+ * true, this function does "uncharge" from old cgroup, but it doesn't if
+ * @uncharge is false, so a caller should do "uncharge".
+ */
+static int mem_cgroup_move_account(struct page *page,
+ unsigned int nr_pages,
+ struct page_cgroup *pc,
+ struct mem_cgroup *from,
+ struct mem_cgroup *to,
+ bool uncharge)
+{
+ unsigned long flags;
+ int ret;
+ bool anon = PageAnon(page);
+
+ VM_BUG_ON(from == to);
+ VM_BUG_ON(PageLRU(page));
+ /*
+ * The page is isolated from LRU. So, collapse function
+ * will not handle this page. But page splitting can happen.
+ * Do this check under compound_page_lock(). The caller should
+ * hold it.
+ */
+ ret = -EBUSY;
+ if (nr_pages > 1 && !PageTransHuge(page))
+ goto out;
+
+ lock_page_cgroup(pc);
+
+ ret = -EINVAL;
+ if (!PageCgroupUsed(pc) || pc->mem_cgroup != from)
+ goto unlock;
+
+ move_lock_mem_cgroup(from, &flags);
+
+ if (!anon && page_mapped(page)) {
+ /* Update mapped_file data for mem_cgroup */
+ preempt_disable();
+ __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
+ __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
+ preempt_enable();
+ }
+ mem_cgroup_charge_statistics(from, anon, -nr_pages);
+ if (uncharge)
+ /* This is not "cancel", but cancel_charge does all we need. */
+ __mem_cgroup_cancel_charge(from, nr_pages);
+
+ /* caller should have done css_get */
+ pc->mem_cgroup = to;
+ mem_cgroup_charge_statistics(to, anon, nr_pages);
+ /*
+ * We charges against "to" which may not have any tasks. Then, "to"
+ * can be under rmdir(). But in current implementation, caller of
+ * this function is just force_empty() and move charge, so it's
+ * guaranteed that "to" is never removed. So, we don't check rmdir
+ * status here.
+ */
+ move_unlock_mem_cgroup(from, &flags);
+ ret = 0;
+unlock:
+ unlock_page_cgroup(pc);
+ /*
+ * check events
+ */
+ memcg_check_events(to, page);
+ memcg_check_events(from, page);
+out:
+ return ret;
+}
+
+/*
+ * move charges to its parent.
+ */
+
+static int mem_cgroup_move_parent(struct page *page,
+ struct page_cgroup *pc,
+ struct mem_cgroup *child,
+ gfp_t gfp_mask)
+{
+ struct cgroup *cg = child->css.cgroup;
+ struct cgroup *pcg = cg->parent;
+ struct mem_cgroup *parent;
+ unsigned int nr_pages;
+ unsigned long uninitialized_var(flags);
+ int ret;
+
+ /* Is ROOT ? */
+ if (!pcg)
+ return -EINVAL;
+
+ ret = -EBUSY;
+ if (!get_page_unless_zero(page))
+ goto out;
+ if (isolate_lru_page(page))
+ goto put;
+
+ nr_pages = hpage_nr_pages(page);
+
+ parent = mem_cgroup_from_cont(pcg);
+ ret = __mem_cgroup_try_charge(NULL, gfp_mask, nr_pages, &parent, false);
+ if (ret)
+ goto put_back;
+
+ if (nr_pages > 1)
+ flags = compound_lock_irqsave(page);
+
+ ret = mem_cgroup_move_account(page, nr_pages, pc, child, parent, true);
+ if (ret)
+ __mem_cgroup_cancel_charge(parent, nr_pages);
+
+ if (nr_pages > 1)
+ compound_unlock_irqrestore(page, flags);
+put_back:
+ putback_lru_page(page);
+put:
+ put_page(page);
+out:
+ return ret;
+}
+
+/*
+ * Charge the memory controller for page usage.
+ * Return
+ * 0 if the charge was successful
+ * < 0 if the cgroup is over its limit
+ */
+static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
+ gfp_t gfp_mask, enum charge_type ctype)
+{
+ struct mem_cgroup *memcg = NULL;
+ unsigned int nr_pages = 1;
+ bool oom = true;
+ int ret;
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON(!PageTransHuge(page));
+ /*
+ * Never OOM-kill a process for a huge page. The
+ * fault handler will fall back to regular pages.
+ */
+ oom = false;
+ }
+
+ ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
+ if (ret == -ENOMEM)
+ return ret;
+ __mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false);
+ return 0;
+}
+
+int mem_cgroup_newpage_charge(struct page *page,
+ struct mm_struct *mm, gfp_t gfp_mask)
+{
+ if (mem_cgroup_disabled())
+ return 0;
+ VM_BUG_ON(page_mapped(page));
+ VM_BUG_ON(page->mapping && !PageAnon(page));
+ VM_BUG_ON(!mm);
+ return mem_cgroup_charge_common(page, mm, gfp_mask,
+ MEM_CGROUP_CHARGE_TYPE_MAPPED);
+}
+
+static void
+__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
+ enum charge_type ctype);
+
+int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
+ gfp_t gfp_mask)
+{
+ struct mem_cgroup *memcg = NULL;
+ enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
+ int ret;
+
+ if (mem_cgroup_disabled())
+ return 0;
+ if (PageCompound(page))
+ return 0;
+
+ if (unlikely(!mm))
+ mm = &init_mm;
+ if (!page_is_file_cache(page))
+ type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
+
+ if (!PageSwapCache(page))
+ ret = mem_cgroup_charge_common(page, mm, gfp_mask, type);
+ else { /* page is swapcache/shmem */
+ ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg);
+ if (!ret)
+ __mem_cgroup_commit_charge_swapin(page, memcg, type);
+ }
+ return ret;
+}
+
+/*
+ * While swap-in, try_charge -> commit or cancel, the page is locked.
+ * And when try_charge() successfully returns, one refcnt to memcg without
+ * struct page_cgroup is acquired. This refcnt will be consumed by
+ * "commit()" or removed by "cancel()"
+ */
+int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
+ struct page *page,
+ gfp_t mask, struct mem_cgroup **memcgp)
+{
+ struct mem_cgroup *memcg;
+ int ret;
+
+ *memcgp = NULL;
+
+ if (mem_cgroup_disabled())
+ return 0;
+
+ if (!do_swap_account)
+ goto charge_cur_mm;
+ /*
+ * A racing thread's fault, or swapoff, may have already updated
+ * the pte, and even removed page from swap cache: in those cases
+ * do_swap_page()'s pte_same() test will fail; but there's also a
+ * KSM case which does need to charge the page.
+ */
+ if (!PageSwapCache(page))
+ goto charge_cur_mm;
+ memcg = try_get_mem_cgroup_from_page(page);
+ if (!memcg)
+ goto charge_cur_mm;
+ *memcgp = memcg;
+ ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true);
+ css_put(&memcg->css);
+ if (ret == -EINTR)
+ ret = 0;
+ return ret;
+charge_cur_mm:
+ if (unlikely(!mm))
+ mm = &init_mm;
+ ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true);
+ if (ret == -EINTR)
+ ret = 0;
+ return ret;
+}
+
+static void
+__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
+ enum charge_type ctype)
+{
+ if (mem_cgroup_disabled())
+ return;
+ if (!memcg)
+ return;
+ cgroup_exclude_rmdir(&memcg->css);
+
+ __mem_cgroup_commit_charge(memcg, page, 1, ctype, true);
+ /*
+ * Now swap is on-memory. This means this page may be
+ * counted both as mem and swap....double count.
+ * Fix it by uncharging from memsw. Basically, this SwapCache is stable
+ * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
+ * may call delete_from_swap_cache() before reach here.
+ */
+ if (do_swap_account && PageSwapCache(page)) {
+ swp_entry_t ent = {.val = page_private(page)};
+ struct mem_cgroup *swap_memcg;
+ unsigned short id;
+
+ id = swap_cgroup_record(ent, 0);
+ rcu_read_lock();
+ swap_memcg = mem_cgroup_lookup(id);
+ if (swap_memcg) {
+ /*
+ * This recorded memcg can be obsolete one. So, avoid
+ * calling css_tryget
+ */
+ if (!mem_cgroup_is_root(swap_memcg))
+ res_counter_uncharge(&swap_memcg->memsw,
+ PAGE_SIZE);
+ mem_cgroup_swap_statistics(swap_memcg, false);
+ mem_cgroup_put(swap_memcg);
+ }
+ rcu_read_unlock();
+ }
+ /*
+ * At swapin, we may charge account against cgroup which has no tasks.
+ * So, rmdir()->pre_destroy() can be called while we do this charge.
+ * In that case, we need to call pre_destroy() again. check it here.
+ */
+ cgroup_release_and_wakeup_rmdir(&memcg->css);
+}
+
+void mem_cgroup_commit_charge_swapin(struct page *page,
+ struct mem_cgroup *memcg)
+{
+ __mem_cgroup_commit_charge_swapin(page, memcg,
+ MEM_CGROUP_CHARGE_TYPE_MAPPED);
+}
+
+void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
+{
+ if (mem_cgroup_disabled())
+ return;
+ if (!memcg)
+ return;
+ __mem_cgroup_cancel_charge(memcg, 1);
+}
+
+static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg,
+ unsigned int nr_pages,
+ const enum charge_type ctype)
+{
+ struct memcg_batch_info *batch = NULL;
+ bool uncharge_memsw = true;
+
+ /* If swapout, usage of swap doesn't decrease */
+ if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
+ uncharge_memsw = false;
+
+ batch = ¤t->memcg_batch;
+ /*
+ * In usual, we do css_get() when we remember memcg pointer.
+ * But in this case, we keep res->usage until end of a series of
+ * uncharges. Then, it's ok to ignore memcg's refcnt.
+ */
+ if (!batch->memcg)
+ batch->memcg = memcg;
+ /*
+ * do_batch > 0 when unmapping pages or inode invalidate/truncate.
+ * In those cases, all pages freed continuously can be expected to be in
+ * the same cgroup and we have chance to coalesce uncharges.
+ * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
+ * because we want to do uncharge as soon as possible.
+ */
+
+ if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
+ goto direct_uncharge;
+
+ if (nr_pages > 1)
+ goto direct_uncharge;
+
+ /*
+ * In typical case, batch->memcg == mem. This means we can
+ * merge a series of uncharges to an uncharge of res_counter.
+ * If not, we uncharge res_counter ony by one.
+ */
+ if (batch->memcg != memcg)
+ goto direct_uncharge;
+ /* remember freed charge and uncharge it later */
+ batch->nr_pages++;
+ if (uncharge_memsw)
+ batch->memsw_nr_pages++;
+ return;
+direct_uncharge:
+ res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE);
+ if (uncharge_memsw)
+ res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE);
+ if (unlikely(batch->memcg != memcg))
+ memcg_oom_recover(memcg);
+}
+
+/*
+ * uncharge if !page_mapped(page)
+ */
+static struct mem_cgroup *
+__mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
+{
+ struct mem_cgroup *memcg = NULL;
+ unsigned int nr_pages = 1;
+ struct page_cgroup *pc;
+ bool anon;
+
+ if (mem_cgroup_disabled())
+ return NULL;
+
+ if (PageSwapCache(page))
+ return NULL;
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON(!PageTransHuge(page));
+ }
+ /*
+ * Check if our page_cgroup is valid
+ */
+ pc = lookup_page_cgroup(page);
+ if (unlikely(!PageCgroupUsed(pc)))
+ return NULL;
+
+ lock_page_cgroup(pc);
+
+ memcg = pc->mem_cgroup;
+
+ if (!PageCgroupUsed(pc))
+ goto unlock_out;
+
+ anon = PageAnon(page);
+
+ switch (ctype) {
+ case MEM_CGROUP_CHARGE_TYPE_MAPPED:
+ /*
+ * Generally PageAnon tells if it's the anon statistics to be
+ * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
+ * used before page reached the stage of being marked PageAnon.
+ */
+ anon = true;
+ /* fallthrough */
+ case MEM_CGROUP_CHARGE_TYPE_DROP:
+ /* See mem_cgroup_prepare_migration() */
+ if (page_mapped(page) || PageCgroupMigration(pc))
+ goto unlock_out;
+ break;
+ case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
+ if (!PageAnon(page)) { /* Shared memory */
+ if (page->mapping && !page_is_file_cache(page))
+ goto unlock_out;
+ } else if (page_mapped(page)) /* Anon */
+ goto unlock_out;
+ break;
+ default:
+ break;
+ }
+
+ mem_cgroup_charge_statistics(memcg, anon, -nr_pages);
+
+ ClearPageCgroupUsed(pc);
+ /*
+ * pc->mem_cgroup is not cleared here. It will be accessed when it's
+ * freed from LRU. This is safe because uncharged page is expected not
+ * to be reused (freed soon). Exception is SwapCache, it's handled by
+ * special functions.
+ */
+
+ unlock_page_cgroup(pc);
+ /*
+ * even after unlock, we have memcg->res.usage here and this memcg
+ * will never be freed.
+ */
+ memcg_check_events(memcg, page);
+ if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
+ mem_cgroup_swap_statistics(memcg, true);
+ mem_cgroup_get(memcg);
+ }
+ if (!mem_cgroup_is_root(memcg))
+ mem_cgroup_do_uncharge(memcg, nr_pages, ctype);
+
+ return memcg;
+
+unlock_out:
+ unlock_page_cgroup(pc);
+ return NULL;
+}
+
+void mem_cgroup_uncharge_page(struct page *page)
+{
+ /* early check. */
+ if (page_mapped(page))
+ return;
+ VM_BUG_ON(page->mapping && !PageAnon(page));
+ __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
+}
+
+void mem_cgroup_uncharge_cache_page(struct page *page)
+{
+ VM_BUG_ON(page_mapped(page));
+ VM_BUG_ON(page->mapping);
+ __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
+}
+
+/*
+ * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
+ * In that cases, pages are freed continuously and we can expect pages
+ * are in the same memcg. All these calls itself limits the number of
+ * pages freed at once, then uncharge_start/end() is called properly.
+ * This may be called prural(2) times in a context,
+ */
+
+void mem_cgroup_uncharge_start(void)
+{
+ current->memcg_batch.do_batch++;
+ /* We can do nest. */
+ if (current->memcg_batch.do_batch == 1) {
+ current->memcg_batch.memcg = NULL;
+ current->memcg_batch.nr_pages = 0;
+ current->memcg_batch.memsw_nr_pages = 0;
+ }
+}
+
+void mem_cgroup_uncharge_end(void)
+{
+ struct memcg_batch_info *batch = ¤t->memcg_batch;
+
+ if (!batch->do_batch)
+ return;
+
+ batch->do_batch--;
+ if (batch->do_batch) /* If stacked, do nothing. */
+ return;
+
+ if (!batch->memcg)
+ return;
+ /*
+ * This "batch->memcg" is valid without any css_get/put etc...
+ * bacause we hide charges behind us.
+ */
+ if (batch->nr_pages)
+ res_counter_uncharge(&batch->memcg->res,
+ batch->nr_pages * PAGE_SIZE);
+ if (batch->memsw_nr_pages)
+ res_counter_uncharge(&batch->memcg->memsw,
+ batch->memsw_nr_pages * PAGE_SIZE);
+ memcg_oom_recover(batch->memcg);
+ /* forget this pointer (for sanity check) */
+ batch->memcg = NULL;
+}
+
+#ifdef CONFIG_SWAP
+/*
+ * called after __delete_from_swap_cache() and drop "page" account.
+ * memcg information is recorded to swap_cgroup of "ent"
+ */
+void
+mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
+{
+ struct mem_cgroup *memcg;
+ int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
+
+ if (!swapout) /* this was a swap cache but the swap is unused ! */
+ ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
+
+ memcg = __mem_cgroup_uncharge_common(page, ctype);
+
+ /*
+ * record memcg information, if swapout && memcg != NULL,
+ * mem_cgroup_get() was called in uncharge().
+ */
+ if (do_swap_account && swapout && memcg)
+ swap_cgroup_record(ent, css_id(&memcg->css));
+}
+#endif
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+/*
+ * called from swap_entry_free(). remove record in swap_cgroup and
+ * uncharge "memsw" account.
+ */
+void mem_cgroup_uncharge_swap(swp_entry_t ent)
+{
+ struct mem_cgroup *memcg;
+ unsigned short id;
+
+ if (!do_swap_account)
+ return;
+
+ id = swap_cgroup_record(ent, 0);
+ rcu_read_lock();
+ memcg = mem_cgroup_lookup(id);
+ if (memcg) {
+ /*
+ * We uncharge this because swap is freed.
+ * This memcg can be obsolete one. We avoid calling css_tryget
+ */
+ if (!mem_cgroup_is_root(memcg))
+ res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
+ mem_cgroup_swap_statistics(memcg, false);
+ mem_cgroup_put(memcg);
+ }
+ rcu_read_unlock();
+}
+
+/**
+ * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
+ * @entry: swap entry to be moved
+ * @from: mem_cgroup which the entry is moved from
+ * @to: mem_cgroup which the entry is moved to
+ * @need_fixup: whether we should fixup res_counters and refcounts.
+ *
+ * It succeeds only when the swap_cgroup's record for this entry is the same
+ * as the mem_cgroup's id of @from.
+ *
+ * Returns 0 on success, -EINVAL on failure.
+ *
+ * The caller must have charged to @to, IOW, called res_counter_charge() about
+ * both res and memsw, and called css_get().
+ */
+static int mem_cgroup_move_swap_account(swp_entry_t entry,
+ struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
+{
+ unsigned short old_id, new_id;
+
+ old_id = css_id(&from->css);
+ new_id = css_id(&to->css);
+
+ if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
+ mem_cgroup_swap_statistics(from, false);
+ mem_cgroup_swap_statistics(to, true);
+ /*
+ * This function is only called from task migration context now.
+ * It postpones res_counter and refcount handling till the end
+ * of task migration(mem_cgroup_clear_mc()) for performance
+ * improvement. But we cannot postpone mem_cgroup_get(to)
+ * because if the process that has been moved to @to does
+ * swap-in, the refcount of @to might be decreased to 0.
+ */
+ mem_cgroup_get(to);
+ if (need_fixup) {
+ if (!mem_cgroup_is_root(from))
+ res_counter_uncharge(&from->memsw, PAGE_SIZE);
+ mem_cgroup_put(from);
+ /*
+ * we charged both to->res and to->memsw, so we should
+ * uncharge to->res.
+ */
+ if (!mem_cgroup_is_root(to))
+ res_counter_uncharge(&to->res, PAGE_SIZE);
+ }
+ return 0;
+ }
+ return -EINVAL;
+}
+#else
+static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
+ struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
+{
+ return -EINVAL;
+}
+#endif
+
+/*
+ * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
+ * page belongs to.
+ */
+int mem_cgroup_prepare_migration(struct page *page,
+ struct page *newpage, struct mem_cgroup **memcgp, gfp_t gfp_mask)
+{
+ struct mem_cgroup *memcg = NULL;
+ struct page_cgroup *pc;
+ enum charge_type ctype;
+ int ret = 0;
+
+ *memcgp = NULL;
+
+ VM_BUG_ON(PageTransHuge(page));
+ if (mem_cgroup_disabled())
+ return 0;
+
+ pc = lookup_page_cgroup(page);
+ lock_page_cgroup(pc);
+ if (PageCgroupUsed(pc)) {
+ memcg = pc->mem_cgroup;
+ css_get(&memcg->css);
+ /*
+ * At migrating an anonymous page, its mapcount goes down
+ * to 0 and uncharge() will be called. But, even if it's fully
+ * unmapped, migration may fail and this page has to be
+ * charged again. We set MIGRATION flag here and delay uncharge
+ * until end_migration() is called
+ *
+ * Corner Case Thinking
+ * A)
+ * When the old page was mapped as Anon and it's unmap-and-freed
+ * while migration was ongoing.
+ * If unmap finds the old page, uncharge() of it will be delayed
+ * until end_migration(). If unmap finds a new page, it's
+ * uncharged when it make mapcount to be 1->0. If unmap code
+ * finds swap_migration_entry, the new page will not be mapped
+ * and end_migration() will find it(mapcount==0).
+ *
+ * B)
+ * When the old page was mapped but migraion fails, the kernel
+ * remaps it. A charge for it is kept by MIGRATION flag even
+ * if mapcount goes down to 0. We can do remap successfully
+ * without charging it again.
+ *
+ * C)
+ * The "old" page is under lock_page() until the end of
+ * migration, so, the old page itself will not be swapped-out.
+ * If the new page is swapped out before end_migraton, our
+ * hook to usual swap-out path will catch the event.
+ */
+ if (PageAnon(page))
+ SetPageCgroupMigration(pc);
+ }
+ unlock_page_cgroup(pc);
+ /*
+ * If the page is not charged at this point,
+ * we return here.
+ */
+ if (!memcg)
+ return 0;
+
+ *memcgp = memcg;
+ ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, memcgp, false);
+ css_put(&memcg->css);/* drop extra refcnt */
+ if (ret) {
+ if (PageAnon(page)) {
+ lock_page_cgroup(pc);
+ ClearPageCgroupMigration(pc);
+ unlock_page_cgroup(pc);
+ /*
+ * The old page may be fully unmapped while we kept it.
+ */
+ mem_cgroup_uncharge_page(page);
+ }
+ /* we'll need to revisit this error code (we have -EINTR) */
+ return -ENOMEM;
+ }
+ /*
+ * We charge new page before it's used/mapped. So, even if unlock_page()
+ * is called before end_migration, we can catch all events on this new
+ * page. In the case new page is migrated but not remapped, new page's
+ * mapcount will be finally 0 and we call uncharge in end_migration().
+ */
+ if (PageAnon(page))
+ ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
+ else if (page_is_file_cache(page))
+ ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
+ else
+ ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
+ __mem_cgroup_commit_charge(memcg, newpage, 1, ctype, false);
+ return ret;
+}
+
+/* remove redundant charge if migration failed*/
+void mem_cgroup_end_migration(struct mem_cgroup *memcg,
+ struct page *oldpage, struct page *newpage, bool migration_ok)
+{
+ struct page *used, *unused;
+ struct page_cgroup *pc;
+ bool anon;
+
+ if (!memcg)
+ return;
+ /* blocks rmdir() */
+ cgroup_exclude_rmdir(&memcg->css);
+ if (!migration_ok) {
+ used = oldpage;
+ unused = newpage;
+ } else {
+ used = newpage;
+ unused = oldpage;
+ }
+ /*
+ * We disallowed uncharge of pages under migration because mapcount
+ * of the page goes down to zero, temporarly.
+ * Clear the flag and check the page should be charged.
+ */
+ pc = lookup_page_cgroup(oldpage);
+ lock_page_cgroup(pc);
+ ClearPageCgroupMigration(pc);
+ unlock_page_cgroup(pc);
+ anon = PageAnon(used);
+ __mem_cgroup_uncharge_common(unused,
+ anon ? MEM_CGROUP_CHARGE_TYPE_MAPPED
+ : MEM_CGROUP_CHARGE_TYPE_CACHE);
+
+ /*
+ * If a page is a file cache, radix-tree replacement is very atomic
+ * and we can skip this check. When it was an Anon page, its mapcount
+ * goes down to 0. But because we added MIGRATION flage, it's not
+ * uncharged yet. There are several case but page->mapcount check
+ * and USED bit check in mem_cgroup_uncharge_page() will do enough
+ * check. (see prepare_charge() also)
+ */
+ if (anon)
+ mem_cgroup_uncharge_page(used);
+ /*
+ * At migration, we may charge account against cgroup which has no
+ * tasks.
+ * So, rmdir()->pre_destroy() can be called while we do this charge.
+ * In that case, we need to call pre_destroy() again. check it here.
+ */
+ cgroup_release_and_wakeup_rmdir(&memcg->css);
+}
+
+/*
+ * At replace page cache, newpage is not under any memcg but it's on
+ * LRU. So, this function doesn't touch res_counter but handles LRU
+ * in correct way. Both pages are locked so we cannot race with uncharge.
+ */
+void mem_cgroup_replace_page_cache(struct page *oldpage,
+ struct page *newpage)
+{
+ struct mem_cgroup *memcg;
+ struct page_cgroup *pc;
+ enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
+
+ if (mem_cgroup_disabled())
+ return;
+
+ pc = lookup_page_cgroup(oldpage);
+ /* fix accounting on old pages */
+ lock_page_cgroup(pc);
+ memcg = pc->mem_cgroup;
+ mem_cgroup_charge_statistics(memcg, false, -1);
+ ClearPageCgroupUsed(pc);
+ unlock_page_cgroup(pc);
+
+ if (PageSwapBacked(oldpage))
+ type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
+
+ /*
+ * Even if newpage->mapping was NULL before starting replacement,
+ * the newpage may be on LRU(or pagevec for LRU) already. We lock
+ * LRU while we overwrite pc->mem_cgroup.
+ */
+ __mem_cgroup_commit_charge(memcg, newpage, 1, type, true);
+}
+
+#ifdef CONFIG_DEBUG_VM
+static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
+{
+ struct page_cgroup *pc;
+
+ pc = lookup_page_cgroup(page);
+ /*
+ * Can be NULL while feeding pages into the page allocator for
+ * the first time, i.e. during boot or memory hotplug;
+ * or when mem_cgroup_disabled().
+ */
+ if (likely(pc) && PageCgroupUsed(pc))
+ return pc;
+ return NULL;
+}
+
+bool mem_cgroup_bad_page_check(struct page *page)
+{
+ if (mem_cgroup_disabled())
+ return false;
+
+ return lookup_page_cgroup_used(page) != NULL;
+}
+
+void mem_cgroup_print_bad_page(struct page *page)
+{
+ struct page_cgroup *pc;
+
+ pc = lookup_page_cgroup_used(page);
+ if (pc) {
+ printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
+ pc, pc->flags, pc->mem_cgroup);
+ }
+}
+#endif
+
+static DEFINE_MUTEX(set_limit_mutex);
+
+static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
+ unsigned long long val)
+{
+ int retry_count;
+ u64 memswlimit, memlimit;
+ int ret = 0;
+ int children = mem_cgroup_count_children(memcg);
+ u64 curusage, oldusage;
+ int enlarge;
+
+ /*
+ * For keeping hierarchical_reclaim simple, how long we should retry
+ * is depends on callers. We set our retry-count to be function
+ * of # of children which we should visit in this loop.
+ */
+ retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
+
+ oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
+
+ enlarge = 0;
+ while (retry_count) {
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+ /*
+ * Rather than hide all in some function, I do this in
+ * open coded manner. You see what this really does.
+ * We have to guarantee memcg->res.limit < memcg->memsw.limit.
+ */
+ mutex_lock(&set_limit_mutex);
+ memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+ if (memswlimit < val) {
+ ret = -EINVAL;
+ mutex_unlock(&set_limit_mutex);
+ break;
+ }
+
+ memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
+ if (memlimit < val)
+ enlarge = 1;
+
+ ret = res_counter_set_limit(&memcg->res, val);
+ if (!ret) {
+ if (memswlimit == val)
+ memcg->memsw_is_minimum = true;
+ else
+ memcg->memsw_is_minimum = false;
+ }
+ mutex_unlock(&set_limit_mutex);
+
+ if (!ret)
+ break;
+
+ mem_cgroup_reclaim(memcg, GFP_KERNEL,
+ MEM_CGROUP_RECLAIM_SHRINK);
+ curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
+ /* Usage is reduced ? */
+ if (curusage >= oldusage)
+ retry_count--;
+ else
+ oldusage = curusage;
+ }
+ if (!ret && enlarge)
+ memcg_oom_recover(memcg);
+
+ return ret;
+}
+
+static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
+ unsigned long long val)
+{
+ int retry_count;
+ u64 memlimit, memswlimit, oldusage, curusage;
+ int children = mem_cgroup_count_children(memcg);
+ int ret = -EBUSY;
+ int enlarge = 0;
+
+ /* see mem_cgroup_resize_res_limit */
+ retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
+ oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
+ while (retry_count) {
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+ /*
+ * Rather than hide all in some function, I do this in
+ * open coded manner. You see what this really does.
+ * We have to guarantee memcg->res.limit < memcg->memsw.limit.
+ */
+ mutex_lock(&set_limit_mutex);
+ memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
+ if (memlimit > val) {
+ ret = -EINVAL;
+ mutex_unlock(&set_limit_mutex);
+ break;
+ }
+ memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+ if (memswlimit < val)
+ enlarge = 1;
+ ret = res_counter_set_limit(&memcg->memsw, val);
+ if (!ret) {
+ if (memlimit == val)
+ memcg->memsw_is_minimum = true;
+ else
+ memcg->memsw_is_minimum = false;
+ }
+ mutex_unlock(&set_limit_mutex);
+
+ if (!ret)
+ break;
+
+ mem_cgroup_reclaim(memcg, GFP_KERNEL,
+ MEM_CGROUP_RECLAIM_NOSWAP |
+ MEM_CGROUP_RECLAIM_SHRINK);
+ curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
+ /* Usage is reduced ? */
+ if (curusage >= oldusage)
+ retry_count--;
+ else
+ oldusage = curusage;
+ }
+ if (!ret && enlarge)
+ memcg_oom_recover(memcg);
+ return ret;
+}
+
+unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
+ gfp_t gfp_mask,
+ unsigned long *total_scanned)
+{
+ unsigned long nr_reclaimed = 0;
+ struct mem_cgroup_per_zone *mz, *next_mz = NULL;
+ unsigned long reclaimed;
+ int loop = 0;
+ struct mem_cgroup_tree_per_zone *mctz;
+ unsigned long long excess;
+ unsigned long nr_scanned;
+
+ if (order > 0)
+ return 0;
+
+ mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
+ /*
+ * This loop can run a while, specially if mem_cgroup's continuously
+ * keep exceeding their soft limit and putting the system under
+ * pressure
+ */
+ do {
+ if (next_mz)
+ mz = next_mz;
+ else
+ mz = mem_cgroup_largest_soft_limit_node(mctz);
+ if (!mz)
+ break;
+
+ nr_scanned = 0;
+ reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone,
+ gfp_mask, &nr_scanned);
+ nr_reclaimed += reclaimed;
+ *total_scanned += nr_scanned;
+ spin_lock(&mctz->lock);
+
+ /*
+ * If we failed to reclaim anything from this memory cgroup
+ * it is time to move on to the next cgroup
+ */
+ next_mz = NULL;
+ if (!reclaimed) {
+ do {
+ /*
+ * Loop until we find yet another one.
+ *
+ * By the time we get the soft_limit lock
+ * again, someone might have aded the
+ * group back on the RB tree. Iterate to
+ * make sure we get a different mem.
+ * mem_cgroup_largest_soft_limit_node returns
+ * NULL if no other cgroup is present on
+ * the tree
+ */
+ next_mz =
+ __mem_cgroup_largest_soft_limit_node(mctz);
+ if (next_mz == mz)
+ css_put(&next_mz->memcg->css);
+ else /* next_mz == NULL or other memcg */
+ break;
+ } while (1);
+ }
+ __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz);
+ excess = res_counter_soft_limit_excess(&mz->memcg->res);
+ /*
+ * One school of thought says that we should not add
+ * back the node to the tree if reclaim returns 0.
+ * But our reclaim could return 0, simply because due
+ * to priority we are exposing a smaller subset of
+ * memory to reclaim from. Consider this as a longer
+ * term TODO.
+ */
+ /* If excess == 0, no tree ops */
+ __mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess);
+ spin_unlock(&mctz->lock);
+ css_put(&mz->memcg->css);
+ loop++;
+ /*
+ * Could not reclaim anything and there are no more
+ * mem cgroups to try or we seem to be looping without
+ * reclaiming anything.
+ */
+ if (!nr_reclaimed &&
+ (next_mz == NULL ||
+ loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
+ break;
+ } while (!nr_reclaimed);
+ if (next_mz)
+ css_put(&next_mz->memcg->css);
+ return nr_reclaimed;
+}
+
+/*
+ * This routine traverse page_cgroup in given list and drop them all.
+ * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
+ */
+static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
+ int node, int zid, enum lru_list lru)
+{
+ struct mem_cgroup_per_zone *mz;
+ unsigned long flags, loop;
+ struct list_head *list;
+ struct page *busy;
+ struct zone *zone;
+ int ret = 0;
+
+ zone = &NODE_DATA(node)->node_zones[zid];
+ mz = mem_cgroup_zoneinfo(memcg, node, zid);
+ list = &mz->lruvec.lists[lru];
+
+ loop = mz->lru_size[lru];
+ /* give some margin against EBUSY etc...*/
+ loop += 256;
+ busy = NULL;
+ while (loop--) {
+ struct page_cgroup *pc;
+ struct page *page;
+
+ ret = 0;
+ spin_lock_irqsave(&zone->lru_lock, flags);
+ if (list_empty(list)) {
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
+ break;
+ }
+ page = list_entry(list->prev, struct page, lru);
+ if (busy == page) {
+ list_move(&page->lru, list);
+ busy = NULL;
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
+ continue;
+ }
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
+
+ pc = lookup_page_cgroup(page);
+
+ ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL);
+ if (ret == -ENOMEM || ret == -EINTR)
+ break;
+
+ if (ret == -EBUSY || ret == -EINVAL) {
+ /* found lock contention or "pc" is obsolete. */
+ busy = page;
+ cond_resched();
+ } else
+ busy = NULL;
+ }
+
+ if (!ret && !list_empty(list))
+ return -EBUSY;
+ return ret;
+}
+
+/*
+ * make mem_cgroup's charge to be 0 if there is no task.
+ * This enables deleting this mem_cgroup.
+ */
+static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all)
+{
+ int ret;
+ int node, zid, shrink;
+ int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
+ struct cgroup *cgrp = memcg->css.cgroup;
+
+ css_get(&memcg->css);
+
+ shrink = 0;
+ /* should free all ? */
+ if (free_all)
+ goto try_to_free;
+move_account:
+ do {
+ ret = -EBUSY;
+ if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
+ goto out;
+ ret = -EINTR;
+ if (signal_pending(current))
+ goto out;
+ /* This is for making all *used* pages to be on LRU. */
+ lru_add_drain_all();
+ drain_all_stock_sync(memcg);
+ ret = 0;
+ mem_cgroup_start_move(memcg);
+ for_each_node_state(node, N_HIGH_MEMORY) {
+ for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
+ enum lru_list lru;
+ for_each_lru(lru) {
+ ret = mem_cgroup_force_empty_list(memcg,
+ node, zid, lru);
+ if (ret)
+ break;
+ }
+ }
+ if (ret)
+ break;
+ }
+ mem_cgroup_end_move(memcg);
+ memcg_oom_recover(memcg);
+ /* it seems parent cgroup doesn't have enough mem */
+ if (ret == -ENOMEM)
+ goto try_to_free;
+ cond_resched();
+ /* "ret" should also be checked to ensure all lists are empty. */
+ } while (res_counter_read_u64(&memcg->res, RES_USAGE) > 0 || ret);
+out:
+ css_put(&memcg->css);
+ return ret;
+
+try_to_free:
+ /* returns EBUSY if there is a task or if we come here twice. */
+ if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
+ ret = -EBUSY;
+ goto out;
+ }
+ /* we call try-to-free pages for make this cgroup empty */
+ lru_add_drain_all();
+ /* try to free all pages in this cgroup */
+ shrink = 1;
+ while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) {
+ int progress;
+
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ goto out;
+ }
+ progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL,
+ false);
+ if (!progress) {
+ nr_retries--;
+ /* maybe some writeback is necessary */
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+ }
+
+ }
+ lru_add_drain();
+ /* try move_account...there may be some *locked* pages. */
+ goto move_account;
+}
+
+int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
+{
+ return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
+}
+
+
+static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
+{
+ return mem_cgroup_from_cont(cont)->use_hierarchy;
+}
+
+static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
+ u64 val)
+{
+ int retval = 0;
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+ struct cgroup *parent = cont->parent;
+ struct mem_cgroup *parent_memcg = NULL;
+
+ if (parent)
+ parent_memcg = mem_cgroup_from_cont(parent);
+
+ cgroup_lock();
+ /*
+ * If parent's use_hierarchy is set, we can't make any modifications
+ * in the child subtrees. If it is unset, then the change can
+ * occur, provided the current cgroup has no children.
+ *
+ * For the root cgroup, parent_mem is NULL, we allow value to be
+ * set if there are no children.
+ */
+ if ((!parent_memcg || !parent_memcg->use_hierarchy) &&
+ (val == 1 || val == 0)) {
+ if (list_empty(&cont->children))
+ memcg->use_hierarchy = val;
+ else
+ retval = -EBUSY;
+ } else
+ retval = -EINVAL;
+ cgroup_unlock();
+
+ return retval;
+}
+
+
+static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg,
+ enum mem_cgroup_stat_index idx)
+{
+ struct mem_cgroup *iter;
+ long val = 0;
+
+ /* Per-cpu values can be negative, use a signed accumulator */
+ for_each_mem_cgroup_tree(iter, memcg)
+ val += mem_cgroup_read_stat(iter, idx);
+
+ if (val < 0) /* race ? */
+ val = 0;
+ return val;
+}
+
+static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
+{
+ u64 val;
+
+ if (!mem_cgroup_is_root(memcg)) {
+ if (!swap)
+ return res_counter_read_u64(&memcg->res, RES_USAGE);
+ else
+ return res_counter_read_u64(&memcg->memsw, RES_USAGE);
+ }
+
+ val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE);
+ val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS);
+
+ if (swap)
+ val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAPOUT);
+
+ return val << PAGE_SHIFT;
+}
+
+static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+ u64 val;
+ int type, name;
+
+ type = MEMFILE_TYPE(cft->private);
+ name = MEMFILE_ATTR(cft->private);
+ switch (type) {
+ case _MEM:
+ if (name == RES_USAGE)
+ val = mem_cgroup_usage(memcg, false);
+ else
+ val = res_counter_read_u64(&memcg->res, name);
+ break;
+ case _MEMSWAP:
+ if (name == RES_USAGE)
+ val = mem_cgroup_usage(memcg, true);
+ else
+ val = res_counter_read_u64(&memcg->memsw, name);
+ break;
+ default:
+ BUG();
+ }
+ return val;
+}
+/*
+ * The user of this function is...
+ * RES_LIMIT.
+ */
+static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
+ const char *buffer)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+ int type, name;
+ unsigned long long val;
+ int ret;
+
+ type = MEMFILE_TYPE(cft->private);
+ name = MEMFILE_ATTR(cft->private);
+ switch (name) {
+ case RES_LIMIT:
+ if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
+ ret = -EINVAL;
+ break;
+ }
+ /* This function does all necessary parse...reuse it */
+ ret = res_counter_memparse_write_strategy(buffer, &val);
+ if (ret)
+ break;
+ if (type == _MEM)
+ ret = mem_cgroup_resize_limit(memcg, val);
+ else
+ ret = mem_cgroup_resize_memsw_limit(memcg, val);
+ break;
+ case RES_SOFT_LIMIT:
+ ret = res_counter_memparse_write_strategy(buffer, &val);
+ if (ret)
+ break;
+ /*
+ * For memsw, soft limits are hard to implement in terms
+ * of semantics, for now, we support soft limits for
+ * control without swap
+ */
+ if (type == _MEM)
+ ret = res_counter_set_soft_limit(&memcg->res, val);
+ else
+ ret = -EINVAL;
+ break;
+ default:
+ ret = -EINVAL; /* should be BUG() ? */
+ break;
+ }
+ return ret;
+}
+
+static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
+ unsigned long long *mem_limit, unsigned long long *memsw_limit)
+{
+ struct cgroup *cgroup;
+ unsigned long long min_limit, min_memsw_limit, tmp;
+
+ min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
+ min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+ cgroup = memcg->css.cgroup;
+ if (!memcg->use_hierarchy)
+ goto out;
+
+ while (cgroup->parent) {
+ cgroup = cgroup->parent;
+ memcg = mem_cgroup_from_cont(cgroup);
+ if (!memcg->use_hierarchy)
+ break;
+ tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
+ min_limit = min(min_limit, tmp);
+ tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+ min_memsw_limit = min(min_memsw_limit, tmp);
+ }
+out:
+ *mem_limit = min_limit;
+ *memsw_limit = min_memsw_limit;
+}
+
+static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
+{
+ struct mem_cgroup *memcg;
+ int type, name;
+
+ memcg = mem_cgroup_from_cont(cont);
+ type = MEMFILE_TYPE(event);
+ name = MEMFILE_ATTR(event);
+ switch (name) {
+ case RES_MAX_USAGE:
+ if (type == _MEM)
+ res_counter_reset_max(&memcg->res);
+ else
+ res_counter_reset_max(&memcg->memsw);
+ break;
+ case RES_FAILCNT:
+ if (type == _MEM)
+ res_counter_reset_failcnt(&memcg->res);
+ else
+ res_counter_reset_failcnt(&memcg->memsw);
+ break;
+ }
+
+ return 0;
+}
+
+static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp,
+ struct cftype *cft)
+{
+ return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate;
+}
+
+#ifdef CONFIG_MMU
+static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
+ struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+
+ if (val >= (1 << NR_MOVE_TYPE))
+ return -EINVAL;
+ /*
+ * We check this value several times in both in can_attach() and
+ * attach(), so we need cgroup lock to prevent this value from being
+ * inconsistent.
+ */
+ cgroup_lock();
+ memcg->move_charge_at_immigrate = val;
+ cgroup_unlock();
+
+ return 0;
+}
+#else
+static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
+ struct cftype *cft, u64 val)
+{
+ return -ENOSYS;
+}
+#endif
+
+
+/* For read statistics */
+enum {
+ MCS_CACHE,
+ MCS_RSS,
+ MCS_FILE_MAPPED,
+ MCS_PGPGIN,
+ MCS_PGPGOUT,
+ MCS_SWAP,
+ MCS_PGFAULT,
+ MCS_PGMAJFAULT,
+ MCS_INACTIVE_ANON,
+ MCS_ACTIVE_ANON,
+ MCS_INACTIVE_FILE,
+ MCS_ACTIVE_FILE,
+ MCS_UNEVICTABLE,
+ NR_MCS_STAT,
+};
+
+struct mcs_total_stat {
+ s64 stat[NR_MCS_STAT];
+};
+
+struct {
+ char *local_name;
+ char *total_name;
+} memcg_stat_strings[NR_MCS_STAT] = {
+ {"cache", "total_cache"},
+ {"rss", "total_rss"},
+ {"mapped_file", "total_mapped_file"},
+ {"pgpgin", "total_pgpgin"},
+ {"pgpgout", "total_pgpgout"},
+ {"swap", "total_swap"},
+ {"pgfault", "total_pgfault"},
+ {"pgmajfault", "total_pgmajfault"},
+ {"inactive_anon", "total_inactive_anon"},
+ {"active_anon", "total_active_anon"},
+ {"inactive_file", "total_inactive_file"},
+ {"active_file", "total_active_file"},
+ {"unevictable", "total_unevictable"}
+};
+
+
+static void
+mem_cgroup_get_local_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s)
+{
+ s64 val;
+
+ /* per cpu stat */
+ val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_CACHE);
+ s->stat[MCS_CACHE] += val * PAGE_SIZE;
+ val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_RSS);
+ s->stat[MCS_RSS] += val * PAGE_SIZE;
+ val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED);
+ s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
+ val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGIN);
+ s->stat[MCS_PGPGIN] += val;
+ val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGOUT);
+ s->stat[MCS_PGPGOUT] += val;
+ if (do_swap_account) {
+ val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_SWAPOUT);
+ s->stat[MCS_SWAP] += val * PAGE_SIZE;
+ }
+ val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGFAULT);
+ s->stat[MCS_PGFAULT] += val;
+ val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGMAJFAULT);
+ s->stat[MCS_PGMAJFAULT] += val;
+
+ /* per zone stat */
+ val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_ANON));
+ s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
+ val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_ANON));
+ s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
+ val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_FILE));
+ s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
+ val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_FILE));
+ s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
+ val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE));
+ s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
+}
+
+static void
+mem_cgroup_get_total_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s)
+{
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg)
+ mem_cgroup_get_local_stat(iter, s);
+}
+
+#ifdef CONFIG_NUMA
+static int mem_control_numa_stat_show(struct seq_file *m, void *arg)
+{
+ int nid;
+ unsigned long total_nr, file_nr, anon_nr, unevictable_nr;
+ unsigned long node_nr;
+ struct cgroup *cont = m->private;
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+
+ total_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL);
+ seq_printf(m, "total=%lu", total_nr);
+ for_each_node_state(nid, N_HIGH_MEMORY) {
+ node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL);
+ seq_printf(m, " N%d=%lu", nid, node_nr);
+ }
+ seq_putc(m, '\n');
+
+ file_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_FILE);
+ seq_printf(m, "file=%lu", file_nr);
+ for_each_node_state(nid, N_HIGH_MEMORY) {
+ node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
+ LRU_ALL_FILE);
+ seq_printf(m, " N%d=%lu", nid, node_nr);
+ }
+ seq_putc(m, '\n');
+
+ anon_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_ANON);
+ seq_printf(m, "anon=%lu", anon_nr);
+ for_each_node_state(nid, N_HIGH_MEMORY) {
+ node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
+ LRU_ALL_ANON);
+ seq_printf(m, " N%d=%lu", nid, node_nr);
+ }
+ seq_putc(m, '\n');
+
+ unevictable_nr = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE));
+ seq_printf(m, "unevictable=%lu", unevictable_nr);
+ for_each_node_state(nid, N_HIGH_MEMORY) {
+ node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
+ BIT(LRU_UNEVICTABLE));
+ seq_printf(m, " N%d=%lu", nid, node_nr);
+ }
+ seq_putc(m, '\n');
+ return 0;
+}
+#endif /* CONFIG_NUMA */
+
+static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
+ struct cgroup_map_cb *cb)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+ struct mcs_total_stat mystat;
+ int i;
+
+ memset(&mystat, 0, sizeof(mystat));
+ mem_cgroup_get_local_stat(memcg, &mystat);
+
+
+ for (i = 0; i < NR_MCS_STAT; i++) {
+ if (i == MCS_SWAP && !do_swap_account)
+ continue;
+ cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
+ }
+
+ /* Hierarchical information */
+ {
+ unsigned long long limit, memsw_limit;
+ memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit);
+ cb->fill(cb, "hierarchical_memory_limit", limit);
+ if (do_swap_account)
+ cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
+ }
+
+ memset(&mystat, 0, sizeof(mystat));
+ mem_cgroup_get_total_stat(memcg, &mystat);
+ for (i = 0; i < NR_MCS_STAT; i++) {
+ if (i == MCS_SWAP && !do_swap_account)
+ continue;
+ cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
+ }
+
+#ifdef CONFIG_DEBUG_VM
+ {
+ int nid, zid;
+ struct mem_cgroup_per_zone *mz;
+ unsigned long recent_rotated[2] = {0, 0};
+ unsigned long recent_scanned[2] = {0, 0};
+
+ for_each_online_node(nid)
+ for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+ mz = mem_cgroup_zoneinfo(memcg, nid, zid);
+
+ recent_rotated[0] +=
+ mz->reclaim_stat.recent_rotated[0];
+ recent_rotated[1] +=
+ mz->reclaim_stat.recent_rotated[1];
+ recent_scanned[0] +=
+ mz->reclaim_stat.recent_scanned[0];
+ recent_scanned[1] +=
+ mz->reclaim_stat.recent_scanned[1];
+ }
+ cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
+ cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
+ cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
+ cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
+ }
+#endif
+
+ return 0;
+}
+
+static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+
+ return mem_cgroup_swappiness(memcg);
+}
+
+static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
+ u64 val)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+ struct mem_cgroup *parent;
+
+ if (val > 100)
+ return -EINVAL;
+
+ if (cgrp->parent == NULL)
+ return -EINVAL;
+
+ parent = mem_cgroup_from_cont(cgrp->parent);
+
+ cgroup_lock();
+
+ /* If under hierarchy, only empty-root can set this value */
+ if ((parent->use_hierarchy) ||
+ (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
+ cgroup_unlock();
+ return -EINVAL;
+ }
+
+ memcg->swappiness = val;
+
+ cgroup_unlock();
+
+ return 0;
+}
+
+static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
+{
+ struct mem_cgroup_threshold_ary *t;
+ u64 usage;
+ int i;
+
+ rcu_read_lock();
+ if (!swap)
+ t = rcu_dereference(memcg->thresholds.primary);
+ else
+ t = rcu_dereference(memcg->memsw_thresholds.primary);
+
+ if (!t)
+ goto unlock;
+
+ usage = mem_cgroup_usage(memcg, swap);
+
+ /*
+ * current_threshold points to threshold just below usage.
+ * If it's not true, a threshold was crossed after last
+ * call of __mem_cgroup_threshold().
+ */
+ i = t->current_threshold;
+
+ /*
+ * Iterate backward over array of thresholds starting from
+ * current_threshold and check if a threshold is crossed.
+ * If none of thresholds below usage is crossed, we read
+ * only one element of the array here.
+ */
+ for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
+ eventfd_signal(t->entries[i].eventfd, 1);
+
+ /* i = current_threshold + 1 */
+ i++;
+
+ /*
+ * Iterate forward over array of thresholds starting from
+ * current_threshold+1 and check if a threshold is crossed.
+ * If none of thresholds above usage is crossed, we read
+ * only one element of the array here.
+ */
+ for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
+ eventfd_signal(t->entries[i].eventfd, 1);
+
+ /* Update current_threshold */
+ t->current_threshold = i - 1;
+unlock:
+ rcu_read_unlock();
+}
+
+static void mem_cgroup_threshold(struct mem_cgroup *memcg)
+{
+ while (memcg) {
+ __mem_cgroup_threshold(memcg, false);
+ if (do_swap_account)
+ __mem_cgroup_threshold(memcg, true);
+
+ memcg = parent_mem_cgroup(memcg);
+ }
+}
+
+static int compare_thresholds(const void *a, const void *b)
+{
+ const struct mem_cgroup_threshold *_a = a;
+ const struct mem_cgroup_threshold *_b = b;
+
+ if (_a->threshold > _b->threshold)
+ return 1;
+
+ if (_a->threshold < _b->threshold)
+ return -1;
+
+ return 0;
+}
+
+static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup_eventfd_list *ev;
+
+ list_for_each_entry(ev, &memcg->oom_notify, list)
+ eventfd_signal(ev->eventfd, 1);
+ return 0;
+}
+
+static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg)
+ mem_cgroup_oom_notify_cb(iter);
+}
+
+static int mem_cgroup_usage_register_event(struct cgroup *cgrp,
+ struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+ struct mem_cgroup_thresholds *thresholds;
+ struct mem_cgroup_threshold_ary *new;
+ int type = MEMFILE_TYPE(cft->private);
+ u64 threshold, usage;
+ int i, size, ret;
+
+ ret = res_counter_memparse_write_strategy(args, &threshold);
+ if (ret)
+ return ret;
+
+ mutex_lock(&memcg->thresholds_lock);
+
+ if (type == _MEM)
+ thresholds = &memcg->thresholds;
+ else if (type == _MEMSWAP)
+ thresholds = &memcg->memsw_thresholds;
+ else
+ BUG();
+
+ usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
+
+ /* Check if a threshold crossed before adding a new one */
+ if (thresholds->primary)
+ __mem_cgroup_threshold(memcg, type == _MEMSWAP);
+
+ size = thresholds->primary ? thresholds->primary->size + 1 : 1;
+
+ /* Allocate memory for new array of thresholds */
+ new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
+ GFP_KERNEL);
+ if (!new) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+ new->size = size;
+
+ /* Copy thresholds (if any) to new array */
+ if (thresholds->primary) {
+ memcpy(new->entries, thresholds->primary->entries, (size - 1) *
+ sizeof(struct mem_cgroup_threshold));
+ }
+
+ /* Add new threshold */
+ new->entries[size - 1].eventfd = eventfd;
+ new->entries[size - 1].threshold = threshold;
+
+ /* Sort thresholds. Registering of new threshold isn't time-critical */
+ sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
+ compare_thresholds, NULL);
+
+ /* Find current threshold */
+ new->current_threshold = -1;
+ for (i = 0; i < size; i++) {
+ if (new->entries[i].threshold < usage) {
+ /*
+ * new->current_threshold will not be used until
+ * rcu_assign_pointer(), so it's safe to increment
+ * it here.
+ */
+ ++new->current_threshold;
+ }
+ }
+
+ /* Free old spare buffer and save old primary buffer as spare */
+ kfree(thresholds->spare);
+ thresholds->spare = thresholds->primary;
+
+ rcu_assign_pointer(thresholds->primary, new);
+
+ /* To be sure that nobody uses thresholds */
+ synchronize_rcu();
+
+unlock:
+ mutex_unlock(&memcg->thresholds_lock);
+
+ return ret;
+}
+
+static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
+ struct cftype *cft, struct eventfd_ctx *eventfd)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+ struct mem_cgroup_thresholds *thresholds;
+ struct mem_cgroup_threshold_ary *new;
+ int type = MEMFILE_TYPE(cft->private);
+ u64 usage;
+ int i, j, size;
+
+ mutex_lock(&memcg->thresholds_lock);
+ if (type == _MEM)
+ thresholds = &memcg->thresholds;
+ else if (type == _MEMSWAP)
+ thresholds = &memcg->memsw_thresholds;
+ else
+ BUG();
+
+ if (!thresholds->primary)
+ goto unlock;
+
+ usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
+
+ /* Check if a threshold crossed before removing */
+ __mem_cgroup_threshold(memcg, type == _MEMSWAP);
+
+ /* Calculate new number of threshold */
+ size = 0;
+ for (i = 0; i < thresholds->primary->size; i++) {
+ if (thresholds->primary->entries[i].eventfd != eventfd)
+ size++;
+ }
+
+ new = thresholds->spare;
+
+ /* Set thresholds array to NULL if we don't have thresholds */
+ if (!size) {
+ kfree(new);
+ new = NULL;
+ goto swap_buffers;
+ }
+
+ new->size = size;
+
+ /* Copy thresholds and find current threshold */
+ new->current_threshold = -1;
+ for (i = 0, j = 0; i < thresholds->primary->size; i++) {
+ if (thresholds->primary->entries[i].eventfd == eventfd)
+ continue;
+
+ new->entries[j] = thresholds->primary->entries[i];
+ if (new->entries[j].threshold < usage) {
+ /*
+ * new->current_threshold will not be used
+ * until rcu_assign_pointer(), so it's safe to increment
+ * it here.
+ */
+ ++new->current_threshold;
+ }
+ j++;
+ }
+
+swap_buffers:
+ /* Swap primary and spare array */
+ thresholds->spare = thresholds->primary;
+ /* If all events are unregistered, free the spare array */
+ if (!new) {
+ kfree(thresholds->spare);
+ thresholds->spare = NULL;
+ }
+
+ rcu_assign_pointer(thresholds->primary, new);
+
+ /* To be sure that nobody uses thresholds */
+ synchronize_rcu();
+unlock:
+ mutex_unlock(&memcg->thresholds_lock);
+}
+
+static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
+ struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+ struct mem_cgroup_eventfd_list *event;
+ int type = MEMFILE_TYPE(cft->private);
+
+ BUG_ON(type != _OOM_TYPE);
+ event = kmalloc(sizeof(*event), GFP_KERNEL);
+ if (!event)
+ return -ENOMEM;
+
+ spin_lock(&memcg_oom_lock);
+
+ event->eventfd = eventfd;
+ list_add(&event->list, &memcg->oom_notify);
+
+ /* already in OOM ? */
+ if (atomic_read(&memcg->under_oom))
+ eventfd_signal(eventfd, 1);
+ spin_unlock(&memcg_oom_lock);
+
+ return 0;
+}
+
+static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
+ struct cftype *cft, struct eventfd_ctx *eventfd)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+ struct mem_cgroup_eventfd_list *ev, *tmp;
+ int type = MEMFILE_TYPE(cft->private);
+
+ BUG_ON(type != _OOM_TYPE);
+
+ spin_lock(&memcg_oom_lock);
+
+ list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) {
+ if (ev->eventfd == eventfd) {
+ list_del(&ev->list);
+ kfree(ev);
+ }
+ }
+
+ spin_unlock(&memcg_oom_lock);
+}
+
+static int mem_cgroup_oom_control_read(struct cgroup *cgrp,
+ struct cftype *cft, struct cgroup_map_cb *cb)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+
+ cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable);
+
+ if (atomic_read(&memcg->under_oom))
+ cb->fill(cb, "under_oom", 1);
+ else
+ cb->fill(cb, "under_oom", 0);
+ return 0;
+}
+
+static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
+ struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+ struct mem_cgroup *parent;
+
+ /* cannot set to root cgroup and only 0 and 1 are allowed */
+ if (!cgrp->parent || !((val == 0) || (val == 1)))
+ return -EINVAL;
+
+ parent = mem_cgroup_from_cont(cgrp->parent);
+
+ cgroup_lock();
+ /* oom-kill-disable is a flag for subhierarchy. */
+ if ((parent->use_hierarchy) ||
+ (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
+ cgroup_unlock();
+ return -EINVAL;
+ }
+ memcg->oom_kill_disable = val;
+ if (!val)
+ memcg_oom_recover(memcg);
+ cgroup_unlock();
+ return 0;
+}
+
+#ifdef CONFIG_NUMA
+static const struct file_operations mem_control_numa_stat_file_operations = {
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int mem_control_numa_stat_open(struct inode *unused, struct file *file)
+{
+ struct cgroup *cont = file->f_dentry->d_parent->d_fsdata;
+
+ file->f_op = &mem_control_numa_stat_file_operations;
+ return single_open(file, mem_control_numa_stat_show, cont);
+}
+#endif /* CONFIG_NUMA */
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
+{
+ /*
+ * Part of this would be better living in a separate allocation
+ * function, leaving us with just the cgroup tree population work.
+ * We, however, depend on state such as network's proto_list that
+ * is only initialized after cgroup creation. I found the less
+ * cumbersome way to deal with it to defer it all to populate time
+ */
+ return mem_cgroup_sockets_init(cont, ss);
+};
+
+static void kmem_cgroup_destroy(struct cgroup *cont)
+{
+ mem_cgroup_sockets_destroy(cont);
+}
+#else
+static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
+{
+ return 0;
+}
+
+static void kmem_cgroup_destroy(struct cgroup *cont)
+{
+}
+#endif
+
+static struct cftype mem_cgroup_files[] = {
+ {
+ .name = "usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
+ .read_u64 = mem_cgroup_read,
+ .register_event = mem_cgroup_usage_register_event,
+ .unregister_event = mem_cgroup_usage_unregister_event,
+ },
+ {
+ .name = "max_usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
+ .trigger = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read,
+ },
+ {
+ .name = "limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
+ .write_string = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read,
+ },
+ {
+ .name = "soft_limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
+ .write_string = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read,
+ },
+ {
+ .name = "failcnt",
+ .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
+ .trigger = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read,
+ },
+ {
+ .name = "stat",
+ .read_map = mem_control_stat_show,
+ },
+ {
+ .name = "force_empty",
+ .trigger = mem_cgroup_force_empty_write,
+ },
+ {
+ .name = "use_hierarchy",
+ .write_u64 = mem_cgroup_hierarchy_write,
+ .read_u64 = mem_cgroup_hierarchy_read,
+ },
+ {
+ .name = "swappiness",
+ .read_u64 = mem_cgroup_swappiness_read,
+ .write_u64 = mem_cgroup_swappiness_write,
+ },
+ {
+ .name = "move_charge_at_immigrate",
+ .read_u64 = mem_cgroup_move_charge_read,
+ .write_u64 = mem_cgroup_move_charge_write,
+ },
+ {
+ .name = "oom_control",
+ .read_map = mem_cgroup_oom_control_read,
+ .write_u64 = mem_cgroup_oom_control_write,
+ .register_event = mem_cgroup_oom_register_event,
+ .unregister_event = mem_cgroup_oom_unregister_event,
+ .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
+ },
+#ifdef CONFIG_NUMA
+ {
+ .name = "numa_stat",
+ .open = mem_control_numa_stat_open,
+ .mode = S_IRUGO,
+ },
+#endif
+};
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+static struct cftype memsw_cgroup_files[] = {
+ {
+ .name = "memsw.usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
+ .read_u64 = mem_cgroup_read,
+ .register_event = mem_cgroup_usage_register_event,
+ .unregister_event = mem_cgroup_usage_unregister_event,
+ },
+ {
+ .name = "memsw.max_usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
+ .trigger = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read,
+ },
+ {
+ .name = "memsw.limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
+ .write_string = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read,
+ },
+ {
+ .name = "memsw.failcnt",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
+ .trigger = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read,
+ },
+};
+
+static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
+{
+ if (!do_swap_account)
+ return 0;
+ return cgroup_add_files(cont, ss, memsw_cgroup_files,
+ ARRAY_SIZE(memsw_cgroup_files));
+};
+#else
+static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
+{
+ return 0;
+}
+#endif
+
+static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
+{
+ struct mem_cgroup_per_node *pn;
+ struct mem_cgroup_per_zone *mz;
+ enum lru_list lru;
+ int zone, tmp = node;
+ /*
+ * This routine is called against possible nodes.
+ * But it's BUG to call kmalloc() against offline node.
+ *
+ * TODO: this routine can waste much memory for nodes which will
+ * never be onlined. It's better to use memory hotplug callback
+ * function.
+ */
+ if (!node_state(node, N_NORMAL_MEMORY))
+ tmp = -1;
+ pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
+ if (!pn)
+ return 1;
+
+ for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+ mz = &pn->zoneinfo[zone];
+ for_each_lru(lru)
+ INIT_LIST_HEAD(&mz->lruvec.lists[lru]);
+ mz->usage_in_excess = 0;
+ mz->on_tree = false;
+ mz->memcg = memcg;
+ }
+ memcg->info.nodeinfo[node] = pn;
+ return 0;
+}
+
+static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
+{
+ kfree(memcg->info.nodeinfo[node]);
+}
+
+static struct mem_cgroup *mem_cgroup_alloc(void)
+{
+ struct mem_cgroup *memcg;
+ int size = sizeof(struct mem_cgroup);
+
+ /* Can be very big if MAX_NUMNODES is very big */
+ if (size < PAGE_SIZE)
+ memcg = kzalloc(size, GFP_KERNEL);
+ else
+ memcg = vzalloc(size);
+
+ if (!memcg)
+ return NULL;
+
+ memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
+ if (!memcg->stat)
+ goto out_free;
+ spin_lock_init(&memcg->pcp_counter_lock);
+ return memcg;
+
+out_free:
+ if (size < PAGE_SIZE)
+ kfree(memcg);
+ else
+ vfree(memcg);
+ return NULL;
+}
+
+/*
+ * Helpers for freeing a vzalloc()ed mem_cgroup by RCU,
+ * but in process context. The work_freeing structure is overlaid
+ * on the rcu_freeing structure, which itself is overlaid on memsw.
+ */
+static void vfree_work(struct work_struct *work)
+{
+ struct mem_cgroup *memcg;
+
+ memcg = container_of(work, struct mem_cgroup, work_freeing);
+ vfree(memcg);
+}
+static void vfree_rcu(struct rcu_head *rcu_head)
+{
+ struct mem_cgroup *memcg;
+
+ memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing);
+ INIT_WORK(&memcg->work_freeing, vfree_work);
+ schedule_work(&memcg->work_freeing);
+}
+
+/*
+ * At destroying mem_cgroup, references from swap_cgroup can remain.
+ * (scanning all at force_empty is too costly...)
+ *
+ * Instead of clearing all references at force_empty, we remember
+ * the number of reference from swap_cgroup and free mem_cgroup when
+ * it goes down to 0.
+ *
+ * Removal of cgroup itself succeeds regardless of refs from swap.
+ */
+
+static void __mem_cgroup_free(struct mem_cgroup *memcg)
+{
+ int node;
+
+ mem_cgroup_remove_from_trees(memcg);
+ free_css_id(&mem_cgroup_subsys, &memcg->css);
+
+ for_each_node(node)
+ free_mem_cgroup_per_zone_info(memcg, node);
+
+ free_percpu(memcg->stat);
+ if (sizeof(struct mem_cgroup) < PAGE_SIZE)
+ kfree_rcu(memcg, rcu_freeing);
+ else
+ call_rcu(&memcg->rcu_freeing, vfree_rcu);
+}
+
+static void mem_cgroup_get(struct mem_cgroup *memcg)
+{
+ atomic_inc(&memcg->refcnt);
+}
+
+static void __mem_cgroup_put(struct mem_cgroup *memcg, int count)
+{
+ if (atomic_sub_and_test(count, &memcg->refcnt)) {
+ struct mem_cgroup *parent = parent_mem_cgroup(memcg);
+ __mem_cgroup_free(memcg);
+ if (parent)
+ mem_cgroup_put(parent);
+ }
+}
+
+static void mem_cgroup_put(struct mem_cgroup *memcg)
+{
+ __mem_cgroup_put(memcg, 1);
+}
+
+/*
+ * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
+ */
+struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
+{
+ if (!memcg->res.parent)
+ return NULL;
+ return mem_cgroup_from_res_counter(memcg->res.parent, res);
+}
+EXPORT_SYMBOL(parent_mem_cgroup);
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+static void __init enable_swap_cgroup(void)
+{
+ if (!mem_cgroup_disabled() && really_do_swap_account)
+ do_swap_account = 1;
+}
+#else
+static void __init enable_swap_cgroup(void)
+{
+}
+#endif
+
+static int mem_cgroup_soft_limit_tree_init(void)
+{
+ struct mem_cgroup_tree_per_node *rtpn;
+ struct mem_cgroup_tree_per_zone *rtpz;
+ int tmp, node, zone;
+
+ for_each_node(node) {
+ tmp = node;
+ if (!node_state(node, N_NORMAL_MEMORY))
+ tmp = -1;
+ rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
+ if (!rtpn)
+ goto err_cleanup;
+
+ soft_limit_tree.rb_tree_per_node[node] = rtpn;
+
+ for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+ rtpz = &rtpn->rb_tree_per_zone[zone];
+ rtpz->rb_root = RB_ROOT;
+ spin_lock_init(&rtpz->lock);
+ }
+ }
+ return 0;
+
+err_cleanup:
+ for_each_node(node) {
+ if (!soft_limit_tree.rb_tree_per_node[node])
+ break;
+ kfree(soft_limit_tree.rb_tree_per_node[node]);
+ soft_limit_tree.rb_tree_per_node[node] = NULL;
+ }
+ return 1;
+
+}
+
+static struct cgroup_subsys_state * __ref
+mem_cgroup_create(struct cgroup *cont)
+{
+ struct mem_cgroup *memcg, *parent;
+ long error = -ENOMEM;
+ int node;
+
+ memcg = mem_cgroup_alloc();
+ if (!memcg)
+ return ERR_PTR(error);
+
+ for_each_node(node)
+ if (alloc_mem_cgroup_per_zone_info(memcg, node))
+ goto free_out;
+
+ /* root ? */
+ if (cont->parent == NULL) {
+ int cpu;
+ enable_swap_cgroup();
+ parent = NULL;
+ if (mem_cgroup_soft_limit_tree_init())
+ goto free_out;
+ root_mem_cgroup = memcg;
+ for_each_possible_cpu(cpu) {
+ struct memcg_stock_pcp *stock =
+ &per_cpu(memcg_stock, cpu);
+ INIT_WORK(&stock->work, drain_local_stock);
+ }
+ hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
+ } else {
+ parent = mem_cgroup_from_cont(cont->parent);
+ memcg->use_hierarchy = parent->use_hierarchy;
+ memcg->oom_kill_disable = parent->oom_kill_disable;
+ }
+
+ if (parent && parent->use_hierarchy) {
+ res_counter_init(&memcg->res, &parent->res);
+ res_counter_init(&memcg->memsw, &parent->memsw);
+ /*
+ * We increment refcnt of the parent to ensure that we can
+ * safely access it on res_counter_charge/uncharge.
+ * This refcnt will be decremented when freeing this
+ * mem_cgroup(see mem_cgroup_put).
+ */
+ mem_cgroup_get(parent);
+ } else {
+ res_counter_init(&memcg->res, NULL);
+ res_counter_init(&memcg->memsw, NULL);
+ }
+ memcg->last_scanned_node = MAX_NUMNODES;
+ INIT_LIST_HEAD(&memcg->oom_notify);
+
+ if (parent)
+ memcg->swappiness = mem_cgroup_swappiness(parent);
+ atomic_set(&memcg->refcnt, 1);
+ memcg->move_charge_at_immigrate = 0;
+ mutex_init(&memcg->thresholds_lock);
+ spin_lock_init(&memcg->move_lock);
+ return &memcg->css;
+free_out:
+ __mem_cgroup_free(memcg);
+ return ERR_PTR(error);
+}
+
+static int mem_cgroup_pre_destroy(struct cgroup *cont)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+
+ return mem_cgroup_force_empty(memcg, false);
+}
+
+static void mem_cgroup_destroy(struct cgroup *cont)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+
+ kmem_cgroup_destroy(cont);
+
+ mem_cgroup_put(memcg);
+}
+
+static int mem_cgroup_populate(struct cgroup_subsys *ss,
+ struct cgroup *cont)
+{
+ int ret;
+
+ ret = cgroup_add_files(cont, ss, mem_cgroup_files,
+ ARRAY_SIZE(mem_cgroup_files));
+
+ if (!ret)
+ ret = register_memsw_files(cont, ss);
+
+ if (!ret)
+ ret = register_kmem_files(cont, ss);
+
+ return ret;
+}
+
+#ifdef CONFIG_MMU
+/* Handlers for move charge at task migration. */
+#define PRECHARGE_COUNT_AT_ONCE 256
+static int mem_cgroup_do_precharge(unsigned long count)
+{
+ int ret = 0;
+ int batch_count = PRECHARGE_COUNT_AT_ONCE;
+ struct mem_cgroup *memcg = mc.to;
+
+ if (mem_cgroup_is_root(memcg)) {
+ mc.precharge += count;
+ /* we don't need css_get for root */
+ return ret;
+ }
+ /* try to charge at once */
+ if (count > 1) {
+ struct res_counter *dummy;
+ /*
+ * "memcg" cannot be under rmdir() because we've already checked
+ * by cgroup_lock_live_cgroup() that it is not removed and we
+ * are still under the same cgroup_mutex. So we can postpone
+ * css_get().
+ */
+ if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy))
+ goto one_by_one;
+ if (do_swap_account && res_counter_charge(&memcg->memsw,
+ PAGE_SIZE * count, &dummy)) {
+ res_counter_uncharge(&memcg->res, PAGE_SIZE * count);
+ goto one_by_one;
+ }
+ mc.precharge += count;
+ return ret;
+ }
+one_by_one:
+ /* fall back to one by one charge */
+ while (count--) {
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+ if (!batch_count--) {
+ batch_count = PRECHARGE_COUNT_AT_ONCE;
+ cond_resched();
+ }
+ ret = __mem_cgroup_try_charge(NULL,
+ GFP_KERNEL, 1, &memcg, false);
+ if (ret)
+ /* mem_cgroup_clear_mc() will do uncharge later */
+ return ret;
+ mc.precharge++;
+ }
+ return ret;
+}
+
+/**
+ * get_mctgt_type - get target type of moving charge
+ * @vma: the vma the pte to be checked belongs
+ * @addr: the address corresponding to the pte to be checked
+ * @ptent: the pte to be checked
+ * @target: the pointer the target page or swap ent will be stored(can be NULL)
+ *
+ * Returns
+ * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
+ * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
+ * move charge. if @target is not NULL, the page is stored in target->page
+ * with extra refcnt got(Callers should handle it).
+ * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
+ * target for charge migration. if @target is not NULL, the entry is stored
+ * in target->ent.
+ *
+ * Called with pte lock held.
+ */
+union mc_target {
+ struct page *page;
+ swp_entry_t ent;
+};
+
+enum mc_target_type {
+ MC_TARGET_NONE = 0,
+ MC_TARGET_PAGE,
+ MC_TARGET_SWAP,
+};
+
+static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent)
+{
+ struct page *page = vm_normal_page(vma, addr, ptent);
+
+ if (!page || !page_mapped(page))
+ return NULL;
+ if (PageAnon(page)) {
+ /* we don't move shared anon */
+ if (!move_anon() || page_mapcount(page) > 2)
+ return NULL;
+ } else if (!move_file())
+ /* we ignore mapcount for file pages */
+ return NULL;
+ if (!get_page_unless_zero(page))
+ return NULL;
+
+ return page;
+}
+
+static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent, swp_entry_t *entry)
+{
+ int usage_count;
+ struct page *page = NULL;
+ swp_entry_t ent = pte_to_swp_entry(ptent);
+
+ if (!move_anon() || non_swap_entry(ent))
+ return NULL;
+ usage_count = mem_cgroup_count_swap_user(ent, &page);
+ if (usage_count > 1) { /* we don't move shared anon */
+ if (page)
+ put_page(page);
+ return NULL;
+ }
+ if (do_swap_account)
+ entry->val = ent.val;
+
+ return page;
+}
+
+static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent, swp_entry_t *entry)
+{
+ struct page *page = NULL;
+ struct inode *inode;
+ struct address_space *mapping;
+ pgoff_t pgoff;
+
+ if (!vma->vm_file) /* anonymous vma */
+ return NULL;
+ if (!move_file())
+ return NULL;
+
+ inode = vma->vm_file->f_path.dentry->d_inode;
+ mapping = vma->vm_file->f_mapping;
+ if (pte_none(ptent))
+ pgoff = linear_page_index(vma, addr);
+ else /* pte_file(ptent) is true */
+ pgoff = pte_to_pgoff(ptent);
+
+ /* page is moved even if it's not RSS of this task(page-faulted). */
+ page = find_get_page(mapping, pgoff);
+
+#ifdef CONFIG_SWAP
+ /* shmem/tmpfs may report page out on swap: account for that too. */
+ if (radix_tree_exceptional_entry(page)) {
+ swp_entry_t swap = radix_to_swp_entry(page);
+ if (do_swap_account)
+ *entry = swap;
+ page = find_get_page(&swapper_space, swap.val);
+ }
+#endif
+ return page;
+}
+
+static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent, union mc_target *target)
+{
+ struct page *page = NULL;
+ struct page_cgroup *pc;
+ enum mc_target_type ret = MC_TARGET_NONE;
+ swp_entry_t ent = { .val = 0 };
+
+ if (pte_present(ptent))
+ page = mc_handle_present_pte(vma, addr, ptent);
+ else if (is_swap_pte(ptent))
+ page = mc_handle_swap_pte(vma, addr, ptent, &ent);
+ else if (pte_none(ptent) || pte_file(ptent))
+ page = mc_handle_file_pte(vma, addr, ptent, &ent);
+
+ if (!page && !ent.val)
+ return ret;
+ if (page) {
+ pc = lookup_page_cgroup(page);
+ /*
+ * Do only loose check w/o page_cgroup lock.
+ * mem_cgroup_move_account() checks the pc is valid or not under
+ * the lock.
+ */
+ if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
+ ret = MC_TARGET_PAGE;
+ if (target)
+ target->page = page;
+ }
+ if (!ret || !target)
+ put_page(page);
+ }
+ /* There is a swap entry and a page doesn't exist or isn't charged */
+ if (ent.val && !ret &&
+ css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) {
+ ret = MC_TARGET_SWAP;
+ if (target)
+ target->ent = ent;
+ }
+ return ret;
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+/*
+ * We don't consider swapping or file mapped pages because THP does not
+ * support them for now.
+ * Caller should make sure that pmd_trans_huge(pmd) is true.
+ */
+static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t pmd, union mc_target *target)
+{
+ struct page *page = NULL;
+ struct page_cgroup *pc;
+ enum mc_target_type ret = MC_TARGET_NONE;
+
+ page = pmd_page(pmd);
+ VM_BUG_ON(!page || !PageHead(page));
+ if (!move_anon())
+ return ret;
+ pc = lookup_page_cgroup(page);
+ if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
+ ret = MC_TARGET_PAGE;
+ if (target) {
+ get_page(page);
+ target->page = page;
+ }
+ }
+ return ret;
+}
+#else
+static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t pmd, union mc_target *target)
+{
+ return MC_TARGET_NONE;
+}
+#endif
+
+static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ struct vm_area_struct *vma = walk->private;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ if (pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
+ mc.precharge += HPAGE_PMD_NR;
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ return 0;
+ }
+
+ if (pmd_trans_unstable(pmd))
+ return 0;
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ for (; addr != end; pte++, addr += PAGE_SIZE)
+ if (get_mctgt_type(vma, addr, *pte, NULL))
+ mc.precharge++; /* increment precharge temporarily */
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
+
+ return 0;
+}
+
+static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
+{
+ unsigned long precharge;
+ struct vm_area_struct *vma;
+
+ down_read(&mm->mmap_sem);
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ struct mm_walk mem_cgroup_count_precharge_walk = {
+ .pmd_entry = mem_cgroup_count_precharge_pte_range,
+ .mm = mm,
+ .private = vma,
+ };
+ if (is_vm_hugetlb_page(vma))
+ continue;
+ walk_page_range(vma->vm_start, vma->vm_end,
+ &mem_cgroup_count_precharge_walk);
+ }
+ up_read(&mm->mmap_sem);
+
+ precharge = mc.precharge;
+ mc.precharge = 0;
+
+ return precharge;
+}
+
+static int mem_cgroup_precharge_mc(struct mm_struct *mm)
+{
+ unsigned long precharge = mem_cgroup_count_precharge(mm);
+
+ VM_BUG_ON(mc.moving_task);
+ mc.moving_task = current;
+ return mem_cgroup_do_precharge(precharge);
+}
+
+/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
+static void __mem_cgroup_clear_mc(void)
+{
+ struct mem_cgroup *from = mc.from;
+ struct mem_cgroup *to = mc.to;
+
+ /* we must uncharge all the leftover precharges from mc.to */
+ if (mc.precharge) {
+ __mem_cgroup_cancel_charge(mc.to, mc.precharge);
+ mc.precharge = 0;
+ }
+ /*
+ * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
+ * we must uncharge here.
+ */
+ if (mc.moved_charge) {
+ __mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
+ mc.moved_charge = 0;
+ }
+ /* we must fixup refcnts and charges */
+ if (mc.moved_swap) {
+ /* uncharge swap account from the old cgroup */
+ if (!mem_cgroup_is_root(mc.from))
+ res_counter_uncharge(&mc.from->memsw,
+ PAGE_SIZE * mc.moved_swap);
+ __mem_cgroup_put(mc.from, mc.moved_swap);
+
+ if (!mem_cgroup_is_root(mc.to)) {
+ /*
+ * we charged both to->res and to->memsw, so we should
+ * uncharge to->res.
+ */
+ res_counter_uncharge(&mc.to->res,
+ PAGE_SIZE * mc.moved_swap);
+ }
+ /* we've already done mem_cgroup_get(mc.to) */
+ mc.moved_swap = 0;
+ }
+ memcg_oom_recover(from);
+ memcg_oom_recover(to);
+ wake_up_all(&mc.waitq);
+}
+
+static void mem_cgroup_clear_mc(void)
+{
+ struct mem_cgroup *from = mc.from;
+
+ /*
+ * we must clear moving_task before waking up waiters at the end of
+ * task migration.
+ */
+ mc.moving_task = NULL;
+ __mem_cgroup_clear_mc();
+ spin_lock(&mc.lock);
+ mc.from = NULL;
+ mc.to = NULL;
+ spin_unlock(&mc.lock);
+ mem_cgroup_end_move(from);
+}
+
+static int mem_cgroup_can_attach(struct cgroup *cgroup,
+ struct cgroup_taskset *tset)
+{
+ struct task_struct *p = cgroup_taskset_first(tset);
+ int ret = 0;
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup);
+
+ if (memcg->move_charge_at_immigrate) {
+ struct mm_struct *mm;
+ struct mem_cgroup *from = mem_cgroup_from_task(p);
+
+ VM_BUG_ON(from == memcg);
+
+ mm = get_task_mm(p);
+ if (!mm)
+ return 0;
+ /* We move charges only when we move a owner of the mm */
+ if (mm->owner == p) {
+ VM_BUG_ON(mc.from);
+ VM_BUG_ON(mc.to);
+ VM_BUG_ON(mc.precharge);
+ VM_BUG_ON(mc.moved_charge);
+ VM_BUG_ON(mc.moved_swap);
+ mem_cgroup_start_move(from);
+ spin_lock(&mc.lock);
+ mc.from = from;
+ mc.to = memcg;
+ spin_unlock(&mc.lock);
+ /* We set mc.moving_task later */
+
+ ret = mem_cgroup_precharge_mc(mm);
+ if (ret)
+ mem_cgroup_clear_mc();
+ }
+ mmput(mm);
+ }
+ return ret;
+}
+
+static void mem_cgroup_cancel_attach(struct cgroup *cgroup,
+ struct cgroup_taskset *tset)
+{
+ mem_cgroup_clear_mc();
+}
+
+static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ int ret = 0;
+ struct vm_area_struct *vma = walk->private;
+ pte_t *pte;
+ spinlock_t *ptl;
+ enum mc_target_type target_type;
+ union mc_target target;
+ struct page *page;
+ struct page_cgroup *pc;
+
+ /*
+ * We don't take compound_lock() here but no race with splitting thp
+ * happens because:
+ * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
+ * under splitting, which means there's no concurrent thp split,
+ * - if another thread runs into split_huge_page() just after we
+ * entered this if-block, the thread must wait for page table lock
+ * to be unlocked in __split_huge_page_splitting(), where the main
+ * part of thp split is not executed yet.
+ */
+ if (pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (mc.precharge < HPAGE_PMD_NR) {
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ return 0;
+ }
+ target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
+ if (target_type == MC_TARGET_PAGE) {
+ page = target.page;
+ if (!isolate_lru_page(page)) {
+ pc = lookup_page_cgroup(page);
+ if (!mem_cgroup_move_account(page, HPAGE_PMD_NR,
+ pc, mc.from, mc.to,
+ false)) {
+ mc.precharge -= HPAGE_PMD_NR;
+ mc.moved_charge += HPAGE_PMD_NR;
+ }
+ putback_lru_page(page);
+ }
+ put_page(page);
+ }
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ return 0;
+ }
+
+ if (pmd_trans_unstable(pmd))
+ return 0;
+retry:
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ for (; addr != end; addr += PAGE_SIZE) {
+ pte_t ptent = *(pte++);
+ swp_entry_t ent;
+
+ if (!mc.precharge)
+ break;
+
+ switch (get_mctgt_type(vma, addr, ptent, &target)) {
+ case MC_TARGET_PAGE:
+ page = target.page;
+ if (isolate_lru_page(page))
+ goto put;
+ pc = lookup_page_cgroup(page);
+ if (!mem_cgroup_move_account(page, 1, pc,
+ mc.from, mc.to, false)) {
+ mc.precharge--;
+ /* we uncharge from mc.from later. */
+ mc.moved_charge++;
+ }
+ putback_lru_page(page);
+put: /* get_mctgt_type() gets the page */
+ put_page(page);
+ break;
+ case MC_TARGET_SWAP:
+ ent = target.ent;
+ if (!mem_cgroup_move_swap_account(ent,
+ mc.from, mc.to, false)) {
+ mc.precharge--;
+ /* we fixup refcnts and charges later. */
+ mc.moved_swap++;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
+
+ if (addr != end) {
+ /*
+ * We have consumed all precharges we got in can_attach().
+ * We try charge one by one, but don't do any additional
+ * charges to mc.to if we have failed in charge once in attach()
+ * phase.
+ */
+ ret = mem_cgroup_do_precharge(1);
+ if (!ret)
+ goto retry;
+ }
+
+ return ret;
+}
+
+static void mem_cgroup_move_charge(struct mm_struct *mm)
+{
+ struct vm_area_struct *vma;
+
+ lru_add_drain_all();
+retry:
+ if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
+ /*
+ * Someone who are holding the mmap_sem might be waiting in
+ * waitq. So we cancel all extra charges, wake up all waiters,
+ * and retry. Because we cancel precharges, we might not be able
+ * to move enough charges, but moving charge is a best-effort
+ * feature anyway, so it wouldn't be a big problem.
+ */
+ __mem_cgroup_clear_mc();
+ cond_resched();
+ goto retry;
+ }
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ int ret;
+ struct mm_walk mem_cgroup_move_charge_walk = {
+ .pmd_entry = mem_cgroup_move_charge_pte_range,
+ .mm = mm,
+ .private = vma,
+ };
+ if (is_vm_hugetlb_page(vma))
+ continue;
+ ret = walk_page_range(vma->vm_start, vma->vm_end,
+ &mem_cgroup_move_charge_walk);
+ if (ret)
+ /*
+ * means we have consumed all precharges and failed in
+ * doing additional charge. Just abandon here.
+ */
+ break;
+ }
+ up_read(&mm->mmap_sem);
+}
+
+static void mem_cgroup_move_task(struct cgroup *cont,
+ struct cgroup_taskset *tset)
+{
+ struct task_struct *p = cgroup_taskset_first(tset);
+ struct mm_struct *mm = get_task_mm(p);
+
+ if (mm) {
+ if (mc.to)
+ mem_cgroup_move_charge(mm);
+ put_swap_token(mm);
+ mmput(mm);
+ }
+ if (mc.to)
+ mem_cgroup_clear_mc();
+}
+#else /* !CONFIG_MMU */
+static int mem_cgroup_can_attach(struct cgroup *cgroup,
+ struct cgroup_taskset *tset)
+{
+ return 0;
+}
+static void mem_cgroup_cancel_attach(struct cgroup *cgroup,
+ struct cgroup_taskset *tset)
+{
+}
+static void mem_cgroup_move_task(struct cgroup *cont,
+ struct cgroup_taskset *tset)
+{
+}
+#endif
+
+struct cgroup_subsys mem_cgroup_subsys = {
+ .name = "memory",
+ .subsys_id = mem_cgroup_subsys_id,
+ .create = mem_cgroup_create,
+ .pre_destroy = mem_cgroup_pre_destroy,
+ .destroy = mem_cgroup_destroy,
+ .populate = mem_cgroup_populate,
+ .can_attach = mem_cgroup_can_attach,
+ .cancel_attach = mem_cgroup_cancel_attach,
+ .attach = mem_cgroup_move_task,
+ .early_init = 0,
+ .use_id = 1,
+};
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+static int __init enable_swap_account(char *s)
+{
+ /* consider enabled if no parameter or 1 is given */
+ if (!strcmp(s, "1"))
+ really_do_swap_account = 1;
+ else if (!strcmp(s, "0"))
+ really_do_swap_account = 0;
+ return 1;
+}
+__setup("swapaccount=", enable_swap_account);
+
+#endif
diff --git a/ap/os/linux/linux-3.4.x/mm/memory-failure.c b/ap/os/linux/linux-3.4.x/mm/memory-failure.c
new file mode 100644
index 0000000..c957a37
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/memory-failure.c
@@ -0,0 +1,1608 @@
+/*
+ * Copyright (C) 2008, 2009 Intel Corporation
+ * Authors: Andi Kleen, Fengguang Wu
+ *
+ * This software may be redistributed and/or modified under the terms of
+ * the GNU General Public License ("GPL") version 2 only as published by the
+ * Free Software Foundation.
+ *
+ * High level machine check handler. Handles pages reported by the
+ * hardware as being corrupted usually due to a multi-bit ECC memory or cache
+ * failure.
+ *
+ * In addition there is a "soft offline" entry point that allows stop using
+ * not-yet-corrupted-by-suspicious pages without killing anything.
+ *
+ * Handles page cache pages in various states. The tricky part
+ * here is that we can access any page asynchronously in respect to
+ * other VM users, because memory failures could happen anytime and
+ * anywhere. This could violate some of their assumptions. This is why
+ * this code has to be extremely careful. Generally it tries to use
+ * normal locking rules, as in get the standard locks, even if that means
+ * the error handling takes potentially a long time.
+ *
+ * There are several operations here with exponential complexity because
+ * of unsuitable VM data structures. For example the operation to map back
+ * from RMAP chains to processes has to walk the complete process list and
+ * has non linear complexity with the number. But since memory corruptions
+ * are rare we hope to get away with this. This avoids impacting the core
+ * VM.
+ */
+
+/*
+ * Notebook:
+ * - hugetlb needs more code
+ * - kcore/oldmem/vmcore/mem/kmem check for hwpoison pages
+ * - pass bad pages to kdump next kernel
+ */
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/page-flags.h>
+#include <linux/kernel-page-flags.h>
+#include <linux/sched.h>
+#include <linux/ksm.h>
+#include <linux/rmap.h>
+#include <linux/export.h>
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+#include <linux/backing-dev.h>
+#include <linux/migrate.h>
+#include <linux/page-isolation.h>
+#include <linux/suspend.h>
+#include <linux/slab.h>
+#include <linux/swapops.h>
+#include <linux/hugetlb.h>
+#include <linux/memory_hotplug.h>
+#include <linux/mm_inline.h>
+#include <linux/kfifo.h>
+#include "internal.h"
+
+int sysctl_memory_failure_early_kill __read_mostly = 0;
+
+int sysctl_memory_failure_recovery __read_mostly = 1;
+
+atomic_long_t mce_bad_pages __read_mostly = ATOMIC_LONG_INIT(0);
+
+#if defined(CONFIG_HWPOISON_INJECT) || defined(CONFIG_HWPOISON_INJECT_MODULE)
+
+u32 hwpoison_filter_enable = 0;
+u32 hwpoison_filter_dev_major = ~0U;
+u32 hwpoison_filter_dev_minor = ~0U;
+u64 hwpoison_filter_flags_mask;
+u64 hwpoison_filter_flags_value;
+EXPORT_SYMBOL_GPL(hwpoison_filter_enable);
+EXPORT_SYMBOL_GPL(hwpoison_filter_dev_major);
+EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor);
+EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask);
+EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value);
+
+static int hwpoison_filter_dev(struct page *p)
+{
+ struct address_space *mapping;
+ dev_t dev;
+
+ if (hwpoison_filter_dev_major == ~0U &&
+ hwpoison_filter_dev_minor == ~0U)
+ return 0;
+
+ /*
+ * page_mapping() does not accept slab pages.
+ */
+ if (PageSlab(p))
+ return -EINVAL;
+
+ mapping = page_mapping(p);
+ if (mapping == NULL || mapping->host == NULL)
+ return -EINVAL;
+
+ dev = mapping->host->i_sb->s_dev;
+ if (hwpoison_filter_dev_major != ~0U &&
+ hwpoison_filter_dev_major != MAJOR(dev))
+ return -EINVAL;
+ if (hwpoison_filter_dev_minor != ~0U &&
+ hwpoison_filter_dev_minor != MINOR(dev))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int hwpoison_filter_flags(struct page *p)
+{
+ if (!hwpoison_filter_flags_mask)
+ return 0;
+
+ if ((stable_page_flags(p) & hwpoison_filter_flags_mask) ==
+ hwpoison_filter_flags_value)
+ return 0;
+ else
+ return -EINVAL;
+}
+
+/*
+ * This allows stress tests to limit test scope to a collection of tasks
+ * by putting them under some memcg. This prevents killing unrelated/important
+ * processes such as /sbin/init. Note that the target task may share clean
+ * pages with init (eg. libc text), which is harmless. If the target task
+ * share _dirty_ pages with another task B, the test scheme must make sure B
+ * is also included in the memcg. At last, due to race conditions this filter
+ * can only guarantee that the page either belongs to the memcg tasks, or is
+ * a freed page.
+ */
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+u64 hwpoison_filter_memcg;
+EXPORT_SYMBOL_GPL(hwpoison_filter_memcg);
+static int hwpoison_filter_task(struct page *p)
+{
+ struct mem_cgroup *mem;
+ struct cgroup_subsys_state *css;
+ unsigned long ino;
+
+ if (!hwpoison_filter_memcg)
+ return 0;
+
+ mem = try_get_mem_cgroup_from_page(p);
+ if (!mem)
+ return -EINVAL;
+
+ css = mem_cgroup_css(mem);
+ /* root_mem_cgroup has NULL dentries */
+ if (!css->cgroup->dentry)
+ return -EINVAL;
+
+ ino = css->cgroup->dentry->d_inode->i_ino;
+ css_put(css);
+
+ if (ino != hwpoison_filter_memcg)
+ return -EINVAL;
+
+ return 0;
+}
+#else
+static int hwpoison_filter_task(struct page *p) { return 0; }
+#endif
+
+int hwpoison_filter(struct page *p)
+{
+ if (!hwpoison_filter_enable)
+ return 0;
+
+ if (hwpoison_filter_dev(p))
+ return -EINVAL;
+
+ if (hwpoison_filter_flags(p))
+ return -EINVAL;
+
+ if (hwpoison_filter_task(p))
+ return -EINVAL;
+
+ return 0;
+}
+#else
+int hwpoison_filter(struct page *p)
+{
+ return 0;
+}
+#endif
+
+EXPORT_SYMBOL_GPL(hwpoison_filter);
+
+/*
+ * Send all the processes who have the page mapped a signal.
+ * ``action optional'' if they are not immediately affected by the error
+ * ``action required'' if error happened in current execution context
+ */
+static int kill_proc(struct task_struct *t, unsigned long addr, int trapno,
+ unsigned long pfn, struct page *page, int flags)
+{
+ struct siginfo si;
+ int ret;
+
+ printk(KERN_ERR
+ "MCE %#lx: Killing %s:%d due to hardware memory corruption\n",
+ pfn, t->comm, t->pid);
+ si.si_signo = SIGBUS;
+ si.si_errno = 0;
+ si.si_addr = (void *)addr;
+#ifdef __ARCH_SI_TRAPNO
+ si.si_trapno = trapno;
+#endif
+ si.si_addr_lsb = compound_trans_order(compound_head(page)) + PAGE_SHIFT;
+
+ if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) {
+ si.si_code = BUS_MCEERR_AR;
+ ret = force_sig_info(SIGBUS, &si, current);
+ } else {
+ /*
+ * Don't use force here, it's convenient if the signal
+ * can be temporarily blocked.
+ * This could cause a loop when the user sets SIGBUS
+ * to SIG_IGN, but hopefully no one will do that?
+ */
+ si.si_code = BUS_MCEERR_AO;
+ ret = send_sig_info(SIGBUS, &si, t); /* synchronous? */
+ }
+ if (ret < 0)
+ printk(KERN_INFO "MCE: Error sending signal to %s:%d: %d\n",
+ t->comm, t->pid, ret);
+ return ret;
+}
+
+/*
+ * When a unknown page type is encountered drain as many buffers as possible
+ * in the hope to turn the page into a LRU or free page, which we can handle.
+ */
+void shake_page(struct page *p, int access)
+{
+ if (!PageSlab(p)) {
+ lru_add_drain_all();
+ if (PageLRU(p))
+ return;
+ drain_all_pages();
+ if (PageLRU(p) || is_free_buddy_page(p))
+ return;
+ }
+
+ /*
+ * Only call shrink_slab here (which would also shrink other caches) if
+ * access is not potentially fatal.
+ */
+ if (access) {
+ int nr;
+ do {
+ struct shrink_control shrink = {
+ .gfp_mask = GFP_KERNEL,
+ };
+
+ nr = shrink_slab(&shrink, 1000, 1000);
+ if (page_count(p) == 1)
+ break;
+ } while (nr > 10);
+ }
+}
+EXPORT_SYMBOL_GPL(shake_page);
+
+/*
+ * Kill all processes that have a poisoned page mapped and then isolate
+ * the page.
+ *
+ * General strategy:
+ * Find all processes having the page mapped and kill them.
+ * But we keep a page reference around so that the page is not
+ * actually freed yet.
+ * Then stash the page away
+ *
+ * There's no convenient way to get back to mapped processes
+ * from the VMAs. So do a brute-force search over all
+ * running processes.
+ *
+ * Remember that machine checks are not common (or rather
+ * if they are common you have other problems), so this shouldn't
+ * be a performance issue.
+ *
+ * Also there are some races possible while we get from the
+ * error detection to actually handle it.
+ */
+
+struct to_kill {
+ struct list_head nd;
+ struct task_struct *tsk;
+ unsigned long addr;
+ char addr_valid;
+};
+
+/*
+ * Failure handling: if we can't find or can't kill a process there's
+ * not much we can do. We just print a message and ignore otherwise.
+ */
+
+/*
+ * Schedule a process for later kill.
+ * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM.
+ * TBD would GFP_NOIO be enough?
+ */
+static void add_to_kill(struct task_struct *tsk, struct page *p,
+ struct vm_area_struct *vma,
+ struct list_head *to_kill,
+ struct to_kill **tkc)
+{
+ struct to_kill *tk;
+
+ if (*tkc) {
+ tk = *tkc;
+ *tkc = NULL;
+ } else {
+ tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC);
+ if (!tk) {
+ printk(KERN_ERR
+ "MCE: Out of memory while machine check handling\n");
+ return;
+ }
+ }
+ tk->addr = page_address_in_vma(p, vma);
+ tk->addr_valid = 1;
+
+ /*
+ * In theory we don't have to kill when the page was
+ * munmaped. But it could be also a mremap. Since that's
+ * likely very rare kill anyways just out of paranoia, but use
+ * a SIGKILL because the error is not contained anymore.
+ */
+ if (tk->addr == -EFAULT) {
+ pr_info("MCE: Unable to find user space address %lx in %s\n",
+ page_to_pfn(p), tsk->comm);
+ tk->addr_valid = 0;
+ }
+ get_task_struct(tsk);
+ tk->tsk = tsk;
+ list_add_tail(&tk->nd, to_kill);
+}
+
+/*
+ * Kill the processes that have been collected earlier.
+ *
+ * Only do anything when DOIT is set, otherwise just free the list
+ * (this is used for clean pages which do not need killing)
+ * Also when FAIL is set do a force kill because something went
+ * wrong earlier.
+ */
+static void kill_procs(struct list_head *to_kill, int forcekill, int trapno,
+ int fail, struct page *page, unsigned long pfn,
+ int flags)
+{
+ struct to_kill *tk, *next;
+
+ list_for_each_entry_safe (tk, next, to_kill, nd) {
+ if (forcekill) {
+ /*
+ * In case something went wrong with munmapping
+ * make sure the process doesn't catch the
+ * signal and then access the memory. Just kill it.
+ */
+ if (fail || tk->addr_valid == 0) {
+ printk(KERN_ERR
+ "MCE %#lx: forcibly killing %s:%d because of failure to unmap corrupted page\n",
+ pfn, tk->tsk->comm, tk->tsk->pid);
+ force_sig(SIGKILL, tk->tsk);
+ }
+
+ /*
+ * In theory the process could have mapped
+ * something else on the address in-between. We could
+ * check for that, but we need to tell the
+ * process anyways.
+ */
+ else if (kill_proc(tk->tsk, tk->addr, trapno,
+ pfn, page, flags) < 0)
+ printk(KERN_ERR
+ "MCE %#lx: Cannot send advisory machine check signal to %s:%d\n",
+ pfn, tk->tsk->comm, tk->tsk->pid);
+ }
+ put_task_struct(tk->tsk);
+ kfree(tk);
+ }
+}
+
+static int task_early_kill(struct task_struct *tsk, int force_early)
+{
+ if (!tsk->mm)
+ return 0;
+ if (force_early)
+ return 1;
+ if (tsk->flags & PF_MCE_PROCESS)
+ return !!(tsk->flags & PF_MCE_EARLY);
+ return sysctl_memory_failure_early_kill;
+}
+
+/*
+ * Collect processes when the error hit an anonymous page.
+ */
+static void collect_procs_anon(struct page *page, struct list_head *to_kill,
+ struct to_kill **tkc, int force_early)
+{
+ struct vm_area_struct *vma;
+ struct task_struct *tsk;
+ struct anon_vma *av;
+
+ av = page_lock_anon_vma(page);
+ if (av == NULL) /* Not actually mapped anymore */
+ return;
+
+ read_lock(&tasklist_lock);
+ for_each_process (tsk) {
+ struct anon_vma_chain *vmac;
+
+ if (!task_early_kill(tsk, force_early))
+ continue;
+ list_for_each_entry(vmac, &av->head, same_anon_vma) {
+ vma = vmac->vma;
+ if (!page_mapped_in_vma(page, vma))
+ continue;
+ if (vma->vm_mm == tsk->mm)
+ add_to_kill(tsk, page, vma, to_kill, tkc);
+ }
+ }
+ read_unlock(&tasklist_lock);
+ page_unlock_anon_vma(av);
+}
+
+/*
+ * Collect processes when the error hit a file mapped page.
+ */
+static void collect_procs_file(struct page *page, struct list_head *to_kill,
+ struct to_kill **tkc, int force_early)
+{
+ struct vm_area_struct *vma;
+ struct task_struct *tsk;
+ struct prio_tree_iter iter;
+ struct address_space *mapping = page->mapping;
+
+ mutex_lock(&mapping->i_mmap_mutex);
+ read_lock(&tasklist_lock);
+ for_each_process(tsk) {
+ pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+
+ if (!task_early_kill(tsk, force_early))
+ continue;
+
+ vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff,
+ pgoff) {
+ /*
+ * Send early kill signal to tasks where a vma covers
+ * the page but the corrupted page is not necessarily
+ * mapped it in its pte.
+ * Assume applications who requested early kill want
+ * to be informed of all such data corruptions.
+ */
+ if (vma->vm_mm == tsk->mm)
+ add_to_kill(tsk, page, vma, to_kill, tkc);
+ }
+ }
+ read_unlock(&tasklist_lock);
+ mutex_unlock(&mapping->i_mmap_mutex);
+}
+
+/*
+ * Collect the processes who have the corrupted page mapped to kill.
+ * This is done in two steps for locking reasons.
+ * First preallocate one tokill structure outside the spin locks,
+ * so that we can kill at least one process reasonably reliable.
+ */
+static void collect_procs(struct page *page, struct list_head *tokill,
+ int force_early)
+{
+ struct to_kill *tk;
+
+ if (!page->mapping)
+ return;
+
+ tk = kmalloc(sizeof(struct to_kill), GFP_NOIO);
+ if (!tk)
+ return;
+ if (PageAnon(page))
+ collect_procs_anon(page, tokill, &tk, force_early);
+ else
+ collect_procs_file(page, tokill, &tk, force_early);
+ kfree(tk);
+}
+
+/*
+ * Error handlers for various types of pages.
+ */
+
+enum outcome {
+ IGNORED, /* Error: cannot be handled */
+ FAILED, /* Error: handling failed */
+ DELAYED, /* Will be handled later */
+ RECOVERED, /* Successfully recovered */
+};
+
+static const char *action_name[] = {
+ [IGNORED] = "Ignored",
+ [FAILED] = "Failed",
+ [DELAYED] = "Delayed",
+ [RECOVERED] = "Recovered",
+};
+
+/*
+ * XXX: It is possible that a page is isolated from LRU cache,
+ * and then kept in swap cache or failed to remove from page cache.
+ * The page count will stop it from being freed by unpoison.
+ * Stress tests should be aware of this memory leak problem.
+ */
+static int delete_from_lru_cache(struct page *p)
+{
+ if (!isolate_lru_page(p)) {
+ /*
+ * Clear sensible page flags, so that the buddy system won't
+ * complain when the page is unpoison-and-freed.
+ */
+ ClearPageActive(p);
+ ClearPageUnevictable(p);
+ /*
+ * drop the page count elevated by isolate_lru_page()
+ */
+ page_cache_release(p);
+ return 0;
+ }
+ return -EIO;
+}
+
+/*
+ * Error hit kernel page.
+ * Do nothing, try to be lucky and not touch this instead. For a few cases we
+ * could be more sophisticated.
+ */
+static int me_kernel(struct page *p, unsigned long pfn)
+{
+ return IGNORED;
+}
+
+/*
+ * Page in unknown state. Do nothing.
+ */
+static int me_unknown(struct page *p, unsigned long pfn)
+{
+ printk(KERN_ERR "MCE %#lx: Unknown page state\n", pfn);
+ return FAILED;
+}
+
+/*
+ * Clean (or cleaned) page cache page.
+ */
+static int me_pagecache_clean(struct page *p, unsigned long pfn)
+{
+ int err;
+ int ret = FAILED;
+ struct address_space *mapping;
+
+ delete_from_lru_cache(p);
+
+ /*
+ * For anonymous pages we're done the only reference left
+ * should be the one m_f() holds.
+ */
+ if (PageAnon(p))
+ return RECOVERED;
+
+ /*
+ * Now truncate the page in the page cache. This is really
+ * more like a "temporary hole punch"
+ * Don't do this for block devices when someone else
+ * has a reference, because it could be file system metadata
+ * and that's not safe to truncate.
+ */
+ mapping = page_mapping(p);
+ if (!mapping) {
+ /*
+ * Page has been teared down in the meanwhile
+ */
+ return FAILED;
+ }
+
+ /*
+ * Truncation is a bit tricky. Enable it per file system for now.
+ *
+ * Open: to take i_mutex or not for this? Right now we don't.
+ */
+ if (mapping->a_ops->error_remove_page) {
+ err = mapping->a_ops->error_remove_page(mapping, p);
+ if (err != 0) {
+ printk(KERN_INFO "MCE %#lx: Failed to punch page: %d\n",
+ pfn, err);
+ } else if (page_has_private(p) &&
+ !try_to_release_page(p, GFP_NOIO)) {
+ pr_info("MCE %#lx: failed to release buffers\n", pfn);
+ } else {
+ ret = RECOVERED;
+ }
+ } else {
+ /*
+ * If the file system doesn't support it just invalidate
+ * This fails on dirty or anything with private pages
+ */
+ if (invalidate_inode_page(p))
+ ret = RECOVERED;
+ else
+ printk(KERN_INFO "MCE %#lx: Failed to invalidate\n",
+ pfn);
+ }
+ return ret;
+}
+
+/*
+ * Dirty cache page page
+ * Issues: when the error hit a hole page the error is not properly
+ * propagated.
+ */
+static int me_pagecache_dirty(struct page *p, unsigned long pfn)
+{
+ struct address_space *mapping = page_mapping(p);
+
+ SetPageError(p);
+ /* TBD: print more information about the file. */
+ if (mapping) {
+ /*
+ * IO error will be reported by write(), fsync(), etc.
+ * who check the mapping.
+ * This way the application knows that something went
+ * wrong with its dirty file data.
+ *
+ * There's one open issue:
+ *
+ * The EIO will be only reported on the next IO
+ * operation and then cleared through the IO map.
+ * Normally Linux has two mechanisms to pass IO error
+ * first through the AS_EIO flag in the address space
+ * and then through the PageError flag in the page.
+ * Since we drop pages on memory failure handling the
+ * only mechanism open to use is through AS_AIO.
+ *
+ * This has the disadvantage that it gets cleared on
+ * the first operation that returns an error, while
+ * the PageError bit is more sticky and only cleared
+ * when the page is reread or dropped. If an
+ * application assumes it will always get error on
+ * fsync, but does other operations on the fd before
+ * and the page is dropped between then the error
+ * will not be properly reported.
+ *
+ * This can already happen even without hwpoisoned
+ * pages: first on metadata IO errors (which only
+ * report through AS_EIO) or when the page is dropped
+ * at the wrong time.
+ *
+ * So right now we assume that the application DTRT on
+ * the first EIO, but we're not worse than other parts
+ * of the kernel.
+ */
+ mapping_set_error(mapping, EIO);
+ }
+
+ return me_pagecache_clean(p, pfn);
+}
+
+/*
+ * Clean and dirty swap cache.
+ *
+ * Dirty swap cache page is tricky to handle. The page could live both in page
+ * cache and swap cache(ie. page is freshly swapped in). So it could be
+ * referenced concurrently by 2 types of PTEs:
+ * normal PTEs and swap PTEs. We try to handle them consistently by calling
+ * try_to_unmap(TTU_IGNORE_HWPOISON) to convert the normal PTEs to swap PTEs,
+ * and then
+ * - clear dirty bit to prevent IO
+ * - remove from LRU
+ * - but keep in the swap cache, so that when we return to it on
+ * a later page fault, we know the application is accessing
+ * corrupted data and shall be killed (we installed simple
+ * interception code in do_swap_page to catch it).
+ *
+ * Clean swap cache pages can be directly isolated. A later page fault will
+ * bring in the known good data from disk.
+ */
+static int me_swapcache_dirty(struct page *p, unsigned long pfn)
+{
+ ClearPageDirty(p);
+ /* Trigger EIO in shmem: */
+ ClearPageUptodate(p);
+
+ if (!delete_from_lru_cache(p))
+ return DELAYED;
+ else
+ return FAILED;
+}
+
+static int me_swapcache_clean(struct page *p, unsigned long pfn)
+{
+ delete_from_swap_cache(p);
+
+ if (!delete_from_lru_cache(p))
+ return RECOVERED;
+ else
+ return FAILED;
+}
+
+/*
+ * Huge pages. Needs work.
+ * Issues:
+ * - Error on hugepage is contained in hugepage unit (not in raw page unit.)
+ * To narrow down kill region to one page, we need to break up pmd.
+ */
+static int me_huge_page(struct page *p, unsigned long pfn)
+{
+ int res = 0;
+ struct page *hpage = compound_head(p);
+ /*
+ * We can safely recover from error on free or reserved (i.e.
+ * not in-use) hugepage by dequeuing it from freelist.
+ * To check whether a hugepage is in-use or not, we can't use
+ * page->lru because it can be used in other hugepage operations,
+ * such as __unmap_hugepage_range() and gather_surplus_pages().
+ * So instead we use page_mapping() and PageAnon().
+ * We assume that this function is called with page lock held,
+ * so there is no race between isolation and mapping/unmapping.
+ */
+ if (!(page_mapping(hpage) || PageAnon(hpage))) {
+ res = dequeue_hwpoisoned_huge_page(hpage);
+ if (!res)
+ return RECOVERED;
+ }
+ return DELAYED;
+}
+
+/*
+ * Various page states we can handle.
+ *
+ * A page state is defined by its current page->flags bits.
+ * The table matches them in order and calls the right handler.
+ *
+ * This is quite tricky because we can access page at any time
+ * in its live cycle, so all accesses have to be extremely careful.
+ *
+ * This is not complete. More states could be added.
+ * For any missing state don't attempt recovery.
+ */
+
+#define dirty (1UL << PG_dirty)
+#define sc (1UL << PG_swapcache)
+#define unevict (1UL << PG_unevictable)
+#define mlock (1UL << PG_mlocked)
+#define writeback (1UL << PG_writeback)
+#define lru (1UL << PG_lru)
+#define swapbacked (1UL << PG_swapbacked)
+#define head (1UL << PG_head)
+#define tail (1UL << PG_tail)
+#define compound (1UL << PG_compound)
+#define slab (1UL << PG_slab)
+#define reserved (1UL << PG_reserved)
+
+static struct page_state {
+ unsigned long mask;
+ unsigned long res;
+ char *msg;
+ int (*action)(struct page *p, unsigned long pfn);
+} error_states[] = {
+ { reserved, reserved, "reserved kernel", me_kernel },
+ /*
+ * free pages are specially detected outside this table:
+ * PG_buddy pages only make a small fraction of all free pages.
+ */
+
+ /*
+ * Could in theory check if slab page is free or if we can drop
+ * currently unused objects without touching them. But just
+ * treat it as standard kernel for now.
+ */
+ { slab, slab, "kernel slab", me_kernel },
+
+#ifdef CONFIG_PAGEFLAGS_EXTENDED
+ { head, head, "huge", me_huge_page },
+ { tail, tail, "huge", me_huge_page },
+#else
+ { compound, compound, "huge", me_huge_page },
+#endif
+
+ { sc|dirty, sc|dirty, "swapcache", me_swapcache_dirty },
+ { sc|dirty, sc, "swapcache", me_swapcache_clean },
+
+ { unevict|dirty, unevict|dirty, "unevictable LRU", me_pagecache_dirty},
+ { unevict, unevict, "unevictable LRU", me_pagecache_clean},
+
+ { mlock|dirty, mlock|dirty, "mlocked LRU", me_pagecache_dirty },
+ { mlock, mlock, "mlocked LRU", me_pagecache_clean },
+
+ { lru|dirty, lru|dirty, "LRU", me_pagecache_dirty },
+ { lru|dirty, lru, "clean LRU", me_pagecache_clean },
+
+ /*
+ * Catchall entry: must be at end.
+ */
+ { 0, 0, "unknown page state", me_unknown },
+};
+
+#undef dirty
+#undef sc
+#undef unevict
+#undef mlock
+#undef writeback
+#undef lru
+#undef swapbacked
+#undef head
+#undef tail
+#undef compound
+#undef slab
+#undef reserved
+
+static void action_result(unsigned long pfn, char *msg, int result)
+{
+ struct page *page = pfn_to_page(pfn);
+
+ printk(KERN_ERR "MCE %#lx: %s%s page recovery: %s\n",
+ pfn,
+ PageDirty(page) ? "dirty " : "",
+ msg, action_name[result]);
+}
+
+static int page_action(struct page_state *ps, struct page *p,
+ unsigned long pfn)
+{
+ int result;
+ int count;
+
+ result = ps->action(p, pfn);
+ action_result(pfn, ps->msg, result);
+
+ count = page_count(p) - 1;
+ if (ps->action == me_swapcache_dirty && result == DELAYED)
+ count--;
+ if (count != 0) {
+ printk(KERN_ERR
+ "MCE %#lx: %s page still referenced by %d users\n",
+ pfn, ps->msg, count);
+ result = FAILED;
+ }
+
+ /* Could do more checks here if page looks ok */
+ /*
+ * Could adjust zone counters here to correct for the missing page.
+ */
+
+ return (result == RECOVERED || result == DELAYED) ? 0 : -EBUSY;
+}
+
+/*
+ * Do all that is necessary to remove user space mappings. Unmap
+ * the pages and send SIGBUS to the processes if the data was dirty.
+ */
+static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
+ int trapno, int flags)
+{
+ enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS;
+ struct address_space *mapping;
+ LIST_HEAD(tokill);
+ int ret;
+ int kill = 1, forcekill;
+ struct page *hpage = compound_head(p);
+ struct page *ppage;
+
+ if (PageReserved(p) || PageSlab(p))
+ return SWAP_SUCCESS;
+
+ /*
+ * This check implies we don't kill processes if their pages
+ * are in the swap cache early. Those are always late kills.
+ */
+ if (!page_mapped(hpage))
+ return SWAP_SUCCESS;
+
+ if (PageKsm(p))
+ return SWAP_FAIL;
+
+ if (PageSwapCache(p)) {
+ printk(KERN_ERR
+ "MCE %#lx: keeping poisoned page in swap cache\n", pfn);
+ ttu |= TTU_IGNORE_HWPOISON;
+ }
+
+ /*
+ * Propagate the dirty bit from PTEs to struct page first, because we
+ * need this to decide if we should kill or just drop the page.
+ * XXX: the dirty test could be racy: set_page_dirty() may not always
+ * be called inside page lock (it's recommended but not enforced).
+ */
+ mapping = page_mapping(hpage);
+ if (!(flags & MF_MUST_KILL) && !PageDirty(hpage) && mapping &&
+ mapping_cap_writeback_dirty(mapping)) {
+ if (page_mkclean(hpage)) {
+ SetPageDirty(hpage);
+ } else {
+ kill = 0;
+ ttu |= TTU_IGNORE_HWPOISON;
+ printk(KERN_INFO
+ "MCE %#lx: corrupted page was clean: dropped without side effects\n",
+ pfn);
+ }
+ }
+
+ /*
+ * ppage: poisoned page
+ * if p is regular page(4k page)
+ * ppage == real poisoned page;
+ * else p is hugetlb or THP, ppage == head page.
+ */
+ ppage = hpage;
+
+ if (PageTransHuge(hpage)) {
+ /*
+ * Verify that this isn't a hugetlbfs head page, the check for
+ * PageAnon is just for avoid tripping a split_huge_page
+ * internal debug check, as split_huge_page refuses to deal with
+ * anything that isn't an anon page. PageAnon can't go away fro
+ * under us because we hold a refcount on the hpage, without a
+ * refcount on the hpage. split_huge_page can't be safely called
+ * in the first place, having a refcount on the tail isn't
+ * enough * to be safe.
+ */
+ if (!PageHuge(hpage) && PageAnon(hpage)) {
+ if (unlikely(split_huge_page(hpage))) {
+ /*
+ * FIXME: if splitting THP is failed, it is
+ * better to stop the following operation rather
+ * than causing panic by unmapping. System might
+ * survive if the page is freed later.
+ */
+ printk(KERN_INFO
+ "MCE %#lx: failed to split THP\n", pfn);
+
+ BUG_ON(!PageHWPoison(p));
+ return SWAP_FAIL;
+ }
+ /* THP is split, so ppage should be the real poisoned page. */
+ ppage = p;
+ }
+ }
+
+ /*
+ * First collect all the processes that have the page
+ * mapped in dirty form. This has to be done before try_to_unmap,
+ * because ttu takes the rmap data structures down.
+ *
+ * Error handling: We ignore errors here because
+ * there's nothing that can be done.
+ */
+ if (kill)
+ collect_procs(ppage, &tokill, flags & MF_ACTION_REQUIRED);
+
+ if (hpage != ppage)
+ lock_page(ppage);
+
+ ret = try_to_unmap(ppage, ttu);
+ if (ret != SWAP_SUCCESS)
+ printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
+ pfn, page_mapcount(ppage));
+
+ if (hpage != ppage)
+ unlock_page(ppage);
+
+ /*
+ * Now that the dirty bit has been propagated to the
+ * struct page and all unmaps done we can decide if
+ * killing is needed or not. Only kill when the page
+ * was dirty or the process is not restartable,
+ * otherwise the tokill list is merely
+ * freed. When there was a problem unmapping earlier
+ * use a more force-full uncatchable kill to prevent
+ * any accesses to the poisoned memory.
+ */
+ forcekill = PageDirty(ppage) || (flags & MF_MUST_KILL);
+ kill_procs(&tokill, forcekill, trapno,
+ ret != SWAP_SUCCESS, p, pfn, flags);
+
+ return ret;
+}
+
+static void set_page_hwpoison_huge_page(struct page *hpage)
+{
+ int i;
+ int nr_pages = 1 << compound_trans_order(hpage);
+ for (i = 0; i < nr_pages; i++)
+ SetPageHWPoison(hpage + i);
+}
+
+static void clear_page_hwpoison_huge_page(struct page *hpage)
+{
+ int i;
+ int nr_pages = 1 << compound_trans_order(hpage);
+ for (i = 0; i < nr_pages; i++)
+ ClearPageHWPoison(hpage + i);
+}
+
+/**
+ * memory_failure - Handle memory failure of a page.
+ * @pfn: Page Number of the corrupted page
+ * @trapno: Trap number reported in the signal to user space.
+ * @flags: fine tune action taken
+ *
+ * This function is called by the low level machine check code
+ * of an architecture when it detects hardware memory corruption
+ * of a page. It tries its best to recover, which includes
+ * dropping pages, killing processes etc.
+ *
+ * The function is primarily of use for corruptions that
+ * happen outside the current execution context (e.g. when
+ * detected by a background scrubber)
+ *
+ * Must run in process context (e.g. a work queue) with interrupts
+ * enabled and no spinlocks hold.
+ */
+int memory_failure(unsigned long pfn, int trapno, int flags)
+{
+ struct page_state *ps;
+ struct page *p;
+ struct page *hpage;
+ int res;
+ unsigned int nr_pages;
+
+ if (!sysctl_memory_failure_recovery)
+ panic("Memory failure from trap %d on page %lx", trapno, pfn);
+
+ if (!pfn_valid(pfn)) {
+ printk(KERN_ERR
+ "MCE %#lx: memory outside kernel control\n",
+ pfn);
+ return -ENXIO;
+ }
+
+ p = pfn_to_page(pfn);
+ hpage = compound_head(p);
+ if (TestSetPageHWPoison(p)) {
+ printk(KERN_ERR "MCE %#lx: already hardware poisoned\n", pfn);
+ return 0;
+ }
+
+ nr_pages = 1 << compound_trans_order(hpage);
+ atomic_long_add(nr_pages, &mce_bad_pages);
+
+ /*
+ * We need/can do nothing about count=0 pages.
+ * 1) it's a free page, and therefore in safe hand:
+ * prep_new_page() will be the gate keeper.
+ * 2) it's a free hugepage, which is also safe:
+ * an affected hugepage will be dequeued from hugepage freelist,
+ * so there's no concern about reusing it ever after.
+ * 3) it's part of a non-compound high order page.
+ * Implies some kernel user: cannot stop them from
+ * R/W the page; let's pray that the page has been
+ * used and will be freed some time later.
+ * In fact it's dangerous to directly bump up page count from 0,
+ * that may make page_freeze_refs()/page_unfreeze_refs() mismatch.
+ */
+ if (!(flags & MF_COUNT_INCREASED) &&
+ !get_page_unless_zero(hpage)) {
+ if (is_free_buddy_page(p)) {
+ action_result(pfn, "free buddy", DELAYED);
+ return 0;
+ } else if (PageHuge(hpage)) {
+ /*
+ * Check "filter hit" and "race with other subpage."
+ */
+ lock_page(hpage);
+ if (PageHWPoison(hpage)) {
+ if ((hwpoison_filter(p) && TestClearPageHWPoison(p))
+ || (p != hpage && TestSetPageHWPoison(hpage))) {
+ atomic_long_sub(nr_pages, &mce_bad_pages);
+ unlock_page(hpage);
+ return 0;
+ }
+ }
+ set_page_hwpoison_huge_page(hpage);
+ res = dequeue_hwpoisoned_huge_page(hpage);
+ action_result(pfn, "free huge",
+ res ? IGNORED : DELAYED);
+ unlock_page(hpage);
+ return res;
+ } else {
+ action_result(pfn, "high order kernel", IGNORED);
+ return -EBUSY;
+ }
+ }
+
+ /*
+ * We ignore non-LRU pages for good reasons.
+ * - PG_locked is only well defined for LRU pages and a few others
+ * - to avoid races with __set_page_locked()
+ * - to avoid races with __SetPageSlab*() (and more non-atomic ops)
+ * The check (unnecessarily) ignores LRU pages being isolated and
+ * walked by the page reclaim code, however that's not a big loss.
+ */
+ if (!PageHuge(p)) {
+ if (!PageLRU(hpage))
+ shake_page(hpage, 0);
+ if (!PageLRU(hpage)) {
+ /*
+ * shake_page could have turned it free.
+ */
+ if (is_free_buddy_page(p)) {
+ action_result(pfn, "free buddy, 2nd try",
+ DELAYED);
+ return 0;
+ }
+ action_result(pfn, "non LRU", IGNORED);
+ put_page(p);
+ return -EBUSY;
+ }
+ }
+
+ /*
+ * Lock the page and wait for writeback to finish.
+ * It's very difficult to mess with pages currently under IO
+ * and in many cases impossible, so we just avoid it here.
+ */
+ lock_page(hpage);
+
+ /*
+ * unpoison always clear PG_hwpoison inside page lock
+ */
+ if (!PageHWPoison(p)) {
+ printk(KERN_ERR "MCE %#lx: just unpoisoned\n", pfn);
+ atomic_long_sub(nr_pages, &mce_bad_pages);
+ put_page(hpage);
+ res = 0;
+ goto out;
+ }
+ if (hwpoison_filter(p)) {
+ if (TestClearPageHWPoison(p))
+ atomic_long_sub(nr_pages, &mce_bad_pages);
+ unlock_page(hpage);
+ put_page(hpage);
+ return 0;
+ }
+
+ /*
+ * For error on the tail page, we should set PG_hwpoison
+ * on the head page to show that the hugepage is hwpoisoned
+ */
+ if (PageHuge(p) && PageTail(p) && TestSetPageHWPoison(hpage)) {
+ action_result(pfn, "hugepage already hardware poisoned",
+ IGNORED);
+ unlock_page(hpage);
+ put_page(hpage);
+ return 0;
+ }
+ /*
+ * Set PG_hwpoison on all pages in an error hugepage,
+ * because containment is done in hugepage unit for now.
+ * Since we have done TestSetPageHWPoison() for the head page with
+ * page lock held, we can safely set PG_hwpoison bits on tail pages.
+ */
+ if (PageHuge(p))
+ set_page_hwpoison_huge_page(hpage);
+
+ wait_on_page_writeback(p);
+
+ /*
+ * Now take care of user space mappings.
+ * Abort on fail: __delete_from_page_cache() assumes unmapped page.
+ */
+ if (hwpoison_user_mappings(p, pfn, trapno, flags) != SWAP_SUCCESS) {
+ printk(KERN_ERR "MCE %#lx: cannot unmap page, give up\n", pfn);
+ res = -EBUSY;
+ goto out;
+ }
+
+ /*
+ * Torn down by someone else?
+ */
+ if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
+ action_result(pfn, "already truncated LRU", IGNORED);
+ res = -EBUSY;
+ goto out;
+ }
+
+ res = -EBUSY;
+ for (ps = error_states;; ps++) {
+ if ((p->flags & ps->mask) == ps->res) {
+ res = page_action(ps, p, pfn);
+ break;
+ }
+ }
+out:
+ unlock_page(hpage);
+ return res;
+}
+EXPORT_SYMBOL_GPL(memory_failure);
+
+#define MEMORY_FAILURE_FIFO_ORDER 4
+#define MEMORY_FAILURE_FIFO_SIZE (1 << MEMORY_FAILURE_FIFO_ORDER)
+
+struct memory_failure_entry {
+ unsigned long pfn;
+ int trapno;
+ int flags;
+};
+
+struct memory_failure_cpu {
+ DECLARE_KFIFO(fifo, struct memory_failure_entry,
+ MEMORY_FAILURE_FIFO_SIZE);
+ spinlock_t lock;
+ struct work_struct work;
+};
+
+static DEFINE_PER_CPU(struct memory_failure_cpu, memory_failure_cpu);
+
+/**
+ * memory_failure_queue - Schedule handling memory failure of a page.
+ * @pfn: Page Number of the corrupted page
+ * @trapno: Trap number reported in the signal to user space.
+ * @flags: Flags for memory failure handling
+ *
+ * This function is called by the low level hardware error handler
+ * when it detects hardware memory corruption of a page. It schedules
+ * the recovering of error page, including dropping pages, killing
+ * processes etc.
+ *
+ * The function is primarily of use for corruptions that
+ * happen outside the current execution context (e.g. when
+ * detected by a background scrubber)
+ *
+ * Can run in IRQ context.
+ */
+void memory_failure_queue(unsigned long pfn, int trapno, int flags)
+{
+ struct memory_failure_cpu *mf_cpu;
+ unsigned long proc_flags;
+ struct memory_failure_entry entry = {
+ .pfn = pfn,
+ .trapno = trapno,
+ .flags = flags,
+ };
+
+ mf_cpu = &get_cpu_var(memory_failure_cpu);
+ spin_lock_irqsave(&mf_cpu->lock, proc_flags);
+ if (kfifo_put(&mf_cpu->fifo, &entry))
+ schedule_work_on(smp_processor_id(), &mf_cpu->work);
+ else
+ pr_err("Memory failure: buffer overflow when queuing memory failure at 0x%#lx\n",
+ pfn);
+ spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
+ put_cpu_var(memory_failure_cpu);
+}
+EXPORT_SYMBOL_GPL(memory_failure_queue);
+
+static void memory_failure_work_func(struct work_struct *work)
+{
+ struct memory_failure_cpu *mf_cpu;
+ struct memory_failure_entry entry = { 0, };
+ unsigned long proc_flags;
+ int gotten;
+
+ mf_cpu = &__get_cpu_var(memory_failure_cpu);
+ for (;;) {
+ spin_lock_irqsave(&mf_cpu->lock, proc_flags);
+ gotten = kfifo_get(&mf_cpu->fifo, &entry);
+ spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
+ if (!gotten)
+ break;
+ memory_failure(entry.pfn, entry.trapno, entry.flags);
+ }
+}
+
+static int __init memory_failure_init(void)
+{
+ struct memory_failure_cpu *mf_cpu;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ mf_cpu = &per_cpu(memory_failure_cpu, cpu);
+ spin_lock_init(&mf_cpu->lock);
+ INIT_KFIFO(mf_cpu->fifo);
+ INIT_WORK(&mf_cpu->work, memory_failure_work_func);
+ }
+
+ return 0;
+}
+core_initcall(memory_failure_init);
+
+/**
+ * unpoison_memory - Unpoison a previously poisoned page
+ * @pfn: Page number of the to be unpoisoned page
+ *
+ * Software-unpoison a page that has been poisoned by
+ * memory_failure() earlier.
+ *
+ * This is only done on the software-level, so it only works
+ * for linux injected failures, not real hardware failures
+ *
+ * Returns 0 for success, otherwise -errno.
+ */
+int unpoison_memory(unsigned long pfn)
+{
+ struct page *page;
+ struct page *p;
+ int freeit = 0;
+ unsigned int nr_pages;
+
+ if (!pfn_valid(pfn))
+ return -ENXIO;
+
+ p = pfn_to_page(pfn);
+ page = compound_head(p);
+
+ if (!PageHWPoison(p)) {
+ pr_info("MCE: Page was already unpoisoned %#lx\n", pfn);
+ return 0;
+ }
+
+ nr_pages = 1 << compound_trans_order(page);
+
+ if (!get_page_unless_zero(page)) {
+ /*
+ * Since HWPoisoned hugepage should have non-zero refcount,
+ * race between memory failure and unpoison seems to happen.
+ * In such case unpoison fails and memory failure runs
+ * to the end.
+ */
+ if (PageHuge(page)) {
+ pr_info("MCE: Memory failure is now running on free hugepage %#lx\n", pfn);
+ return 0;
+ }
+ if (TestClearPageHWPoison(p))
+ atomic_long_sub(nr_pages, &mce_bad_pages);
+ pr_info("MCE: Software-unpoisoned free page %#lx\n", pfn);
+ return 0;
+ }
+
+ lock_page(page);
+ /*
+ * This test is racy because PG_hwpoison is set outside of page lock.
+ * That's acceptable because that won't trigger kernel panic. Instead,
+ * the PG_hwpoison page will be caught and isolated on the entrance to
+ * the free buddy page pool.
+ */
+ if (TestClearPageHWPoison(page)) {
+ pr_info("MCE: Software-unpoisoned page %#lx\n", pfn);
+ atomic_long_sub(nr_pages, &mce_bad_pages);
+ freeit = 1;
+ if (PageHuge(page))
+ clear_page_hwpoison_huge_page(page);
+ }
+ unlock_page(page);
+
+ put_page(page);
+ if (freeit)
+ put_page(page);
+
+ return 0;
+}
+EXPORT_SYMBOL(unpoison_memory);
+
+static struct page *new_page(struct page *p, unsigned long private, int **x)
+{
+ int nid = page_to_nid(p);
+ if (PageHuge(p))
+ return alloc_huge_page_node(page_hstate(compound_head(p)),
+ nid);
+ else
+ return alloc_pages_exact_node(nid, GFP_HIGHUSER_MOVABLE, 0);
+}
+
+/*
+ * Safely get reference count of an arbitrary page.
+ * Returns 0 for a free page, -EIO for a zero refcount page
+ * that is not free, and 1 for any other page type.
+ * For 1 the page is returned with increased page count, otherwise not.
+ */
+static int get_any_page(struct page *p, unsigned long pfn, int flags)
+{
+ int ret;
+
+ if (flags & MF_COUNT_INCREASED)
+ return 1;
+
+ /*
+ * The lock_memory_hotplug prevents a race with memory hotplug.
+ * This is a big hammer, a better would be nicer.
+ */
+ lock_memory_hotplug();
+
+ /*
+ * Isolate the page, so that it doesn't get reallocated if it
+ * was free.
+ */
+ set_migratetype_isolate(p);
+ /*
+ * When the target page is a free hugepage, just remove it
+ * from free hugepage list.
+ */
+ if (!get_page_unless_zero(compound_head(p))) {
+ if (PageHuge(p)) {
+ pr_info("get_any_page: %#lx free huge page\n", pfn);
+ ret = dequeue_hwpoisoned_huge_page(compound_head(p));
+ } else if (is_free_buddy_page(p)) {
+ pr_info("get_any_page: %#lx free buddy page\n", pfn);
+ /* Set hwpoison bit while page is still isolated */
+ SetPageHWPoison(p);
+ ret = 0;
+ } else {
+ pr_info("get_any_page: %#lx: unknown zero refcount page type %lx\n",
+ pfn, p->flags);
+ ret = -EIO;
+ }
+ } else {
+ /* Not a free page */
+ ret = 1;
+ }
+ unset_migratetype_isolate(p);
+ unlock_memory_hotplug();
+ return ret;
+}
+
+static int soft_offline_huge_page(struct page *page, int flags)
+{
+ int ret;
+ unsigned long pfn = page_to_pfn(page);
+ struct page *hpage = compound_head(page);
+ LIST_HEAD(pagelist);
+
+ ret = get_any_page(page, pfn, flags);
+ if (ret < 0)
+ return ret;
+ if (ret == 0)
+ goto done;
+
+ if (PageHWPoison(hpage)) {
+ put_page(hpage);
+ pr_info("soft offline: %#lx hugepage already poisoned\n", pfn);
+ return -EBUSY;
+ }
+
+ /* Keep page count to indicate a given hugepage is isolated. */
+
+ list_add(&hpage->lru, &pagelist);
+ ret = migrate_huge_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, false,
+ MIGRATE_SYNC);
+ if (ret) {
+ struct page *page1, *page2;
+ list_for_each_entry_safe(page1, page2, &pagelist, lru)
+ put_page(page1);
+
+ pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
+ pfn, ret, page->flags);
+ if (ret > 0)
+ ret = -EIO;
+ return ret;
+ }
+done:
+ /* overcommit hugetlb page will be freed to buddy */
+ if (PageHuge(hpage)) {
+ if (!PageHWPoison(hpage))
+ atomic_long_add(1 << compound_trans_order(hpage),
+ &mce_bad_pages);
+ set_page_hwpoison_huge_page(hpage);
+ dequeue_hwpoisoned_huge_page(hpage);
+ } else {
+ SetPageHWPoison(page);
+ atomic_long_inc(&mce_bad_pages);
+ }
+
+ /* keep elevated page count for bad page */
+ return ret;
+}
+
+/**
+ * soft_offline_page - Soft offline a page.
+ * @page: page to offline
+ * @flags: flags. Same as memory_failure().
+ *
+ * Returns 0 on success, otherwise negated errno.
+ *
+ * Soft offline a page, by migration or invalidation,
+ * without killing anything. This is for the case when
+ * a page is not corrupted yet (so it's still valid to access),
+ * but has had a number of corrected errors and is better taken
+ * out.
+ *
+ * The actual policy on when to do that is maintained by
+ * user space.
+ *
+ * This should never impact any application or cause data loss,
+ * however it might take some time.
+ *
+ * This is not a 100% solution for all memory, but tries to be
+ * ``good enough'' for the majority of memory.
+ */
+int soft_offline_page(struct page *page, int flags)
+{
+ int ret;
+ unsigned long pfn = page_to_pfn(page);
+ struct page *hpage = compound_trans_head(page);
+
+ if (PageHuge(page))
+ return soft_offline_huge_page(page, flags);
+ if (PageTransHuge(hpage)) {
+ if (PageAnon(hpage) && unlikely(split_huge_page(hpage))) {
+ pr_info("soft offline: %#lx: failed to split THP\n",
+ pfn);
+ return -EBUSY;
+ }
+ }
+
+ ret = get_any_page(page, pfn, flags);
+ if (ret < 0)
+ return ret;
+ if (ret == 0)
+ goto done;
+
+ /*
+ * Page cache page we can handle?
+ */
+ if (!PageLRU(page)) {
+ /*
+ * Try to free it.
+ */
+ put_page(page);
+ shake_page(page, 1);
+
+ /*
+ * Did it turn free?
+ */
+ ret = get_any_page(page, pfn, 0);
+ if (ret < 0)
+ return ret;
+ if (ret == 0)
+ goto done;
+ }
+ if (!PageLRU(page)) {
+ pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
+ pfn, page->flags);
+ return -EIO;
+ }
+
+ lock_page(page);
+ wait_on_page_writeback(page);
+
+ /*
+ * Synchronized using the page lock with memory_failure()
+ */
+ if (PageHWPoison(page)) {
+ unlock_page(page);
+ put_page(page);
+ pr_info("soft offline: %#lx page already poisoned\n", pfn);
+ return -EBUSY;
+ }
+
+ /*
+ * Try to invalidate first. This should work for
+ * non dirty unmapped page cache pages.
+ */
+ ret = invalidate_inode_page(page);
+ unlock_page(page);
+ /*
+ * RED-PEN would be better to keep it isolated here, but we
+ * would need to fix isolation locking first.
+ */
+ if (ret == 1) {
+ put_page(page);
+ ret = 0;
+ pr_info("soft_offline: %#lx: invalidated\n", pfn);
+ goto done;
+ }
+
+ /*
+ * Simple invalidation didn't work.
+ * Try to migrate to a new page instead. migrate.c
+ * handles a large number of cases for us.
+ */
+ ret = isolate_lru_page(page);
+ /*
+ * Drop page reference which is came from get_any_page()
+ * successful isolate_lru_page() already took another one.
+ */
+ put_page(page);
+ if (!ret) {
+ LIST_HEAD(pagelist);
+ inc_zone_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+ list_add(&page->lru, &pagelist);
+ ret = migrate_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL,
+ false, MIGRATE_SYNC);
+ if (ret) {
+ putback_lru_pages(&pagelist);
+ pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
+ pfn, ret, page->flags);
+ if (ret > 0)
+ ret = -EIO;
+ }
+ } else {
+ pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
+ pfn, ret, page_count(page), page->flags);
+ }
+ if (ret)
+ return ret;
+
+done:
+ atomic_long_add(1, &mce_bad_pages);
+ SetPageHWPoison(page);
+ /* keep elevated page count for bad page */
+ return ret;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/memory.c b/ap/os/linux/linux-3.4.x/mm/memory.c
new file mode 100644
index 0000000..fa3062d
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/memory.c
@@ -0,0 +1,4155 @@
+/*
+ * linux/mm/memory.c
+ *
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ */
+
+/*
+ * demand-loading started 01.12.91 - seems it is high on the list of
+ * things wanted, and it should be easy to implement. - Linus
+ */
+
+/*
+ * Ok, demand-loading was easy, shared pages a little bit tricker. Shared
+ * pages started 02.12.91, seems to work. - Linus.
+ *
+ * Tested sharing by executing about 30 /bin/sh: under the old kernel it
+ * would have taken more than the 6M I have free, but it worked well as
+ * far as I could see.
+ *
+ * Also corrected some "invalidate()"s - I wasn't doing enough of them.
+ */
+
+/*
+ * Real VM (paging to/from disk) started 18.12.91. Much more work and
+ * thought has to go into this. Oh, well..
+ * 19.12.91 - works, somewhat. Sometimes I get faults, don't know why.
+ * Found it. Everything seems to work now.
+ * 20.12.91 - Ok, making the swap-device changeable like the root.
+ */
+
+/*
+ * 05.04.94 - Multi-page memory management added for v1.1.
+ * Idea by Alex Bligh (alex@cconcepts.co.uk)
+ *
+ * 16.07.99 - Support of BIGMEM added by Gerhard Wichert, Siemens AG
+ * (Gerhard.Wichert@pdb.siemens.de)
+ *
+ * Aug/Sep 2004 Changed to four level page tables (Andi Kleen)
+ */
+
+#include <linux/kernel_stat.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/mman.h>
+#include <linux/swap.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/ksm.h>
+#include <linux/rmap.h>
+#include <linux/export.h>
+#include <linux/delayacct.h>
+#include <linux/init.h>
+#include <linux/writeback.h>
+#include <linux/memcontrol.h>
+#include <linux/mmu_notifier.h>
+#include <linux/kallsyms.h>
+#include <linux/swapops.h>
+#include <linux/elf.h>
+#include <linux/gfp.h>
+
+#include <asm/io.h>
+#include <asm/pgalloc.h>
+#include <asm/uaccess.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/pgtable.h>
+
+#include "internal.h"
+
+#ifndef CONFIG_NEED_MULTIPLE_NODES
+/* use the per-pgdat data instead for discontigmem - mbligh */
+unsigned long max_mapnr;
+struct page *mem_map;
+
+EXPORT_SYMBOL(max_mapnr);
+EXPORT_SYMBOL(mem_map);
+#endif
+
+unsigned long num_physpages;
+/*
+ * A number of key systems in x86 including ioremap() rely on the assumption
+ * that high_memory defines the upper bound on direct map memory, then end
+ * of ZONE_NORMAL. Under CONFIG_DISCONTIG this means that max_low_pfn and
+ * highstart_pfn must be the same; there must be no gap between ZONE_NORMAL
+ * and ZONE_HIGHMEM.
+ */
+void * high_memory;
+
+EXPORT_SYMBOL(num_physpages);
+EXPORT_SYMBOL(high_memory);
+
+/*
+ * Randomize the address space (stacks, mmaps, brk, etc.).
+ *
+ * ( When CONFIG_COMPAT_BRK=y we exclude brk from randomization,
+ * as ancient (libc5 based) binaries can segfault. )
+ */
+int randomize_va_space __read_mostly =
+#ifdef CONFIG_COMPAT_BRK
+ 1;
+#else
+ 2;
+#endif
+
+static int __init disable_randmaps(char *s)
+{
+ randomize_va_space = 0;
+ return 1;
+}
+__setup("norandmaps", disable_randmaps);
+
+unsigned long zero_pfn __read_mostly;
+unsigned long highest_memmap_pfn __read_mostly;
+
+/*
+ * CONFIG_MMU architectures set up ZERO_PAGE in their paging_init()
+ */
+static int __init init_zero_pfn(void)
+{
+ zero_pfn = page_to_pfn(ZERO_PAGE(0));
+ return 0;
+}
+core_initcall(init_zero_pfn);
+
+
+#if defined(SPLIT_RSS_COUNTING)
+
+void sync_mm_rss(struct mm_struct *mm)
+{
+ int i;
+
+ for (i = 0; i < NR_MM_COUNTERS; i++) {
+ if (current->rss_stat.count[i]) {
+ add_mm_counter(mm, i, current->rss_stat.count[i]);
+ current->rss_stat.count[i] = 0;
+ }
+ }
+ current->rss_stat.events = 0;
+}
+
+static void add_mm_counter_fast(struct mm_struct *mm, int member, int val)
+{
+ struct task_struct *task = current;
+
+ if (likely(task->mm == mm))
+ task->rss_stat.count[member] += val;
+ else
+ add_mm_counter(mm, member, val);
+}
+#define inc_mm_counter_fast(mm, member) add_mm_counter_fast(mm, member, 1)
+#define dec_mm_counter_fast(mm, member) add_mm_counter_fast(mm, member, -1)
+
+/* sync counter once per 64 page faults */
+#define TASK_RSS_EVENTS_THRESH (64)
+static void check_sync_rss_stat(struct task_struct *task)
+{
+ if (unlikely(task != current))
+ return;
+ if (unlikely(task->rss_stat.events++ > TASK_RSS_EVENTS_THRESH))
+ sync_mm_rss(task->mm);
+}
+#else /* SPLIT_RSS_COUNTING */
+
+#define inc_mm_counter_fast(mm, member) inc_mm_counter(mm, member)
+#define dec_mm_counter_fast(mm, member) dec_mm_counter(mm, member)
+
+static void check_sync_rss_stat(struct task_struct *task)
+{
+}
+
+#endif /* SPLIT_RSS_COUNTING */
+
+#ifdef HAVE_GENERIC_MMU_GATHER
+
+static int tlb_next_batch(struct mmu_gather *tlb)
+{
+ struct mmu_gather_batch *batch;
+
+ batch = tlb->active;
+ if (batch->next) {
+ tlb->active = batch->next;
+ return 1;
+ }
+
+ if (tlb->batch_count == MAX_GATHER_BATCH_COUNT)
+ return 0;
+
+ batch = (void *)__get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0);
+ if (!batch)
+ return 0;
+
+ tlb->batch_count++;
+ batch->next = NULL;
+ batch->nr = 0;
+ batch->max = MAX_GATHER_BATCH;
+
+ tlb->active->next = batch;
+ tlb->active = batch;
+
+ return 1;
+}
+
+/* tlb_gather_mmu
+ * Called to initialize an (on-stack) mmu_gather structure for page-table
+ * tear-down from @mm. The @fullmm argument is used when @mm is without
+ * users and we're going to destroy the full address space (exit/execve).
+ */
+void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm)
+{
+ tlb->mm = mm;
+
+ tlb->fullmm = fullmm;
+ tlb->need_flush = 0;
+ tlb->fast_mode = (num_possible_cpus() == 1);
+ tlb->local.next = NULL;
+ tlb->local.nr = 0;
+ tlb->local.max = ARRAY_SIZE(tlb->__pages);
+ tlb->active = &tlb->local;
+ tlb->batch_count = 0;
+
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+ tlb->batch = NULL;
+#endif
+}
+
+void tlb_flush_mmu(struct mmu_gather *tlb)
+{
+ struct mmu_gather_batch *batch;
+
+ if (!tlb->need_flush)
+ return;
+ tlb->need_flush = 0;
+ tlb_flush(tlb);
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+ tlb_table_flush(tlb);
+#endif
+
+ if (tlb_fast_mode(tlb))
+ return;
+
+ for (batch = &tlb->local; batch; batch = batch->next) {
+ free_pages_and_swap_cache(batch->pages, batch->nr);
+ batch->nr = 0;
+ }
+ tlb->active = &tlb->local;
+}
+
+/* tlb_finish_mmu
+ * Called at the end of the shootdown operation to free up any resources
+ * that were required.
+ */
+void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
+{
+ struct mmu_gather_batch *batch, *next;
+
+ tlb_flush_mmu(tlb);
+
+ /* keep the page table cache within bounds */
+ check_pgt_cache();
+
+ for (batch = tlb->local.next; batch; batch = next) {
+ next = batch->next;
+ free_pages((unsigned long)batch, 0);
+ }
+ tlb->local.next = NULL;
+}
+
+/* __tlb_remove_page
+ * Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)), while
+ * handling the additional races in SMP caused by other CPUs caching valid
+ * mappings in their TLBs. Returns the number of free page slots left.
+ * When out of page slots we must call tlb_flush_mmu().
+ */
+int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+{
+ struct mmu_gather_batch *batch;
+
+ VM_BUG_ON(!tlb->need_flush);
+
+ if (tlb_fast_mode(tlb)) {
+ free_page_and_swap_cache(page);
+ return 1; /* avoid calling tlb_flush_mmu() */
+ }
+
+ batch = tlb->active;
+ batch->pages[batch->nr++] = page;
+ if (batch->nr == batch->max) {
+ if (!tlb_next_batch(tlb))
+ return 0;
+ batch = tlb->active;
+ }
+ VM_BUG_ON(batch->nr > batch->max);
+
+ return batch->max - batch->nr;
+}
+
+#endif /* HAVE_GENERIC_MMU_GATHER */
+
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+
+/*
+ * See the comment near struct mmu_table_batch.
+ */
+
+static void tlb_remove_table_smp_sync(void *arg)
+{
+ /* Simply deliver the interrupt */
+}
+
+static void tlb_remove_table_one(void *table)
+{
+ /*
+ * This isn't an RCU grace period and hence the page-tables cannot be
+ * assumed to be actually RCU-freed.
+ *
+ * It is however sufficient for software page-table walkers that rely on
+ * IRQ disabling. See the comment near struct mmu_table_batch.
+ */
+ smp_call_function(tlb_remove_table_smp_sync, NULL, 1);
+ __tlb_remove_table(table);
+}
+
+static void tlb_remove_table_rcu(struct rcu_head *head)
+{
+ struct mmu_table_batch *batch;
+ int i;
+
+ batch = container_of(head, struct mmu_table_batch, rcu);
+
+ for (i = 0; i < batch->nr; i++)
+ __tlb_remove_table(batch->tables[i]);
+
+ free_page((unsigned long)batch);
+}
+
+void tlb_table_flush(struct mmu_gather *tlb)
+{
+ struct mmu_table_batch **batch = &tlb->batch;
+
+ if (*batch) {
+ call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu);
+ *batch = NULL;
+ }
+}
+
+void tlb_remove_table(struct mmu_gather *tlb, void *table)
+{
+ struct mmu_table_batch **batch = &tlb->batch;
+
+ tlb->need_flush = 1;
+
+ /*
+ * When there's less then two users of this mm there cannot be a
+ * concurrent page-table walk.
+ */
+ if (atomic_read(&tlb->mm->mm_users) < 2) {
+ __tlb_remove_table(table);
+ return;
+ }
+
+ if (*batch == NULL) {
+ *batch = (struct mmu_table_batch *)__get_free_page(GFP_NOWAIT | __GFP_NOWARN);
+ if (*batch == NULL) {
+ tlb_remove_table_one(table);
+ return;
+ }
+ (*batch)->nr = 0;
+ }
+ (*batch)->tables[(*batch)->nr++] = table;
+ if ((*batch)->nr == MAX_TABLE_BATCH)
+ tlb_table_flush(tlb);
+}
+
+#endif /* CONFIG_HAVE_RCU_TABLE_FREE */
+
+/*
+ * If a p?d_bad entry is found while walking page tables, report
+ * the error, before resetting entry to p?d_none. Usually (but
+ * very seldom) called out from the p?d_none_or_clear_bad macros.
+ */
+
+void pgd_clear_bad(pgd_t *pgd)
+{
+ pgd_ERROR(*pgd);
+ pgd_clear(pgd);
+}
+
+void pud_clear_bad(pud_t *pud)
+{
+ pud_ERROR(*pud);
+ pud_clear(pud);
+}
+
+void pmd_clear_bad(pmd_t *pmd)
+{
+ pmd_ERROR(*pmd);
+ pmd_clear(pmd);
+}
+
+/*
+ * Note: this doesn't free the actual pages themselves. That
+ * has been handled earlier when unmapping all the memory regions.
+ */
+static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
+ unsigned long addr)
+{
+ pgtable_t token = pmd_pgtable(*pmd);
+ pmd_clear(pmd);
+ pte_free_tlb(tlb, token, addr);
+ tlb->mm->nr_ptes--;
+}
+
+static inline void free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ unsigned long floor, unsigned long ceiling)
+{
+ pmd_t *pmd;
+ unsigned long next;
+ unsigned long start;
+
+ start = addr;
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_none_or_clear_bad(pmd))
+ continue;
+ free_pte_range(tlb, pmd, addr);
+ } while (pmd++, addr = next, addr != end);
+
+ start &= PUD_MASK;
+ if (start < floor)
+ return;
+ if (ceiling) {
+ ceiling &= PUD_MASK;
+ if (!ceiling)
+ return;
+ }
+ if (end - 1 > ceiling - 1)
+ return;
+
+ pmd = pmd_offset(pud, start);
+ pud_clear(pud);
+ pmd_free_tlb(tlb, pmd, start);
+}
+
+static inline void free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ unsigned long floor, unsigned long ceiling)
+{
+ pud_t *pud;
+ unsigned long next;
+ unsigned long start;
+
+ start = addr;
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ free_pmd_range(tlb, pud, addr, next, floor, ceiling);
+ } while (pud++, addr = next, addr != end);
+
+ start &= PGDIR_MASK;
+ if (start < floor)
+ return;
+ if (ceiling) {
+ ceiling &= PGDIR_MASK;
+ if (!ceiling)
+ return;
+ }
+ if (end - 1 > ceiling - 1)
+ return;
+
+ pud = pud_offset(pgd, start);
+ pgd_clear(pgd);
+ pud_free_tlb(tlb, pud, start);
+}
+
+/*
+ * This function frees user-level page tables of a process.
+ *
+ * Must be called with pagetable lock held.
+ */
+void free_pgd_range(struct mmu_gather *tlb,
+ unsigned long addr, unsigned long end,
+ unsigned long floor, unsigned long ceiling)
+{
+ pgd_t *pgd;
+ unsigned long next;
+
+ /*
+ * The next few lines have given us lots of grief...
+ *
+ * Why are we testing PMD* at this top level? Because often
+ * there will be no work to do at all, and we'd prefer not to
+ * go all the way down to the bottom just to discover that.
+ *
+ * Why all these "- 1"s? Because 0 represents both the bottom
+ * of the address space and the top of it (using -1 for the
+ * top wouldn't help much: the masks would do the wrong thing).
+ * The rule is that addr 0 and floor 0 refer to the bottom of
+ * the address space, but end 0 and ceiling 0 refer to the top
+ * Comparisons need to use "end - 1" and "ceiling - 1" (though
+ * that end 0 case should be mythical).
+ *
+ * Wherever addr is brought up or ceiling brought down, we must
+ * be careful to reject "the opposite 0" before it confuses the
+ * subsequent tests. But what about where end is brought down
+ * by PMD_SIZE below? no, end can't go down to 0 there.
+ *
+ * Whereas we round start (addr) and ceiling down, by different
+ * masks at different levels, in order to test whether a table
+ * now has no other vmas using it, so can be freed, we don't
+ * bother to round floor or end up - the tests don't need that.
+ */
+
+ addr &= PMD_MASK;
+ if (addr < floor) {
+ addr += PMD_SIZE;
+ if (!addr)
+ return;
+ }
+ if (ceiling) {
+ ceiling &= PMD_MASK;
+ if (!ceiling)
+ return;
+ }
+ if (end - 1 > ceiling - 1)
+ end -= PMD_SIZE;
+ if (addr > end - 1)
+ return;
+
+ pgd = pgd_offset(tlb->mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ free_pud_range(tlb, pgd, addr, next, floor, ceiling);
+ } while (pgd++, addr = next, addr != end);
+}
+
+void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma,
+ unsigned long floor, unsigned long ceiling)
+{
+ while (vma) {
+ struct vm_area_struct *next = vma->vm_next;
+ unsigned long addr = vma->vm_start;
+
+ /*
+ * Hide vma from rmap and truncate_pagecache before freeing
+ * pgtables
+ */
+ unlink_anon_vmas(vma);
+ unlink_file_vma(vma);
+
+ if (is_vm_hugetlb_page(vma)) {
+ hugetlb_free_pgd_range(tlb, addr, vma->vm_end,
+ floor, next? next->vm_start: ceiling);
+ } else {
+ /*
+ * Optimization: gather nearby vmas into one call down
+ */
+ while (next && next->vm_start <= vma->vm_end + PMD_SIZE
+ && !is_vm_hugetlb_page(next)) {
+ vma = next;
+ next = vma->vm_next;
+ unlink_anon_vmas(vma);
+ unlink_file_vma(vma);
+ }
+ free_pgd_range(tlb, addr, vma->vm_end,
+ floor, next? next->vm_start: ceiling);
+ }
+ vma = next;
+ }
+}
+
+int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
+ pmd_t *pmd, unsigned long address)
+{
+ pgtable_t new = pte_alloc_one(mm, address);
+ int wait_split_huge_page;
+ if (!new)
+ return -ENOMEM;
+
+ /*
+ * Ensure all pte setup (eg. pte page lock and page clearing) are
+ * visible before the pte is made visible to other CPUs by being
+ * put into page tables.
+ *
+ * The other side of the story is the pointer chasing in the page
+ * table walking code (when walking the page table without locking;
+ * ie. most of the time). Fortunately, these data accesses consist
+ * of a chain of data-dependent loads, meaning most CPUs (alpha
+ * being the notable exception) will already guarantee loads are
+ * seen in-order. See the alpha page table accessors for the
+ * smp_read_barrier_depends() barriers in page table walking code.
+ */
+ smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */
+
+ spin_lock(&mm->page_table_lock);
+ wait_split_huge_page = 0;
+ if (likely(pmd_none(*pmd))) { /* Has another populated it ? */
+ mm->nr_ptes++;
+ pmd_populate(mm, pmd, new);
+ new = NULL;
+ } else if (unlikely(pmd_trans_splitting(*pmd)))
+ wait_split_huge_page = 1;
+ spin_unlock(&mm->page_table_lock);
+ if (new)
+ pte_free(mm, new);
+ if (wait_split_huge_page)
+ wait_split_huge_page(vma->anon_vma, pmd);
+ return 0;
+}
+
+int __pte_alloc_kernel(pmd_t *pmd, unsigned long address)
+{
+ pte_t *new = pte_alloc_one_kernel(&init_mm, address);
+ if (!new)
+ return -ENOMEM;
+
+ smp_wmb(); /* See comment in __pte_alloc */
+
+ spin_lock(&init_mm.page_table_lock);
+ if (likely(pmd_none(*pmd))) { /* Has another populated it ? */
+ pmd_populate_kernel(&init_mm, pmd, new);
+ new = NULL;
+ } else
+ VM_BUG_ON(pmd_trans_splitting(*pmd));
+ spin_unlock(&init_mm.page_table_lock);
+ if (new)
+ pte_free_kernel(&init_mm, new);
+ return 0;
+}
+
+static inline void init_rss_vec(int *rss)
+{
+ memset(rss, 0, sizeof(int) * NR_MM_COUNTERS);
+}
+
+static inline void add_mm_rss_vec(struct mm_struct *mm, int *rss)
+{
+ int i;
+
+ if (current->mm == mm)
+ sync_mm_rss(mm);
+ for (i = 0; i < NR_MM_COUNTERS; i++)
+ if (rss[i])
+ add_mm_counter(mm, i, rss[i]);
+}
+
+/*
+ * This function is called to print an error when a bad pte
+ * is found. For example, we might have a PFN-mapped pte in
+ * a region that doesn't allow it.
+ *
+ * The calling function must still handle the error.
+ */
+static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
+ pte_t pte, struct page *page)
+{
+ pgd_t *pgd = pgd_offset(vma->vm_mm, addr);
+ pud_t *pud = pud_offset(pgd, addr);
+ pmd_t *pmd = pmd_offset(pud, addr);
+ struct address_space *mapping;
+ pgoff_t index;
+ static unsigned long resume;
+ static unsigned long nr_shown;
+ static unsigned long nr_unshown;
+
+ /*
+ * Allow a burst of 60 reports, then keep quiet for that minute;
+ * or allow a steady drip of one report per second.
+ */
+ if (nr_shown == 60) {
+ if (time_before(jiffies, resume)) {
+ nr_unshown++;
+ return;
+ }
+ if (nr_unshown) {
+ printk(KERN_ALERT
+ "BUG: Bad page map: %lu messages suppressed\n",
+ nr_unshown);
+ nr_unshown = 0;
+ }
+ nr_shown = 0;
+ }
+ if (nr_shown++ == 0)
+ resume = jiffies + 60 * HZ;
+
+ mapping = vma->vm_file ? vma->vm_file->f_mapping : NULL;
+ index = linear_page_index(vma, addr);
+
+ printk(KERN_ALERT
+ "BUG: Bad page map in process %s pte:%08llx pmd:%08llx\n",
+ current->comm,
+ (long long)pte_val(pte), (long long)pmd_val(*pmd));
+ if (page)
+ dump_page(page);
+ printk(KERN_ALERT
+ "addr:%p vm_flags:%08lx anon_vma:%p mapping:%p index:%lx\n",
+ (void *)addr, vma->vm_flags, vma->anon_vma, mapping, index);
+ /*
+ * Choose text because data symbols depend on CONFIG_KALLSYMS_ALL=y
+ */
+ if (vma->vm_ops)
+ print_symbol(KERN_ALERT "vma->vm_ops->fault: %s\n",
+ (unsigned long)vma->vm_ops->fault);
+ if (vma->vm_file && vma->vm_file->f_op)
+ print_symbol(KERN_ALERT "vma->vm_file->f_op->mmap: %s\n",
+ (unsigned long)vma->vm_file->f_op->mmap);
+ dump_stack();
+ add_taint(TAINT_BAD_PAGE);
+}
+
+static inline int is_cow_mapping(vm_flags_t flags)
+{
+ return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
+}
+
+#ifndef is_zero_pfn
+static inline int is_zero_pfn(unsigned long pfn)
+{
+ return pfn == zero_pfn;
+}
+#endif
+
+#ifndef my_zero_pfn
+static inline unsigned long my_zero_pfn(unsigned long addr)
+{
+ return zero_pfn;
+}
+#endif
+
+/*
+ * vm_normal_page -- This function gets the "struct page" associated with a pte.
+ *
+ * "Special" mappings do not wish to be associated with a "struct page" (either
+ * it doesn't exist, or it exists but they don't want to touch it). In this
+ * case, NULL is returned here. "Normal" mappings do have a struct page.
+ *
+ * There are 2 broad cases. Firstly, an architecture may define a pte_special()
+ * pte bit, in which case this function is trivial. Secondly, an architecture
+ * may not have a spare pte bit, which requires a more complicated scheme,
+ * described below.
+ *
+ * A raw VM_PFNMAP mapping (ie. one that is not COWed) is always considered a
+ * special mapping (even if there are underlying and valid "struct pages").
+ * COWed pages of a VM_PFNMAP are always normal.
+ *
+ * The way we recognize COWed pages within VM_PFNMAP mappings is through the
+ * rules set up by "remap_pfn_range()": the vma will have the VM_PFNMAP bit
+ * set, and the vm_pgoff will point to the first PFN mapped: thus every special
+ * mapping will always honor the rule
+ *
+ * pfn_of_page == vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT)
+ *
+ * And for normal mappings this is false.
+ *
+ * This restricts such mappings to be a linear translation from virtual address
+ * to pfn. To get around this restriction, we allow arbitrary mappings so long
+ * as the vma is not a COW mapping; in that case, we know that all ptes are
+ * special (because none can have been COWed).
+ *
+ *
+ * In order to support COW of arbitrary special mappings, we have VM_MIXEDMAP.
+ *
+ * VM_MIXEDMAP mappings can likewise contain memory with or without "struct
+ * page" backing, however the difference is that _all_ pages with a struct
+ * page (that is, those where pfn_valid is true) are refcounted and considered
+ * normal pages by the VM. The disadvantage is that pages are refcounted
+ * (which can be slower and simply not an option for some PFNMAP users). The
+ * advantage is that we don't have to follow the strict linearity rule of
+ * PFNMAP mappings in order to support COWable mappings.
+ *
+ */
+#ifdef __HAVE_ARCH_PTE_SPECIAL
+# define HAVE_PTE_SPECIAL 1
+#else
+# define HAVE_PTE_SPECIAL 0
+#endif
+struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
+ pte_t pte)
+{
+ unsigned long pfn = pte_pfn(pte);
+
+ if (HAVE_PTE_SPECIAL) {
+ if (likely(!pte_special(pte)))
+ goto check_pfn;
+ if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
+ return NULL;
+ if (!is_zero_pfn(pfn))
+ print_bad_pte(vma, addr, pte, NULL);
+ return NULL;
+ }
+
+ /* !HAVE_PTE_SPECIAL case follows: */
+
+ if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
+ if (vma->vm_flags & VM_MIXEDMAP) {
+ if (!pfn_valid(pfn))
+ return NULL;
+ goto out;
+ } else {
+ unsigned long off;
+ off = (addr - vma->vm_start) >> PAGE_SHIFT;
+ if (pfn == vma->vm_pgoff + off)
+ return NULL;
+ if (!is_cow_mapping(vma->vm_flags))
+ return NULL;
+ }
+ }
+
+ if (is_zero_pfn(pfn))
+ return NULL;
+check_pfn:
+ if (unlikely(pfn > highest_memmap_pfn)) {
+ print_bad_pte(vma, addr, pte, NULL);
+ return NULL;
+ }
+
+ /*
+ * NOTE! We still have PageReserved() pages in the page tables.
+ * eg. VDSO mappings can cause them to exist.
+ */
+out:
+ return pfn_to_page(pfn);
+}
+
+/*
+ * copy one vm_area from one task to the other. Assumes the page tables
+ * already present in the new task to be cleared in the whole range
+ * covered by this vma.
+ */
+
+static inline unsigned long
+copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
+ pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma,
+ unsigned long addr, int *rss)
+{
+ unsigned long vm_flags = vma->vm_flags;
+ pte_t pte = *src_pte;
+ struct page *page;
+
+ /* pte contains position in swap or file, so copy. */
+ if (unlikely(!pte_present(pte))) {
+ if (!pte_file(pte)) {
+ swp_entry_t entry = pte_to_swp_entry(pte);
+
+ if (likely(!non_swap_entry(entry))) {
+ if (swap_duplicate(entry) < 0)
+ return entry.val;
+
+ /* make sure dst_mm is on swapoff's mmlist. */
+ if (unlikely(list_empty(&dst_mm->mmlist))) {
+ spin_lock(&mmlist_lock);
+ if (list_empty(&dst_mm->mmlist))
+ list_add(&dst_mm->mmlist,
+ &src_mm->mmlist);
+ spin_unlock(&mmlist_lock);
+ }
+ rss[MM_SWAPENTS]++;
+ } else if (is_migration_entry(entry)) {
+ page = migration_entry_to_page(entry);
+
+ if (PageAnon(page))
+ rss[MM_ANONPAGES]++;
+ else
+ rss[MM_FILEPAGES]++;
+
+ if (is_write_migration_entry(entry) &&
+ is_cow_mapping(vm_flags)) {
+ /*
+ * COW mappings require pages in both
+ * parent and child to be set to read.
+ */
+ make_migration_entry_read(&entry);
+ pte = swp_entry_to_pte(entry);
+ set_pte_at(src_mm, addr, src_pte, pte);
+ }
+ }
+ }
+ goto out_set_pte;
+ }
+
+ /*
+ * If it's a COW mapping, write protect it both
+ * in the parent and the child
+ */
+ if (is_cow_mapping(vm_flags)) {
+ ptep_set_wrprotect(src_mm, addr, src_pte);
+ pte = pte_wrprotect(pte);
+ }
+
+ /*
+ * If it's a shared mapping, mark it clean in
+ * the child
+ */
+ if (vm_flags & VM_SHARED)
+ pte = pte_mkclean(pte);
+ pte = pte_mkold(pte);
+
+ page = vm_normal_page(vma, addr, pte);
+ if (page) {
+ get_page(page);
+ page_dup_rmap(page);
+ if (PageAnon(page))
+ rss[MM_ANONPAGES]++;
+ else
+ rss[MM_FILEPAGES]++;
+ }
+
+out_set_pte:
+ set_pte_at(dst_mm, addr, dst_pte, pte);
+ return 0;
+}
+
+int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
+ pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end)
+{
+ pte_t *orig_src_pte, *orig_dst_pte;
+ pte_t *src_pte, *dst_pte;
+ spinlock_t *src_ptl, *dst_ptl;
+ int progress = 0;
+ int rss[NR_MM_COUNTERS];
+ swp_entry_t entry = (swp_entry_t){0};
+
+again:
+ init_rss_vec(rss);
+
+ dst_pte = pte_alloc_map_lock(dst_mm, dst_pmd, addr, &dst_ptl);
+ if (!dst_pte)
+ return -ENOMEM;
+ src_pte = pte_offset_map(src_pmd, addr);
+ src_ptl = pte_lockptr(src_mm, src_pmd);
+ spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
+ orig_src_pte = src_pte;
+ orig_dst_pte = dst_pte;
+ arch_enter_lazy_mmu_mode();
+
+ do {
+ /*
+ * We are holding two locks at this point - either of them
+ * could generate latencies in another task on another CPU.
+ */
+ if (progress >= 32) {
+ progress = 0;
+ if (need_resched() ||
+ spin_needbreak(src_ptl) || spin_needbreak(dst_ptl))
+ break;
+ }
+ if (pte_none(*src_pte)) {
+ progress++;
+ continue;
+ }
+ entry.val = copy_one_pte(dst_mm, src_mm, dst_pte, src_pte,
+ vma, addr, rss);
+ if (entry.val)
+ break;
+ progress += 8;
+ } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end);
+
+ arch_leave_lazy_mmu_mode();
+ spin_unlock(src_ptl);
+ pte_unmap(orig_src_pte);
+ add_mm_rss_vec(dst_mm, rss);
+ pte_unmap_unlock(orig_dst_pte, dst_ptl);
+ cond_resched();
+
+ if (entry.val) {
+ if (add_swap_count_continuation(entry, GFP_KERNEL) < 0)
+ return -ENOMEM;
+ progress = 0;
+ }
+ if (addr != end)
+ goto again;
+ return 0;
+}
+
+static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
+ pud_t *dst_pud, pud_t *src_pud, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end)
+{
+ pmd_t *src_pmd, *dst_pmd;
+ unsigned long next;
+
+ dst_pmd = pmd_alloc(dst_mm, dst_pud, addr);
+ if (!dst_pmd)
+ return -ENOMEM;
+ src_pmd = pmd_offset(src_pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_trans_huge(*src_pmd)) {
+ int err;
+ VM_BUG_ON(next-addr != HPAGE_PMD_SIZE);
+ err = copy_huge_pmd(dst_mm, src_mm,
+ dst_pmd, src_pmd, addr, vma);
+ if (err == -ENOMEM)
+ return -ENOMEM;
+ if (!err)
+ continue;
+ /* fall through */
+ }
+ if (pmd_none_or_clear_bad(src_pmd))
+ continue;
+ if (copy_pte_range(dst_mm, src_mm, dst_pmd, src_pmd,
+ vma, addr, next))
+ return -ENOMEM;
+ } while (dst_pmd++, src_pmd++, addr = next, addr != end);
+ return 0;
+}
+
+static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
+ pgd_t *dst_pgd, pgd_t *src_pgd, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end)
+{
+ pud_t *src_pud, *dst_pud;
+ unsigned long next;
+
+ dst_pud = pud_alloc(dst_mm, dst_pgd, addr);
+ if (!dst_pud)
+ return -ENOMEM;
+ src_pud = pud_offset(src_pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(src_pud))
+ continue;
+ if (copy_pmd_range(dst_mm, src_mm, dst_pud, src_pud,
+ vma, addr, next))
+ return -ENOMEM;
+ } while (dst_pud++, src_pud++, addr = next, addr != end);
+ return 0;
+}
+
+int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
+ struct vm_area_struct *vma)
+{
+ pgd_t *src_pgd, *dst_pgd;
+ unsigned long next;
+ unsigned long addr = vma->vm_start;
+ unsigned long end = vma->vm_end;
+ int ret;
+
+ /*
+ * Don't copy ptes where a page fault will fill them correctly.
+ * Fork becomes much lighter when there are big shared or private
+ * readonly mappings. The tradeoff is that copy_page_range is more
+ * efficient than faulting.
+ */
+ if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_PFNMAP|VM_INSERTPAGE))) {
+ if (!vma->anon_vma)
+ return 0;
+ }
+
+ if (is_vm_hugetlb_page(vma))
+ return copy_hugetlb_page_range(dst_mm, src_mm, vma);
+
+ if (unlikely(is_pfn_mapping(vma))) {
+ /*
+ * We do not free on error cases below as remove_vma
+ * gets called on error from higher level routine
+ */
+ ret = track_pfn_vma_copy(vma);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * We need to invalidate the secondary MMU mappings only when
+ * there could be a permission downgrade on the ptes of the
+ * parent mm. And a permission downgrade will only happen if
+ * is_cow_mapping() returns true.
+ */
+ if (is_cow_mapping(vma->vm_flags))
+ mmu_notifier_invalidate_range_start(src_mm, addr, end);
+
+ ret = 0;
+ dst_pgd = pgd_offset(dst_mm, addr);
+ src_pgd = pgd_offset(src_mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(src_pgd))
+ continue;
+ if (unlikely(copy_pud_range(dst_mm, src_mm, dst_pgd, src_pgd,
+ vma, addr, next))) {
+ ret = -ENOMEM;
+ break;
+ }
+ } while (dst_pgd++, src_pgd++, addr = next, addr != end);
+
+ if (is_cow_mapping(vma->vm_flags))
+ mmu_notifier_invalidate_range_end(src_mm,
+ vma->vm_start, end);
+ return ret;
+}
+
+static unsigned long zap_pte_range(struct mmu_gather *tlb,
+ struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ struct zap_details *details)
+{
+ struct mm_struct *mm = tlb->mm;
+ int force_flush = 0;
+ int rss[NR_MM_COUNTERS];
+ spinlock_t *ptl;
+ pte_t *start_pte;
+ pte_t *pte;
+
+again:
+ init_rss_vec(rss);
+ start_pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
+ pte = start_pte;
+ arch_enter_lazy_mmu_mode();
+ do {
+ pte_t ptent = *pte;
+ if (pte_none(ptent)) {
+ continue;
+ }
+
+ if (pte_present(ptent)) {
+ struct page *page;
+
+ page = vm_normal_page(vma, addr, ptent);
+ if (unlikely(details) && page) {
+ /*
+ * unmap_shared_mapping_pages() wants to
+ * invalidate cache without truncating:
+ * unmap shared but keep private pages.
+ */
+ if (details->check_mapping &&
+ details->check_mapping != page->mapping)
+ continue;
+ /*
+ * Each page->index must be checked when
+ * invalidating or truncating nonlinear.
+ */
+ if (details->nonlinear_vma &&
+ (page->index < details->first_index ||
+ page->index > details->last_index))
+ continue;
+ }
+ ptent = ptep_get_and_clear_full(mm, addr, pte,
+ tlb->fullmm);
+ tlb_remove_tlb_entry(tlb, pte, addr);
+ if (unlikely(!page))
+ continue;
+ if (unlikely(details) && details->nonlinear_vma
+ && linear_page_index(details->nonlinear_vma,
+ addr) != page->index)
+ set_pte_at(mm, addr, pte,
+ pgoff_to_pte(page->index));
+ if (PageAnon(page))
+ rss[MM_ANONPAGES]--;
+ else {
+ if (pte_dirty(ptent))
+ set_page_dirty(page);
+ if (pte_young(ptent) &&
+ likely(!VM_SequentialReadHint(vma)))
+ mark_page_accessed(page);
+ rss[MM_FILEPAGES]--;
+ }
+ page_remove_rmap(page);
+ if (unlikely(page_mapcount(page) < 0))
+ print_bad_pte(vma, addr, ptent, page);
+ force_flush = !__tlb_remove_page(tlb, page);
+ if (force_flush) {
+ addr += PAGE_SIZE;
+ break;
+ }
+ continue;
+ }
+ /*
+ * If details->check_mapping, we leave swap entries;
+ * if details->nonlinear_vma, we leave file entries.
+ */
+ if (unlikely(details))
+ continue;
+ if (pte_file(ptent)) {
+ if (unlikely(!(vma->vm_flags & VM_NONLINEAR)))
+ print_bad_pte(vma, addr, ptent, NULL);
+ } else {
+ swp_entry_t entry = pte_to_swp_entry(ptent);
+
+ if (!non_swap_entry(entry))
+ rss[MM_SWAPENTS]--;
+ else if (is_migration_entry(entry)) {
+ struct page *page;
+
+ page = migration_entry_to_page(entry);
+
+ if (PageAnon(page))
+ rss[MM_ANONPAGES]--;
+ else
+ rss[MM_FILEPAGES]--;
+ }
+ if (unlikely(!free_swap_and_cache(entry)))
+ print_bad_pte(vma, addr, ptent, NULL);
+ }
+ pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+
+ add_mm_rss_vec(mm, rss);
+ arch_leave_lazy_mmu_mode();
+ pte_unmap_unlock(start_pte, ptl);
+
+ /*
+ * mmu_gather ran out of room to batch pages, we break out of
+ * the PTE lock to avoid doing the potential expensive TLB invalidate
+ * and page-free while holding it.
+ */
+ if (force_flush) {
+ force_flush = 0;
+ tlb_flush_mmu(tlb);
+ if (addr != end)
+ goto again;
+ }
+
+ return addr;
+}
+
+static inline unsigned long zap_pmd_range(struct mmu_gather *tlb,
+ struct vm_area_struct *vma, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ struct zap_details *details)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_trans_huge(*pmd)) {
+ if (next - addr != HPAGE_PMD_SIZE) {
+ VM_BUG_ON(!rwsem_is_locked(&tlb->mm->mmap_sem));
+ split_huge_page_pmd(vma->vm_mm, pmd);
+ } else if (zap_huge_pmd(tlb, vma, pmd, addr))
+ goto next;
+ /* fall through */
+ }
+ /*
+ * Here there can be other concurrent MADV_DONTNEED or
+ * trans huge page faults running, and if the pmd is
+ * none or trans huge it can change under us. This is
+ * because MADV_DONTNEED holds the mmap_sem in read
+ * mode.
+ */
+ if (pmd_none_or_trans_huge_or_clear_bad(pmd))
+ goto next;
+ next = zap_pte_range(tlb, vma, pmd, addr, next, details);
+next:
+ cond_resched();
+ } while (pmd++, addr = next, addr != end);
+
+ return addr;
+}
+
+static inline unsigned long zap_pud_range(struct mmu_gather *tlb,
+ struct vm_area_struct *vma, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ struct zap_details *details)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ next = zap_pmd_range(tlb, vma, pud, addr, next, details);
+ } while (pud++, addr = next, addr != end);
+
+ return addr;
+}
+
+static void unmap_page_range(struct mmu_gather *tlb,
+ struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end,
+ struct zap_details *details)
+{
+ pgd_t *pgd;
+ unsigned long next;
+
+ if (details && !details->check_mapping && !details->nonlinear_vma)
+ details = NULL;
+
+ BUG_ON(addr >= end);
+ mem_cgroup_uncharge_start();
+ tlb_start_vma(tlb, vma);
+ pgd = pgd_offset(vma->vm_mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ next = zap_pud_range(tlb, vma, pgd, addr, next, details);
+ } while (pgd++, addr = next, addr != end);
+ tlb_end_vma(tlb, vma);
+ mem_cgroup_uncharge_end();
+}
+
+
+static void unmap_single_vma(struct mmu_gather *tlb,
+ struct vm_area_struct *vma, unsigned long start_addr,
+ unsigned long end_addr, unsigned long *nr_accounted,
+ struct zap_details *details)
+{
+ unsigned long start = max(vma->vm_start, start_addr);
+ unsigned long end;
+
+ if (start >= vma->vm_end)
+ return;
+ end = min(vma->vm_end, end_addr);
+ if (end <= vma->vm_start)
+ return;
+
+ if (vma->vm_flags & VM_ACCOUNT)
+ *nr_accounted += (end - start) >> PAGE_SHIFT;
+
+ if (unlikely(is_pfn_mapping(vma)))
+ untrack_pfn_vma(vma, 0, 0);
+
+ if (start != end) {
+ if (unlikely(is_vm_hugetlb_page(vma))) {
+ /*
+ * It is undesirable to test vma->vm_file as it
+ * should be non-null for valid hugetlb area.
+ * However, vm_file will be NULL in the error
+ * cleanup path of do_mmap_pgoff. When
+ * hugetlbfs ->mmap method fails,
+ * do_mmap_pgoff() nullifies vma->vm_file
+ * before calling this function to clean up.
+ * Since no pte has actually been setup, it is
+ * safe to do nothing in this case.
+ */
+ if (vma->vm_file)
+ unmap_hugepage_range(vma, start, end, NULL);
+ } else
+ unmap_page_range(tlb, vma, start, end, details);
+ }
+}
+
+/**
+ * unmap_vmas - unmap a range of memory covered by a list of vma's
+ * @tlb: address of the caller's struct mmu_gather
+ * @vma: the starting vma
+ * @start_addr: virtual address at which to start unmapping
+ * @end_addr: virtual address at which to end unmapping
+ * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here
+ * @details: details of nonlinear truncation or shared cache invalidation
+ *
+ * Unmap all pages in the vma list.
+ *
+ * Only addresses between `start' and `end' will be unmapped.
+ *
+ * The VMA list must be sorted in ascending virtual address order.
+ *
+ * unmap_vmas() assumes that the caller will flush the whole unmapped address
+ * range after unmap_vmas() returns. So the only responsibility here is to
+ * ensure that any thus-far unmapped pages are flushed before unmap_vmas()
+ * drops the lock and schedules.
+ */
+void unmap_vmas(struct mmu_gather *tlb,
+ struct vm_area_struct *vma, unsigned long start_addr,
+ unsigned long end_addr, unsigned long *nr_accounted,
+ struct zap_details *details)
+{
+ struct mm_struct *mm = vma->vm_mm;
+
+ mmu_notifier_invalidate_range_start(mm, start_addr, end_addr);
+ for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next)
+ unmap_single_vma(tlb, vma, start_addr, end_addr, nr_accounted,
+ details);
+ mmu_notifier_invalidate_range_end(mm, start_addr, end_addr);
+}
+
+/**
+ * zap_page_range - remove user pages in a given range
+ * @vma: vm_area_struct holding the applicable pages
+ * @address: starting address of pages to zap
+ * @size: number of bytes to zap
+ * @details: details of nonlinear truncation or shared cache invalidation
+ *
+ * Caller must protect the VMA list
+ */
+void zap_page_range(struct vm_area_struct *vma, unsigned long address,
+ unsigned long size, struct zap_details *details)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ struct mmu_gather tlb;
+ unsigned long end = address + size;
+ unsigned long nr_accounted = 0;
+
+ lru_add_drain();
+ tlb_gather_mmu(&tlb, mm, 0);
+ update_hiwater_rss(mm);
+ unmap_vmas(&tlb, vma, address, end, &nr_accounted, details);
+ tlb_finish_mmu(&tlb, address, end);
+}
+
+/**
+ * zap_page_range_single - remove user pages in a given range
+ * @vma: vm_area_struct holding the applicable pages
+ * @address: starting address of pages to zap
+ * @size: number of bytes to zap
+ * @details: details of nonlinear truncation or shared cache invalidation
+ *
+ * The range must fit into one VMA.
+ */
+static void zap_page_range_single(struct vm_area_struct *vma, unsigned long address,
+ unsigned long size, struct zap_details *details)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ struct mmu_gather tlb;
+ unsigned long end = address + size;
+ unsigned long nr_accounted = 0;
+
+ lru_add_drain();
+ tlb_gather_mmu(&tlb, mm, 0);
+ update_hiwater_rss(mm);
+ mmu_notifier_invalidate_range_start(mm, address, end);
+ unmap_single_vma(&tlb, vma, address, end, &nr_accounted, details);
+ mmu_notifier_invalidate_range_end(mm, address, end);
+ tlb_finish_mmu(&tlb, address, end);
+}
+
+/**
+ * zap_vma_ptes - remove ptes mapping the vma
+ * @vma: vm_area_struct holding ptes to be zapped
+ * @address: starting address of pages to zap
+ * @size: number of bytes to zap
+ *
+ * This function only unmaps ptes assigned to VM_PFNMAP vmas.
+ *
+ * The entire address range must be fully contained within the vma.
+ *
+ * Returns 0 if successful.
+ */
+int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
+ unsigned long size)
+{
+ if (address < vma->vm_start || address + size > vma->vm_end ||
+ !(vma->vm_flags & VM_PFNMAP))
+ return -1;
+ zap_page_range_single(vma, address, size, NULL);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(zap_vma_ptes);
+
+/**
+ * follow_page - look up a page descriptor from a user-virtual address
+ * @vma: vm_area_struct mapping @address
+ * @address: virtual address to look up
+ * @flags: flags modifying lookup behaviour
+ *
+ * @flags can have FOLL_ flags set, defined in <linux/mm.h>
+ *
+ * Returns the mapped (struct page *), %NULL if no mapping exists, or
+ * an error pointer if there is a mapping to something not represented
+ * by a page descriptor (see also vm_normal_page()).
+ */
+struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
+ unsigned int flags)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *ptep, pte;
+ spinlock_t *ptl;
+ struct page *page;
+ struct mm_struct *mm = vma->vm_mm;
+
+ page = follow_huge_addr(mm, address, flags & FOLL_WRITE);
+ if (!IS_ERR(page)) {
+ BUG_ON(flags & FOLL_GET);
+ goto out;
+ }
+
+ page = NULL;
+ pgd = pgd_offset(mm, address);
+ if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
+ goto no_page_table;
+
+ pud = pud_offset(pgd, address);
+ if (pud_none(*pud))
+ goto no_page_table;
+ if (pud_huge(*pud) && vma->vm_flags & VM_HUGETLB) {
+ BUG_ON(flags & FOLL_GET);
+ page = follow_huge_pud(mm, address, pud, flags & FOLL_WRITE);
+ goto out;
+ }
+ if (unlikely(pud_bad(*pud)))
+ goto no_page_table;
+
+ pmd = pmd_offset(pud, address);
+ if (pmd_none(*pmd))
+ goto no_page_table;
+ if (pmd_huge(*pmd) && vma->vm_flags & VM_HUGETLB) {
+ BUG_ON(flags & FOLL_GET);
+ page = follow_huge_pmd(mm, address, pmd, flags & FOLL_WRITE);
+ goto out;
+ }
+ if (pmd_trans_huge(*pmd)) {
+ if (flags & FOLL_SPLIT) {
+ split_huge_page_pmd(mm, pmd);
+ goto split_fallthrough;
+ }
+ spin_lock(&mm->page_table_lock);
+ if (likely(pmd_trans_huge(*pmd))) {
+ if (unlikely(pmd_trans_splitting(*pmd))) {
+ spin_unlock(&mm->page_table_lock);
+ wait_split_huge_page(vma->anon_vma, pmd);
+ } else {
+ page = follow_trans_huge_pmd(mm, address,
+ pmd, flags);
+ spin_unlock(&mm->page_table_lock);
+ goto out;
+ }
+ } else
+ spin_unlock(&mm->page_table_lock);
+ /* fall through */
+ }
+split_fallthrough:
+ if (unlikely(pmd_bad(*pmd)))
+ goto no_page_table;
+
+ ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
+
+ pte = *ptep;
+ if (!pte_present(pte))
+ goto no_page;
+ if ((flags & FOLL_WRITE) && !pte_write(pte))
+ goto unlock;
+
+ page = vm_normal_page(vma, address, pte);
+ if (unlikely(!page)) {
+ if ((flags & FOLL_DUMP) ||
+ !is_zero_pfn(pte_pfn(pte)))
+ goto bad_page;
+ page = pte_page(pte);
+ }
+
+ if (flags & FOLL_GET)
+ get_page_foll(page);
+ if (flags & FOLL_TOUCH) {
+ if ((flags & FOLL_WRITE) &&
+ !pte_dirty(pte) && !PageDirty(page))
+ set_page_dirty(page);
+ /*
+ * pte_mkyoung() would be more correct here, but atomic care
+ * is needed to avoid losing the dirty bit: it is easier to use
+ * mark_page_accessed().
+ */
+ mark_page_accessed(page);
+ }
+ if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) {
+ /*
+ * The preliminary mapping check is mainly to avoid the
+ * pointless overhead of lock_page on the ZERO_PAGE
+ * which might bounce very badly if there is contention.
+ *
+ * If the page is already locked, we don't need to
+ * handle it now - vmscan will handle it later if and
+ * when it attempts to reclaim the page.
+ */
+ if (page->mapping && trylock_page(page)) {
+ lru_add_drain(); /* push cached pages to LRU */
+ /*
+ * Because we lock page here and migration is
+ * blocked by the pte's page reference, we need
+ * only check for file-cache page truncation.
+ */
+ if (page->mapping)
+ mlock_vma_page(page);
+ unlock_page(page);
+ }
+ }
+unlock:
+ pte_unmap_unlock(ptep, ptl);
+out:
+ return page;
+
+bad_page:
+ pte_unmap_unlock(ptep, ptl);
+ return ERR_PTR(-EFAULT);
+
+no_page:
+ pte_unmap_unlock(ptep, ptl);
+ if (!pte_none(pte))
+ return page;
+
+no_page_table:
+ /*
+ * When core dumping an enormous anonymous area that nobody
+ * has touched so far, we don't want to allocate unnecessary pages or
+ * page tables. Return error instead of NULL to skip handle_mm_fault,
+ * then get_dump_page() will return NULL to leave a hole in the dump.
+ * But we can only make this optimization where a hole would surely
+ * be zero-filled if handle_mm_fault() actually did handle it.
+ */
+ if ((flags & FOLL_DUMP) &&
+ (!vma->vm_ops || !vma->vm_ops->fault))
+ return ERR_PTR(-EFAULT);
+ return page;
+}
+
+static inline int stack_guard_page(struct vm_area_struct *vma, unsigned long addr)
+{
+ return stack_guard_page_start(vma, addr) ||
+ stack_guard_page_end(vma, addr+PAGE_SIZE);
+}
+
+/**
+ * __get_user_pages() - pin user pages in memory
+ * @tsk: task_struct of target task
+ * @mm: mm_struct of target mm
+ * @start: starting user address
+ * @nr_pages: number of pages from start to pin
+ * @gup_flags: flags modifying pin behaviour
+ * @pages: array that receives pointers to the pages pinned.
+ * Should be at least nr_pages long. Or NULL, if caller
+ * only intends to ensure the pages are faulted in.
+ * @vmas: array of pointers to vmas corresponding to each page.
+ * Or NULL if the caller does not require them.
+ * @nonblocking: whether waiting for disk IO or mmap_sem contention
+ *
+ * Returns number of pages pinned. This may be fewer than the number
+ * requested. If nr_pages is 0 or negative, returns 0. If no pages
+ * were pinned, returns -errno. Each page returned must be released
+ * with a put_page() call when it is finished with. vmas will only
+ * remain valid while mmap_sem is held.
+ *
+ * Must be called with mmap_sem held for read or write.
+ *
+ * __get_user_pages walks a process's page tables and takes a reference to
+ * each struct page that each user address corresponds to at a given
+ * instant. That is, it takes the page that would be accessed if a user
+ * thread accesses the given user virtual address at that instant.
+ *
+ * This does not guarantee that the page exists in the user mappings when
+ * __get_user_pages returns, and there may even be a completely different
+ * page there in some cases (eg. if mmapped pagecache has been invalidated
+ * and subsequently re faulted). However it does guarantee that the page
+ * won't be freed completely. And mostly callers simply care that the page
+ * contains data that was valid *at some point in time*. Typically, an IO
+ * or similar operation cannot guarantee anything stronger anyway because
+ * locks can't be held over the syscall boundary.
+ *
+ * If @gup_flags & FOLL_WRITE == 0, the page must not be written to. If
+ * the page is written to, set_page_dirty (or set_page_dirty_lock, as
+ * appropriate) must be called after the page is finished with, and
+ * before put_page is called.
+ *
+ * If @nonblocking != NULL, __get_user_pages will not wait for disk IO
+ * or mmap_sem contention, and if waiting is needed to pin all pages,
+ * *@nonblocking will be set to 0.
+ *
+ * In most cases, get_user_pages or get_user_pages_fast should be used
+ * instead of __get_user_pages. __get_user_pages should be used only if
+ * you need some special @gup_flags.
+ */
+int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long start, int nr_pages, unsigned int gup_flags,
+ struct page **pages, struct vm_area_struct **vmas,
+ int *nonblocking)
+{
+ int i;
+ unsigned long vm_flags;
+
+ if (nr_pages <= 0)
+ return 0;
+
+ VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET));
+
+ /*
+ * Require read or write permissions.
+ * If FOLL_FORCE is set, we only require the "MAY" flags.
+ */
+ vm_flags = (gup_flags & FOLL_WRITE) ?
+ (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
+ vm_flags &= (gup_flags & FOLL_FORCE) ?
+ (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
+ i = 0;
+
+ do {
+ struct vm_area_struct *vma;
+
+ vma = find_extend_vma(mm, start);
+ if (!vma && in_gate_area(mm, start)) {
+ unsigned long pg = start & PAGE_MASK;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ /* user gate pages are read-only */
+ if (gup_flags & FOLL_WRITE)
+ return i ? : -EFAULT;
+ if (pg > TASK_SIZE)
+ pgd = pgd_offset_k(pg);
+ else
+ pgd = pgd_offset_gate(mm, pg);
+ BUG_ON(pgd_none(*pgd));
+ pud = pud_offset(pgd, pg);
+ BUG_ON(pud_none(*pud));
+ pmd = pmd_offset(pud, pg);
+ if (pmd_none(*pmd))
+ return i ? : -EFAULT;
+ VM_BUG_ON(pmd_trans_huge(*pmd));
+ pte = pte_offset_map(pmd, pg);
+ if (pte_none(*pte)) {
+ pte_unmap(pte);
+ return i ? : -EFAULT;
+ }
+ vma = get_gate_vma(mm);
+ if (pages) {
+ struct page *page;
+
+ page = vm_normal_page(vma, start, *pte);
+ if (!page) {
+ if (!(gup_flags & FOLL_DUMP) &&
+ is_zero_pfn(pte_pfn(*pte)))
+ page = pte_page(*pte);
+ else {
+ pte_unmap(pte);
+ return i ? : -EFAULT;
+ }
+ }
+ pages[i] = page;
+ get_page(page);
+ }
+ pte_unmap(pte);
+ goto next_page;
+ }
+
+ if (!vma ||
+ (vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
+ !(vm_flags & vma->vm_flags))
+ return i ? : -EFAULT;
+
+ if (is_vm_hugetlb_page(vma)) {
+ i = follow_hugetlb_page(mm, vma, pages, vmas,
+ &start, &nr_pages, i, gup_flags);
+ continue;
+ }
+
+ do {
+ struct page *page;
+ unsigned int foll_flags = gup_flags;
+
+ /*
+ * If we have a pending SIGKILL, don't keep faulting
+ * pages and potentially allocating memory.
+ */
+ if (unlikely(fatal_signal_pending(current)))
+ return i ? i : -ERESTARTSYS;
+
+ cond_resched();
+ while (!(page = follow_page(vma, start, foll_flags))) {
+ int ret;
+ unsigned int fault_flags = 0;
+
+ /* For mlock, just skip the stack guard page. */
+ if (foll_flags & FOLL_MLOCK) {
+ if (stack_guard_page(vma, start))
+ goto next_page;
+ }
+ if (foll_flags & FOLL_WRITE)
+ fault_flags |= FAULT_FLAG_WRITE;
+ if (nonblocking)
+ fault_flags |= FAULT_FLAG_ALLOW_RETRY;
+ if (foll_flags & FOLL_NOWAIT)
+ fault_flags |= (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT);
+
+ ret = handle_mm_fault(mm, vma, start,
+ fault_flags);
+
+ if (ret & VM_FAULT_ERROR) {
+ if (ret & VM_FAULT_OOM)
+ return i ? i : -ENOMEM;
+ if (ret & (VM_FAULT_HWPOISON |
+ VM_FAULT_HWPOISON_LARGE)) {
+ if (i)
+ return i;
+ else if (gup_flags & FOLL_HWPOISON)
+ return -EHWPOISON;
+ else
+ return -EFAULT;
+ }
+ if (ret & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV))
+ return i ? i : -EFAULT;
+ BUG();
+ }
+
+ if (tsk) {
+ if (ret & VM_FAULT_MAJOR)
+ tsk->maj_flt++;
+ else
+ tsk->min_flt++;
+ }
+
+ if (ret & VM_FAULT_RETRY) {
+ if (nonblocking)
+ *nonblocking = 0;
+ return i;
+ }
+
+ /*
+ * The VM_FAULT_WRITE bit tells us that
+ * do_wp_page has broken COW when necessary,
+ * even if maybe_mkwrite decided not to set
+ * pte_write. We can thus safely do subsequent
+ * page lookups as if they were reads. But only
+ * do so when looping for pte_write is futile:
+ * in some cases userspace may also be wanting
+ * to write to the gotten user page, which a
+ * read fault here might prevent (a readonly
+ * page might get reCOWed by userspace write).
+ */
+ if ((ret & VM_FAULT_WRITE) &&
+ !(vma->vm_flags & VM_WRITE))
+ foll_flags &= ~FOLL_WRITE;
+
+ cond_resched();
+ }
+ if (IS_ERR(page))
+ return i ? i : PTR_ERR(page);
+ if (pages) {
+ pages[i] = page;
+
+ flush_anon_page(vma, page, start);
+ flush_dcache_page(page);
+ }
+next_page:
+ if (vmas)
+ vmas[i] = vma;
+ i++;
+ start += PAGE_SIZE;
+ nr_pages--;
+ } while (nr_pages && start < vma->vm_end);
+ } while (nr_pages);
+ return i;
+}
+EXPORT_SYMBOL(__get_user_pages);
+
+/*
+ * fixup_user_fault() - manually resolve a user page fault
+ * @tsk: the task_struct to use for page fault accounting, or
+ * NULL if faults are not to be recorded.
+ * @mm: mm_struct of target mm
+ * @address: user address
+ * @fault_flags:flags to pass down to handle_mm_fault()
+ *
+ * This is meant to be called in the specific scenario where for locking reasons
+ * we try to access user memory in atomic context (within a pagefault_disable()
+ * section), this returns -EFAULT, and we want to resolve the user fault before
+ * trying again.
+ *
+ * Typically this is meant to be used by the futex code.
+ *
+ * The main difference with get_user_pages() is that this function will
+ * unconditionally call handle_mm_fault() which will in turn perform all the
+ * necessary SW fixup of the dirty and young bits in the PTE, while
+ * handle_mm_fault() only guarantees to update these in the struct page.
+ *
+ * This is important for some architectures where those bits also gate the
+ * access permission to the page because they are maintained in software. On
+ * such architectures, gup() will not be enough to make a subsequent access
+ * succeed.
+ *
+ * This should be called with the mm_sem held for read.
+ */
+int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long address, unsigned int fault_flags)
+{
+ struct vm_area_struct *vma;
+ vm_flags_t vm_flags;
+ int ret;
+
+ vma = find_extend_vma(mm, address);
+ if (!vma || address < vma->vm_start)
+ return -EFAULT;
+
+ vm_flags = (fault_flags & FAULT_FLAG_WRITE) ? VM_WRITE : VM_READ;
+ if (!(vm_flags & vma->vm_flags))
+ return -EFAULT;
+
+ ret = handle_mm_fault(mm, vma, address, fault_flags);
+ if (ret & VM_FAULT_ERROR) {
+ if (ret & VM_FAULT_OOM)
+ return -ENOMEM;
+ if (ret & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE))
+ return -EHWPOISON;
+ if (ret & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV))
+ return -EFAULT;
+ BUG();
+ }
+ if (tsk) {
+ if (ret & VM_FAULT_MAJOR)
+ tsk->maj_flt++;
+ else
+ tsk->min_flt++;
+ }
+ return 0;
+}
+
+/*
+ * get_user_pages() - pin user pages in memory
+ * @tsk: the task_struct to use for page fault accounting, or
+ * NULL if faults are not to be recorded.
+ * @mm: mm_struct of target mm
+ * @start: starting user address
+ * @nr_pages: number of pages from start to pin
+ * @write: whether pages will be written to by the caller
+ * @force: whether to force write access even if user mapping is
+ * readonly. This will result in the page being COWed even
+ * in MAP_SHARED mappings. You do not want this.
+ * @pages: array that receives pointers to the pages pinned.
+ * Should be at least nr_pages long. Or NULL, if caller
+ * only intends to ensure the pages are faulted in.
+ * @vmas: array of pointers to vmas corresponding to each page.
+ * Or NULL if the caller does not require them.
+ *
+ * Returns number of pages pinned. This may be fewer than the number
+ * requested. If nr_pages is 0 or negative, returns 0. If no pages
+ * were pinned, returns -errno. Each page returned must be released
+ * with a put_page() call when it is finished with. vmas will only
+ * remain valid while mmap_sem is held.
+ *
+ * Must be called with mmap_sem held for read or write.
+ *
+ * get_user_pages walks a process's page tables and takes a reference to
+ * each struct page that each user address corresponds to at a given
+ * instant. That is, it takes the page that would be accessed if a user
+ * thread accesses the given user virtual address at that instant.
+ *
+ * This does not guarantee that the page exists in the user mappings when
+ * get_user_pages returns, and there may even be a completely different
+ * page there in some cases (eg. if mmapped pagecache has been invalidated
+ * and subsequently re faulted). However it does guarantee that the page
+ * won't be freed completely. And mostly callers simply care that the page
+ * contains data that was valid *at some point in time*. Typically, an IO
+ * or similar operation cannot guarantee anything stronger anyway because
+ * locks can't be held over the syscall boundary.
+ *
+ * If write=0, the page must not be written to. If the page is written to,
+ * set_page_dirty (or set_page_dirty_lock, as appropriate) must be called
+ * after the page is finished with, and before put_page is called.
+ *
+ * get_user_pages is typically used for fewer-copy IO operations, to get a
+ * handle on the memory by some means other than accesses via the user virtual
+ * addresses. The pages may be submitted for DMA to devices or accessed via
+ * their kernel linear mapping (via the kmap APIs). Care should be taken to
+ * use the correct cache flushing APIs.
+ *
+ * See also get_user_pages_fast, for performance critical applications.
+ */
+int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long start, int nr_pages, int write, int force,
+ struct page **pages, struct vm_area_struct **vmas)
+{
+ int flags = FOLL_TOUCH;
+
+ if (pages)
+ flags |= FOLL_GET;
+ if (write)
+ flags |= FOLL_WRITE;
+ if (force)
+ flags |= FOLL_FORCE;
+
+ return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas,
+ NULL);
+}
+EXPORT_SYMBOL(get_user_pages);
+
+/**
+ * get_dump_page() - pin user page in memory while writing it to core dump
+ * @addr: user address
+ *
+ * Returns struct page pointer of user page pinned for dump,
+ * to be freed afterwards by page_cache_release() or put_page().
+ *
+ * Returns NULL on any kind of failure - a hole must then be inserted into
+ * the corefile, to preserve alignment with its headers; and also returns
+ * NULL wherever the ZERO_PAGE, or an anonymous pte_none, has been found -
+ * allowing a hole to be left in the corefile to save diskspace.
+ *
+ * Called without mmap_sem, but after all other threads have been killed.
+ */
+#ifdef CONFIG_ELF_CORE
+struct page *get_dump_page(unsigned long addr)
+{
+ struct vm_area_struct *vma;
+ struct page *page;
+
+ if (__get_user_pages(current, current->mm, addr, 1,
+ FOLL_FORCE | FOLL_DUMP | FOLL_GET, &page, &vma,
+ NULL) < 1)
+ return NULL;
+ flush_cache_page(vma, addr, page_to_pfn(page));
+ return page;
+}
+#endif /* CONFIG_ELF_CORE */
+
+pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
+ spinlock_t **ptl)
+{
+ pgd_t * pgd = pgd_offset(mm, addr);
+ pud_t * pud = pud_alloc(mm, pgd, addr);
+ if (pud) {
+ pmd_t * pmd = pmd_alloc(mm, pud, addr);
+ if (pmd) {
+ VM_BUG_ON(pmd_trans_huge(*pmd));
+ return pte_alloc_map_lock(mm, pmd, addr, ptl);
+ }
+ }
+ return NULL;
+}
+
+/*
+ * This is the old fallback for page remapping.
+ *
+ * For historical reasons, it only allows reserved pages. Only
+ * old drivers should use this, and they needed to mark their
+ * pages reserved for the old functions anyway.
+ */
+static int insert_page(struct vm_area_struct *vma, unsigned long addr,
+ struct page *page, pgprot_t prot)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int retval;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ retval = -EINVAL;
+ if (PageAnon(page))
+ goto out;
+ retval = -ENOMEM;
+ flush_dcache_page(page);
+ pte = get_locked_pte(mm, addr, &ptl);
+ if (!pte)
+ goto out;
+ retval = -EBUSY;
+ if (!pte_none(*pte))
+ goto out_unlock;
+
+ /* Ok, finally just insert the thing.. */
+ get_page(page);
+ inc_mm_counter_fast(mm, MM_FILEPAGES);
+ page_add_file_rmap(page);
+ set_pte_at(mm, addr, pte, mk_pte(page, prot));
+
+ retval = 0;
+ pte_unmap_unlock(pte, ptl);
+ return retval;
+out_unlock:
+ pte_unmap_unlock(pte, ptl);
+out:
+ return retval;
+}
+
+/**
+ * vm_insert_page - insert single page into user vma
+ * @vma: user vma to map to
+ * @addr: target user address of this page
+ * @page: source kernel page
+ *
+ * This allows drivers to insert individual pages they've allocated
+ * into a user vma.
+ *
+ * The page has to be a nice clean _individual_ kernel allocation.
+ * If you allocate a compound page, you need to have marked it as
+ * such (__GFP_COMP), or manually just split the page up yourself
+ * (see split_page()).
+ *
+ * NOTE! Traditionally this was done with "remap_pfn_range()" which
+ * took an arbitrary page protection parameter. This doesn't allow
+ * that. Your vma protection will have to be set up correctly, which
+ * means that if you want a shared writable mapping, you'd better
+ * ask for a shared writable mapping!
+ *
+ * The page does not need to be reserved.
+ */
+int vm_insert_page(struct vm_area_struct *vma, unsigned long addr,
+ struct page *page)
+{
+ if (addr < vma->vm_start || addr >= vma->vm_end)
+ return -EFAULT;
+ if (!page_count(page))
+ return -EINVAL;
+ vma->vm_flags |= VM_INSERTPAGE;
+ return insert_page(vma, addr, page, vma->vm_page_prot);
+}
+EXPORT_SYMBOL(vm_insert_page);
+
+static int insert_pfn(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn, pgprot_t prot)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int retval;
+ pte_t *pte, entry;
+ spinlock_t *ptl;
+
+ retval = -ENOMEM;
+ pte = get_locked_pte(mm, addr, &ptl);
+ if (!pte)
+ goto out;
+ retval = -EBUSY;
+ if (!pte_none(*pte))
+ goto out_unlock;
+
+ /* Ok, finally just insert the thing.. */
+ entry = pte_mkspecial(pfn_pte(pfn, prot));
+ set_pte_at(mm, addr, pte, entry);
+ update_mmu_cache(vma, addr, pte); /* XXX: why not for insert_page? */
+
+ retval = 0;
+out_unlock:
+ pte_unmap_unlock(pte, ptl);
+out:
+ return retval;
+}
+
+/**
+ * vm_insert_pfn - insert single pfn into user vma
+ * @vma: user vma to map to
+ * @addr: target user address of this page
+ * @pfn: source kernel pfn
+ *
+ * Similar to vm_inert_page, this allows drivers to insert individual pages
+ * they've allocated into a user vma. Same comments apply.
+ *
+ * This function should only be called from a vm_ops->fault handler, and
+ * in that case the handler should return NULL.
+ *
+ * vma cannot be a COW mapping.
+ *
+ * As this is called only for pages that do not currently exist, we
+ * do not need to flush old virtual caches or the TLB.
+ */
+int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn)
+{
+ int ret;
+ pgprot_t pgprot = vma->vm_page_prot;
+ /*
+ * Technically, architectures with pte_special can avoid all these
+ * restrictions (same for remap_pfn_range). However we would like
+ * consistency in testing and feature parity among all, so we should
+ * try to keep these invariants in place for everybody.
+ */
+ BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
+ BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
+ (VM_PFNMAP|VM_MIXEDMAP));
+ BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
+ BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn));
+
+ if (addr < vma->vm_start || addr >= vma->vm_end)
+ return -EFAULT;
+ if (track_pfn_vma_new(vma, &pgprot, pfn, PAGE_SIZE))
+ return -EINVAL;
+
+ ret = insert_pfn(vma, addr, pfn, pgprot);
+
+ if (ret)
+ untrack_pfn_vma(vma, pfn, PAGE_SIZE);
+
+ return ret;
+}
+EXPORT_SYMBOL(vm_insert_pfn);
+
+int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn)
+{
+ BUG_ON(!(vma->vm_flags & VM_MIXEDMAP));
+
+ if (addr < vma->vm_start || addr >= vma->vm_end)
+ return -EFAULT;
+
+ /*
+ * If we don't have pte special, then we have to use the pfn_valid()
+ * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
+ * refcount the page if pfn_valid is true (hence insert_page rather
+ * than insert_pfn). If a zero_pfn were inserted into a VM_MIXEDMAP
+ * without pte special, it would there be refcounted as a normal page.
+ */
+ if (!HAVE_PTE_SPECIAL && pfn_valid(pfn)) {
+ struct page *page;
+
+ page = pfn_to_page(pfn);
+ return insert_page(vma, addr, page, vma->vm_page_prot);
+ }
+ return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
+}
+EXPORT_SYMBOL(vm_insert_mixed);
+
+/*
+ * maps a range of physical memory into the requested pages. the old
+ * mappings are removed. any references to nonexistent pages results
+ * in null mappings (currently treated as "copy-on-access")
+ */
+static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ unsigned long pfn, pgprot_t prot)
+{
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
+ if (!pte)
+ return -ENOMEM;
+ arch_enter_lazy_mmu_mode();
+ do {
+ BUG_ON(!pte_none(*pte));
+ set_pte_at(mm, addr, pte, pte_mkspecial(pfn_pte(pfn, prot)));
+ pfn++;
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ arch_leave_lazy_mmu_mode();
+ pte_unmap_unlock(pte - 1, ptl);
+ return 0;
+}
+
+static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ unsigned long pfn, pgprot_t prot)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ pfn -= addr >> PAGE_SHIFT;
+ pmd = pmd_alloc(mm, pud, addr);
+ if (!pmd)
+ return -ENOMEM;
+ VM_BUG_ON(pmd_trans_huge(*pmd));
+ do {
+ next = pmd_addr_end(addr, end);
+ if (remap_pte_range(mm, pmd, addr, next,
+ pfn + (addr >> PAGE_SHIFT), prot))
+ return -ENOMEM;
+ } while (pmd++, addr = next, addr != end);
+ return 0;
+}
+
+static inline int remap_pud_range(struct mm_struct *mm, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ unsigned long pfn, pgprot_t prot)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ pfn -= addr >> PAGE_SHIFT;
+ pud = pud_alloc(mm, pgd, addr);
+ if (!pud)
+ return -ENOMEM;
+ do {
+ next = pud_addr_end(addr, end);
+ if (remap_pmd_range(mm, pud, addr, next,
+ pfn + (addr >> PAGE_SHIFT), prot))
+ return -ENOMEM;
+ } while (pud++, addr = next, addr != end);
+ return 0;
+}
+
+/**
+ * remap_pfn_range - remap kernel memory to userspace
+ * @vma: user vma to map to
+ * @addr: target user address to start at
+ * @pfn: physical address of kernel memory
+ * @size: size of map area
+ * @prot: page protection flags for this mapping
+ *
+ * Note: this is only safe if the mm semaphore is held when called.
+ */
+int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn, unsigned long size, pgprot_t prot)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ unsigned long end = addr + PAGE_ALIGN(size);
+ struct mm_struct *mm = vma->vm_mm;
+ int err;
+
+ /*
+ * Physically remapped pages are special. Tell the
+ * rest of the world about it:
+ * VM_IO tells people not to look at these pages
+ * (accesses can have side effects).
+ * VM_RESERVED is specified all over the place, because
+ * in 2.4 it kept swapout's vma scan off this vma; but
+ * in 2.6 the LRU scan won't even find its pages, so this
+ * flag means no more than count its pages in reserved_vm,
+ * and omit it from core dump, even when VM_IO turned off.
+ * VM_PFNMAP tells the core MM that the base pages are just
+ * raw PFN mappings, and do not have a "struct page" associated
+ * with them.
+ *
+ * There's a horrible special case to handle copy-on-write
+ * behaviour that some programs depend on. We mark the "original"
+ * un-COW'ed pages by matching them up with "vma->vm_pgoff".
+ */
+ if (addr == vma->vm_start && end == vma->vm_end) {
+ vma->vm_pgoff = pfn;
+ vma->vm_flags |= VM_PFN_AT_MMAP;
+ } else if (is_cow_mapping(vma->vm_flags))
+ return -EINVAL;
+
+ vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
+
+ err = track_pfn_vma_new(vma, &prot, pfn, PAGE_ALIGN(size));
+ if (err) {
+ /*
+ * To indicate that track_pfn related cleanup is not
+ * needed from higher level routine calling unmap_vmas
+ */
+ vma->vm_flags &= ~(VM_IO | VM_RESERVED | VM_PFNMAP);
+ vma->vm_flags &= ~VM_PFN_AT_MMAP;
+ return -EINVAL;
+ }
+
+ BUG_ON(addr >= end);
+ pfn -= addr >> PAGE_SHIFT;
+ pgd = pgd_offset(mm, addr);
+ flush_cache_range(vma, addr, end);
+ do {
+ next = pgd_addr_end(addr, end);
+ err = remap_pud_range(mm, pgd, addr, next,
+ pfn + (addr >> PAGE_SHIFT), prot);
+ if (err)
+ break;
+ } while (pgd++, addr = next, addr != end);
+
+ if (err)
+ untrack_pfn_vma(vma, pfn, PAGE_ALIGN(size));
+
+ return err;
+}
+EXPORT_SYMBOL(remap_pfn_range);
+
+/**
+ * vm_iomap_memory - remap memory to userspace
+ * @vma: user vma to map to
+ * @start: start of area
+ * @len: size of area
+ *
+ * This is a simplified io_remap_pfn_range() for common driver use. The
+ * driver just needs to give us the physical memory range to be mapped,
+ * we'll figure out the rest from the vma information.
+ *
+ * NOTE! Some drivers might want to tweak vma->vm_page_prot first to get
+ * whatever write-combining details or similar.
+ */
+int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len)
+{
+ unsigned long vm_len, pfn, pages;
+
+ /* Check that the physical memory area passed in looks valid */
+ if (start + len < start)
+ return -EINVAL;
+ /*
+ * You *really* shouldn't map things that aren't page-aligned,
+ * but we've historically allowed it because IO memory might
+ * just have smaller alignment.
+ */
+ len += start & ~PAGE_MASK;
+ pfn = start >> PAGE_SHIFT;
+ pages = (len + ~PAGE_MASK) >> PAGE_SHIFT;
+ if (pfn + pages < pfn)
+ return -EINVAL;
+
+ /* We start the mapping 'vm_pgoff' pages into the area */
+ if (vma->vm_pgoff > pages)
+ return -EINVAL;
+ pfn += vma->vm_pgoff;
+ pages -= vma->vm_pgoff;
+
+ /* Can we fit all of the mapping? */
+ vm_len = vma->vm_end - vma->vm_start;
+ if (vm_len >> PAGE_SHIFT > pages)
+ return -EINVAL;
+
+ /* Ok, let it rip */
+ return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len, vma->vm_page_prot);
+}
+EXPORT_SYMBOL(vm_iomap_memory);
+
+static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ pte_fn_t fn, void *data)
+{
+ pte_t *pte;
+ int err;
+ pgtable_t token;
+ spinlock_t *uninitialized_var(ptl);
+
+ pte = (mm == &init_mm) ?
+ pte_alloc_kernel(pmd, addr) :
+ pte_alloc_map_lock(mm, pmd, addr, &ptl);
+ if (!pte)
+ return -ENOMEM;
+
+ BUG_ON(pmd_huge(*pmd));
+
+ arch_enter_lazy_mmu_mode();
+
+ token = pmd_pgtable(*pmd);
+
+ do {
+ err = fn(pte++, token, addr, data);
+ if (err)
+ break;
+ } while (addr += PAGE_SIZE, addr != end);
+
+ arch_leave_lazy_mmu_mode();
+
+ if (mm != &init_mm)
+ pte_unmap_unlock(pte-1, ptl);
+ return err;
+}
+
+static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ pte_fn_t fn, void *data)
+{
+ pmd_t *pmd;
+ unsigned long next;
+ int err;
+
+ BUG_ON(pud_huge(*pud));
+
+ pmd = pmd_alloc(mm, pud, addr);
+ if (!pmd)
+ return -ENOMEM;
+ do {
+ next = pmd_addr_end(addr, end);
+ err = apply_to_pte_range(mm, pmd, addr, next, fn, data);
+ if (err)
+ break;
+ } while (pmd++, addr = next, addr != end);
+ return err;
+}
+
+static int apply_to_pud_range(struct mm_struct *mm, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ pte_fn_t fn, void *data)
+{
+ pud_t *pud;
+ unsigned long next;
+ int err;
+
+ pud = pud_alloc(mm, pgd, addr);
+ if (!pud)
+ return -ENOMEM;
+ do {
+ next = pud_addr_end(addr, end);
+ err = apply_to_pmd_range(mm, pud, addr, next, fn, data);
+ if (err)
+ break;
+ } while (pud++, addr = next, addr != end);
+ return err;
+}
+
+/*
+ * Scan a region of virtual memory, filling in page tables as necessary
+ * and calling a provided function on each leaf page table.
+ */
+int apply_to_page_range(struct mm_struct *mm, unsigned long addr,
+ unsigned long size, pte_fn_t fn, void *data)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ unsigned long end = addr + size;
+ int err;
+
+ BUG_ON(addr >= end);
+ pgd = pgd_offset(mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ err = apply_to_pud_range(mm, pgd, addr, next, fn, data);
+ if (err)
+ break;
+ } while (pgd++, addr = next, addr != end);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(apply_to_page_range);
+
+/*
+ * handle_pte_fault chooses page fault handler according to an entry
+ * which was read non-atomically. Before making any commitment, on
+ * those architectures or configurations (e.g. i386 with PAE) which
+ * might give a mix of unmatched parts, do_swap_page and do_nonlinear_fault
+ * must check under lock before unmapping the pte and proceeding
+ * (but do_wp_page is only called after already making such a check;
+ * and do_anonymous_page can safely check later on).
+ */
+static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd,
+ pte_t *page_table, pte_t orig_pte)
+{
+ int same = 1;
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
+ if (sizeof(pte_t) > sizeof(unsigned long)) {
+ spinlock_t *ptl = pte_lockptr(mm, pmd);
+ spin_lock(ptl);
+ same = pte_same(*page_table, orig_pte);
+ spin_unlock(ptl);
+ }
+#endif
+ pte_unmap(page_table);
+ return same;
+}
+
+static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va, struct vm_area_struct *vma)
+{
+ /*
+ * If the source page was a PFN mapping, we don't have
+ * a "struct page" for it. We do a best-effort copy by
+ * just copying from the original user address. If that
+ * fails, we just zero-fill it. Live with it.
+ */
+ if (unlikely(!src)) {
+ void *kaddr = kmap_atomic(dst);
+ void __user *uaddr = (void __user *)(va & PAGE_MASK);
+
+ /*
+ * This really shouldn't fail, because the page is there
+ * in the page tables. But it might just be unreadable,
+ * in which case we just give up and fill the result with
+ * zeroes.
+ */
+ if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE))
+ clear_page(kaddr);
+ kunmap_atomic(kaddr);
+ flush_dcache_page(dst);
+ } else
+ copy_user_highpage(dst, src, va, vma);
+}
+
+/*
+ * This routine handles present pages, when users try to write
+ * to a shared page. It is done by copying the page to a new address
+ * and decrementing the shared-page counter for the old page.
+ *
+ * Note that this routine assumes that the protection checks have been
+ * done by the caller (the low-level page fault routine in most cases).
+ * Thus we can safely just mark it writable once we've done any necessary
+ * COW.
+ *
+ * We also mark the page dirty at this point even though the page will
+ * change only once the write actually happens. This avoids a few races,
+ * and potentially makes it more efficient.
+ *
+ * We enter with non-exclusive mmap_sem (to exclude vma changes,
+ * but allow concurrent faults), with pte both mapped and locked.
+ * We return with mmap_sem still held, but pte unmapped and unlocked.
+ */
+static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *page_table, pmd_t *pmd,
+ spinlock_t *ptl, pte_t orig_pte)
+ __releases(ptl)
+{
+ struct page *old_page, *new_page;
+ pte_t entry;
+ int ret = 0;
+ int page_mkwrite = 0;
+ struct page *dirty_page = NULL;
+
+ old_page = vm_normal_page(vma, address, orig_pte);
+ if (!old_page) {
+ /*
+ * VM_MIXEDMAP !pfn_valid() case
+ *
+ * We should not cow pages in a shared writeable mapping.
+ * Just mark the pages writable as we can't do any dirty
+ * accounting on raw pfn maps.
+ */
+ if ((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
+ (VM_WRITE|VM_SHARED))
+ goto reuse;
+ goto gotten;
+ }
+
+ /*
+ * Take out anonymous pages first, anonymous shared vmas are
+ * not dirty accountable.
+ */
+ if (PageAnon(old_page) && !PageKsm(old_page)) {
+ if (!trylock_page(old_page)) {
+ page_cache_get(old_page);
+ pte_unmap_unlock(page_table, ptl);
+ lock_page(old_page);
+ page_table = pte_offset_map_lock(mm, pmd, address,
+ &ptl);
+ if (!pte_same(*page_table, orig_pte)) {
+ unlock_page(old_page);
+ goto unlock;
+ }
+ page_cache_release(old_page);
+ }
+ if (reuse_swap_page(old_page)) {
+ /*
+ * The page is all ours. Move it to our anon_vma so
+ * the rmap code will not search our parent or siblings.
+ * Protected against the rmap code by the page lock.
+ */
+ page_move_anon_rmap(old_page, vma, address);
+ unlock_page(old_page);
+ goto reuse;
+ }
+ unlock_page(old_page);
+ } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
+ (VM_WRITE|VM_SHARED))) {
+ /*
+ * Only catch write-faults on shared writable pages,
+ * read-only shared pages can get COWed by
+ * get_user_pages(.write=1, .force=1).
+ */
+ if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
+ struct vm_fault vmf;
+ int tmp;
+
+ vmf.virtual_address = (void __user *)(address &
+ PAGE_MASK);
+ vmf.pgoff = old_page->index;
+ vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
+ vmf.page = old_page;
+
+ /*
+ * Notify the address space that the page is about to
+ * become writable so that it can prohibit this or wait
+ * for the page to get into an appropriate state.
+ *
+ * We do this without the lock held, so that it can
+ * sleep if it needs to.
+ */
+ page_cache_get(old_page);
+ pte_unmap_unlock(page_table, ptl);
+
+ tmp = vma->vm_ops->page_mkwrite(vma, &vmf);
+ if (unlikely(tmp &
+ (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) {
+ ret = tmp;
+ goto unwritable_page;
+ }
+ if (unlikely(!(tmp & VM_FAULT_LOCKED))) {
+ lock_page(old_page);
+ if (!old_page->mapping) {
+ ret = 0; /* retry the fault */
+ unlock_page(old_page);
+ goto unwritable_page;
+ }
+ } else
+ VM_BUG_ON(!PageLocked(old_page));
+
+ /*
+ * Since we dropped the lock we need to revalidate
+ * the PTE as someone else may have changed it. If
+ * they did, we just return, as we can count on the
+ * MMU to tell us if they didn't also make it writable.
+ */
+ page_table = pte_offset_map_lock(mm, pmd, address,
+ &ptl);
+ if (!pte_same(*page_table, orig_pte)) {
+ unlock_page(old_page);
+ goto unlock;
+ }
+
+ page_mkwrite = 1;
+ }
+ dirty_page = old_page;
+ get_page(dirty_page);
+
+reuse:
+ flush_cache_page(vma, address, pte_pfn(orig_pte));
+ entry = pte_mkyoung(orig_pte);
+ entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ if (ptep_set_access_flags(vma, address, page_table, entry,1))
+ update_mmu_cache(vma, address, page_table);
+ pte_unmap_unlock(page_table, ptl);
+ ret |= VM_FAULT_WRITE;
+
+ if (!dirty_page)
+ return ret;
+
+ if (!page_mkwrite) {
+ struct address_space *mapping;
+ int dirtied;
+
+ lock_page(dirty_page);
+ dirtied = set_page_dirty(dirty_page);
+ VM_BUG_ON(dirty_page);
+ mapping = dirty_page->mapping;
+ unlock_page(dirty_page);
+
+ if (dirtied && mapping) {
+ /*
+ * Some device drivers do not set page.mapping
+ * but still dirty their pages
+ */
+ balance_dirty_pages_ratelimited(mapping);
+ }
+ }
+
+ put_page(dirty_page);
+ if (page_mkwrite) {
+ struct address_space *mapping = dirty_page->mapping;
+
+ set_page_dirty(dirty_page);
+ unlock_page(dirty_page);
+ page_cache_release(dirty_page);
+ if (mapping) {
+ /*
+ * Some device drivers do not set page.mapping
+ * but still dirty their pages
+ */
+ balance_dirty_pages_ratelimited(mapping);
+ }
+ }
+
+ /* file_update_time outside page_lock */
+ if (vma->vm_file)
+ file_update_time(vma->vm_file);
+
+ return ret;
+ }
+
+ /*
+ * Ok, we need to copy. Oh, well..
+ */
+ page_cache_get(old_page);
+gotten:
+ pte_unmap_unlock(page_table, ptl);
+
+ if (unlikely(anon_vma_prepare(vma)))
+ goto oom;
+
+ if (is_zero_pfn(pte_pfn(orig_pte))) {
+ new_page = alloc_zeroed_user_highpage_movable(vma, address);
+ if (!new_page)
+ goto oom;
+ } else {
+ new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
+ if (!new_page)
+ goto oom;
+ cow_user_page(new_page, old_page, address, vma);
+ }
+ __SetPageUptodate(new_page);
+
+ if (mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))
+ goto oom_free_new;
+
+ /*
+ * Re-check the pte - we dropped the lock
+ */
+ page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+ if (likely(pte_same(*page_table, orig_pte))) {
+ if (old_page) {
+ if (!PageAnon(old_page)) {
+ dec_mm_counter_fast(mm, MM_FILEPAGES);
+ inc_mm_counter_fast(mm, MM_ANONPAGES);
+ }
+ } else
+ inc_mm_counter_fast(mm, MM_ANONPAGES);
+ flush_cache_page(vma, address, pte_pfn(orig_pte));
+ entry = mk_pte(new_page, vma->vm_page_prot);
+ entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ /*
+ * Clear the pte entry and flush it first, before updating the
+ * pte with the new entry. This will avoid a race condition
+ * seen in the presence of one thread doing SMC and another
+ * thread doing COW.
+ */
+ ptep_clear_flush(vma, address, page_table);
+ page_add_new_anon_rmap(new_page, vma, address);
+ /*
+ * We call the notify macro here because, when using secondary
+ * mmu page tables (such as kvm shadow page tables), we want the
+ * new page to be mapped directly into the secondary page table.
+ */
+ set_pte_at_notify(mm, address, page_table, entry);
+ update_mmu_cache(vma, address, page_table);
+ if (old_page) {
+ /*
+ * Only after switching the pte to the new page may
+ * we remove the mapcount here. Otherwise another
+ * process may come and find the rmap count decremented
+ * before the pte is switched to the new page, and
+ * "reuse" the old page writing into it while our pte
+ * here still points into it and can be read by other
+ * threads.
+ *
+ * The critical issue is to order this
+ * page_remove_rmap with the ptp_clear_flush above.
+ * Those stores are ordered by (if nothing else,)
+ * the barrier present in the atomic_add_negative
+ * in page_remove_rmap.
+ *
+ * Then the TLB flush in ptep_clear_flush ensures that
+ * no process can access the old page before the
+ * decremented mapcount is visible. And the old page
+ * cannot be reused until after the decremented
+ * mapcount is visible. So transitively, TLBs to
+ * old page will be flushed before it can be reused.
+ */
+ page_remove_rmap(old_page);
+ }
+
+ /* Free the old page.. */
+ new_page = old_page;
+ ret |= VM_FAULT_WRITE;
+ } else
+ mem_cgroup_uncharge_page(new_page);
+
+ if (new_page)
+ page_cache_release(new_page);
+unlock:
+ pte_unmap_unlock(page_table, ptl);
+ if (old_page) {
+ /*
+ * Don't let another task, with possibly unlocked vma,
+ * keep the mlocked page.
+ */
+ if ((ret & VM_FAULT_WRITE) && (vma->vm_flags & VM_LOCKED)) {
+ lock_page(old_page); /* LRU manipulation */
+ munlock_vma_page(old_page);
+ unlock_page(old_page);
+ }
+ page_cache_release(old_page);
+ }
+ return ret;
+oom_free_new:
+ page_cache_release(new_page);
+oom:
+ if (old_page) {
+ if (page_mkwrite) {
+ unlock_page(old_page);
+ page_cache_release(old_page);
+ }
+ page_cache_release(old_page);
+ }
+ return VM_FAULT_OOM;
+
+unwritable_page:
+ page_cache_release(old_page);
+ return ret;
+}
+
+static void unmap_mapping_range_vma(struct vm_area_struct *vma,
+ unsigned long start_addr, unsigned long end_addr,
+ struct zap_details *details)
+{
+ zap_page_range_single(vma, start_addr, end_addr - start_addr, details);
+}
+
+static inline void unmap_mapping_range_tree(struct prio_tree_root *root,
+ struct zap_details *details)
+{
+ struct vm_area_struct *vma;
+ struct prio_tree_iter iter;
+ pgoff_t vba, vea, zba, zea;
+
+ vma_prio_tree_foreach(vma, &iter, root,
+ details->first_index, details->last_index) {
+
+ vba = vma->vm_pgoff;
+ vea = vba + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) - 1;
+ /* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */
+ zba = details->first_index;
+ if (zba < vba)
+ zba = vba;
+ zea = details->last_index;
+ if (zea > vea)
+ zea = vea;
+
+ unmap_mapping_range_vma(vma,
+ ((zba - vba) << PAGE_SHIFT) + vma->vm_start,
+ ((zea - vba + 1) << PAGE_SHIFT) + vma->vm_start,
+ details);
+ }
+}
+
+static inline void unmap_mapping_range_list(struct list_head *head,
+ struct zap_details *details)
+{
+ struct vm_area_struct *vma;
+
+ /*
+ * In nonlinear VMAs there is no correspondence between virtual address
+ * offset and file offset. So we must perform an exhaustive search
+ * across *all* the pages in each nonlinear VMA, not just the pages
+ * whose virtual address lies outside the file truncation point.
+ */
+ list_for_each_entry(vma, head, shared.vm_set.list) {
+ details->nonlinear_vma = vma;
+ unmap_mapping_range_vma(vma, vma->vm_start, vma->vm_end, details);
+ }
+}
+
+/**
+ * unmap_mapping_range - unmap the portion of all mmaps in the specified address_space corresponding to the specified page range in the underlying file.
+ * @mapping: the address space containing mmaps to be unmapped.
+ * @holebegin: byte in first page to unmap, relative to the start of
+ * the underlying file. This will be rounded down to a PAGE_SIZE
+ * boundary. Note that this is different from truncate_pagecache(), which
+ * must keep the partial page. In contrast, we must get rid of
+ * partial pages.
+ * @holelen: size of prospective hole in bytes. This will be rounded
+ * up to a PAGE_SIZE boundary. A holelen of zero truncates to the
+ * end of the file.
+ * @even_cows: 1 when truncating a file, unmap even private COWed pages;
+ * but 0 when invalidating pagecache, don't throw away private data.
+ */
+void unmap_mapping_range(struct address_space *mapping,
+ loff_t const holebegin, loff_t const holelen, int even_cows)
+{
+ struct zap_details details;
+ pgoff_t hba = holebegin >> PAGE_SHIFT;
+ pgoff_t hlen = (holelen + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+ /* Check for overflow. */
+ if (sizeof(holelen) > sizeof(hlen)) {
+ long long holeend =
+ (holebegin + holelen + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ if (holeend & ~(long long)ULONG_MAX)
+ hlen = ULONG_MAX - hba + 1;
+ }
+
+ details.check_mapping = even_cows? NULL: mapping;
+ details.nonlinear_vma = NULL;
+ details.first_index = hba;
+ details.last_index = hba + hlen - 1;
+ if (details.last_index < details.first_index)
+ details.last_index = ULONG_MAX;
+
+
+ mutex_lock(&mapping->i_mmap_mutex);
+ if (unlikely(!prio_tree_empty(&mapping->i_mmap)))
+ unmap_mapping_range_tree(&mapping->i_mmap, &details);
+ if (unlikely(!list_empty(&mapping->i_mmap_nonlinear)))
+ unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details);
+ mutex_unlock(&mapping->i_mmap_mutex);
+}
+EXPORT_SYMBOL(unmap_mapping_range);
+
+/*
+ * We enter with non-exclusive mmap_sem (to exclude vma changes,
+ * but allow concurrent faults), and pte mapped but not yet locked.
+ * We return with mmap_sem still held, but pte unmapped and unlocked.
+ */
+static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *page_table, pmd_t *pmd,
+ unsigned int flags, pte_t orig_pte)
+{
+ spinlock_t *ptl;
+ struct page *page, *swapcache = NULL;
+ swp_entry_t entry;
+ pte_t pte;
+ int locked;
+ struct mem_cgroup *ptr;
+ int exclusive = 0;
+ int ret = 0;
+
+ if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
+ goto out;
+
+ entry = pte_to_swp_entry(orig_pte);
+ if (unlikely(non_swap_entry(entry))) {
+ if (is_migration_entry(entry)) {
+ migration_entry_wait(mm, pmd, address);
+ } else if (is_hwpoison_entry(entry)) {
+ ret = VM_FAULT_HWPOISON;
+ } else {
+ print_bad_pte(vma, address, orig_pte, NULL);
+ ret = VM_FAULT_SIGBUS;
+ }
+ goto out;
+ }
+ delayacct_set_flag(DELAYACCT_PF_SWAPIN);
+ page = lookup_swap_cache(entry);
+ if (!page) {
+ grab_swap_token(mm); /* Contend for token _before_ read-in */
+ page = swapin_readahead(entry,
+ GFP_HIGHUSER_MOVABLE, vma, address);
+ if (!page) {
+ /*
+ * Back out if somebody else faulted in this pte
+ * while we released the pte lock.
+ */
+ page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+ if (likely(pte_same(*page_table, orig_pte)))
+ ret = VM_FAULT_OOM;
+ delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+ goto unlock;
+ }
+
+ /* Had to read the page from swap area: Major fault */
+ ret = VM_FAULT_MAJOR;
+ count_vm_event(PGMAJFAULT);
+ mem_cgroup_count_vm_event(mm, PGMAJFAULT);
+ } else if (PageHWPoison(page)) {
+ /*
+ * hwpoisoned dirty swapcache pages are kept for killing
+ * owner processes (which may be unknown at hwpoison time)
+ */
+ ret = VM_FAULT_HWPOISON;
+ delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+ goto out_release;
+ }
+
+ locked = lock_page_or_retry(page, mm, flags);
+ delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+ if (!locked) {
+ ret |= VM_FAULT_RETRY;
+ goto out_release;
+ }
+
+ /*
+ * Make sure try_to_free_swap or reuse_swap_page or swapoff did not
+ * release the swapcache from under us. The page pin, and pte_same
+ * test below, are not enough to exclude that. Even if it is still
+ * swapcache, we need to check that the page's swap has not changed.
+ */
+ if (unlikely(!PageSwapCache(page) || page_private(page) != entry.val))
+ goto out_page;
+
+ if (ksm_might_need_to_copy(page, vma, address)) {
+ swapcache = page;
+ page = ksm_does_need_to_copy(page, vma, address);
+
+ if (unlikely(!page)) {
+ ret = VM_FAULT_OOM;
+ page = swapcache;
+ swapcache = NULL;
+ goto out_page;
+ }
+ }
+
+ if (mem_cgroup_try_charge_swapin(mm, page, GFP_KERNEL, &ptr)) {
+ ret = VM_FAULT_OOM;
+ goto out_page;
+ }
+
+ /*
+ * Back out if somebody else already faulted in this pte.
+ */
+ page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+ if (unlikely(!pte_same(*page_table, orig_pte)))
+ goto out_nomap;
+
+ if (unlikely(!PageUptodate(page))) {
+ ret = VM_FAULT_SIGBUS;
+ goto out_nomap;
+ }
+
+ /*
+ * The page isn't present yet, go ahead with the fault.
+ *
+ * Be careful about the sequence of operations here.
+ * To get its accounting right, reuse_swap_page() must be called
+ * while the page is counted on swap but not yet in mapcount i.e.
+ * before page_add_anon_rmap() and swap_free(); try_to_free_swap()
+ * must be called after the swap_free(), or it will never succeed.
+ * Because delete_from_swap_page() may be called by reuse_swap_page(),
+ * mem_cgroup_commit_charge_swapin() may not be able to find swp_entry
+ * in page->private. In this case, a record in swap_cgroup is silently
+ * discarded at swap_free().
+ */
+
+ inc_mm_counter_fast(mm, MM_ANONPAGES);
+ dec_mm_counter_fast(mm, MM_SWAPENTS);
+ pte = mk_pte(page, vma->vm_page_prot);
+ if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page)) {
+ pte = maybe_mkwrite(pte_mkdirty(pte), vma);
+ flags &= ~FAULT_FLAG_WRITE;
+ ret |= VM_FAULT_WRITE;
+ exclusive = 1;
+ }
+ flush_icache_page(vma, page);
+ set_pte_at(mm, address, page_table, pte);
+ do_page_add_anon_rmap(page, vma, address, exclusive);
+ /* It's better to call commit-charge after rmap is established */
+ mem_cgroup_commit_charge_swapin(page, ptr);
+
+ swap_free(entry);
+ if (vm_swap_full() || (vma->vm_flags & VM_LOCKED) || PageMlocked(page))
+ try_to_free_swap(page);
+ unlock_page(page);
+ if (swapcache) {
+ /*
+ * Hold the lock to avoid the swap entry to be reused
+ * until we take the PT lock for the pte_same() check
+ * (to avoid false positives from pte_same). For
+ * further safety release the lock after the swap_free
+ * so that the swap count won't change under a
+ * parallel locked swapcache.
+ */
+ unlock_page(swapcache);
+ page_cache_release(swapcache);
+ }
+
+ if (flags & FAULT_FLAG_WRITE) {
+ ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte);
+ if (ret & VM_FAULT_ERROR)
+ ret &= VM_FAULT_ERROR;
+ goto out;
+ }
+
+ /* No need to invalidate - it was non-present before */
+ update_mmu_cache(vma, address, page_table);
+unlock:
+ pte_unmap_unlock(page_table, ptl);
+out:
+ return ret;
+out_nomap:
+ mem_cgroup_cancel_charge_swapin(ptr);
+ pte_unmap_unlock(page_table, ptl);
+out_page:
+ unlock_page(page);
+out_release:
+ page_cache_release(page);
+ if (swapcache) {
+ unlock_page(swapcache);
+ page_cache_release(swapcache);
+ }
+ return ret;
+}
+
+/*
+ * This is like a special single-page "expand_{down|up}wards()",
+ * except we must first make sure that 'address{-|+}PAGE_SIZE'
+ * doesn't hit another vma.
+ */
+static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned long address)
+{
+ address &= PAGE_MASK;
+ if ((vma->vm_flags & VM_GROWSDOWN) && address == vma->vm_start) {
+ struct vm_area_struct *prev = vma->vm_prev;
+
+ /*
+ * Is there a mapping abutting this one below?
+ *
+ * That's only ok if it's the same stack mapping
+ * that has gotten split..
+ */
+ if (prev && prev->vm_end == address)
+ return prev->vm_flags & VM_GROWSDOWN ? 0 : -ENOMEM;
+
+ return expand_downwards(vma, address - PAGE_SIZE);
+ }
+ if ((vma->vm_flags & VM_GROWSUP) && address + PAGE_SIZE == vma->vm_end) {
+ struct vm_area_struct *next = vma->vm_next;
+
+ /* As VM_GROWSDOWN but s/below/above/ */
+ if (next && next->vm_start == address + PAGE_SIZE)
+ return next->vm_flags & VM_GROWSUP ? 0 : -ENOMEM;
+
+ return expand_upwards(vma, address + PAGE_SIZE);
+ }
+ return 0;
+}
+
+/*
+ * We enter with non-exclusive mmap_sem (to exclude vma changes,
+ * but allow concurrent faults), and pte mapped but not yet locked.
+ * We return with mmap_sem still held, but pte unmapped and unlocked.
+ */
+static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *page_table, pmd_t *pmd,
+ unsigned int flags)
+{
+ struct page *page;
+ spinlock_t *ptl;
+ pte_t entry;
+
+ pte_unmap(page_table);
+
+ /*Fix for HUB: CVE-2015-3288*/
+ /* File mapping without ->vm_ops ? */
+ if (vma->vm_flags & VM_SHARED)
+ return VM_FAULT_SIGBUS;
+
+ /* Check if we need to add a guard page to the stack */
+ if (check_stack_guard_page(vma, address) < 0)
+ return VM_FAULT_SIGSEGV;
+
+ /* Use the zero-page for reads */
+ if (!(flags & FAULT_FLAG_WRITE)) {
+ entry = pte_mkspecial(pfn_pte(my_zero_pfn(address),
+ vma->vm_page_prot));
+ page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+ if (!pte_none(*page_table))
+ goto unlock;
+ goto setpte;
+ }
+
+ /* Allocate our own private page. */
+ if (unlikely(anon_vma_prepare(vma)))
+ goto oom;
+ page = alloc_zeroed_user_highpage_movable(vma, address);
+ if (!page)
+ goto oom;
+ __SetPageUptodate(page);
+
+ if (mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))
+ goto oom_free_page;
+
+ entry = mk_pte(page, vma->vm_page_prot);
+ if (vma->vm_flags & VM_WRITE)
+ entry = pte_mkwrite(pte_mkdirty(entry));
+
+ page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+ if (!pte_none(*page_table))
+ goto release;
+
+ inc_mm_counter_fast(mm, MM_ANONPAGES);
+ page_add_new_anon_rmap(page, vma, address);
+setpte:
+ set_pte_at(mm, address, page_table, entry);
+
+ /* No need to invalidate - it was non-present before */
+ update_mmu_cache(vma, address, page_table);
+unlock:
+ pte_unmap_unlock(page_table, ptl);
+ return 0;
+release:
+ mem_cgroup_uncharge_page(page);
+ page_cache_release(page);
+ goto unlock;
+oom_free_page:
+ page_cache_release(page);
+oom:
+ return VM_FAULT_OOM;
+}
+
+/*
+ * __do_fault() tries to create a new page mapping. It aggressively
+ * tries to share with existing pages, but makes a separate copy if
+ * the FAULT_FLAG_WRITE is set in the flags parameter in order to avoid
+ * the next page fault.
+ *
+ * As this is called only for pages that do not currently exist, we
+ * do not need to flush old virtual caches or the TLB.
+ *
+ * We enter with non-exclusive mmap_sem (to exclude vma changes,
+ * but allow concurrent faults), and pte neither mapped nor locked.
+ * We return with mmap_sem still held, but pte unmapped and unlocked.
+ */
+static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmd,
+ pgoff_t pgoff, unsigned int flags, pte_t orig_pte)
+{
+ pte_t *page_table;
+ spinlock_t *ptl;
+ struct page *page;
+ struct page *cow_page;
+ pte_t entry;
+ int anon = 0;
+ struct page *dirty_page = NULL;
+ struct vm_fault vmf;
+ int ret;
+ int page_mkwrite = 0;
+
+ /*Fix for HUB: CVE-2015-3288*/
+ if (!vma->vm_ops->fault)
+ return VM_FAULT_SIGBUS;
+ /*
+ * If we do COW later, allocate page befor taking lock_page()
+ * on the file cache page. This will reduce lock holding time.
+ */
+ if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
+
+ if (unlikely(anon_vma_prepare(vma)))
+ return VM_FAULT_OOM;
+
+ cow_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
+ if (!cow_page)
+ return VM_FAULT_OOM;
+
+ if (mem_cgroup_newpage_charge(cow_page, mm, GFP_KERNEL)) {
+ page_cache_release(cow_page);
+ return VM_FAULT_OOM;
+ }
+ } else
+ cow_page = NULL;
+
+ vmf.virtual_address = (void __user *)(address & PAGE_MASK);
+ vmf.pgoff = pgoff;
+ vmf.flags = flags;
+ vmf.page = NULL;
+
+ ret = vma->vm_ops->fault(vma, &vmf);
+ if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE |
+ VM_FAULT_RETRY)))
+ goto uncharge_out;
+
+ if (unlikely(PageHWPoison(vmf.page))) {
+ if (ret & VM_FAULT_LOCKED)
+ unlock_page(vmf.page);
+ ret = VM_FAULT_HWPOISON;
+ goto uncharge_out;
+ }
+
+ /*
+ * For consistency in subsequent calls, make the faulted page always
+ * locked.
+ */
+ if (unlikely(!(ret & VM_FAULT_LOCKED)))
+ lock_page(vmf.page);
+ else
+ VM_BUG_ON(!PageLocked(vmf.page));
+
+ /*
+ * Should we do an early C-O-W break?
+ */
+ page = vmf.page;
+ if (flags & FAULT_FLAG_WRITE) {
+ if (!(vma->vm_flags & VM_SHARED)) {
+ page = cow_page;
+ anon = 1;
+ copy_user_highpage(page, vmf.page, address, vma);
+ __SetPageUptodate(page);
+ } else {
+ /*
+ * If the page will be shareable, see if the backing
+ * address space wants to know that the page is about
+ * to become writable
+ */
+ if (vma->vm_ops->page_mkwrite) {
+ int tmp;
+
+ unlock_page(page);
+ vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
+ tmp = vma->vm_ops->page_mkwrite(vma, &vmf);
+ if (unlikely(tmp &
+ (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) {
+ ret = tmp;
+ goto unwritable_page;
+ }
+ if (unlikely(!(tmp & VM_FAULT_LOCKED))) {
+ lock_page(page);
+ if (!page->mapping) {
+ ret = 0; /* retry the fault */
+ unlock_page(page);
+ goto unwritable_page;
+ }
+ } else
+ VM_BUG_ON(!PageLocked(page));
+ page_mkwrite = 1;
+ }
+ }
+
+ }
+
+ page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+
+ /*
+ * This silly early PAGE_DIRTY setting removes a race
+ * due to the bad i386 page protection. But it's valid
+ * for other architectures too.
+ *
+ * Note that if FAULT_FLAG_WRITE is set, we either now have
+ * an exclusive copy of the page, or this is a shared mapping,
+ * so we can make it writable and dirty to avoid having to
+ * handle that later.
+ */
+ /* Only go through if we didn't race with anybody else... */
+ if (likely(pte_same(*page_table, orig_pte))) {
+ flush_icache_page(vma, page);
+ entry = mk_pte(page, vma->vm_page_prot);
+ if (flags & FAULT_FLAG_WRITE)
+ entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ if (anon) {
+ inc_mm_counter_fast(mm, MM_ANONPAGES);
+ page_add_new_anon_rmap(page, vma, address);
+ } else {
+ inc_mm_counter_fast(mm, MM_FILEPAGES);
+ page_add_file_rmap(page);
+ if (flags & FAULT_FLAG_WRITE) {
+ dirty_page = page;
+ get_page(dirty_page);
+ }
+ }
+ set_pte_at(mm, address, page_table, entry);
+
+ /* no need to invalidate: a not-present page won't be cached */
+ update_mmu_cache(vma, address, page_table);
+ } else {
+ if (cow_page)
+ mem_cgroup_uncharge_page(cow_page);
+ if (anon)
+ page_cache_release(page);
+ else
+ anon = 1; /* no anon but release faulted_page */
+ }
+
+ pte_unmap_unlock(page_table, ptl);
+
+ if (dirty_page) {
+ struct address_space *mapping = page->mapping;
+
+ if (set_page_dirty(dirty_page))
+ page_mkwrite = 1;
+ unlock_page(dirty_page);
+ put_page(dirty_page);
+ if (page_mkwrite && mapping) {
+ /*
+ * Some device drivers do not set page.mapping but still
+ * dirty their pages
+ */
+ balance_dirty_pages_ratelimited(mapping);
+ }
+
+ /* file_update_time outside page_lock */
+ if (vma->vm_file)
+ file_update_time(vma->vm_file);
+ } else {
+ unlock_page(vmf.page);
+ if (anon)
+ page_cache_release(vmf.page);
+ }
+
+ return ret;
+
+unwritable_page:
+ page_cache_release(page);
+ return ret;
+uncharge_out:
+ /* fs's fault handler get error */
+ if (cow_page) {
+ mem_cgroup_uncharge_page(cow_page);
+ page_cache_release(cow_page);
+ }
+ return ret;
+}
+
+static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *page_table, pmd_t *pmd,
+ unsigned int flags, pte_t orig_pte)
+{
+ pgoff_t pgoff = (((address & PAGE_MASK)
+ - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+
+ pte_unmap(page_table);
+ return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
+}
+
+/*
+ * Fault of a previously existing named mapping. Repopulate the pte
+ * from the encoded file_pte if possible. This enables swappable
+ * nonlinear vmas.
+ *
+ * We enter with non-exclusive mmap_sem (to exclude vma changes,
+ * but allow concurrent faults), and pte mapped but not yet locked.
+ * We return with mmap_sem still held, but pte unmapped and unlocked.
+ */
+static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *page_table, pmd_t *pmd,
+ unsigned int flags, pte_t orig_pte)
+{
+ pgoff_t pgoff;
+
+ flags |= FAULT_FLAG_NONLINEAR;
+
+ if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
+ return 0;
+
+ if (unlikely(!(vma->vm_flags & VM_NONLINEAR))) {
+ /*
+ * Page table corrupted: show pte and kill process.
+ */
+ print_bad_pte(vma, address, orig_pte, NULL);
+ return VM_FAULT_SIGBUS;
+ }
+
+ pgoff = pte_to_pgoff(orig_pte);
+ return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
+}
+
+/*
+ * These routines also need to handle stuff like marking pages dirty
+ * and/or accessed for architectures that don't do it in hardware (most
+ * RISC architectures). The early dirtying is also good on the i386.
+ *
+ * There is also a hook called "update_mmu_cache()" that architectures
+ * with external mmu caches can use to update those (ie the Sparc or
+ * PowerPC hashed page tables that act as extended TLBs).
+ *
+ * We enter with non-exclusive mmap_sem (to exclude vma changes,
+ * but allow concurrent faults), and pte mapped but not yet locked.
+ * We return with mmap_sem still held, but pte unmapped and unlocked.
+ */
+int handle_pte_fault(struct mm_struct *mm,
+ struct vm_area_struct *vma, unsigned long address,
+ pte_t *pte, pmd_t *pmd, unsigned int flags)
+{
+ pte_t entry;
+ spinlock_t *ptl;
+
+ entry = *pte;
+ if (!pte_present(entry)) {
+ if (pte_none(entry)) {
+ /*Fix for HUB: CVE-2015-3288*/
+ if (vma->vm_ops) {
+ return do_linear_fault(mm, vma, address,
+ pte, pmd, flags, entry);
+ }
+ return do_anonymous_page(mm, vma, address,
+ pte, pmd, flags);
+ }
+ if (pte_file(entry))
+ return do_nonlinear_fault(mm, vma, address,
+ pte, pmd, flags, entry);
+ return do_swap_page(mm, vma, address,
+ pte, pmd, flags, entry);
+ }
+
+ ptl = pte_lockptr(mm, pmd);
+ spin_lock(ptl);
+ if (unlikely(!pte_same(*pte, entry)))
+ goto unlock;
+ if (flags & FAULT_FLAG_WRITE) {
+ if (!pte_write(entry))
+ return do_wp_page(mm, vma, address,
+ pte, pmd, ptl, entry);
+ entry = pte_mkdirty(entry);
+ }
+ entry = pte_mkyoung(entry);
+ if (ptep_set_access_flags(vma, address, pte, entry, flags & FAULT_FLAG_WRITE)) {
+ update_mmu_cache(vma, address, pte);
+ } else {
+ /*
+ * This is needed only for protection faults but the arch code
+ * is not yet telling us if this is a protection fault or not.
+ * This still avoids useless tlb flushes for .text page faults
+ * with threads.
+ */
+ if (flags & FAULT_FLAG_WRITE)
+ flush_tlb_fix_spurious_fault(vma, address);
+ }
+unlock:
+ pte_unmap_unlock(pte, ptl);
+ return 0;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+void pagefault_disable(void)
+{
+ migrate_disable();
+ current->pagefault_disabled++;
+ /*
+ * make sure to have issued the store before a pagefault
+ * can hit.
+ */
+ barrier();
+}
+EXPORT_SYMBOL_GPL(pagefault_disable);
+
+void pagefault_enable(void)
+{
+ /*
+ * make sure to issue those last loads/stores before enabling
+ * the pagefault handler again.
+ */
+ barrier();
+ current->pagefault_disabled--;
+ migrate_enable();
+}
+EXPORT_SYMBOL_GPL(pagefault_enable);
+#endif
+
+/*
+ * By the time we get here, we already hold the mm semaphore
+ */
+int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, unsigned int flags)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ __set_current_state(TASK_RUNNING);
+
+ count_vm_event(PGFAULT);
+ mem_cgroup_count_vm_event(mm, PGFAULT);
+
+ /* do counter updates before entering really critical section. */
+ check_sync_rss_stat(current);
+
+ if (unlikely(is_vm_hugetlb_page(vma)))
+ return hugetlb_fault(mm, vma, address, flags);
+
+retry:
+ pgd = pgd_offset(mm, address);
+ pud = pud_alloc(mm, pgd, address);
+ if (!pud)
+ return VM_FAULT_OOM;
+ pmd = pmd_alloc(mm, pud, address);
+ if (!pmd)
+ return VM_FAULT_OOM;
+ if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) {
+ if (!vma->vm_ops)
+ return do_huge_pmd_anonymous_page(mm, vma, address,
+ pmd, flags);
+ } else {
+ pmd_t orig_pmd = *pmd;
+ int ret;
+
+ barrier();
+ if (pmd_trans_huge(orig_pmd)) {
+ if (flags & FAULT_FLAG_WRITE &&
+ !pmd_write(orig_pmd) &&
+ !pmd_trans_splitting(orig_pmd)) {
+ ret = do_huge_pmd_wp_page(mm, vma, address, pmd,
+ orig_pmd);
+ /*
+ * If COW results in an oom, the huge pmd will
+ * have been split, so retry the fault on the
+ * pte for a smaller charge.
+ */
+ if (unlikely(ret & VM_FAULT_OOM))
+ goto retry;
+ return ret;
+ }
+ return 0;
+ }
+ }
+
+ /*
+ * Use __pte_alloc instead of pte_alloc_map, because we can't
+ * run pte_offset_map on the pmd, if an huge pmd could
+ * materialize from under us from a different thread.
+ */
+ if (unlikely(pmd_none(*pmd)) && __pte_alloc(mm, vma, pmd, address))
+ return VM_FAULT_OOM;
+ /* if an huge pmd materialized from under us just retry later */
+ if (unlikely(pmd_trans_huge(*pmd)))
+ return 0;
+ /*
+ * A regular pmd is established and it can't morph into a huge pmd
+ * from under us anymore at this point because we hold the mmap_sem
+ * read mode and khugepaged takes it in write mode. So now it's
+ * safe to run pte_offset_map().
+ */
+ pte = pte_offset_map(pmd, address);
+
+ return handle_pte_fault(mm, vma, address, pte, pmd, flags);
+}
+
+#ifndef __PAGETABLE_PUD_FOLDED
+/*
+ * Allocate page upper directory.
+ * We've already handled the fast-path in-line.
+ */
+int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
+{
+ pud_t *new = pud_alloc_one(mm, address);
+ if (!new)
+ return -ENOMEM;
+
+ smp_wmb(); /* See comment in __pte_alloc */
+
+ spin_lock(&mm->page_table_lock);
+ if (pgd_present(*pgd)) /* Another has populated it */
+ pud_free(mm, new);
+ else
+ pgd_populate(mm, pgd, new);
+ spin_unlock(&mm->page_table_lock);
+ return 0;
+}
+#endif /* __PAGETABLE_PUD_FOLDED */
+
+#ifndef __PAGETABLE_PMD_FOLDED
+/*
+ * Allocate page middle directory.
+ * We've already handled the fast-path in-line.
+ */
+int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
+{
+ pmd_t *new = pmd_alloc_one(mm, address);
+ if (!new)
+ return -ENOMEM;
+
+ smp_wmb(); /* See comment in __pte_alloc */
+
+ spin_lock(&mm->page_table_lock);
+#ifndef __ARCH_HAS_4LEVEL_HACK
+ if (pud_present(*pud)) /* Another has populated it */
+ pmd_free(mm, new);
+ else
+ pud_populate(mm, pud, new);
+#else
+ if (pgd_present(*pud)) /* Another has populated it */
+ pmd_free(mm, new);
+ else
+ pgd_populate(mm, pud, new);
+#endif /* __ARCH_HAS_4LEVEL_HACK */
+ spin_unlock(&mm->page_table_lock);
+ return 0;
+}
+#endif /* __PAGETABLE_PMD_FOLDED */
+
+int make_pages_present(unsigned long addr, unsigned long end)
+{
+ int ret, len, write;
+ struct vm_area_struct * vma;
+
+ vma = find_vma(current->mm, addr);
+ if (!vma)
+ return -ENOMEM;
+ /*
+ * We want to touch writable mappings with a write fault in order
+ * to break COW, except for shared mappings because these don't COW
+ * and we would not want to dirty them for nothing.
+ */
+ write = (vma->vm_flags & (VM_WRITE | VM_SHARED)) == VM_WRITE;
+ BUG_ON(addr >= end);
+ BUG_ON(end > vma->vm_end);
+ len = DIV_ROUND_UP(end, PAGE_SIZE) - addr/PAGE_SIZE;
+ ret = get_user_pages(current, current->mm, addr,
+ len, write, 0, NULL, NULL);
+ if (ret < 0)
+ return ret;
+ return ret == len ? 0 : -EFAULT;
+}
+
+#if !defined(__HAVE_ARCH_GATE_AREA)
+
+#if defined(AT_SYSINFO_EHDR)
+static struct vm_area_struct gate_vma;
+
+static int __init gate_vma_init(void)
+{
+ gate_vma.vm_mm = NULL;
+ gate_vma.vm_start = FIXADDR_USER_START;
+ gate_vma.vm_end = FIXADDR_USER_END;
+ gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
+ gate_vma.vm_page_prot = __P101;
+
+ return 0;
+}
+__initcall(gate_vma_init);
+#endif
+
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
+{
+#ifdef AT_SYSINFO_EHDR
+ return &gate_vma;
+#else
+ return NULL;
+#endif
+}
+
+int in_gate_area_no_mm(unsigned long addr)
+{
+#ifdef AT_SYSINFO_EHDR
+ if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
+ return 1;
+#endif
+ return 0;
+}
+
+#endif /* __HAVE_ARCH_GATE_AREA */
+
+static int __follow_pte(struct mm_struct *mm, unsigned long address,
+ pte_t **ptepp, spinlock_t **ptlp)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *ptep;
+
+ pgd = pgd_offset(mm, address);
+ if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
+ goto out;
+
+ pud = pud_offset(pgd, address);
+ if (pud_none(*pud) || unlikely(pud_bad(*pud)))
+ goto out;
+
+ pmd = pmd_offset(pud, address);
+ VM_BUG_ON(pmd_trans_huge(*pmd));
+ if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
+ goto out;
+
+ /* We cannot handle huge page PFN maps. Luckily they don't exist. */
+ if (pmd_huge(*pmd))
+ goto out;
+
+ ptep = pte_offset_map_lock(mm, pmd, address, ptlp);
+ if (!ptep)
+ goto out;
+ if (!pte_present(*ptep))
+ goto unlock;
+ *ptepp = ptep;
+ return 0;
+unlock:
+ pte_unmap_unlock(ptep, *ptlp);
+out:
+ return -EINVAL;
+}
+
+static inline int follow_pte(struct mm_struct *mm, unsigned long address,
+ pte_t **ptepp, spinlock_t **ptlp)
+{
+ int res;
+
+ /* (void) is needed to make gcc happy */
+ (void) __cond_lock(*ptlp,
+ !(res = __follow_pte(mm, address, ptepp, ptlp)));
+ return res;
+}
+
+/**
+ * follow_pfn - look up PFN at a user virtual address
+ * @vma: memory mapping
+ * @address: user virtual address
+ * @pfn: location to store found PFN
+ *
+ * Only IO mappings and raw PFN mappings are allowed.
+ *
+ * Returns zero and the pfn at @pfn on success, -ve otherwise.
+ */
+int follow_pfn(struct vm_area_struct *vma, unsigned long address,
+ unsigned long *pfn)
+{
+ int ret = -EINVAL;
+ spinlock_t *ptl;
+ pte_t *ptep;
+
+ if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
+ return ret;
+
+ ret = follow_pte(vma->vm_mm, address, &ptep, &ptl);
+ if (ret)
+ return ret;
+ *pfn = pte_pfn(*ptep);
+ pte_unmap_unlock(ptep, ptl);
+ return 0;
+}
+EXPORT_SYMBOL(follow_pfn);
+
+#ifdef CONFIG_HAVE_IOREMAP_PROT
+int follow_phys(struct vm_area_struct *vma,
+ unsigned long address, unsigned int flags,
+ unsigned long *prot, resource_size_t *phys)
+{
+ int ret = -EINVAL;
+ pte_t *ptep, pte;
+ spinlock_t *ptl;
+
+ if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
+ goto out;
+
+ if (follow_pte(vma->vm_mm, address, &ptep, &ptl))
+ goto out;
+ pte = *ptep;
+
+ if ((flags & FOLL_WRITE) && !pte_write(pte))
+ goto unlock;
+
+ *prot = pgprot_val(pte_pgprot(pte));
+ *phys = (resource_size_t)pte_pfn(pte) << PAGE_SHIFT;
+
+ ret = 0;
+unlock:
+ pte_unmap_unlock(ptep, ptl);
+out:
+ return ret;
+}
+
+int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
+ void *buf, int len, int write)
+{
+ resource_size_t phys_addr;
+ unsigned long prot = 0;
+ void __iomem *maddr;
+ int offset = addr & (PAGE_SIZE-1);
+
+ if (follow_phys(vma, addr, write, &prot, &phys_addr))
+ return -EINVAL;
+
+ maddr = ioremap_prot(phys_addr, PAGE_ALIGN(len + offset), prot);
+ if (write)
+ memcpy_toio(maddr + offset, buf, len);
+ else
+ memcpy_fromio(buf, maddr + offset, len);
+ iounmap(maddr);
+
+ return len;
+}
+#endif
+
+/*
+ * Access another process' address space as given in mm. If non-NULL, use the
+ * given task for page fault accounting.
+ */
+static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long addr, void *buf, int len, int write)
+{
+ struct vm_area_struct *vma;
+ void *old_buf = buf;
+
+ down_read(&mm->mmap_sem);
+ /* ignore errors, just check how much was successfully transferred */
+ while (len) {
+ int bytes, ret, offset;
+ void *maddr;
+ struct page *page = NULL;
+
+ ret = get_user_pages(tsk, mm, addr, 1,
+ write, 1, &page, &vma);
+ if (ret <= 0) {
+ /*
+ * Check if this is a VM_IO | VM_PFNMAP VMA, which
+ * we can access using slightly different code.
+ */
+#ifdef CONFIG_HAVE_IOREMAP_PROT
+ vma = find_vma(mm, addr);
+ if (!vma || vma->vm_start > addr)
+ break;
+ if (vma->vm_ops && vma->vm_ops->access)
+ ret = vma->vm_ops->access(vma, addr, buf,
+ len, write);
+ if (ret <= 0)
+#endif
+ break;
+ bytes = ret;
+ } else {
+ bytes = len;
+ offset = addr & (PAGE_SIZE-1);
+ if (bytes > PAGE_SIZE-offset)
+ bytes = PAGE_SIZE-offset;
+
+ maddr = kmap(page);
+ if (write) {
+ copy_to_user_page(vma, page, addr,
+ maddr + offset, buf, bytes);
+ set_page_dirty_lock(page);
+ } else {
+ copy_from_user_page(vma, page, addr,
+ buf, maddr + offset, bytes);
+ }
+ kunmap(page);
+ page_cache_release(page);
+ }
+ len -= bytes;
+ buf += bytes;
+ addr += bytes;
+ }
+ up_read(&mm->mmap_sem);
+
+ return buf - old_buf;
+}
+
+/**
+ * access_remote_vm - access another process' address space
+ * @mm: the mm_struct of the target address space
+ * @addr: start address to access
+ * @buf: source or destination buffer
+ * @len: number of bytes to transfer
+ * @write: whether the access is a write
+ *
+ * The caller must hold a reference on @mm.
+ */
+int access_remote_vm(struct mm_struct *mm, unsigned long addr,
+ void *buf, int len, int write)
+{
+ return __access_remote_vm(NULL, mm, addr, buf, len, write);
+}
+
+/*
+ * Access another process' address space.
+ * Source/target buffer must be kernel space,
+ * Do not walk the page table directly, use get_user_pages
+ */
+int access_process_vm(struct task_struct *tsk, unsigned long addr,
+ void *buf, int len, int write)
+{
+ struct mm_struct *mm;
+ int ret;
+
+ mm = get_task_mm(tsk);
+ if (!mm)
+ return 0;
+
+ ret = __access_remote_vm(tsk, mm, addr, buf, len, write);
+ mmput(mm);
+
+ return ret;
+}
+
+/*
+ * Print the name of a VMA.
+ */
+void print_vma_addr(char *prefix, unsigned long ip)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+
+ /*
+ * Do not print if we are in atomic
+ * contexts (in exception stacks, etc.):
+ */
+ if (preempt_count())
+ return;
+
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, ip);
+ if (vma && vma->vm_file) {
+ struct file *f = vma->vm_file;
+ char *buf = (char *)__get_free_page(GFP_KERNEL);
+ if (buf) {
+ char *p, *s;
+
+ p = d_path(&f->f_path, buf, PAGE_SIZE);
+ if (IS_ERR(p))
+ p = "?";
+ s = strrchr(p, '/');
+ if (s)
+ p = s+1;
+ printk("%s%s[%lx+%lx]", prefix, p,
+ vma->vm_start,
+ vma->vm_end - vma->vm_start);
+ free_page((unsigned long)buf);
+ }
+ }
+ up_read(¤t->mm->mmap_sem);
+}
+
+#ifdef CONFIG_PROVE_LOCKING
+void might_fault(void)
+{
+ /*
+ * Some code (nfs/sunrpc) uses socket ops on kernel memory while
+ * holding the mmap_sem, this is safe because kernel memory doesn't
+ * get paged out, therefore we'll never actually fault, and the
+ * below annotations will generate false positives.
+ */
+ if (segment_eq(get_fs(), KERNEL_DS))
+ return;
+
+ might_sleep();
+ /*
+ * it would be nicer only to annotate paths which are not under
+ * pagefault_disable, however that requires a larger audit and
+ * providing helpers like get_user_atomic.
+ */
+ if (!in_atomic() && current->mm)
+ might_lock_read(¤t->mm->mmap_sem);
+}
+EXPORT_SYMBOL(might_fault);
+#endif
+
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
+static void clear_gigantic_page(struct page *page,
+ unsigned long addr,
+ unsigned int pages_per_huge_page)
+{
+ int i;
+ struct page *p = page;
+
+ might_sleep();
+ for (i = 0; i < pages_per_huge_page;
+ i++, p = mem_map_next(p, page, i)) {
+ cond_resched();
+ clear_user_highpage(p, addr + i * PAGE_SIZE);
+ }
+}
+void clear_huge_page(struct page *page,
+ unsigned long addr, unsigned int pages_per_huge_page)
+{
+ int i;
+
+ if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) {
+ clear_gigantic_page(page, addr, pages_per_huge_page);
+ return;
+ }
+
+ might_sleep();
+ for (i = 0; i < pages_per_huge_page; i++) {
+ cond_resched();
+ clear_user_highpage(page + i, addr + i * PAGE_SIZE);
+ }
+}
+
+static void copy_user_gigantic_page(struct page *dst, struct page *src,
+ unsigned long addr,
+ struct vm_area_struct *vma,
+ unsigned int pages_per_huge_page)
+{
+ int i;
+ struct page *dst_base = dst;
+ struct page *src_base = src;
+
+ for (i = 0; i < pages_per_huge_page; ) {
+ cond_resched();
+ copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
+
+ i++;
+ dst = mem_map_next(dst, dst_base, i);
+ src = mem_map_next(src, src_base, i);
+ }
+}
+
+void copy_user_huge_page(struct page *dst, struct page *src,
+ unsigned long addr, struct vm_area_struct *vma,
+ unsigned int pages_per_huge_page)
+{
+ int i;
+
+ if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) {
+ copy_user_gigantic_page(dst, src, addr, vma,
+ pages_per_huge_page);
+ return;
+ }
+
+ might_sleep();
+ for (i = 0; i < pages_per_huge_page; i++) {
+ cond_resched();
+ copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
+ }
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
+
+#if defined(CONFIG_PREEMPT_RT_FULL) && (USE_SPLIT_PTLOCKS > 0)
+/*
+ * Heinous hack, relies on the caller doing something like:
+ *
+ * pte = alloc_pages(PGALLOC_GFP, 0);
+ * if (pte)
+ * pgtable_page_ctor(pte);
+ * return pte;
+ *
+ * This ensures we release the page and return NULL when the
+ * lock allocation fails.
+ */
+struct page *pte_lock_init(struct page *page)
+{
+ page->ptl = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
+ if (page->ptl) {
+ spin_lock_init(__pte_lockptr(page));
+ } else {
+ __free_page(page);
+ page = NULL;
+ }
+ return page;
+}
+
+void pte_lock_deinit(struct page *page)
+{
+ kfree(page->ptl);
+ page->mapping = NULL;
+}
+
+#endif
diff --git a/ap/os/linux/linux-3.4.x/mm/memory_hotplug.c b/ap/os/linux/linux-3.4.x/mm/memory_hotplug.c
new file mode 100644
index 0000000..09d87b7
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/memory_hotplug.c
@@ -0,0 +1,1010 @@
+/*
+ * linux/mm/memory_hotplug.c
+ *
+ * Copyright (C)
+ */
+
+#include <linux/stddef.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/interrupt.h>
+#include <linux/pagemap.h>
+#include <linux/bootmem.h>
+#include <linux/compiler.h>
+#include <linux/export.h>
+#include <linux/pagevec.h>
+#include <linux/writeback.h>
+#include <linux/slab.h>
+#include <linux/sysctl.h>
+#include <linux/cpu.h>
+#include <linux/memory.h>
+#include <linux/memory_hotplug.h>
+#include <linux/highmem.h>
+#include <linux/vmalloc.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/migrate.h>
+#include <linux/page-isolation.h>
+#include <linux/pfn.h>
+#include <linux/suspend.h>
+#include <linux/mm_inline.h>
+#include <linux/firmware-map.h>
+
+#include <asm/tlbflush.h>
+
+#include "internal.h"
+
+/*
+ * online_page_callback contains pointer to current page onlining function.
+ * Initially it is generic_online_page(). If it is required it could be
+ * changed by calling set_online_page_callback() for callback registration
+ * and restore_online_page_callback() for generic callback restore.
+ */
+
+static void generic_online_page(struct page *page);
+
+static online_page_callback_t online_page_callback = generic_online_page;
+
+DEFINE_MUTEX(mem_hotplug_mutex);
+
+void lock_memory_hotplug(void)
+{
+ mutex_lock(&mem_hotplug_mutex);
+
+ /* for exclusive hibernation if CONFIG_HIBERNATION=y */
+ lock_system_sleep();
+}
+
+void unlock_memory_hotplug(void)
+{
+ unlock_system_sleep();
+ mutex_unlock(&mem_hotplug_mutex);
+}
+
+
+/* add this memory to iomem resource */
+static struct resource *register_memory_resource(u64 start, u64 size)
+{
+ struct resource *res;
+ res = kzalloc(sizeof(struct resource), GFP_KERNEL);
+ BUG_ON(!res);
+
+ res->name = "System RAM";
+ res->start = start;
+ res->end = start + size - 1;
+ res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+ if (request_resource(&iomem_resource, res) < 0) {
+ printk("System RAM resource %llx - %llx cannot be added\n",
+ (unsigned long long)res->start, (unsigned long long)res->end);
+ kfree(res);
+ res = NULL;
+ }
+ return res;
+}
+
+static void release_memory_resource(struct resource *res)
+{
+ if (!res)
+ return;
+ release_resource(res);
+ kfree(res);
+ return;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+static void get_page_bootmem(unsigned long info, struct page *page,
+ unsigned long type)
+{
+ page->lru.next = (struct list_head *) type;
+ SetPagePrivate(page);
+ set_page_private(page, info);
+ atomic_inc(&page->_count);
+}
+
+/* reference to __meminit __free_pages_bootmem is valid
+ * so use __ref to tell modpost not to generate a warning */
+void __ref put_page_bootmem(struct page *page)
+{
+ unsigned long type;
+
+ type = (unsigned long) page->lru.next;
+ BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
+ type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
+
+ if (atomic_dec_return(&page->_count) == 1) {
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ INIT_LIST_HEAD(&page->lru);
+ __free_pages_bootmem(page, 0);
+ }
+
+}
+
+static void register_page_bootmem_info_section(unsigned long start_pfn)
+{
+ unsigned long *usemap, mapsize, section_nr, i;
+ struct mem_section *ms;
+ struct page *page, *memmap;
+
+ section_nr = pfn_to_section_nr(start_pfn);
+ ms = __nr_to_section(section_nr);
+
+ /* Get section's memmap address */
+ memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
+
+ /*
+ * Get page for the memmap's phys address
+ * XXX: need more consideration for sparse_vmemmap...
+ */
+ page = virt_to_page(memmap);
+ mapsize = sizeof(struct page) * PAGES_PER_SECTION;
+ mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
+
+ /* remember memmap's page */
+ for (i = 0; i < mapsize; i++, page++)
+ get_page_bootmem(section_nr, page, SECTION_INFO);
+
+ usemap = __nr_to_section(section_nr)->pageblock_flags;
+ page = virt_to_page(usemap);
+
+ mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
+
+ for (i = 0; i < mapsize; i++, page++)
+ get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
+
+}
+
+void register_page_bootmem_info_node(struct pglist_data *pgdat)
+{
+ unsigned long i, pfn, end_pfn, nr_pages;
+ int node = pgdat->node_id;
+ struct page *page;
+ struct zone *zone;
+
+ nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
+ page = virt_to_page(pgdat);
+
+ for (i = 0; i < nr_pages; i++, page++)
+ get_page_bootmem(node, page, NODE_INFO);
+
+ zone = &pgdat->node_zones[0];
+ for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) {
+ if (zone->wait_table) {
+ nr_pages = zone->wait_table_hash_nr_entries
+ * sizeof(wait_queue_head_t);
+ nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT;
+ page = virt_to_page(zone->wait_table);
+
+ for (i = 0; i < nr_pages; i++, page++)
+ get_page_bootmem(node, page, NODE_INFO);
+ }
+ }
+
+ pfn = pgdat->node_start_pfn;
+ end_pfn = pfn + pgdat->node_spanned_pages;
+
+ /* register_section info */
+ for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ /*
+ * Some platforms can assign the same pfn to multiple nodes - on
+ * node0 as well as nodeN. To avoid registering a pfn against
+ * multiple nodes we check that this pfn does not already
+ * reside in some other node.
+ */
+ if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node))
+ register_page_bootmem_info_section(pfn);
+ }
+}
+#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
+
+static void grow_zone_span(struct zone *zone, unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ unsigned long old_zone_end_pfn;
+
+ zone_span_writelock(zone);
+
+ old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
+ if (start_pfn < zone->zone_start_pfn)
+ zone->zone_start_pfn = start_pfn;
+
+ zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
+ zone->zone_start_pfn;
+
+ zone_span_writeunlock(zone);
+}
+
+static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ unsigned long old_pgdat_end_pfn =
+ pgdat->node_start_pfn + pgdat->node_spanned_pages;
+
+ if (start_pfn < pgdat->node_start_pfn)
+ pgdat->node_start_pfn = start_pfn;
+
+ pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
+ pgdat->node_start_pfn;
+}
+
+static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
+{
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ int nr_pages = PAGES_PER_SECTION;
+ int nid = pgdat->node_id;
+ int zone_type;
+ unsigned long flags;
+
+ zone_type = zone - pgdat->node_zones;
+ if (!zone->wait_table) {
+ int ret;
+
+ ret = init_currently_empty_zone(zone, phys_start_pfn,
+ nr_pages, MEMMAP_HOTPLUG);
+ if (ret)
+ return ret;
+ }
+ pgdat_resize_lock(zone->zone_pgdat, &flags);
+ grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages);
+ grow_pgdat_span(zone->zone_pgdat, phys_start_pfn,
+ phys_start_pfn + nr_pages);
+ pgdat_resize_unlock(zone->zone_pgdat, &flags);
+ memmap_init_zone(nr_pages, nid, zone_type,
+ phys_start_pfn, MEMMAP_HOTPLUG);
+ return 0;
+}
+
+static int __meminit __add_section(int nid, struct zone *zone,
+ unsigned long phys_start_pfn)
+{
+ int nr_pages = PAGES_PER_SECTION;
+ int ret;
+
+ if (pfn_valid(phys_start_pfn))
+ return -EEXIST;
+
+ ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
+
+ if (ret < 0)
+ return ret;
+
+ ret = __add_zone(zone, phys_start_pfn);
+
+ if (ret < 0)
+ return ret;
+
+ return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
+}
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+static int __remove_section(struct zone *zone, struct mem_section *ms)
+{
+ /*
+ * XXX: Freeing memmap with vmemmap is not implement yet.
+ * This should be removed later.
+ */
+ return -EBUSY;
+}
+#else
+static int __remove_section(struct zone *zone, struct mem_section *ms)
+{
+ unsigned long flags;
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ int ret = -EINVAL;
+
+ if (!valid_section(ms))
+ return ret;
+
+ ret = unregister_memory_section(ms);
+ if (ret)
+ return ret;
+
+ pgdat_resize_lock(pgdat, &flags);
+ sparse_remove_one_section(zone, ms);
+ pgdat_resize_unlock(pgdat, &flags);
+ return 0;
+}
+#endif
+
+/*
+ * Reasonably generic function for adding memory. It is
+ * expected that archs that support memory hotplug will
+ * call this function after deciding the zone to which to
+ * add the new pages.
+ */
+int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
+ unsigned long nr_pages)
+{
+ unsigned long i;
+ int err = 0;
+ int start_sec, end_sec;
+ /* during initialize mem_map, align hot-added range to section */
+ start_sec = pfn_to_section_nr(phys_start_pfn);
+ end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
+
+ for (i = start_sec; i <= end_sec; i++) {
+ err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
+
+ /*
+ * EEXIST is finally dealt with by ioresource collision
+ * check. see add_memory() => register_memory_resource()
+ * Warning will be printed if there is collision.
+ */
+ if (err && (err != -EEXIST))
+ break;
+ err = 0;
+ }
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(__add_pages);
+
+/**
+ * __remove_pages() - remove sections of pages from a zone
+ * @zone: zone from which pages need to be removed
+ * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
+ * @nr_pages: number of pages to remove (must be multiple of section size)
+ *
+ * Generic helper function to remove section mappings and sysfs entries
+ * for the section of the memory we are removing. Caller needs to make
+ * sure that pages are marked reserved and zones are adjust properly by
+ * calling offline_pages().
+ */
+int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
+ unsigned long nr_pages)
+{
+ unsigned long i, ret = 0;
+ int sections_to_remove;
+
+ /*
+ * We can only remove entire sections
+ */
+ BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
+ BUG_ON(nr_pages % PAGES_PER_SECTION);
+
+ sections_to_remove = nr_pages / PAGES_PER_SECTION;
+ for (i = 0; i < sections_to_remove; i++) {
+ unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
+ release_mem_region(pfn << PAGE_SHIFT,
+ PAGES_PER_SECTION << PAGE_SHIFT);
+ ret = __remove_section(zone, __pfn_to_section(pfn));
+ if (ret)
+ break;
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__remove_pages);
+
+int set_online_page_callback(online_page_callback_t callback)
+{
+ int rc = -EINVAL;
+
+ lock_memory_hotplug();
+
+ if (online_page_callback == generic_online_page) {
+ online_page_callback = callback;
+ rc = 0;
+ }
+
+ unlock_memory_hotplug();
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(set_online_page_callback);
+
+int restore_online_page_callback(online_page_callback_t callback)
+{
+ int rc = -EINVAL;
+
+ lock_memory_hotplug();
+
+ if (online_page_callback == callback) {
+ online_page_callback = generic_online_page;
+ rc = 0;
+ }
+
+ unlock_memory_hotplug();
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(restore_online_page_callback);
+
+void __online_page_set_limits(struct page *page)
+{
+ unsigned long pfn = page_to_pfn(page);
+
+ if (pfn >= num_physpages)
+ num_physpages = pfn + 1;
+}
+EXPORT_SYMBOL_GPL(__online_page_set_limits);
+
+void __online_page_increment_counters(struct page *page)
+{
+ totalram_pages++;
+
+#ifdef CONFIG_HIGHMEM
+ if (PageHighMem(page))
+ totalhigh_pages++;
+#endif
+}
+EXPORT_SYMBOL_GPL(__online_page_increment_counters);
+
+void __online_page_free(struct page *page)
+{
+ ClearPageReserved(page);
+ init_page_count(page);
+ __free_page(page);
+}
+EXPORT_SYMBOL_GPL(__online_page_free);
+
+static void generic_online_page(struct page *page)
+{
+ __online_page_set_limits(page);
+ __online_page_increment_counters(page);
+ __online_page_free(page);
+}
+
+static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
+ void *arg)
+{
+ unsigned long i;
+ unsigned long onlined_pages = *(unsigned long *)arg;
+ struct page *page;
+ if (PageReserved(pfn_to_page(start_pfn)))
+ for (i = 0; i < nr_pages; i++) {
+ page = pfn_to_page(start_pfn + i);
+ (*online_page_callback)(page);
+ onlined_pages++;
+ }
+ *(unsigned long *)arg = onlined_pages;
+ return 0;
+}
+
+
+int __ref online_pages(unsigned long pfn, unsigned long nr_pages)
+{
+ unsigned long onlined_pages = 0;
+ struct zone *zone;
+ int need_zonelists_rebuild = 0;
+ int nid;
+ int ret;
+ struct memory_notify arg;
+
+ lock_memory_hotplug();
+ arg.start_pfn = pfn;
+ arg.nr_pages = nr_pages;
+ arg.status_change_nid = -1;
+
+ nid = page_to_nid(pfn_to_page(pfn));
+ if (node_present_pages(nid) == 0)
+ arg.status_change_nid = nid;
+
+ ret = memory_notify(MEM_GOING_ONLINE, &arg);
+ ret = notifier_to_errno(ret);
+ if (ret) {
+ memory_notify(MEM_CANCEL_ONLINE, &arg);
+ unlock_memory_hotplug();
+ return ret;
+ }
+ /*
+ * This doesn't need a lock to do pfn_to_page().
+ * The section can't be removed here because of the
+ * memory_block->state_mutex.
+ */
+ zone = page_zone(pfn_to_page(pfn));
+ /*
+ * If this zone is not populated, then it is not in zonelist.
+ * This means the page allocator ignores this zone.
+ * So, zonelist must be updated after online.
+ */
+ mutex_lock(&zonelists_mutex);
+ if (!populated_zone(zone))
+ need_zonelists_rebuild = 1;
+
+ ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
+ online_pages_range);
+ if (ret) {
+ mutex_unlock(&zonelists_mutex);
+ printk(KERN_DEBUG "online_pages %lx at %lx failed\n",
+ nr_pages, pfn);
+ memory_notify(MEM_CANCEL_ONLINE, &arg);
+ unlock_memory_hotplug();
+ return ret;
+ }
+
+ zone->present_pages += onlined_pages;
+ zone->zone_pgdat->node_present_pages += onlined_pages;
+ if (onlined_pages) {
+ node_set_state(zone_to_nid(zone), N_HIGH_MEMORY);
+ if (need_zonelists_rebuild)
+ build_all_zonelists(zone);
+ else
+ zone_pcp_update(zone);
+ }
+
+ mutex_unlock(&zonelists_mutex);
+
+ init_per_zone_wmark_min();
+
+ if (onlined_pages)
+ kswapd_run(zone_to_nid(zone));
+
+ vm_total_pages = nr_free_pagecache_pages();
+
+ writeback_set_ratelimit();
+
+ if (onlined_pages)
+ memory_notify(MEM_ONLINE, &arg);
+ unlock_memory_hotplug();
+
+ return 0;
+}
+#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
+
+/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
+static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
+{
+ struct pglist_data *pgdat;
+ unsigned long zones_size[MAX_NR_ZONES] = {0};
+ unsigned long zholes_size[MAX_NR_ZONES] = {0};
+ unsigned long start_pfn = start >> PAGE_SHIFT;
+
+ pgdat = arch_alloc_nodedata(nid);
+ if (!pgdat)
+ return NULL;
+
+ arch_refresh_nodedata(nid, pgdat);
+
+ /* we can use NODE_DATA(nid) from here */
+
+ /* init node's zones as empty zones, we don't have any present pages.*/
+ free_area_init_node(nid, zones_size, start_pfn, zholes_size);
+
+ /*
+ * The node we allocated has no zone fallback lists. For avoiding
+ * to access not-initialized zonelist, build here.
+ */
+ mutex_lock(&zonelists_mutex);
+ build_all_zonelists(NULL);
+ mutex_unlock(&zonelists_mutex);
+
+ return pgdat;
+}
+
+static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
+{
+ arch_refresh_nodedata(nid, NULL);
+ arch_free_nodedata(pgdat);
+ return;
+}
+
+
+/*
+ * called by cpu_up() to online a node without onlined memory.
+ */
+int mem_online_node(int nid)
+{
+ pg_data_t *pgdat;
+ int ret;
+
+ lock_memory_hotplug();
+ pgdat = hotadd_new_pgdat(nid, 0);
+ if (!pgdat) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ node_set_online(nid);
+ ret = register_one_node(nid);
+ BUG_ON(ret);
+
+out:
+ unlock_memory_hotplug();
+ return ret;
+}
+
+/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
+int __ref add_memory(int nid, u64 start, u64 size)
+{
+ pg_data_t *pgdat = NULL;
+ int new_pgdat = 0;
+ struct resource *res;
+ int ret;
+
+ lock_memory_hotplug();
+
+ res = register_memory_resource(start, size);
+ ret = -EEXIST;
+ if (!res)
+ goto out;
+
+ if (!node_online(nid)) {
+ pgdat = hotadd_new_pgdat(nid, start);
+ ret = -ENOMEM;
+ if (!pgdat)
+ goto out;
+ new_pgdat = 1;
+ }
+
+ /* call arch's memory hotadd */
+ ret = arch_add_memory(nid, start, size);
+
+ if (ret < 0)
+ goto error;
+
+ /* we online node here. we can't roll back from here. */
+ node_set_online(nid);
+
+ if (new_pgdat) {
+ ret = register_one_node(nid);
+ /*
+ * If sysfs file of new node can't create, cpu on the node
+ * can't be hot-added. There is no rollback way now.
+ * So, check by BUG_ON() to catch it reluctantly..
+ */
+ BUG_ON(ret);
+ }
+
+ /* create new memmap entry */
+ firmware_map_add_hotplug(start, start + size, "System RAM");
+
+ goto out;
+
+error:
+ /* rollback pgdat allocation and others */
+ if (new_pgdat)
+ rollback_node_hotadd(nid, pgdat);
+ if (res)
+ release_memory_resource(res);
+
+out:
+ unlock_memory_hotplug();
+ return ret;
+}
+EXPORT_SYMBOL_GPL(add_memory);
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+/*
+ * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
+ * set and the size of the free page is given by page_order(). Using this,
+ * the function determines if the pageblock contains only free pages.
+ * Due to buddy contraints, a free page at least the size of a pageblock will
+ * be located at the start of the pageblock
+ */
+static inline int pageblock_free(struct page *page)
+{
+ return PageBuddy(page) && page_order(page) >= pageblock_order;
+}
+
+/* Return the start of the next active pageblock after a given page */
+static struct page *next_active_pageblock(struct page *page)
+{
+ /* Ensure the starting page is pageblock-aligned */
+ BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1));
+
+ /* If the entire pageblock is free, move to the end of free page */
+ if (pageblock_free(page)) {
+ int order;
+ /* be careful. we don't have locks, page_order can be changed.*/
+ order = page_order(page);
+ if ((order < MAX_ORDER) && (order >= pageblock_order))
+ return page + (1 << order);
+ }
+
+ return page + pageblock_nr_pages;
+}
+
+/* Checks if this range of memory is likely to be hot-removable. */
+int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
+{
+ struct page *page = pfn_to_page(start_pfn);
+ struct page *end_page = page + nr_pages;
+
+ /* Check the starting page of each pageblock within the range */
+ for (; page < end_page; page = next_active_pageblock(page)) {
+ if (!is_pageblock_removable_nolock(page))
+ return 0;
+ cond_resched();
+ }
+
+ /* All pageblocks in the memory block are likely to be hot-removable */
+ return 1;
+}
+
+/*
+ * Confirm all pages in a range [start, end) is belongs to the same zone.
+ */
+static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn)
+{
+ unsigned long pfn;
+ struct zone *zone = NULL;
+ struct page *page;
+ int i;
+ for (pfn = start_pfn;
+ pfn < end_pfn;
+ pfn += MAX_ORDER_NR_PAGES) {
+ i = 0;
+ /* This is just a CONFIG_HOLES_IN_ZONE check.*/
+ while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i))
+ i++;
+ if (i == MAX_ORDER_NR_PAGES)
+ continue;
+ page = pfn_to_page(pfn + i);
+ if (zone && page_zone(page) != zone)
+ return 0;
+ zone = page_zone(page);
+ }
+ return 1;
+}
+
+/*
+ * Scanning pfn is much easier than scanning lru list.
+ * Scan pfn from start to end and Find LRU page.
+ */
+static unsigned long scan_lru_pages(unsigned long start, unsigned long end)
+{
+ unsigned long pfn;
+ struct page *page;
+ for (pfn = start; pfn < end; pfn++) {
+ if (pfn_valid(pfn)) {
+ page = pfn_to_page(pfn);
+ if (PageLRU(page))
+ return pfn;
+ }
+ }
+ return 0;
+}
+
+static struct page *
+hotremove_migrate_alloc(struct page *page, unsigned long private, int **x)
+{
+ /* This should be improooooved!! */
+ return alloc_page(GFP_HIGHUSER_MOVABLE);
+}
+
+#define NR_OFFLINE_AT_ONCE_PAGES (256)
+static int
+do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
+{
+ unsigned long pfn;
+ struct page *page;
+ int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
+ int not_managed = 0;
+ int ret = 0;
+ LIST_HEAD(source);
+
+ for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
+ if (!pfn_valid(pfn))
+ continue;
+ page = pfn_to_page(pfn);
+ if (!get_page_unless_zero(page))
+ continue;
+ /*
+ * We can skip free pages. And we can only deal with pages on
+ * LRU.
+ */
+ ret = isolate_lru_page(page);
+ if (!ret) { /* Success */
+ put_page(page);
+ list_add_tail(&page->lru, &source);
+ move_pages--;
+ inc_zone_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+
+ } else {
+#ifdef CONFIG_DEBUG_VM
+ printk(KERN_ALERT "removing pfn %lx from LRU failed\n",
+ pfn);
+ dump_page(page);
+#endif
+ put_page(page);
+ /* Because we don't have big zone->lock. we should
+ check this again here. */
+ if (page_count(page)) {
+ not_managed++;
+ ret = -EBUSY;
+ break;
+ }
+ }
+ }
+ if (!list_empty(&source)) {
+ if (not_managed) {
+ putback_lru_pages(&source);
+ goto out;
+ }
+ /* this function returns # of failed pages */
+ ret = migrate_pages(&source, hotremove_migrate_alloc, 0,
+ true, MIGRATE_SYNC);
+ if (ret)
+ putback_lru_pages(&source);
+ }
+out:
+ return ret;
+}
+
+/*
+ * remove from free_area[] and mark all as Reserved.
+ */
+static int
+offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
+ void *data)
+{
+ __offline_isolated_pages(start, start + nr_pages);
+ return 0;
+}
+
+static void
+offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
+{
+ walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL,
+ offline_isolated_pages_cb);
+}
+
+/*
+ * Check all pages in range, recoreded as memory resource, are isolated.
+ */
+static int
+check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
+ void *data)
+{
+ int ret;
+ long offlined = *(long *)data;
+ ret = test_pages_isolated(start_pfn, start_pfn + nr_pages);
+ offlined = nr_pages;
+ if (!ret)
+ *(long *)data += offlined;
+ return ret;
+}
+
+static long
+check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
+{
+ long offlined = 0;
+ int ret;
+
+ ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined,
+ check_pages_isolated_cb);
+ if (ret < 0)
+ offlined = (long)ret;
+ return offlined;
+}
+
+static int __ref offline_pages(unsigned long start_pfn,
+ unsigned long end_pfn, unsigned long timeout)
+{
+ unsigned long pfn, nr_pages, expire;
+ long offlined_pages;
+ int ret, drain, retry_max, node;
+ struct zone *zone;
+ struct memory_notify arg;
+
+ BUG_ON(start_pfn >= end_pfn);
+ /* at least, alignment against pageblock is necessary */
+ if (!IS_ALIGNED(start_pfn, pageblock_nr_pages))
+ return -EINVAL;
+ if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
+ return -EINVAL;
+ /* This makes hotplug much easier...and readable.
+ we assume this for now. .*/
+ if (!test_pages_in_a_zone(start_pfn, end_pfn))
+ return -EINVAL;
+
+ lock_memory_hotplug();
+
+ zone = page_zone(pfn_to_page(start_pfn));
+ node = zone_to_nid(zone);
+ nr_pages = end_pfn - start_pfn;
+
+ /* set above range as isolated */
+ ret = start_isolate_page_range(start_pfn, end_pfn);
+ if (ret)
+ goto out;
+
+ arg.start_pfn = start_pfn;
+ arg.nr_pages = nr_pages;
+ arg.status_change_nid = -1;
+ if (nr_pages >= node_present_pages(node))
+ arg.status_change_nid = node;
+
+ ret = memory_notify(MEM_GOING_OFFLINE, &arg);
+ ret = notifier_to_errno(ret);
+ if (ret)
+ goto failed_removal;
+
+ pfn = start_pfn;
+ expire = jiffies + timeout;
+ drain = 0;
+ retry_max = 5;
+repeat:
+ /* start memory hot removal */
+ ret = -EAGAIN;
+ if (time_after(jiffies, expire))
+ goto failed_removal;
+ ret = -EINTR;
+ if (signal_pending(current))
+ goto failed_removal;
+ ret = 0;
+ if (drain) {
+ lru_add_drain_all();
+ cond_resched();
+ drain_all_pages();
+ }
+
+ pfn = scan_lru_pages(start_pfn, end_pfn);
+ if (pfn) { /* We have page on LRU */
+ ret = do_migrate_range(pfn, end_pfn);
+ if (!ret) {
+ drain = 1;
+ goto repeat;
+ } else {
+ if (ret < 0)
+ if (--retry_max == 0)
+ goto failed_removal;
+ yield();
+ drain = 1;
+ goto repeat;
+ }
+ }
+ /* drain all zone's lru pagevec, this is asyncronous... */
+ lru_add_drain_all();
+ yield();
+ /* drain pcp pages , this is synchrouns. */
+ drain_all_pages();
+ /* check again */
+ offlined_pages = check_pages_isolated(start_pfn, end_pfn);
+ if (offlined_pages < 0) {
+ ret = -EBUSY;
+ goto failed_removal;
+ }
+ printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages);
+ /* Ok, all of our target is islaoted.
+ We cannot do rollback at this point. */
+ offline_isolated_pages(start_pfn, end_pfn);
+ /* reset pagetype flags and makes migrate type to be MOVABLE */
+ undo_isolate_page_range(start_pfn, end_pfn);
+ /* removal success */
+ zone->present_pages -= offlined_pages;
+ zone->zone_pgdat->node_present_pages -= offlined_pages;
+ totalram_pages -= offlined_pages;
+
+ init_per_zone_wmark_min();
+
+ if (!node_present_pages(node)) {
+ node_clear_state(node, N_HIGH_MEMORY);
+ kswapd_stop(node);
+ }
+
+ vm_total_pages = nr_free_pagecache_pages();
+ writeback_set_ratelimit();
+
+ memory_notify(MEM_OFFLINE, &arg);
+ unlock_memory_hotplug();
+ return 0;
+
+failed_removal:
+ printk(KERN_INFO "memory offlining %lx to %lx failed\n",
+ start_pfn, end_pfn);
+ memory_notify(MEM_CANCEL_OFFLINE, &arg);
+ /* pushback to free area */
+ undo_isolate_page_range(start_pfn, end_pfn);
+
+out:
+ unlock_memory_hotplug();
+ return ret;
+}
+
+int remove_memory(u64 start, u64 size)
+{
+ unsigned long start_pfn, end_pfn;
+
+ start_pfn = PFN_DOWN(start);
+ end_pfn = start_pfn + PFN_DOWN(size);
+ return offline_pages(start_pfn, end_pfn, 120 * HZ);
+}
+#else
+int remove_memory(u64 start, u64 size)
+{
+ return -EINVAL;
+}
+#endif /* CONFIG_MEMORY_HOTREMOVE */
+EXPORT_SYMBOL_GPL(remove_memory);
diff --git a/ap/os/linux/linux-3.4.x/mm/mempolicy.c b/ap/os/linux/linux-3.4.x/mm/mempolicy.c
new file mode 100644
index 0000000..87a43cc
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mempolicy.c
@@ -0,0 +1,2574 @@
+/*
+ * Simple NUMA memory policy for the Linux kernel.
+ *
+ * Copyright 2003,2004 Andi Kleen, SuSE Labs.
+ * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc.
+ * Subject to the GNU Public License, version 2.
+ *
+ * NUMA policy allows the user to give hints in which node(s) memory should
+ * be allocated.
+ *
+ * Support four policies per VMA and per process:
+ *
+ * The VMA policy has priority over the process policy for a page fault.
+ *
+ * interleave Allocate memory interleaved over a set of nodes,
+ * with normal fallback if it fails.
+ * For VMA based allocations this interleaves based on the
+ * offset into the backing object or offset into the mapping
+ * for anonymous memory. For process policy an process counter
+ * is used.
+ *
+ * bind Only allocate memory on a specific set of nodes,
+ * no fallback.
+ * FIXME: memory is allocated starting with the first node
+ * to the last. It would be better if bind would truly restrict
+ * the allocation to memory nodes instead
+ *
+ * preferred Try a specific node first before normal fallback.
+ * As a special case node -1 here means do the allocation
+ * on the local CPU. This is normally identical to default,
+ * but useful to set in a VMA when you have a non default
+ * process policy.
+ *
+ * default Allocate on the local node first, or when on a VMA
+ * use the process policy. This is what Linux always did
+ * in a NUMA aware kernel and still does by, ahem, default.
+ *
+ * The process policy is applied for most non interrupt memory allocations
+ * in that process' context. Interrupts ignore the policies and always
+ * try to allocate on the local CPU. The VMA policy is only applied for memory
+ * allocations for a VMA in the VM.
+ *
+ * Currently there are a few corner cases in swapping where the policy
+ * is not applied, but the majority should be handled. When process policy
+ * is used it is not remembered over swap outs/swap ins.
+ *
+ * Only the highest zone in the zone hierarchy gets policied. Allocations
+ * requesting a lower zone just use default policy. This implies that
+ * on systems with highmem kernel lowmem allocation don't get policied.
+ * Same with GFP_DMA allocations.
+ *
+ * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between
+ * all users and remembered even when nobody has memory mapped.
+ */
+
+/* Notebook:
+ fix mmap readahead to honour policy and enable policy for any page cache
+ object
+ statistics for bigpages
+ global policy for page cache? currently it uses process policy. Requires
+ first item above.
+ handle mremap for shared memory (currently ignored for the policy)
+ grows down?
+ make bind policy root only? It can trigger oom much faster and the
+ kernel is not always grateful with that.
+*/
+
+#include <linux/mempolicy.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/hugetlb.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/nodemask.h>
+#include <linux/cpuset.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/export.h>
+#include <linux/nsproxy.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/compat.h>
+#include <linux/swap.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/migrate.h>
+#include <linux/ksm.h>
+#include <linux/rmap.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/ctype.h>
+#include <linux/mm_inline.h>
+
+#include <asm/tlbflush.h>
+#include <asm/uaccess.h>
+#include <linux/random.h>
+
+#include "internal.h"
+
+/* Internal flags */
+#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
+#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
+
+static struct kmem_cache *policy_cache;
+static struct kmem_cache *sn_cache;
+
+/* Highest zone. An specific allocation for a zone below that is not
+ policied. */
+enum zone_type policy_zone = 0;
+
+/*
+ * run-time system-wide default policy => local allocation
+ */
+static struct mempolicy default_policy = {
+ .refcnt = ATOMIC_INIT(1), /* never free it */
+ .mode = MPOL_PREFERRED,
+ .flags = MPOL_F_LOCAL,
+};
+
+static const struct mempolicy_operations {
+ int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
+ /*
+ * If read-side task has no lock to protect task->mempolicy, write-side
+ * task will rebind the task->mempolicy by two step. The first step is
+ * setting all the newly nodes, and the second step is cleaning all the
+ * disallowed nodes. In this way, we can avoid finding no node to alloc
+ * page.
+ * If we have a lock to protect task->mempolicy in read-side, we do
+ * rebind directly.
+ *
+ * step:
+ * MPOL_REBIND_ONCE - do rebind work at once
+ * MPOL_REBIND_STEP1 - set all the newly nodes
+ * MPOL_REBIND_STEP2 - clean all the disallowed nodes
+ */
+ void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes,
+ enum mpol_rebind_step step);
+} mpol_ops[MPOL_MAX];
+
+/* Check that the nodemask contains at least one populated zone */
+static int is_valid_nodemask(const nodemask_t *nodemask)
+{
+ int nd, k;
+
+ for_each_node_mask(nd, *nodemask) {
+ struct zone *z;
+
+ for (k = 0; k <= policy_zone; k++) {
+ z = &NODE_DATA(nd)->node_zones[k];
+ if (z->present_pages > 0)
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
+{
+ return pol->flags & MPOL_MODE_FLAGS;
+}
+
+static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
+ const nodemask_t *rel)
+{
+ nodemask_t tmp;
+ nodes_fold(tmp, *orig, nodes_weight(*rel));
+ nodes_onto(*ret, tmp, *rel);
+}
+
+static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
+{
+ if (nodes_empty(*nodes))
+ return -EINVAL;
+ pol->v.nodes = *nodes;
+ return 0;
+}
+
+static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
+{
+ if (!nodes)
+ pol->flags |= MPOL_F_LOCAL; /* local allocation */
+ else if (nodes_empty(*nodes))
+ return -EINVAL; /* no allowed nodes */
+ else
+ pol->v.preferred_node = first_node(*nodes);
+ return 0;
+}
+
+static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
+{
+ if (!is_valid_nodemask(nodes))
+ return -EINVAL;
+ pol->v.nodes = *nodes;
+ return 0;
+}
+
+/*
+ * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
+ * any, for the new policy. mpol_new() has already validated the nodes
+ * parameter with respect to the policy mode and flags. But, we need to
+ * handle an empty nodemask with MPOL_PREFERRED here.
+ *
+ * Must be called holding task's alloc_lock to protect task's mems_allowed
+ * and mempolicy. May also be called holding the mmap_semaphore for write.
+ */
+static int mpol_set_nodemask(struct mempolicy *pol,
+ const nodemask_t *nodes, struct nodemask_scratch *nsc)
+{
+ int ret;
+
+ /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
+ if (pol == NULL)
+ return 0;
+ /* Check N_HIGH_MEMORY */
+ nodes_and(nsc->mask1,
+ cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]);
+
+ VM_BUG_ON(!nodes);
+ if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
+ nodes = NULL; /* explicit local allocation */
+ else {
+ if (pol->flags & MPOL_F_RELATIVE_NODES)
+ mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1);
+ else
+ nodes_and(nsc->mask2, *nodes, nsc->mask1);
+
+ if (mpol_store_user_nodemask(pol))
+ pol->w.user_nodemask = *nodes;
+ else
+ pol->w.cpuset_mems_allowed =
+ cpuset_current_mems_allowed;
+ }
+
+ if (nodes)
+ ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
+ else
+ ret = mpol_ops[pol->mode].create(pol, NULL);
+ return ret;
+}
+
+/*
+ * This function just creates a new policy, does some check and simple
+ * initialization. You must invoke mpol_set_nodemask() to set nodes.
+ */
+static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
+ nodemask_t *nodes)
+{
+ struct mempolicy *policy;
+
+ pr_debug("setting mode %d flags %d nodes[0] %lx\n",
+ mode, flags, nodes ? nodes_addr(*nodes)[0] : -1);
+
+ if (mode == MPOL_DEFAULT) {
+ if (nodes && !nodes_empty(*nodes))
+ return ERR_PTR(-EINVAL);
+ return NULL; /* simply delete any existing policy */
+ }
+ VM_BUG_ON(!nodes);
+
+ /*
+ * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
+ * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
+ * All other modes require a valid pointer to a non-empty nodemask.
+ */
+ if (mode == MPOL_PREFERRED) {
+ if (nodes_empty(*nodes)) {
+ if (((flags & MPOL_F_STATIC_NODES) ||
+ (flags & MPOL_F_RELATIVE_NODES)))
+ return ERR_PTR(-EINVAL);
+ }
+ } else if (nodes_empty(*nodes))
+ return ERR_PTR(-EINVAL);
+ policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
+ if (!policy)
+ return ERR_PTR(-ENOMEM);
+ atomic_set(&policy->refcnt, 1);
+ policy->mode = mode;
+ policy->flags = flags;
+
+ return policy;
+}
+
+/* Slow path of a mpol destructor. */
+void __mpol_put(struct mempolicy *p)
+{
+ if (!atomic_dec_and_test(&p->refcnt))
+ return;
+ kmem_cache_free(policy_cache, p);
+}
+
+static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes,
+ enum mpol_rebind_step step)
+{
+}
+
+/*
+ * step:
+ * MPOL_REBIND_ONCE - do rebind work at once
+ * MPOL_REBIND_STEP1 - set all the newly nodes
+ * MPOL_REBIND_STEP2 - clean all the disallowed nodes
+ */
+static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes,
+ enum mpol_rebind_step step)
+{
+ nodemask_t tmp;
+
+ if (pol->flags & MPOL_F_STATIC_NODES)
+ nodes_and(tmp, pol->w.user_nodemask, *nodes);
+ else if (pol->flags & MPOL_F_RELATIVE_NODES)
+ mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
+ else {
+ /*
+ * if step == 1, we use ->w.cpuset_mems_allowed to cache the
+ * result
+ */
+ if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) {
+ nodes_remap(tmp, pol->v.nodes,
+ pol->w.cpuset_mems_allowed, *nodes);
+ pol->w.cpuset_mems_allowed = step ? tmp : *nodes;
+ } else if (step == MPOL_REBIND_STEP2) {
+ tmp = pol->w.cpuset_mems_allowed;
+ pol->w.cpuset_mems_allowed = *nodes;
+ } else
+ BUG();
+ }
+
+ if (nodes_empty(tmp))
+ tmp = *nodes;
+
+ if (step == MPOL_REBIND_STEP1)
+ nodes_or(pol->v.nodes, pol->v.nodes, tmp);
+ else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2)
+ pol->v.nodes = tmp;
+ else
+ BUG();
+
+ if (!node_isset(current->il_next, tmp)) {
+ current->il_next = next_node(current->il_next, tmp);
+ if (current->il_next >= MAX_NUMNODES)
+ current->il_next = first_node(tmp);
+ if (current->il_next >= MAX_NUMNODES)
+ current->il_next = numa_node_id();
+ }
+}
+
+static void mpol_rebind_preferred(struct mempolicy *pol,
+ const nodemask_t *nodes,
+ enum mpol_rebind_step step)
+{
+ nodemask_t tmp;
+
+ if (pol->flags & MPOL_F_STATIC_NODES) {
+ int node = first_node(pol->w.user_nodemask);
+
+ if (node_isset(node, *nodes)) {
+ pol->v.preferred_node = node;
+ pol->flags &= ~MPOL_F_LOCAL;
+ } else
+ pol->flags |= MPOL_F_LOCAL;
+ } else if (pol->flags & MPOL_F_RELATIVE_NODES) {
+ mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
+ pol->v.preferred_node = first_node(tmp);
+ } else if (!(pol->flags & MPOL_F_LOCAL)) {
+ pol->v.preferred_node = node_remap(pol->v.preferred_node,
+ pol->w.cpuset_mems_allowed,
+ *nodes);
+ pol->w.cpuset_mems_allowed = *nodes;
+ }
+}
+
+/*
+ * mpol_rebind_policy - Migrate a policy to a different set of nodes
+ *
+ * If read-side task has no lock to protect task->mempolicy, write-side
+ * task will rebind the task->mempolicy by two step. The first step is
+ * setting all the newly nodes, and the second step is cleaning all the
+ * disallowed nodes. In this way, we can avoid finding no node to alloc
+ * page.
+ * If we have a lock to protect task->mempolicy in read-side, we do
+ * rebind directly.
+ *
+ * step:
+ * MPOL_REBIND_ONCE - do rebind work at once
+ * MPOL_REBIND_STEP1 - set all the newly nodes
+ * MPOL_REBIND_STEP2 - clean all the disallowed nodes
+ */
+static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask,
+ enum mpol_rebind_step step)
+{
+ if (!pol)
+ return;
+ if (!mpol_store_user_nodemask(pol) && step == 0 &&
+ nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
+ return;
+
+ if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING))
+ return;
+
+ if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING))
+ BUG();
+
+ if (step == MPOL_REBIND_STEP1)
+ pol->flags |= MPOL_F_REBINDING;
+ else if (step == MPOL_REBIND_STEP2)
+ pol->flags &= ~MPOL_F_REBINDING;
+ else if (step >= MPOL_REBIND_NSTEP)
+ BUG();
+
+ mpol_ops[pol->mode].rebind(pol, newmask, step);
+}
+
+/*
+ * Wrapper for mpol_rebind_policy() that just requires task
+ * pointer, and updates task mempolicy.
+ *
+ * Called with task's alloc_lock held.
+ */
+
+void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new,
+ enum mpol_rebind_step step)
+{
+ mpol_rebind_policy(tsk->mempolicy, new, step);
+}
+
+/*
+ * Rebind each vma in mm to new nodemask.
+ *
+ * Call holding a reference to mm. Takes mm->mmap_sem during call.
+ */
+
+void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
+{
+ struct vm_area_struct *vma;
+
+ down_write(&mm->mmap_sem);
+ for (vma = mm->mmap; vma; vma = vma->vm_next)
+ mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE);
+ up_write(&mm->mmap_sem);
+}
+
+static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
+ [MPOL_DEFAULT] = {
+ .rebind = mpol_rebind_default,
+ },
+ [MPOL_INTERLEAVE] = {
+ .create = mpol_new_interleave,
+ .rebind = mpol_rebind_nodemask,
+ },
+ [MPOL_PREFERRED] = {
+ .create = mpol_new_preferred,
+ .rebind = mpol_rebind_preferred,
+ },
+ [MPOL_BIND] = {
+ .create = mpol_new_bind,
+ .rebind = mpol_rebind_nodemask,
+ },
+};
+
+static void migrate_page_add(struct page *page, struct list_head *pagelist,
+ unsigned long flags);
+
+/* Scan through pages checking if pages follow certain conditions. */
+static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ const nodemask_t *nodes, unsigned long flags,
+ void *private)
+{
+ pte_t *orig_pte;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ do {
+ struct page *page;
+ int nid;
+
+ if (!pte_present(*pte))
+ continue;
+ page = vm_normal_page(vma, addr, *pte);
+ if (!page)
+ continue;
+ /*
+ * vm_normal_page() filters out zero pages, but there might
+ * still be PageReserved pages to skip, perhaps in a VDSO.
+ * And we cannot move PageKsm pages sensibly or safely yet.
+ */
+ if (PageReserved(page) || PageKsm(page))
+ continue;
+ nid = page_to_nid(page);
+ if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
+ continue;
+
+ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
+ migrate_page_add(page, private, flags);
+ else
+ break;
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ pte_unmap_unlock(orig_pte, ptl);
+ return addr != end;
+}
+
+static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ const nodemask_t *nodes, unsigned long flags,
+ void *private)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ split_huge_page_pmd(vma->vm_mm, pmd);
+ if (pmd_none_or_trans_huge_or_clear_bad(pmd))
+ continue;
+ if (check_pte_range(vma, pmd, addr, next, nodes,
+ flags, private))
+ return -EIO;
+ } while (pmd++, addr = next, addr != end);
+ return 0;
+}
+
+static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ const nodemask_t *nodes, unsigned long flags,
+ void *private)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ if (check_pmd_range(vma, pud, addr, next, nodes,
+ flags, private))
+ return -EIO;
+ } while (pud++, addr = next, addr != end);
+ return 0;
+}
+
+static inline int check_pgd_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end,
+ const nodemask_t *nodes, unsigned long flags,
+ void *private)
+{
+ pgd_t *pgd;
+ unsigned long next;
+
+ pgd = pgd_offset(vma->vm_mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ if (check_pud_range(vma, pgd, addr, next, nodes,
+ flags, private))
+ return -EIO;
+ } while (pgd++, addr = next, addr != end);
+ return 0;
+}
+
+/*
+ * Check if all pages in a range are on a set of nodes.
+ * If pagelist != NULL then isolate pages from the LRU and
+ * put them on the pagelist.
+ */
+static int
+check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
+ const nodemask_t *nodes, unsigned long flags, void *private)
+{
+ int err = 0;
+ struct vm_area_struct *vma, *prev;
+
+
+ vma = find_vma(mm, start);
+ if (!vma)
+ return -EFAULT;
+ prev = NULL;
+ for (; vma && vma->vm_start < end; vma = vma->vm_next) {
+ if (!(flags & MPOL_MF_DISCONTIG_OK)) {
+ if (!vma->vm_next && vma->vm_end < end)
+ return -EFAULT;
+ if (prev && prev->vm_end < vma->vm_start)
+ return -EFAULT;
+ }
+ if (!is_vm_hugetlb_page(vma) &&
+ ((flags & MPOL_MF_STRICT) ||
+ ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
+ vma_migratable(vma)))) {
+ unsigned long endvma = vma->vm_end;
+
+ if (endvma > end)
+ endvma = end;
+ if (vma->vm_start > start)
+ start = vma->vm_start;
+ err = check_pgd_range(vma, start, endvma, nodes,
+ flags, private);
+ if (err)
+ break;
+ }
+ prev = vma;
+ }
+ return err;
+}
+
+/*
+ * Apply policy to a single VMA
+ * This must be called with the mmap_sem held for writing.
+ */
+static int vma_replace_policy(struct vm_area_struct *vma,
+ struct mempolicy *pol)
+{
+ int err;
+ struct mempolicy *old;
+ struct mempolicy *new;
+
+ pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
+ vma->vm_start, vma->vm_end, vma->vm_pgoff,
+ vma->vm_ops, vma->vm_file,
+ vma->vm_ops ? vma->vm_ops->set_policy : NULL);
+
+ new = mpol_dup(pol);
+ if (IS_ERR(new))
+ return PTR_ERR(new);
+
+ if (vma->vm_ops && vma->vm_ops->set_policy) {
+ err = vma->vm_ops->set_policy(vma, new);
+ if (err)
+ goto err_out;
+ }
+
+ old = vma->vm_policy;
+ vma->vm_policy = new; /* protected by mmap_sem */
+ mpol_put(old);
+
+ return 0;
+ err_out:
+ mpol_put(new);
+ return err;
+}
+
+/* Step 2: apply policy to a range and do splits. */
+static int mbind_range(struct mm_struct *mm, unsigned long start,
+ unsigned long end, struct mempolicy *new_pol)
+{
+ struct vm_area_struct *next;
+ struct vm_area_struct *prev;
+ struct vm_area_struct *vma;
+ int err = 0;
+ pgoff_t pgoff;
+ unsigned long vmstart;
+ unsigned long vmend;
+
+ vma = find_vma(mm, start);
+ if (!vma || vma->vm_start > start)
+ return -EFAULT;
+
+ prev = vma->vm_prev;
+ if (start > vma->vm_start)
+ prev = vma;
+
+ for (; vma && vma->vm_start < end; prev = vma, vma = next) {
+ next = vma->vm_next;
+ vmstart = max(start, vma->vm_start);
+ vmend = min(end, vma->vm_end);
+
+ if (mpol_equal(vma_policy(vma), new_pol))
+ continue;
+
+ pgoff = vma->vm_pgoff +
+ ((vmstart - vma->vm_start) >> PAGE_SHIFT);
+ prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
+ vma->anon_vma, vma->vm_file, pgoff,
+ new_pol);
+ if (prev) {
+ vma = prev;
+ next = vma->vm_next;
+ continue;
+ }
+ if (vma->vm_start != vmstart) {
+ err = split_vma(vma->vm_mm, vma, vmstart, 1);
+ if (err)
+ goto out;
+ }
+ if (vma->vm_end != vmend) {
+ err = split_vma(vma->vm_mm, vma, vmend, 0);
+ if (err)
+ goto out;
+ }
+ err = vma_replace_policy(vma, new_pol);
+ if (err)
+ goto out;
+ }
+
+ out:
+ return err;
+}
+
+/*
+ * Update task->flags PF_MEMPOLICY bit: set iff non-default
+ * mempolicy. Allows more rapid checking of this (combined perhaps
+ * with other PF_* flag bits) on memory allocation hot code paths.
+ *
+ * If called from outside this file, the task 'p' should -only- be
+ * a newly forked child not yet visible on the task list, because
+ * manipulating the task flags of a visible task is not safe.
+ *
+ * The above limitation is why this routine has the funny name
+ * mpol_fix_fork_child_flag().
+ *
+ * It is also safe to call this with a task pointer of current,
+ * which the static wrapper mpol_set_task_struct_flag() does,
+ * for use within this file.
+ */
+
+void mpol_fix_fork_child_flag(struct task_struct *p)
+{
+ if (p->mempolicy)
+ p->flags |= PF_MEMPOLICY;
+ else
+ p->flags &= ~PF_MEMPOLICY;
+}
+
+static void mpol_set_task_struct_flag(void)
+{
+ mpol_fix_fork_child_flag(current);
+}
+
+/* Set the process memory policy */
+static long do_set_mempolicy(unsigned short mode, unsigned short flags,
+ nodemask_t *nodes)
+{
+ struct mempolicy *new, *old;
+ struct mm_struct *mm = current->mm;
+ NODEMASK_SCRATCH(scratch);
+ int ret;
+
+ if (!scratch)
+ return -ENOMEM;
+
+ new = mpol_new(mode, flags, nodes);
+ if (IS_ERR(new)) {
+ ret = PTR_ERR(new);
+ goto out;
+ }
+ /*
+ * prevent changing our mempolicy while show_numa_maps()
+ * is using it.
+ * Note: do_set_mempolicy() can be called at init time
+ * with no 'mm'.
+ */
+ if (mm)
+ down_write(&mm->mmap_sem);
+ task_lock(current);
+ ret = mpol_set_nodemask(new, nodes, scratch);
+ if (ret) {
+ task_unlock(current);
+ if (mm)
+ up_write(&mm->mmap_sem);
+ mpol_put(new);
+ goto out;
+ }
+ old = current->mempolicy;
+ current->mempolicy = new;
+ mpol_set_task_struct_flag();
+ if (new && new->mode == MPOL_INTERLEAVE &&
+ nodes_weight(new->v.nodes))
+ current->il_next = first_node(new->v.nodes);
+ task_unlock(current);
+ if (mm)
+ up_write(&mm->mmap_sem);
+
+ mpol_put(old);
+ ret = 0;
+out:
+ NODEMASK_SCRATCH_FREE(scratch);
+ return ret;
+}
+
+/*
+ * Return nodemask for policy for get_mempolicy() query
+ *
+ * Called with task's alloc_lock held
+ */
+static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
+{
+ nodes_clear(*nodes);
+ if (p == &default_policy)
+ return;
+
+ switch (p->mode) {
+ case MPOL_BIND:
+ /* Fall through */
+ case MPOL_INTERLEAVE:
+ *nodes = p->v.nodes;
+ break;
+ case MPOL_PREFERRED:
+ if (!(p->flags & MPOL_F_LOCAL))
+ node_set(p->v.preferred_node, *nodes);
+ /* else return empty node mask for local allocation */
+ break;
+ default:
+ BUG();
+ }
+}
+
+static int lookup_node(struct mm_struct *mm, unsigned long addr)
+{
+ struct page *p;
+ int err;
+
+ err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL);
+ if (err >= 0) {
+ err = page_to_nid(p);
+ put_page(p);
+ }
+ return err;
+}
+
+/* Retrieve NUMA policy */
+static long do_get_mempolicy(int *policy, nodemask_t *nmask,
+ unsigned long addr, unsigned long flags)
+{
+ int err;
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma = NULL;
+ struct mempolicy *pol = current->mempolicy;
+
+ if (flags &
+ ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
+ return -EINVAL;
+
+ if (flags & MPOL_F_MEMS_ALLOWED) {
+ if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
+ return -EINVAL;
+ *policy = 0; /* just so it's initialized */
+ task_lock(current);
+ *nmask = cpuset_current_mems_allowed;
+ task_unlock(current);
+ return 0;
+ }
+
+ if (flags & MPOL_F_ADDR) {
+ /*
+ * Do NOT fall back to task policy if the
+ * vma/shared policy at addr is NULL. We
+ * want to return MPOL_DEFAULT in this case.
+ */
+ down_read(&mm->mmap_sem);
+ vma = find_vma_intersection(mm, addr, addr+1);
+ if (!vma) {
+ up_read(&mm->mmap_sem);
+ return -EFAULT;
+ }
+ if (vma->vm_ops && vma->vm_ops->get_policy)
+ pol = vma->vm_ops->get_policy(vma, addr);
+ else
+ pol = vma->vm_policy;
+ } else if (addr)
+ return -EINVAL;
+
+ if (!pol)
+ pol = &default_policy; /* indicates default behavior */
+
+ if (flags & MPOL_F_NODE) {
+ if (flags & MPOL_F_ADDR) {
+ err = lookup_node(mm, addr);
+ if (err < 0)
+ goto out;
+ *policy = err;
+ } else if (pol == current->mempolicy &&
+ pol->mode == MPOL_INTERLEAVE) {
+ *policy = current->il_next;
+ } else {
+ err = -EINVAL;
+ goto out;
+ }
+ } else {
+ *policy = pol == &default_policy ? MPOL_DEFAULT :
+ pol->mode;
+ /*
+ * Internal mempolicy flags must be masked off before exposing
+ * the policy to userspace.
+ */
+ *policy |= (pol->flags & MPOL_MODE_FLAGS);
+ }
+
+ if (vma) {
+ up_read(¤t->mm->mmap_sem);
+ vma = NULL;
+ }
+
+ err = 0;
+ if (nmask) {
+ if (mpol_store_user_nodemask(pol)) {
+ *nmask = pol->w.user_nodemask;
+ } else {
+ task_lock(current);
+ get_policy_nodemask(pol, nmask);
+ task_unlock(current);
+ }
+ }
+
+ out:
+ mpol_cond_put(pol);
+ if (vma)
+ up_read(¤t->mm->mmap_sem);
+ return err;
+}
+
+#ifdef CONFIG_MIGRATION
+/*
+ * page migration
+ */
+static void migrate_page_add(struct page *page, struct list_head *pagelist,
+ unsigned long flags)
+{
+ /*
+ * Avoid migrating a page that is shared with others.
+ */
+ if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
+ if (!isolate_lru_page(page)) {
+ list_add_tail(&page->lru, pagelist);
+ inc_zone_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+ }
+ }
+}
+
+static struct page *new_node_page(struct page *page, unsigned long node, int **x)
+{
+ return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
+}
+
+/*
+ * Migrate pages from one node to a target node.
+ * Returns error or the number of pages not migrated.
+ */
+static int migrate_to_node(struct mm_struct *mm, int source, int dest,
+ int flags)
+{
+ nodemask_t nmask;
+ LIST_HEAD(pagelist);
+ int err;
+
+ nodes_clear(nmask);
+ node_set(source, nmask);
+
+ err = check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
+ flags | MPOL_MF_DISCONTIG_OK, &pagelist);
+ if (err)
+ return err;
+
+ if (!list_empty(&pagelist)) {
+ err = migrate_pages(&pagelist, new_node_page, dest,
+ false, MIGRATE_SYNC);
+ if (err)
+ putback_lru_pages(&pagelist);
+ }
+
+ return err;
+}
+
+/*
+ * Move pages between the two nodesets so as to preserve the physical
+ * layout as much as possible.
+ *
+ * Returns the number of page that could not be moved.
+ */
+int do_migrate_pages(struct mm_struct *mm,
+ const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
+{
+ int busy = 0;
+ int err;
+ nodemask_t tmp;
+
+ err = migrate_prep();
+ if (err)
+ return err;
+
+ down_read(&mm->mmap_sem);
+
+ err = migrate_vmas(mm, from_nodes, to_nodes, flags);
+ if (err)
+ goto out;
+
+ /*
+ * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
+ * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
+ * bit in 'tmp', and return that <source, dest> pair for migration.
+ * The pair of nodemasks 'to' and 'from' define the map.
+ *
+ * If no pair of bits is found that way, fallback to picking some
+ * pair of 'source' and 'dest' bits that are not the same. If the
+ * 'source' and 'dest' bits are the same, this represents a node
+ * that will be migrating to itself, so no pages need move.
+ *
+ * If no bits are left in 'tmp', or if all remaining bits left
+ * in 'tmp' correspond to the same bit in 'to', return false
+ * (nothing left to migrate).
+ *
+ * This lets us pick a pair of nodes to migrate between, such that
+ * if possible the dest node is not already occupied by some other
+ * source node, minimizing the risk of overloading the memory on a
+ * node that would happen if we migrated incoming memory to a node
+ * before migrating outgoing memory source that same node.
+ *
+ * A single scan of tmp is sufficient. As we go, we remember the
+ * most recent <s, d> pair that moved (s != d). If we find a pair
+ * that not only moved, but what's better, moved to an empty slot
+ * (d is not set in tmp), then we break out then, with that pair.
+ * Otherwise when we finish scanning from_tmp, we at least have the
+ * most recent <s, d> pair that moved. If we get all the way through
+ * the scan of tmp without finding any node that moved, much less
+ * moved to an empty node, then there is nothing left worth migrating.
+ */
+
+ tmp = *from_nodes;
+ while (!nodes_empty(tmp)) {
+ int s,d;
+ int source = -1;
+ int dest = 0;
+
+ for_each_node_mask(s, tmp) {
+ d = node_remap(s, *from_nodes, *to_nodes);
+ if (s == d)
+ continue;
+
+ source = s; /* Node moved. Memorize */
+ dest = d;
+
+ /* dest not in remaining from nodes? */
+ if (!node_isset(dest, tmp))
+ break;
+ }
+ if (source == -1)
+ break;
+
+ node_clear(source, tmp);
+ err = migrate_to_node(mm, source, dest, flags);
+ if (err > 0)
+ busy += err;
+ if (err < 0)
+ break;
+ }
+out:
+ up_read(&mm->mmap_sem);
+ if (err < 0)
+ return err;
+ return busy;
+
+}
+
+/*
+ * Allocate a new page for page migration based on vma policy.
+ * Start by assuming the page is mapped by the same vma as contains @start.
+ * Search forward from there, if not. N.B., this assumes that the
+ * list of pages handed to migrate_pages()--which is how we get here--
+ * is in virtual address order.
+ */
+static struct page *new_page(struct page *page, unsigned long start, int **x)
+{
+ struct vm_area_struct *vma;
+ unsigned long uninitialized_var(address);
+
+ vma = find_vma(current->mm, start);
+ while (vma) {
+ address = page_address_in_vma(page, vma);
+ if (address != -EFAULT)
+ break;
+ vma = vma->vm_next;
+ }
+
+ /*
+ * if !vma, alloc_page_vma() will use task or system default policy
+ */
+ return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
+}
+#else
+
+static void migrate_page_add(struct page *page, struct list_head *pagelist,
+ unsigned long flags)
+{
+}
+
+int do_migrate_pages(struct mm_struct *mm,
+ const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
+{
+ return -ENOSYS;
+}
+
+static struct page *new_page(struct page *page, unsigned long start, int **x)
+{
+ return NULL;
+}
+#endif
+
+static long do_mbind(unsigned long start, unsigned long len,
+ unsigned short mode, unsigned short mode_flags,
+ nodemask_t *nmask, unsigned long flags)
+{
+ struct mm_struct *mm = current->mm;
+ struct mempolicy *new;
+ unsigned long end;
+ int err;
+ LIST_HEAD(pagelist);
+
+ if (flags & ~(unsigned long)(MPOL_MF_STRICT |
+ MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
+ return -EINVAL;
+ if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
+ return -EPERM;
+
+ if (start & ~PAGE_MASK)
+ return -EINVAL;
+
+ if (mode == MPOL_DEFAULT)
+ flags &= ~MPOL_MF_STRICT;
+
+ len = (len + PAGE_SIZE - 1) & PAGE_MASK;
+ end = start + len;
+
+ if (end < start)
+ return -EINVAL;
+ if (end == start)
+ return 0;
+
+ new = mpol_new(mode, mode_flags, nmask);
+ if (IS_ERR(new))
+ return PTR_ERR(new);
+
+ /*
+ * If we are using the default policy then operation
+ * on discontinuous address spaces is okay after all
+ */
+ if (!new)
+ flags |= MPOL_MF_DISCONTIG_OK;
+
+ pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
+ start, start + len, mode, mode_flags,
+ nmask ? nodes_addr(*nmask)[0] : -1);
+
+ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
+
+ err = migrate_prep();
+ if (err)
+ goto mpol_out;
+ }
+ {
+ NODEMASK_SCRATCH(scratch);
+ if (scratch) {
+ down_write(&mm->mmap_sem);
+ task_lock(current);
+ err = mpol_set_nodemask(new, nmask, scratch);
+ task_unlock(current);
+ if (err)
+ up_write(&mm->mmap_sem);
+ } else
+ err = -ENOMEM;
+ NODEMASK_SCRATCH_FREE(scratch);
+ }
+ if (err)
+ goto mpol_out;
+
+ err = check_range(mm, start, end, nmask,
+ flags | MPOL_MF_INVERT, &pagelist);
+
+ if (!err) {
+ int nr_failed = 0;
+
+ err = mbind_range(mm, start, end, new);
+
+ if (!list_empty(&pagelist)) {
+ nr_failed = migrate_pages(&pagelist, new_page,
+ start, false, true);
+ if (nr_failed)
+ putback_lru_pages(&pagelist);
+ }
+
+ if (!err && nr_failed && (flags & MPOL_MF_STRICT))
+ err = -EIO;
+ } else
+ putback_lru_pages(&pagelist);
+
+ up_write(&mm->mmap_sem);
+ mpol_out:
+ mpol_put(new);
+ return err;
+}
+
+/*
+ * User space interface with variable sized bitmaps for nodelists.
+ */
+
+/* Copy a node mask from user space. */
+static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
+ unsigned long maxnode)
+{
+ unsigned long k;
+ unsigned long nlongs;
+ unsigned long endmask;
+
+ --maxnode;
+ nodes_clear(*nodes);
+ if (maxnode == 0 || !nmask)
+ return 0;
+ if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
+ return -EINVAL;
+
+ nlongs = BITS_TO_LONGS(maxnode);
+ if ((maxnode % BITS_PER_LONG) == 0)
+ endmask = ~0UL;
+ else
+ endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
+
+ /* When the user specified more nodes than supported just check
+ if the non supported part is all zero. */
+ if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
+ if (nlongs > PAGE_SIZE/sizeof(long))
+ return -EINVAL;
+ for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
+ unsigned long t;
+ if (get_user(t, nmask + k))
+ return -EFAULT;
+ if (k == nlongs - 1) {
+ if (t & endmask)
+ return -EINVAL;
+ } else if (t)
+ return -EINVAL;
+ }
+ nlongs = BITS_TO_LONGS(MAX_NUMNODES);
+ endmask = ~0UL;
+ }
+
+ if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
+ return -EFAULT;
+ nodes_addr(*nodes)[nlongs-1] &= endmask;
+ return 0;
+}
+
+/* Copy a kernel node mask to user space */
+static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
+ nodemask_t *nodes)
+{
+ unsigned long copy = ALIGN(maxnode-1, 64) / 8;
+ const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long);
+
+ if (copy > nbytes) {
+ if (copy > PAGE_SIZE)
+ return -EINVAL;
+ if (clear_user((char __user *)mask + nbytes, copy - nbytes))
+ return -EFAULT;
+ copy = nbytes;
+ }
+ return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
+}
+
+SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
+ unsigned long, mode, unsigned long __user *, nmask,
+ unsigned long, maxnode, unsigned, flags)
+{
+ nodemask_t nodes;
+ int err;
+ unsigned short mode_flags;
+
+ mode_flags = mode & MPOL_MODE_FLAGS;
+ mode &= ~MPOL_MODE_FLAGS;
+ if (mode >= MPOL_MAX)
+ return -EINVAL;
+ if ((mode_flags & MPOL_F_STATIC_NODES) &&
+ (mode_flags & MPOL_F_RELATIVE_NODES))
+ return -EINVAL;
+ err = get_nodes(&nodes, nmask, maxnode);
+ if (err)
+ return err;
+ return do_mbind(start, len, mode, mode_flags, &nodes, flags);
+}
+
+/* Set the process memory policy */
+SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask,
+ unsigned long, maxnode)
+{
+ int err;
+ nodemask_t nodes;
+ unsigned short flags;
+
+ flags = mode & MPOL_MODE_FLAGS;
+ mode &= ~MPOL_MODE_FLAGS;
+ if ((unsigned int)mode >= MPOL_MAX)
+ return -EINVAL;
+ if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
+ return -EINVAL;
+ err = get_nodes(&nodes, nmask, maxnode);
+ if (err)
+ return err;
+ return do_set_mempolicy(mode, flags, &nodes);
+}
+
+SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
+ const unsigned long __user *, old_nodes,
+ const unsigned long __user *, new_nodes)
+{
+ const struct cred *cred = current_cred(), *tcred;
+ struct mm_struct *mm = NULL;
+ struct task_struct *task;
+ nodemask_t task_nodes;
+ int err;
+ nodemask_t *old;
+ nodemask_t *new;
+ NODEMASK_SCRATCH(scratch);
+
+ if (!scratch)
+ return -ENOMEM;
+
+ old = &scratch->mask1;
+ new = &scratch->mask2;
+
+ err = get_nodes(old, old_nodes, maxnode);
+ if (err)
+ goto out;
+
+ err = get_nodes(new, new_nodes, maxnode);
+ if (err)
+ goto out;
+
+ /* Find the mm_struct */
+ rcu_read_lock();
+ task = pid ? find_task_by_vpid(pid) : current;
+ if (!task) {
+ rcu_read_unlock();
+ err = -ESRCH;
+ goto out;
+ }
+ get_task_struct(task);
+
+ err = -EINVAL;
+
+ /*
+ * Check if this process has the right to modify the specified
+ * process. The right exists if the process has administrative
+ * capabilities, superuser privileges or the same
+ * userid as the target process.
+ */
+ tcred = __task_cred(task);
+ if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
+ cred->uid != tcred->suid && cred->uid != tcred->uid &&
+ !capable(CAP_SYS_NICE)) {
+ rcu_read_unlock();
+ err = -EPERM;
+ goto out_put;
+ }
+ rcu_read_unlock();
+
+ task_nodes = cpuset_mems_allowed(task);
+ /* Is the user allowed to access the target nodes? */
+ if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
+ err = -EPERM;
+ goto out_put;
+ }
+
+ if (!nodes_subset(*new, node_states[N_HIGH_MEMORY])) {
+ err = -EINVAL;
+ goto out_put;
+ }
+
+ err = security_task_movememory(task);
+ if (err)
+ goto out_put;
+
+ mm = get_task_mm(task);
+ put_task_struct(task);
+
+ if (!mm) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ err = do_migrate_pages(mm, old, new,
+ capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
+
+ mmput(mm);
+out:
+ NODEMASK_SCRATCH_FREE(scratch);
+
+ return err;
+
+out_put:
+ put_task_struct(task);
+ goto out;
+
+}
+
+
+/* Retrieve NUMA policy */
+SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
+ unsigned long __user *, nmask, unsigned long, maxnode,
+ unsigned long, addr, unsigned long, flags)
+{
+ int err;
+ int uninitialized_var(pval);
+ nodemask_t nodes;
+
+ if (nmask != NULL && maxnode < MAX_NUMNODES)
+ return -EINVAL;
+
+ err = do_get_mempolicy(&pval, &nodes, addr, flags);
+
+ if (err)
+ return err;
+
+ if (policy && put_user(pval, policy))
+ return -EFAULT;
+
+ if (nmask)
+ err = copy_nodes_to_user(nmask, maxnode, &nodes);
+
+ return err;
+}
+
+#ifdef CONFIG_COMPAT
+
+asmlinkage long compat_sys_get_mempolicy(int __user *policy,
+ compat_ulong_t __user *nmask,
+ compat_ulong_t maxnode,
+ compat_ulong_t addr, compat_ulong_t flags)
+{
+ long err;
+ unsigned long __user *nm = NULL;
+ unsigned long nr_bits, alloc_size;
+ DECLARE_BITMAP(bm, MAX_NUMNODES);
+
+ nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
+ alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
+
+ if (nmask)
+ nm = compat_alloc_user_space(alloc_size);
+
+ err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
+
+ if (!err && nmask) {
+ unsigned long copy_size;
+ copy_size = min_t(unsigned long, sizeof(bm), alloc_size);
+ err = copy_from_user(bm, nm, copy_size);
+ /* ensure entire bitmap is zeroed */
+ err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
+ err |= compat_put_bitmap(nmask, bm, nr_bits);
+ }
+
+ return err;
+}
+
+asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask,
+ compat_ulong_t maxnode)
+{
+ long err = 0;
+ unsigned long __user *nm = NULL;
+ unsigned long nr_bits, alloc_size;
+ DECLARE_BITMAP(bm, MAX_NUMNODES);
+
+ nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
+ alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
+
+ if (nmask) {
+ err = compat_get_bitmap(bm, nmask, nr_bits);
+ nm = compat_alloc_user_space(alloc_size);
+ err |= copy_to_user(nm, bm, alloc_size);
+ }
+
+ if (err)
+ return -EFAULT;
+
+ return sys_set_mempolicy(mode, nm, nr_bits+1);
+}
+
+asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len,
+ compat_ulong_t mode, compat_ulong_t __user *nmask,
+ compat_ulong_t maxnode, compat_ulong_t flags)
+{
+ long err = 0;
+ unsigned long __user *nm = NULL;
+ unsigned long nr_bits, alloc_size;
+ nodemask_t bm;
+
+ nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
+ alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
+
+ if (nmask) {
+ err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
+ nm = compat_alloc_user_space(alloc_size);
+ err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
+ }
+
+ if (err)
+ return -EFAULT;
+
+ return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
+}
+
+#endif
+
+/*
+ * get_vma_policy(@task, @vma, @addr)
+ * @task - task for fallback if vma policy == default
+ * @vma - virtual memory area whose policy is sought
+ * @addr - address in @vma for shared policy lookup
+ *
+ * Returns effective policy for a VMA at specified address.
+ * Falls back to @task or system default policy, as necessary.
+ * Current or other task's task mempolicy and non-shared vma policies
+ * are protected by the task's mmap_sem, which must be held for read by
+ * the caller.
+ * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
+ * count--added by the get_policy() vm_op, as appropriate--to protect against
+ * freeing by another task. It is the caller's responsibility to free the
+ * extra reference for shared policies.
+ */
+struct mempolicy *get_vma_policy(struct task_struct *task,
+ struct vm_area_struct *vma, unsigned long addr)
+{
+ struct mempolicy *pol = task->mempolicy;
+
+ if (vma) {
+ if (vma->vm_ops && vma->vm_ops->get_policy) {
+ struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
+ addr);
+ if (vpol)
+ pol = vpol;
+ } else if (vma->vm_policy) {
+ pol = vma->vm_policy;
+
+ /*
+ * shmem_alloc_page() passes MPOL_F_SHARED policy with
+ * a pseudo vma whose vma->vm_ops=NULL. Take a reference
+ * count on these policies which will be dropped by
+ * mpol_cond_put() later
+ */
+ if (mpol_needs_cond_ref(pol))
+ mpol_get(pol);
+ }
+ }
+ if (!pol)
+ pol = &default_policy;
+ return pol;
+}
+
+/*
+ * Return a nodemask representing a mempolicy for filtering nodes for
+ * page allocation
+ */
+static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
+{
+ /* Lower zones don't get a nodemask applied for MPOL_BIND */
+ if (unlikely(policy->mode == MPOL_BIND) &&
+ gfp_zone(gfp) >= policy_zone &&
+ cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
+ return &policy->v.nodes;
+
+ return NULL;
+}
+
+/* Return a zonelist indicated by gfp for node representing a mempolicy */
+static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy,
+ int nd)
+{
+ switch (policy->mode) {
+ case MPOL_PREFERRED:
+ if (!(policy->flags & MPOL_F_LOCAL))
+ nd = policy->v.preferred_node;
+ break;
+ case MPOL_BIND:
+ /*
+ * Normally, MPOL_BIND allocations are node-local within the
+ * allowed nodemask. However, if __GFP_THISNODE is set and the
+ * current node isn't part of the mask, we use the zonelist for
+ * the first node in the mask instead.
+ */
+ if (unlikely(gfp & __GFP_THISNODE) &&
+ unlikely(!node_isset(nd, policy->v.nodes)))
+ nd = first_node(policy->v.nodes);
+ break;
+ default:
+ BUG();
+ }
+ return node_zonelist(nd, gfp);
+}
+
+/* Do dynamic interleaving for a process */
+static unsigned interleave_nodes(struct mempolicy *policy)
+{
+ unsigned nid, next;
+ struct task_struct *me = current;
+
+ nid = me->il_next;
+ next = next_node(nid, policy->v.nodes);
+ if (next >= MAX_NUMNODES)
+ next = first_node(policy->v.nodes);
+ if (next < MAX_NUMNODES)
+ me->il_next = next;
+ return nid;
+}
+
+/*
+ * Depending on the memory policy provide a node from which to allocate the
+ * next slab entry.
+ * @policy must be protected by freeing by the caller. If @policy is
+ * the current task's mempolicy, this protection is implicit, as only the
+ * task can change it's policy. The system default policy requires no
+ * such protection.
+ */
+unsigned slab_node(void)
+{
+ struct mempolicy *policy;
+
+ if (in_interrupt())
+ return numa_node_id();
+
+ policy = current->mempolicy;
+ if (!policy || policy->flags & MPOL_F_LOCAL)
+ return numa_node_id();
+
+ switch (policy->mode) {
+ case MPOL_PREFERRED:
+ /*
+ * handled MPOL_F_LOCAL above
+ */
+ return policy->v.preferred_node;
+
+ case MPOL_INTERLEAVE:
+ return interleave_nodes(policy);
+
+ case MPOL_BIND: {
+ /*
+ * Follow bind policy behavior and start allocation at the
+ * first node.
+ */
+ struct zonelist *zonelist;
+ struct zone *zone;
+ enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
+ zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0];
+ (void)first_zones_zonelist(zonelist, highest_zoneidx,
+ &policy->v.nodes,
+ &zone);
+ return zone ? zone->node : numa_node_id();
+ }
+
+ default:
+ BUG();
+ }
+}
+
+/* Do static interleaving for a VMA with known offset. */
+static unsigned offset_il_node(struct mempolicy *pol,
+ struct vm_area_struct *vma, unsigned long off)
+{
+ unsigned nnodes = nodes_weight(pol->v.nodes);
+ unsigned target;
+ int c;
+ int nid = -1;
+
+ if (!nnodes)
+ return numa_node_id();
+ target = (unsigned int)off % nnodes;
+ c = 0;
+ do {
+ nid = next_node(nid, pol->v.nodes);
+ c++;
+ } while (c <= target);
+ return nid;
+}
+
+/* Determine a node number for interleave */
+static inline unsigned interleave_nid(struct mempolicy *pol,
+ struct vm_area_struct *vma, unsigned long addr, int shift)
+{
+ if (vma) {
+ unsigned long off;
+
+ /*
+ * for small pages, there is no difference between
+ * shift and PAGE_SHIFT, so the bit-shift is safe.
+ * for huge pages, since vm_pgoff is in units of small
+ * pages, we need to shift off the always 0 bits to get
+ * a useful offset.
+ */
+ BUG_ON(shift < PAGE_SHIFT);
+ off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
+ off += (addr - vma->vm_start) >> shift;
+ return offset_il_node(pol, vma, off);
+ } else
+ return interleave_nodes(pol);
+}
+
+/*
+ * Return the bit number of a random bit set in the nodemask.
+ * (returns -1 if nodemask is empty)
+ */
+int node_random(const nodemask_t *maskp)
+{
+ int w, bit = -1;
+
+ w = nodes_weight(*maskp);
+ if (w)
+ bit = bitmap_ord_to_pos(maskp->bits,
+ get_random_int() % w, MAX_NUMNODES);
+ return bit;
+}
+
+#ifdef CONFIG_HUGETLBFS
+/*
+ * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
+ * @vma = virtual memory area whose policy is sought
+ * @addr = address in @vma for shared policy lookup and interleave policy
+ * @gfp_flags = for requested zone
+ * @mpol = pointer to mempolicy pointer for reference counted mempolicy
+ * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
+ *
+ * Returns a zonelist suitable for a huge page allocation and a pointer
+ * to the struct mempolicy for conditional unref after allocation.
+ * If the effective policy is 'BIND, returns a pointer to the mempolicy's
+ * @nodemask for filtering the zonelist.
+ *
+ * Must be protected by get_mems_allowed()
+ */
+struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
+ gfp_t gfp_flags, struct mempolicy **mpol,
+ nodemask_t **nodemask)
+{
+ struct zonelist *zl;
+
+ *mpol = get_vma_policy(current, vma, addr);
+ *nodemask = NULL; /* assume !MPOL_BIND */
+
+ if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
+ zl = node_zonelist(interleave_nid(*mpol, vma, addr,
+ huge_page_shift(hstate_vma(vma))), gfp_flags);
+ } else {
+ zl = policy_zonelist(gfp_flags, *mpol, numa_node_id());
+ if ((*mpol)->mode == MPOL_BIND)
+ *nodemask = &(*mpol)->v.nodes;
+ }
+ return zl;
+}
+
+/*
+ * init_nodemask_of_mempolicy
+ *
+ * If the current task's mempolicy is "default" [NULL], return 'false'
+ * to indicate default policy. Otherwise, extract the policy nodemask
+ * for 'bind' or 'interleave' policy into the argument nodemask, or
+ * initialize the argument nodemask to contain the single node for
+ * 'preferred' or 'local' policy and return 'true' to indicate presence
+ * of non-default mempolicy.
+ *
+ * We don't bother with reference counting the mempolicy [mpol_get/put]
+ * because the current task is examining it's own mempolicy and a task's
+ * mempolicy is only ever changed by the task itself.
+ *
+ * N.B., it is the caller's responsibility to free a returned nodemask.
+ */
+bool init_nodemask_of_mempolicy(nodemask_t *mask)
+{
+ struct mempolicy *mempolicy;
+ int nid;
+
+ if (!(mask && current->mempolicy))
+ return false;
+
+ task_lock(current);
+ mempolicy = current->mempolicy;
+ switch (mempolicy->mode) {
+ case MPOL_PREFERRED:
+ if (mempolicy->flags & MPOL_F_LOCAL)
+ nid = numa_node_id();
+ else
+ nid = mempolicy->v.preferred_node;
+ init_nodemask_of_node(mask, nid);
+ break;
+
+ case MPOL_BIND:
+ /* Fall through */
+ case MPOL_INTERLEAVE:
+ *mask = mempolicy->v.nodes;
+ break;
+
+ default:
+ BUG();
+ }
+ task_unlock(current);
+
+ return true;
+}
+#endif
+
+/*
+ * mempolicy_nodemask_intersects
+ *
+ * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
+ * policy. Otherwise, check for intersection between mask and the policy
+ * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
+ * policy, always return true since it may allocate elsewhere on fallback.
+ *
+ * Takes task_lock(tsk) to prevent freeing of its mempolicy.
+ */
+bool mempolicy_nodemask_intersects(struct task_struct *tsk,
+ const nodemask_t *mask)
+{
+ struct mempolicy *mempolicy;
+ bool ret = true;
+
+ if (!mask)
+ return ret;
+ task_lock(tsk);
+ mempolicy = tsk->mempolicy;
+ if (!mempolicy)
+ goto out;
+
+ switch (mempolicy->mode) {
+ case MPOL_PREFERRED:
+ /*
+ * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
+ * allocate from, they may fallback to other nodes when oom.
+ * Thus, it's possible for tsk to have allocated memory from
+ * nodes in mask.
+ */
+ break;
+ case MPOL_BIND:
+ case MPOL_INTERLEAVE:
+ ret = nodes_intersects(mempolicy->v.nodes, *mask);
+ break;
+ default:
+ BUG();
+ }
+out:
+ task_unlock(tsk);
+ return ret;
+}
+
+/* Allocate a page in interleaved policy.
+ Own path because it needs to do special accounting. */
+static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
+ unsigned nid)
+{
+ struct zonelist *zl;
+ struct page *page;
+
+ zl = node_zonelist(nid, gfp);
+ page = __alloc_pages(gfp, order, zl);
+ if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
+ inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
+ return page;
+}
+
+/**
+ * alloc_pages_vma - Allocate a page for a VMA.
+ *
+ * @gfp:
+ * %GFP_USER user allocation.
+ * %GFP_KERNEL kernel allocations,
+ * %GFP_HIGHMEM highmem/user allocations,
+ * %GFP_FS allocation should not call back into a file system.
+ * %GFP_ATOMIC don't sleep.
+ *
+ * @order:Order of the GFP allocation.
+ * @vma: Pointer to VMA or NULL if not available.
+ * @addr: Virtual Address of the allocation. Must be inside the VMA.
+ *
+ * This function allocates a page from the kernel page pool and applies
+ * a NUMA policy associated with the VMA or the current process.
+ * When VMA is not NULL caller must hold down_read on the mmap_sem of the
+ * mm_struct of the VMA to prevent it from going away. Should be used for
+ * all allocations for pages that will be mapped into
+ * user space. Returns NULL when no page can be allocated.
+ *
+ * Should be called with the mm_sem of the vma hold.
+ */
+struct page *
+alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
+ unsigned long addr, int node)
+{
+ struct mempolicy *pol;
+ struct zonelist *zl;
+ struct page *page;
+ unsigned int cpuset_mems_cookie;
+
+retry_cpuset:
+ pol = get_vma_policy(current, vma, addr);
+ cpuset_mems_cookie = get_mems_allowed();
+
+ if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
+ unsigned nid;
+
+ nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order);
+ mpol_cond_put(pol);
+ page = alloc_page_interleave(gfp, order, nid);
+ if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
+ goto retry_cpuset;
+
+ return page;
+ }
+ zl = policy_zonelist(gfp, pol, node);
+ if (unlikely(mpol_needs_cond_ref(pol))) {
+ /*
+ * slow path: ref counted shared policy
+ */
+ struct page *page = __alloc_pages_nodemask(gfp, order,
+ zl, policy_nodemask(gfp, pol));
+ __mpol_put(pol);
+ if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
+ goto retry_cpuset;
+ return page;
+ }
+ /*
+ * fast path: default or task policy
+ */
+ page = __alloc_pages_nodemask(gfp, order, zl,
+ policy_nodemask(gfp, pol));
+ if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
+ goto retry_cpuset;
+ return page;
+}
+
+/**
+ * alloc_pages_current - Allocate pages.
+ *
+ * @gfp:
+ * %GFP_USER user allocation,
+ * %GFP_KERNEL kernel allocation,
+ * %GFP_HIGHMEM highmem allocation,
+ * %GFP_FS don't call back into a file system.
+ * %GFP_ATOMIC don't sleep.
+ * @order: Power of two of allocation size in pages. 0 is a single page.
+ *
+ * Allocate a page from the kernel page pool. When not in
+ * interrupt context and apply the current process NUMA policy.
+ * Returns NULL when no page can be allocated.
+ *
+ * Don't call cpuset_update_task_memory_state() unless
+ * 1) it's ok to take cpuset_sem (can WAIT), and
+ * 2) allocating for current task (not interrupt).
+ */
+struct page *alloc_pages_current(gfp_t gfp, unsigned order)
+{
+ struct mempolicy *pol = current->mempolicy;
+ struct page *page;
+ unsigned int cpuset_mems_cookie;
+
+ if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
+ pol = &default_policy;
+
+retry_cpuset:
+ cpuset_mems_cookie = get_mems_allowed();
+
+ /*
+ * No reference counting needed for current->mempolicy
+ * nor system default_policy
+ */
+ if (pol->mode == MPOL_INTERLEAVE)
+ page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
+ else
+ page = __alloc_pages_nodemask(gfp, order,
+ policy_zonelist(gfp, pol, numa_node_id()),
+ policy_nodemask(gfp, pol));
+
+ if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
+ goto retry_cpuset;
+
+ return page;
+}
+EXPORT_SYMBOL(alloc_pages_current);
+
+/*
+ * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
+ * rebinds the mempolicy its copying by calling mpol_rebind_policy()
+ * with the mems_allowed returned by cpuset_mems_allowed(). This
+ * keeps mempolicies cpuset relative after its cpuset moves. See
+ * further kernel/cpuset.c update_nodemask().
+ *
+ * current's mempolicy may be rebinded by the other task(the task that changes
+ * cpuset's mems), so we needn't do rebind work for current task.
+ */
+
+/* Slow path of a mempolicy duplicate */
+struct mempolicy *__mpol_dup(struct mempolicy *old)
+{
+ struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
+
+ if (!new)
+ return ERR_PTR(-ENOMEM);
+
+ /* task's mempolicy is protected by alloc_lock */
+ if (old == current->mempolicy) {
+ task_lock(current);
+ *new = *old;
+ task_unlock(current);
+ } else
+ *new = *old;
+
+ if (current_cpuset_is_being_rebound()) {
+ nodemask_t mems = cpuset_mems_allowed(current);
+ if (new->flags & MPOL_F_REBINDING)
+ mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2);
+ else
+ mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE);
+ }
+ atomic_set(&new->refcnt, 1);
+ return new;
+}
+
+/* Slow path of a mempolicy comparison */
+bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
+{
+ if (!a || !b)
+ return false;
+ if (a->mode != b->mode)
+ return false;
+ if (a->flags != b->flags)
+ return false;
+ if (mpol_store_user_nodemask(a))
+ if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
+ return false;
+
+ switch (a->mode) {
+ case MPOL_BIND:
+ /* Fall through */
+ case MPOL_INTERLEAVE:
+ return !!nodes_equal(a->v.nodes, b->v.nodes);
+ case MPOL_PREFERRED:
+ return a->v.preferred_node == b->v.preferred_node;
+ default:
+ BUG();
+ return false;
+ }
+}
+
+/*
+ * Shared memory backing store policy support.
+ *
+ * Remember policies even when nobody has shared memory mapped.
+ * The policies are kept in Red-Black tree linked from the inode.
+ * They are protected by the sp->lock spinlock, which should be held
+ * for any accesses to the tree.
+ */
+
+/* lookup first element intersecting start-end */
+/* Caller holds sp->mutex */
+static struct sp_node *
+sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
+{
+ struct rb_node *n = sp->root.rb_node;
+
+ while (n) {
+ struct sp_node *p = rb_entry(n, struct sp_node, nd);
+
+ if (start >= p->end)
+ n = n->rb_right;
+ else if (end <= p->start)
+ n = n->rb_left;
+ else
+ break;
+ }
+ if (!n)
+ return NULL;
+ for (;;) {
+ struct sp_node *w = NULL;
+ struct rb_node *prev = rb_prev(n);
+ if (!prev)
+ break;
+ w = rb_entry(prev, struct sp_node, nd);
+ if (w->end <= start)
+ break;
+ n = prev;
+ }
+ return rb_entry(n, struct sp_node, nd);
+}
+
+/* Insert a new shared policy into the list. */
+/* Caller holds sp->lock */
+static void sp_insert(struct shared_policy *sp, struct sp_node *new)
+{
+ struct rb_node **p = &sp->root.rb_node;
+ struct rb_node *parent = NULL;
+ struct sp_node *nd;
+
+ while (*p) {
+ parent = *p;
+ nd = rb_entry(parent, struct sp_node, nd);
+ if (new->start < nd->start)
+ p = &(*p)->rb_left;
+ else if (new->end > nd->end)
+ p = &(*p)->rb_right;
+ else
+ BUG();
+ }
+ rb_link_node(&new->nd, parent, p);
+ rb_insert_color(&new->nd, &sp->root);
+ pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
+ new->policy ? new->policy->mode : 0);
+}
+
+/* Find shared policy intersecting idx */
+struct mempolicy *
+mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
+{
+ struct mempolicy *pol = NULL;
+ struct sp_node *sn;
+
+ if (!sp->root.rb_node)
+ return NULL;
+ mutex_lock(&sp->mutex);
+ sn = sp_lookup(sp, idx, idx+1);
+ if (sn) {
+ mpol_get(sn->policy);
+ pol = sn->policy;
+ }
+ mutex_unlock(&sp->mutex);
+ return pol;
+}
+
+static void sp_free(struct sp_node *n)
+{
+ mpol_put(n->policy);
+ kmem_cache_free(sn_cache, n);
+}
+
+static void sp_delete(struct shared_policy *sp, struct sp_node *n)
+{
+ pr_debug("deleting %lx-l%lx\n", n->start, n->end);
+ rb_erase(&n->nd, &sp->root);
+ sp_free(n);
+}
+
+static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
+ struct mempolicy *pol)
+{
+ struct sp_node *n;
+ struct mempolicy *newpol;
+
+ n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
+ if (!n)
+ return NULL;
+
+ newpol = mpol_dup(pol);
+ if (IS_ERR(newpol)) {
+ kmem_cache_free(sn_cache, n);
+ return NULL;
+ }
+ newpol->flags |= MPOL_F_SHARED;
+
+ n->start = start;
+ n->end = end;
+ n->policy = newpol;
+
+ return n;
+}
+
+/* Replace a policy range. */
+static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
+ unsigned long end, struct sp_node *new)
+{
+ struct sp_node *n;
+ int ret = 0;
+
+ mutex_lock(&sp->mutex);
+ n = sp_lookup(sp, start, end);
+ /* Take care of old policies in the same range. */
+ while (n && n->start < end) {
+ struct rb_node *next = rb_next(&n->nd);
+ if (n->start >= start) {
+ if (n->end <= end)
+ sp_delete(sp, n);
+ else
+ n->start = end;
+ } else {
+ /* Old policy spanning whole new range. */
+ if (n->end > end) {
+ struct sp_node *new2;
+ new2 = sp_alloc(end, n->end, n->policy);
+ if (!new2) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ n->end = start;
+ sp_insert(sp, new2);
+ break;
+ } else
+ n->end = start;
+ }
+ if (!next)
+ break;
+ n = rb_entry(next, struct sp_node, nd);
+ }
+ if (new)
+ sp_insert(sp, new);
+out:
+ mutex_unlock(&sp->mutex);
+ return ret;
+}
+
+/**
+ * mpol_shared_policy_init - initialize shared policy for inode
+ * @sp: pointer to inode shared policy
+ * @mpol: struct mempolicy to install
+ *
+ * Install non-NULL @mpol in inode's shared policy rb-tree.
+ * On entry, the current task has a reference on a non-NULL @mpol.
+ * This must be released on exit.
+ * This is called at get_inode() calls and we can use GFP_KERNEL.
+ */
+void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
+{
+ int ret;
+
+ sp->root = RB_ROOT; /* empty tree == default mempolicy */
+ mutex_init(&sp->mutex);
+
+ if (mpol) {
+ struct vm_area_struct pvma;
+ struct mempolicy *new;
+ NODEMASK_SCRATCH(scratch);
+
+ if (!scratch)
+ goto put_mpol;
+ /* contextualize the tmpfs mount point mempolicy */
+ new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
+ if (IS_ERR(new))
+ goto free_scratch; /* no valid nodemask intersection */
+
+ task_lock(current);
+ ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
+ task_unlock(current);
+ if (ret)
+ goto put_new;
+
+ /* Create pseudo-vma that contains just the policy */
+ memset(&pvma, 0, sizeof(struct vm_area_struct));
+ pvma.vm_end = TASK_SIZE; /* policy covers entire file */
+ mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
+
+put_new:
+ mpol_put(new); /* drop initial ref */
+free_scratch:
+ NODEMASK_SCRATCH_FREE(scratch);
+put_mpol:
+ mpol_put(mpol); /* drop our incoming ref on sb mpol */
+ }
+}
+
+int mpol_set_shared_policy(struct shared_policy *info,
+ struct vm_area_struct *vma, struct mempolicy *npol)
+{
+ int err;
+ struct sp_node *new = NULL;
+ unsigned long sz = vma_pages(vma);
+
+ pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
+ vma->vm_pgoff,
+ sz, npol ? npol->mode : -1,
+ npol ? npol->flags : -1,
+ npol ? nodes_addr(npol->v.nodes)[0] : -1);
+
+ if (npol) {
+ new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
+ if (!new)
+ return -ENOMEM;
+ }
+ err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
+ if (err && new)
+ sp_free(new);
+ return err;
+}
+
+/* Free a backing policy store on inode delete. */
+void mpol_free_shared_policy(struct shared_policy *p)
+{
+ struct sp_node *n;
+ struct rb_node *next;
+
+ if (!p->root.rb_node)
+ return;
+ mutex_lock(&p->mutex);
+ next = rb_first(&p->root);
+ while (next) {
+ n = rb_entry(next, struct sp_node, nd);
+ next = rb_next(&n->nd);
+ sp_delete(p, n);
+ }
+ mutex_unlock(&p->mutex);
+}
+
+/* assumes fs == KERNEL_DS */
+void __init numa_policy_init(void)
+{
+ nodemask_t interleave_nodes;
+ unsigned long largest = 0;
+ int nid, prefer = 0;
+
+ policy_cache = kmem_cache_create("numa_policy",
+ sizeof(struct mempolicy),
+ 0, SLAB_PANIC, NULL);
+
+ sn_cache = kmem_cache_create("shared_policy_node",
+ sizeof(struct sp_node),
+ 0, SLAB_PANIC, NULL);
+
+ /*
+ * Set interleaving policy for system init. Interleaving is only
+ * enabled across suitably sized nodes (default is >= 16MB), or
+ * fall back to the largest node if they're all smaller.
+ */
+ nodes_clear(interleave_nodes);
+ for_each_node_state(nid, N_HIGH_MEMORY) {
+ unsigned long total_pages = node_present_pages(nid);
+
+ /* Preserve the largest node */
+ if (largest < total_pages) {
+ largest = total_pages;
+ prefer = nid;
+ }
+
+ /* Interleave this node? */
+ if ((total_pages << PAGE_SHIFT) >= (16 << 20))
+ node_set(nid, interleave_nodes);
+ }
+
+ /* All too small, use the largest */
+ if (unlikely(nodes_empty(interleave_nodes)))
+ node_set(prefer, interleave_nodes);
+
+ if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
+ printk("numa_policy_init: interleaving failed\n");
+}
+
+/* Reset policy of current process to default */
+void numa_default_policy(void)
+{
+ do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
+}
+
+/*
+ * Parse and format mempolicy from/to strings
+ */
+
+/*
+ * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag.
+ */
+#define MPOL_LOCAL MPOL_MAX
+static const char * const policy_modes[] =
+{
+ [MPOL_DEFAULT] = "default",
+ [MPOL_PREFERRED] = "prefer",
+ [MPOL_BIND] = "bind",
+ [MPOL_INTERLEAVE] = "interleave",
+ [MPOL_LOCAL] = "local"
+};
+
+
+#ifdef CONFIG_TMPFS
+/**
+ * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option.
+ * @str: string containing mempolicy to parse
+ * @mpol: pointer to struct mempolicy pointer, returned on success.
+ * @unused: redundant argument, to be removed later.
+ *
+ * Format of input:
+ * <mode>[=<flags>][:<nodelist>]
+ *
+ * On success, returns 0, else 1
+ */
+int mpol_parse_str(char *str, struct mempolicy **mpol, int unused)
+{
+ struct mempolicy *new = NULL;
+ unsigned short mode;
+ unsigned short mode_flags;
+ nodemask_t nodes;
+ char *nodelist = strchr(str, ':');
+ char *flags = strchr(str, '=');
+ int err = 1;
+
+ if (nodelist) {
+ /* NUL-terminate mode or flags string */
+ *nodelist++ = '\0';
+ if (nodelist_parse(nodelist, nodes))
+ goto out;
+ if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY]))
+ goto out;
+ } else
+ nodes_clear(nodes);
+
+ if (flags)
+ *flags++ = '\0'; /* terminate mode string */
+
+ for (mode = 0; mode <= MPOL_LOCAL; mode++) {
+ if (!strcmp(str, policy_modes[mode])) {
+ break;
+ }
+ }
+ if (mode > MPOL_LOCAL)
+ goto out;
+
+ switch (mode) {
+ case MPOL_PREFERRED:
+ /*
+ * Insist on a nodelist of one node only
+ */
+ if (nodelist) {
+ char *rest = nodelist;
+ while (isdigit(*rest))
+ rest++;
+ if (*rest)
+ goto out;
+ }
+ break;
+ case MPOL_INTERLEAVE:
+ /*
+ * Default to online nodes with memory if no nodelist
+ */
+ if (!nodelist)
+ nodes = node_states[N_HIGH_MEMORY];
+ break;
+ case MPOL_LOCAL:
+ /*
+ * Don't allow a nodelist; mpol_new() checks flags
+ */
+ if (nodelist)
+ goto out;
+ mode = MPOL_PREFERRED;
+ break;
+ case MPOL_DEFAULT:
+ /*
+ * Insist on a empty nodelist
+ */
+ if (!nodelist)
+ err = 0;
+ goto out;
+ case MPOL_BIND:
+ /*
+ * Insist on a nodelist
+ */
+ if (!nodelist)
+ goto out;
+ }
+
+ mode_flags = 0;
+ if (flags) {
+ /*
+ * Currently, we only support two mutually exclusive
+ * mode flags.
+ */
+ if (!strcmp(flags, "static"))
+ mode_flags |= MPOL_F_STATIC_NODES;
+ else if (!strcmp(flags, "relative"))
+ mode_flags |= MPOL_F_RELATIVE_NODES;
+ else
+ goto out;
+ }
+
+ new = mpol_new(mode, mode_flags, &nodes);
+ if (IS_ERR(new))
+ goto out;
+
+ /*
+ * Save nodes for mpol_to_str() to show the tmpfs mount options
+ * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo.
+ */
+ if (mode != MPOL_PREFERRED)
+ new->v.nodes = nodes;
+ else if (nodelist)
+ new->v.preferred_node = first_node(nodes);
+ else
+ new->flags |= MPOL_F_LOCAL;
+
+ /*
+ * Save nodes for contextualization: this will be used to "clone"
+ * the mempolicy in a specific context [cpuset] at a later time.
+ */
+ new->w.user_nodemask = nodes;
+
+ err = 0;
+
+out:
+ /* Restore string for error message */
+ if (nodelist)
+ *--nodelist = ':';
+ if (flags)
+ *--flags = '=';
+ if (!err)
+ *mpol = new;
+ return err;
+}
+#endif /* CONFIG_TMPFS */
+
+/**
+ * mpol_to_str - format a mempolicy structure for printing
+ * @buffer: to contain formatted mempolicy string
+ * @maxlen: length of @buffer
+ * @pol: pointer to mempolicy to be formatted
+ * @unused: redundant argument, to be removed later.
+ *
+ * Convert a mempolicy into a string.
+ * Returns the number of characters in buffer (if positive)
+ * or an error (negative)
+ */
+int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int unused)
+{
+ char *p = buffer;
+ int l;
+ nodemask_t nodes;
+ unsigned short mode;
+ unsigned short flags = pol ? pol->flags : 0;
+
+ /*
+ * Sanity check: room for longest mode, flag and some nodes
+ */
+ VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16);
+
+ if (!pol || pol == &default_policy)
+ mode = MPOL_DEFAULT;
+ else
+ mode = pol->mode;
+
+ switch (mode) {
+ case MPOL_DEFAULT:
+ nodes_clear(nodes);
+ break;
+
+ case MPOL_PREFERRED:
+ nodes_clear(nodes);
+ if (flags & MPOL_F_LOCAL)
+ mode = MPOL_LOCAL;
+ else
+ node_set(pol->v.preferred_node, nodes);
+ break;
+
+ case MPOL_BIND:
+ /* Fall through */
+ case MPOL_INTERLEAVE:
+ nodes = pol->v.nodes;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ l = strlen(policy_modes[mode]);
+ if (buffer + maxlen < p + l + 1)
+ return -ENOSPC;
+
+ strcpy(p, policy_modes[mode]);
+ p += l;
+
+ if (flags & MPOL_MODE_FLAGS) {
+ if (buffer + maxlen < p + 2)
+ return -ENOSPC;
+ *p++ = '=';
+
+ /*
+ * Currently, the only defined flags are mutually exclusive
+ */
+ if (flags & MPOL_F_STATIC_NODES)
+ p += snprintf(p, buffer + maxlen - p, "static");
+ else if (flags & MPOL_F_RELATIVE_NODES)
+ p += snprintf(p, buffer + maxlen - p, "relative");
+ }
+
+ if (!nodes_empty(nodes)) {
+ if (buffer + maxlen < p + 2)
+ return -ENOSPC;
+ *p++ = ':';
+ p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
+ }
+ return p - buffer;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/mempool.c b/ap/os/linux/linux-3.4.x/mm/mempool.c
new file mode 100644
index 0000000..d904981
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mempool.c
@@ -0,0 +1,369 @@
+/*
+ * linux/mm/mempool.c
+ *
+ * memory buffer pool support. Such pools are mostly used
+ * for guaranteed, deadlock-free memory allocations during
+ * extreme VM load.
+ *
+ * started by Ingo Molnar, Copyright (C) 2001
+ */
+
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/mempool.h>
+#include <linux/blkdev.h>
+#include <linux/writeback.h>
+
+static void add_element(mempool_t *pool, void *element)
+{
+ BUG_ON(pool->curr_nr >= pool->min_nr);
+ pool->elements[pool->curr_nr++] = element;
+}
+
+static void *remove_element(mempool_t *pool)
+{
+ BUG_ON(pool->curr_nr <= 0);
+ return pool->elements[--pool->curr_nr];
+}
+
+/**
+ * mempool_destroy - deallocate a memory pool
+ * @pool: pointer to the memory pool which was allocated via
+ * mempool_create().
+ *
+ * Free all reserved elements in @pool and @pool itself. This function
+ * only sleeps if the free_fn() function sleeps.
+ */
+void mempool_destroy(mempool_t *pool)
+{
+ while (pool->curr_nr) {
+ void *element = remove_element(pool);
+ pool->free(element, pool->pool_data);
+ }
+ kfree(pool->elements);
+ kfree(pool);
+}
+EXPORT_SYMBOL(mempool_destroy);
+
+/**
+ * mempool_create - create a memory pool
+ * @min_nr: the minimum number of elements guaranteed to be
+ * allocated for this pool.
+ * @alloc_fn: user-defined element-allocation function.
+ * @free_fn: user-defined element-freeing function.
+ * @pool_data: optional private data available to the user-defined functions.
+ *
+ * this function creates and allocates a guaranteed size, preallocated
+ * memory pool. The pool can be used from the mempool_alloc() and mempool_free()
+ * functions. This function might sleep. Both the alloc_fn() and the free_fn()
+ * functions might sleep - as long as the mempool_alloc() function is not called
+ * from IRQ contexts.
+ */
+mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
+ mempool_free_t *free_fn, void *pool_data)
+{
+ return mempool_create_node(min_nr,alloc_fn,free_fn, pool_data,-1);
+}
+EXPORT_SYMBOL(mempool_create);
+
+mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
+ mempool_free_t *free_fn, void *pool_data, int node_id)
+{
+ mempool_t *pool;
+ pool = kmalloc_node(sizeof(*pool), GFP_KERNEL | __GFP_ZERO, node_id);
+ if (!pool)
+ return NULL;
+ pool->elements = kmalloc_node(min_nr * sizeof(void *),
+ GFP_KERNEL, node_id);
+ if (!pool->elements) {
+ kfree(pool);
+ return NULL;
+ }
+ spin_lock_init(&pool->lock);
+ pool->min_nr = min_nr;
+ pool->pool_data = pool_data;
+ init_waitqueue_head(&pool->wait);
+ pool->alloc = alloc_fn;
+ pool->free = free_fn;
+
+ /*
+ * First pre-allocate the guaranteed number of buffers.
+ */
+ while (pool->curr_nr < pool->min_nr) {
+ void *element;
+
+ element = pool->alloc(GFP_KERNEL, pool->pool_data);
+ if (unlikely(!element)) {
+ mempool_destroy(pool);
+ return NULL;
+ }
+ add_element(pool, element);
+ }
+ return pool;
+}
+EXPORT_SYMBOL(mempool_create_node);
+
+/**
+ * mempool_resize - resize an existing memory pool
+ * @pool: pointer to the memory pool which was allocated via
+ * mempool_create().
+ * @new_min_nr: the new minimum number of elements guaranteed to be
+ * allocated for this pool.
+ * @gfp_mask: the usual allocation bitmask.
+ *
+ * This function shrinks/grows the pool. In the case of growing,
+ * it cannot be guaranteed that the pool will be grown to the new
+ * size immediately, but new mempool_free() calls will refill it.
+ *
+ * Note, the caller must guarantee that no mempool_destroy is called
+ * while this function is running. mempool_alloc() & mempool_free()
+ * might be called (eg. from IRQ contexts) while this function executes.
+ */
+int mempool_resize(mempool_t *pool, int new_min_nr, gfp_t gfp_mask)
+{
+ void *element;
+ void **new_elements;
+ unsigned long flags;
+
+ BUG_ON(new_min_nr <= 0);
+
+ spin_lock_irqsave(&pool->lock, flags);
+ if (new_min_nr <= pool->min_nr) {
+ while (new_min_nr < pool->curr_nr) {
+ element = remove_element(pool);
+ spin_unlock_irqrestore(&pool->lock, flags);
+ pool->free(element, pool->pool_data);
+ spin_lock_irqsave(&pool->lock, flags);
+ }
+ pool->min_nr = new_min_nr;
+ goto out_unlock;
+ }
+ spin_unlock_irqrestore(&pool->lock, flags);
+
+ /* Grow the pool */
+ new_elements = kmalloc(new_min_nr * sizeof(*new_elements), gfp_mask);
+ if (!new_elements)
+ return -ENOMEM;
+
+ spin_lock_irqsave(&pool->lock, flags);
+ if (unlikely(new_min_nr <= pool->min_nr)) {
+ /* Raced, other resize will do our work */
+ spin_unlock_irqrestore(&pool->lock, flags);
+ kfree(new_elements);
+ goto out;
+ }
+ memcpy(new_elements, pool->elements,
+ pool->curr_nr * sizeof(*new_elements));
+ kfree(pool->elements);
+ pool->elements = new_elements;
+ pool->min_nr = new_min_nr;
+
+ while (pool->curr_nr < pool->min_nr) {
+ spin_unlock_irqrestore(&pool->lock, flags);
+ element = pool->alloc(gfp_mask, pool->pool_data);
+ if (!element)
+ goto out;
+ spin_lock_irqsave(&pool->lock, flags);
+ if (pool->curr_nr < pool->min_nr) {
+ add_element(pool, element);
+ } else {
+ spin_unlock_irqrestore(&pool->lock, flags);
+ pool->free(element, pool->pool_data); /* Raced */
+ goto out;
+ }
+ }
+out_unlock:
+ spin_unlock_irqrestore(&pool->lock, flags);
+out:
+ return 0;
+}
+EXPORT_SYMBOL(mempool_resize);
+
+/**
+ * mempool_alloc - allocate an element from a specific memory pool
+ * @pool: pointer to the memory pool which was allocated via
+ * mempool_create().
+ * @gfp_mask: the usual allocation bitmask.
+ *
+ * this function only sleeps if the alloc_fn() function sleeps or
+ * returns NULL. Note that due to preallocation, this function
+ * *never* fails when called from process contexts. (it might
+ * fail if called from an IRQ context.)
+ */
+void * mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
+{
+ void *element;
+ unsigned long flags;
+ wait_queue_t wait;
+ gfp_t gfp_temp;
+
+ might_sleep_if(gfp_mask & __GFP_WAIT);
+
+ gfp_mask |= __GFP_NOMEMALLOC; /* don't allocate emergency reserves */
+ gfp_mask |= __GFP_NORETRY; /* don't loop in __alloc_pages */
+ gfp_mask |= __GFP_NOWARN; /* failures are OK */
+
+ gfp_temp = gfp_mask & ~(__GFP_WAIT|__GFP_IO);
+
+repeat_alloc:
+
+ element = pool->alloc(gfp_temp, pool->pool_data);
+ if (likely(element != NULL))
+ return element;
+
+ spin_lock_irqsave(&pool->lock, flags);
+ if (likely(pool->curr_nr)) {
+ element = remove_element(pool);
+ spin_unlock_irqrestore(&pool->lock, flags);
+ /* paired with rmb in mempool_free(), read comment there */
+ smp_wmb();
+ return element;
+ }
+
+ /*
+ * We use gfp mask w/o __GFP_WAIT or IO for the first round. If
+ * alloc failed with that and @pool was empty, retry immediately.
+ */
+ if (gfp_temp != gfp_mask) {
+ spin_unlock_irqrestore(&pool->lock, flags);
+ gfp_temp = gfp_mask;
+ goto repeat_alloc;
+ }
+
+ /* We must not sleep if !__GFP_WAIT */
+ if (!(gfp_mask & __GFP_WAIT)) {
+ spin_unlock_irqrestore(&pool->lock, flags);
+ return NULL;
+ }
+
+ /* Let's wait for someone else to return an element to @pool */
+ init_wait(&wait);
+ prepare_to_wait(&pool->wait, &wait, TASK_UNINTERRUPTIBLE);
+
+ spin_unlock_irqrestore(&pool->lock, flags);
+
+ /*
+ * FIXME: this should be io_schedule(). The timeout is there as a
+ * workaround for some DM problems in 2.6.18.
+ */
+ io_schedule_timeout(5*HZ);
+
+ finish_wait(&pool->wait, &wait);
+ goto repeat_alloc;
+}
+EXPORT_SYMBOL(mempool_alloc);
+
+/**
+ * mempool_free - return an element to the pool.
+ * @element: pool element pointer.
+ * @pool: pointer to the memory pool which was allocated via
+ * mempool_create().
+ *
+ * this function only sleeps if the free_fn() function sleeps.
+ */
+void mempool_free(void *element, mempool_t *pool)
+{
+ unsigned long flags;
+
+ if (unlikely(element == NULL))
+ return;
+
+ /*
+ * Paired with the wmb in mempool_alloc(). The preceding read is
+ * for @element and the following @pool->curr_nr. This ensures
+ * that the visible value of @pool->curr_nr is from after the
+ * allocation of @element. This is necessary for fringe cases
+ * where @element was passed to this task without going through
+ * barriers.
+ *
+ * For example, assume @p is %NULL at the beginning and one task
+ * performs "p = mempool_alloc(...);" while another task is doing
+ * "while (!p) cpu_relax(); mempool_free(p, ...);". This function
+ * may end up using curr_nr value which is from before allocation
+ * of @p without the following rmb.
+ */
+ smp_rmb();
+
+ /*
+ * For correctness, we need a test which is guaranteed to trigger
+ * if curr_nr + #allocated == min_nr. Testing curr_nr < min_nr
+ * without locking achieves that and refilling as soon as possible
+ * is desirable.
+ *
+ * Because curr_nr visible here is always a value after the
+ * allocation of @element, any task which decremented curr_nr below
+ * min_nr is guaranteed to see curr_nr < min_nr unless curr_nr gets
+ * incremented to min_nr afterwards. If curr_nr gets incremented
+ * to min_nr after the allocation of @element, the elements
+ * allocated after that are subject to the same guarantee.
+ *
+ * Waiters happen iff curr_nr is 0 and the above guarantee also
+ * ensures that there will be frees which return elements to the
+ * pool waking up the waiters.
+ */
+ if (pool->curr_nr < pool->min_nr) {
+ spin_lock_irqsave(&pool->lock, flags);
+ if (pool->curr_nr < pool->min_nr) {
+ add_element(pool, element);
+ spin_unlock_irqrestore(&pool->lock, flags);
+ wake_up(&pool->wait);
+ return;
+ }
+ spin_unlock_irqrestore(&pool->lock, flags);
+ }
+ pool->free(element, pool->pool_data);
+}
+EXPORT_SYMBOL(mempool_free);
+
+/*
+ * A commonly used alloc and free fn.
+ */
+void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data)
+{
+ struct kmem_cache *mem = pool_data;
+ return kmem_cache_alloc(mem, gfp_mask);
+}
+EXPORT_SYMBOL(mempool_alloc_slab);
+
+void mempool_free_slab(void *element, void *pool_data)
+{
+ struct kmem_cache *mem = pool_data;
+ kmem_cache_free(mem, element);
+}
+EXPORT_SYMBOL(mempool_free_slab);
+
+/*
+ * A commonly used alloc and free fn that kmalloc/kfrees the amount of memory
+ * specified by pool_data
+ */
+void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data)
+{
+ size_t size = (size_t)pool_data;
+ return kmalloc(size, gfp_mask);
+}
+EXPORT_SYMBOL(mempool_kmalloc);
+
+void mempool_kfree(void *element, void *pool_data)
+{
+ kfree(element);
+}
+EXPORT_SYMBOL(mempool_kfree);
+
+/*
+ * A simple mempool-backed page allocator that allocates pages
+ * of the order specified by pool_data.
+ */
+void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data)
+{
+ int order = (int)(long)pool_data;
+ return alloc_pages(gfp_mask, order);
+}
+EXPORT_SYMBOL(mempool_alloc_pages);
+
+void mempool_free_pages(void *element, void *pool_data)
+{
+ int order = (int)(long)pool_data;
+ __free_pages(element, order);
+}
+EXPORT_SYMBOL(mempool_free_pages);
diff --git a/ap/os/linux/linux-3.4.x/mm/migrate.c b/ap/os/linux/linux-3.4.x/mm/migrate.c
new file mode 100644
index 0000000..07b6761
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/migrate.c
@@ -0,0 +1,1455 @@
+/*
+ * Memory Migration functionality - linux/mm/migration.c
+ *
+ * Copyright (C) 2006 Silicon Graphics, Inc., Christoph Lameter
+ *
+ * Page migration was first developed in the context of the memory hotplug
+ * project. The main authors of the migration code are:
+ *
+ * IWAMOTO Toshihiro <iwamoto@valinux.co.jp>
+ * Hirokazu Takahashi <taka@valinux.co.jp>
+ * Dave Hansen <haveblue@us.ibm.com>
+ * Christoph Lameter
+ */
+
+#include <linux/migrate.h>
+#include <linux/export.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/pagemap.h>
+#include <linux/buffer_head.h>
+#include <linux/mm_inline.h>
+#include <linux/nsproxy.h>
+#include <linux/pagevec.h>
+#include <linux/ksm.h>
+#include <linux/rmap.h>
+#include <linux/topology.h>
+#include <linux/cpu.h>
+#include <linux/cpuset.h>
+#include <linux/writeback.h>
+#include <linux/mempolicy.h>
+#include <linux/vmalloc.h>
+#include <linux/security.h>
+#include <linux/memcontrol.h>
+#include <linux/syscalls.h>
+#include <linux/hugetlb.h>
+#include <linux/gfp.h>
+
+#include <asm/tlbflush.h>
+
+#include "internal.h"
+
+/*
+ * migrate_prep() needs to be called before we start compiling a list of pages
+ * to be migrated using isolate_lru_page(). If scheduling work on other CPUs is
+ * undesirable, use migrate_prep_local()
+ */
+int migrate_prep(void)
+{
+ /*
+ * Clear the LRU lists so pages can be isolated.
+ * Note that pages may be moved off the LRU after we have
+ * drained them. Those pages will fail to migrate like other
+ * pages that may be busy.
+ */
+ lru_add_drain_all();
+
+ return 0;
+}
+
+/* Do the necessary work of migrate_prep but not if it involves other CPUs */
+int migrate_prep_local(void)
+{
+ lru_add_drain();
+
+ return 0;
+}
+
+/*
+ * Add isolated pages on the list back to the LRU under page lock
+ * to avoid leaking evictable pages back onto unevictable list.
+ */
+void putback_lru_pages(struct list_head *l)
+{
+ struct page *page;
+ struct page *page2;
+
+ list_for_each_entry_safe(page, page2, l, lru) {
+ list_del(&page->lru);
+ dec_zone_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+ putback_lru_page(page);
+ }
+}
+
+/*
+ * Restore a potential migration pte to a working pte entry
+ */
+static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
+ unsigned long addr, void *old)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ swp_entry_t entry;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *ptep, pte;
+ spinlock_t *ptl;
+
+ if (unlikely(PageHuge(new))) {
+ ptep = huge_pte_offset(mm, addr);
+ if (!ptep)
+ goto out;
+ ptl = &mm->page_table_lock;
+ } else {
+ pgd = pgd_offset(mm, addr);
+ if (!pgd_present(*pgd))
+ goto out;
+
+ pud = pud_offset(pgd, addr);
+ if (!pud_present(*pud))
+ goto out;
+
+ pmd = pmd_offset(pud, addr);
+ if (pmd_trans_huge(*pmd))
+ goto out;
+ if (!pmd_present(*pmd))
+ goto out;
+
+ ptep = pte_offset_map(pmd, addr);
+
+ /*
+ * Peek to check is_swap_pte() before taking ptlock? No, we
+ * can race mremap's move_ptes(), which skips anon_vma lock.
+ */
+
+ ptl = pte_lockptr(mm, pmd);
+ }
+
+ spin_lock(ptl);
+ pte = *ptep;
+ if (!is_swap_pte(pte))
+ goto unlock;
+
+ entry = pte_to_swp_entry(pte);
+
+ if (!is_migration_entry(entry) ||
+ migration_entry_to_page(entry) != old)
+ goto unlock;
+
+ get_page(new);
+ pte = pte_mkold(mk_pte(new, vma->vm_page_prot));
+
+ /* Recheck VMA as permissions can change since migration started */
+ if (is_write_migration_entry(entry))
+ pte = maybe_mkwrite(pte, vma);
+
+#ifdef CONFIG_HUGETLB_PAGE
+ if (PageHuge(new))
+ pte = pte_mkhuge(pte);
+#endif
+ flush_dcache_page(new);
+ set_pte_at(mm, addr, ptep, pte);
+
+ if (PageHuge(new)) {
+ if (PageAnon(new))
+ hugepage_add_anon_rmap(new, vma, addr);
+ else
+ page_dup_rmap(new);
+ } else if (PageAnon(new))
+ page_add_anon_rmap(new, vma, addr);
+ else
+ page_add_file_rmap(new);
+
+ /* No need to invalidate - it was non-present before */
+ update_mmu_cache(vma, addr, ptep);
+unlock:
+ pte_unmap_unlock(ptep, ptl);
+out:
+ return SWAP_AGAIN;
+}
+
+/*
+ * Get rid of all migration entries and replace them by
+ * references to the indicated page.
+ */
+static void remove_migration_ptes(struct page *old, struct page *new)
+{
+ rmap_walk(new, remove_migration_pte, old);
+}
+
+/*
+ * Something used the pte of a page under migration. We need to
+ * get to the page and wait until migration is finished.
+ * When we return from this function the fault will be retried.
+ */
+static void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
+ spinlock_t *ptl)
+{
+ pte_t pte;
+ swp_entry_t entry;
+ struct page *page;
+
+ spin_lock(ptl);
+ pte = *ptep;
+ if (!is_swap_pte(pte))
+ goto out;
+
+ entry = pte_to_swp_entry(pte);
+ if (!is_migration_entry(entry))
+ goto out;
+
+ page = migration_entry_to_page(entry);
+
+ /*
+ * Once radix-tree replacement of page migration started, page_count
+ * *must* be zero. And, we don't want to call wait_on_page_locked()
+ * against a page without get_page().
+ * So, we use get_page_unless_zero(), here. Even failed, page fault
+ * will occur again.
+ */
+ if (!get_page_unless_zero(page))
+ goto out;
+ pte_unmap_unlock(ptep, ptl);
+ wait_on_page_locked(page);
+ put_page(page);
+ return;
+out:
+ pte_unmap_unlock(ptep, ptl);
+}
+
+void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
+ unsigned long address)
+{
+ spinlock_t *ptl = pte_lockptr(mm, pmd);
+ pte_t *ptep = pte_offset_map(pmd, address);
+ __migration_entry_wait(mm, ptep, ptl);
+}
+
+void migration_entry_wait_huge(struct mm_struct *mm, pte_t *pte)
+{
+ spinlock_t *ptl = &(mm)->page_table_lock;
+ __migration_entry_wait(mm, pte, ptl);
+}
+
+#ifdef CONFIG_BLOCK
+/* Returns true if all buffers are successfully locked */
+static bool buffer_migrate_lock_buffers(struct buffer_head *head,
+ enum migrate_mode mode)
+{
+ struct buffer_head *bh = head;
+
+ /* Simple case, sync compaction */
+ if (mode != MIGRATE_ASYNC) {
+ do {
+ get_bh(bh);
+ lock_buffer(bh);
+ bh = bh->b_this_page;
+
+ } while (bh != head);
+
+ return true;
+ }
+
+ /* async case, we cannot block on lock_buffer so use trylock_buffer */
+ do {
+ get_bh(bh);
+ if (!trylock_buffer(bh)) {
+ /*
+ * We failed to lock the buffer and cannot stall in
+ * async migration. Release the taken locks
+ */
+ struct buffer_head *failed_bh = bh;
+ put_bh(failed_bh);
+ bh = head;
+ while (bh != failed_bh) {
+ unlock_buffer(bh);
+ put_bh(bh);
+ bh = bh->b_this_page;
+ }
+ return false;
+ }
+
+ bh = bh->b_this_page;
+ } while (bh != head);
+ return true;
+}
+#else
+static inline bool buffer_migrate_lock_buffers(struct buffer_head *head,
+ enum migrate_mode mode)
+{
+ return true;
+}
+#endif /* CONFIG_BLOCK */
+
+/*
+ * Replace the page in the mapping.
+ *
+ * The number of remaining references must be:
+ * 1 for anonymous pages without a mapping
+ * 2 for pages with a mapping
+ * 3 for pages with a mapping and PagePrivate/PagePrivate2 set.
+ */
+static int migrate_page_move_mapping(struct address_space *mapping,
+ struct page *newpage, struct page *page,
+ struct buffer_head *head, enum migrate_mode mode)
+{
+ int expected_count;
+ void **pslot;
+
+ if (!mapping) {
+ /* Anonymous page without mapping */
+ if (page_count(page) != 1)
+ return -EAGAIN;
+ return 0;
+ }
+
+ spin_lock_irq(&mapping->tree_lock);
+
+ pslot = radix_tree_lookup_slot(&mapping->page_tree,
+ page_index(page));
+
+ expected_count = 2 + page_has_private(page);
+ if (page_count(page) != expected_count ||
+ radix_tree_deref_slot_protected(pslot, &mapping->tree_lock) != page) {
+ spin_unlock_irq(&mapping->tree_lock);
+ return -EAGAIN;
+ }
+
+ if (!page_freeze_refs(page, expected_count)) {
+ spin_unlock_irq(&mapping->tree_lock);
+ return -EAGAIN;
+ }
+
+ /*
+ * In the async migration case of moving a page with buffers, lock the
+ * buffers using trylock before the mapping is moved. If the mapping
+ * was moved, we later failed to lock the buffers and could not move
+ * the mapping back due to an elevated page count, we would have to
+ * block waiting on other references to be dropped.
+ */
+ if (mode == MIGRATE_ASYNC && head &&
+ !buffer_migrate_lock_buffers(head, mode)) {
+ page_unfreeze_refs(page, expected_count);
+ spin_unlock_irq(&mapping->tree_lock);
+ return -EAGAIN;
+ }
+
+ /*
+ * Now we know that no one else is looking at the page.
+ */
+ get_page(newpage); /* add cache reference */
+ if (PageSwapCache(page)) {
+ SetPageSwapCache(newpage);
+ set_page_private(newpage, page_private(page));
+ }
+
+ radix_tree_replace_slot(pslot, newpage);
+
+ /*
+ * Drop cache reference from old page by unfreezing
+ * to one less reference.
+ * We know this isn't the last reference.
+ */
+ page_unfreeze_refs(page, expected_count - 1);
+
+ /*
+ * If moved to a different zone then also account
+ * the page for that zone. Other VM counters will be
+ * taken care of when we establish references to the
+ * new page and drop references to the old page.
+ *
+ * Note that anonymous pages are accounted for
+ * via NR_FILE_PAGES and NR_ANON_PAGES if they
+ * are mapped to swap space.
+ */
+ __dec_zone_page_state(page, NR_FILE_PAGES);
+ __inc_zone_page_state(newpage, NR_FILE_PAGES);
+ if (!PageSwapCache(page) && PageSwapBacked(page)) {
+ __dec_zone_page_state(page, NR_SHMEM);
+ __inc_zone_page_state(newpage, NR_SHMEM);
+ }
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+ if(mapping_gfp_mask(mapping) & __GFP_PAGERAMFS) {
+ __dec_zone_page_state(page, NR_RAMFS_PAGES);
+ __inc_zone_page_state(newpage, NR_RAMFS_PAGES);
+ }
+ else if(mapping_gfp_mask(mapping) & __GFP_PAGETMPFS) {
+ __dec_zone_page_state(page, NR_TMPFS_PAGES);
+ __inc_zone_page_state(newpage, NR_TMPFS_PAGES);
+ }
+
+#endif
+ spin_unlock_irq(&mapping->tree_lock);
+
+ return 0;
+}
+
+/*
+ * The expected number of remaining references is the same as that
+ * of migrate_page_move_mapping().
+ */
+int migrate_huge_page_move_mapping(struct address_space *mapping,
+ struct page *newpage, struct page *page)
+{
+ int expected_count;
+ void **pslot;
+
+ if (!mapping) {
+ if (page_count(page) != 1)
+ return -EAGAIN;
+ return 0;
+ }
+
+ spin_lock_irq(&mapping->tree_lock);
+
+ pslot = radix_tree_lookup_slot(&mapping->page_tree,
+ page_index(page));
+
+ expected_count = 2 + page_has_private(page);
+ if (page_count(page) != expected_count ||
+ radix_tree_deref_slot_protected(pslot, &mapping->tree_lock) != page) {
+ spin_unlock_irq(&mapping->tree_lock);
+ return -EAGAIN;
+ }
+
+ if (!page_freeze_refs(page, expected_count)) {
+ spin_unlock_irq(&mapping->tree_lock);
+ return -EAGAIN;
+ }
+
+ get_page(newpage);
+
+ radix_tree_replace_slot(pslot, newpage);
+
+ page_unfreeze_refs(page, expected_count - 1);
+
+ spin_unlock_irq(&mapping->tree_lock);
+ return 0;
+}
+
+/*
+ * Copy the page to its new location
+ */
+void migrate_page_copy(struct page *newpage, struct page *page)
+{
+ if (PageHuge(page))
+ copy_huge_page(newpage, page);
+ else
+ copy_highpage(newpage, page);
+
+ if (PageError(page))
+ SetPageError(newpage);
+ if (PageReferenced(page))
+ SetPageReferenced(newpage);
+ if (PageUptodate(page))
+ SetPageUptodate(newpage);
+ if (TestClearPageActive(page)) {
+ VM_BUG_ON(PageUnevictable(page));
+ SetPageActive(newpage);
+ } else if (TestClearPageUnevictable(page))
+ SetPageUnevictable(newpage);
+ if (PageChecked(page))
+ SetPageChecked(newpage);
+ if (PageMappedToDisk(page))
+ SetPageMappedToDisk(newpage);
+
+ if (PageDirty(page)) {
+ clear_page_dirty_for_io(page);
+ /*
+ * Want to mark the page and the radix tree as dirty, and
+ * redo the accounting that clear_page_dirty_for_io undid,
+ * but we can't use set_page_dirty because that function
+ * is actually a signal that all of the page has become dirty.
+ * Whereas only part of our page may be dirty.
+ */
+ __set_page_dirty_nobuffers(newpage);
+ }
+
+ mlock_migrate_page(newpage, page);
+ ksm_migrate_page(newpage, page);
+
+ ClearPageSwapCache(page);
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+
+ /*
+ * If any waiters have accumulated on the new page then
+ * wake them up.
+ */
+ if (PageWriteback(newpage))
+ end_page_writeback(newpage);
+}
+
+/************************************************************
+ * Migration functions
+ ***********************************************************/
+
+/* Always fail migration. Used for mappings that are not movable */
+int fail_migrate_page(struct address_space *mapping,
+ struct page *newpage, struct page *page)
+{
+ return -EIO;
+}
+EXPORT_SYMBOL(fail_migrate_page);
+
+/*
+ * Common logic to directly migrate a single page suitable for
+ * pages that do not use PagePrivate/PagePrivate2.
+ *
+ * Pages are locked upon entry and exit.
+ */
+int migrate_page(struct address_space *mapping,
+ struct page *newpage, struct page *page,
+ enum migrate_mode mode)
+{
+ int rc;
+
+ BUG_ON(PageWriteback(page)); /* Writeback must be complete */
+
+ rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode);
+
+ if (rc)
+ return rc;
+
+ migrate_page_copy(newpage, page);
+ return 0;
+}
+EXPORT_SYMBOL(migrate_page);
+
+#ifdef CONFIG_BLOCK
+/*
+ * Migration function for pages with buffers. This function can only be used
+ * if the underlying filesystem guarantees that no other references to "page"
+ * exist.
+ */
+int buffer_migrate_page(struct address_space *mapping,
+ struct page *newpage, struct page *page, enum migrate_mode mode)
+{
+ struct buffer_head *bh, *head;
+ int rc;
+
+ if (!page_has_buffers(page))
+ return migrate_page(mapping, newpage, page, mode);
+
+ head = page_buffers(page);
+
+ rc = migrate_page_move_mapping(mapping, newpage, page, head, mode);
+
+ if (rc)
+ return rc;
+
+ /*
+ * In the async case, migrate_page_move_mapping locked the buffers
+ * with an IRQ-safe spinlock held. In the sync case, the buffers
+ * need to be locked now
+ */
+ if (mode != MIGRATE_ASYNC)
+ BUG_ON(!buffer_migrate_lock_buffers(head, mode));
+
+ ClearPagePrivate(page);
+ set_page_private(newpage, page_private(page));
+ set_page_private(page, 0);
+ put_page(page);
+ get_page(newpage);
+
+ bh = head;
+ do {
+ set_bh_page(bh, newpage, bh_offset(bh));
+ bh = bh->b_this_page;
+
+ } while (bh != head);
+
+ SetPagePrivate(newpage);
+
+ migrate_page_copy(newpage, page);
+
+ bh = head;
+ do {
+ unlock_buffer(bh);
+ put_bh(bh);
+ bh = bh->b_this_page;
+
+ } while (bh != head);
+
+ return 0;
+}
+EXPORT_SYMBOL(buffer_migrate_page);
+#endif
+
+/*
+ * Writeback a page to clean the dirty state
+ */
+static int writeout(struct address_space *mapping, struct page *page)
+{
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_NONE,
+ .nr_to_write = 1,
+ .range_start = 0,
+ .range_end = LLONG_MAX,
+ .for_reclaim = 1
+ };
+ int rc;
+
+ if (!mapping->a_ops->writepage)
+ /* No write method for the address space */
+ return -EINVAL;
+
+ if (!clear_page_dirty_for_io(page))
+ /* Someone else already triggered a write */
+ return -EAGAIN;
+
+ /*
+ * A dirty page may imply that the underlying filesystem has
+ * the page on some queue. So the page must be clean for
+ * migration. Writeout may mean we loose the lock and the
+ * page state is no longer what we checked for earlier.
+ * At this point we know that the migration attempt cannot
+ * be successful.
+ */
+ remove_migration_ptes(page, page);
+
+ rc = mapping->a_ops->writepage(page, &wbc);
+
+ if (rc != AOP_WRITEPAGE_ACTIVATE)
+ /* unlocked. Relock */
+ lock_page(page);
+
+ return (rc < 0) ? -EIO : -EAGAIN;
+}
+
+/*
+ * Default handling if a filesystem does not provide a migration function.
+ */
+static int fallback_migrate_page(struct address_space *mapping,
+ struct page *newpage, struct page *page, enum migrate_mode mode)
+{
+ if (PageDirty(page)) {
+ /* Only writeback pages in full synchronous migration */
+ if (mode != MIGRATE_SYNC)
+ return -EBUSY;
+ return writeout(mapping, page);
+ }
+
+ /*
+ * Buffers may be managed in a filesystem specific way.
+ * We must have no buffers or drop them.
+ */
+ if (page_has_private(page) &&
+ !try_to_release_page(page, GFP_KERNEL))
+ return -EAGAIN;
+
+ return migrate_page(mapping, newpage, page, mode);
+}
+
+/*
+ * Move a page to a newly allocated page
+ * The page is locked and all ptes have been successfully removed.
+ *
+ * The new page will have replaced the old page if this function
+ * is successful.
+ *
+ * Return value:
+ * < 0 - error code
+ * == 0 - success
+ */
+static int move_to_new_page(struct page *newpage, struct page *page,
+ int remap_swapcache, enum migrate_mode mode)
+{
+ struct address_space *mapping;
+ int rc;
+
+ /*
+ * Block others from accessing the page when we get around to
+ * establishing additional references. We are the only one
+ * holding a reference to the new page at this point.
+ */
+ if (!trylock_page(newpage))
+ BUG();
+
+ /* Prepare mapping for the new page.*/
+ newpage->index = page->index;
+ newpage->mapping = page->mapping;
+ if (PageSwapBacked(page))
+ SetPageSwapBacked(newpage);
+
+ mapping = page_mapping(page);
+ if (!mapping)
+ rc = migrate_page(mapping, newpage, page, mode);
+ else if (mapping->a_ops->migratepage)
+ /*
+ * Most pages have a mapping and most filesystems provide a
+ * migratepage callback. Anonymous pages are part of swap
+ * space which also has its own migratepage callback. This
+ * is the most common path for page migration.
+ */
+ rc = mapping->a_ops->migratepage(mapping,
+ newpage, page, mode);
+ else
+ rc = fallback_migrate_page(mapping, newpage, page, mode);
+
+ if (rc) {
+ newpage->mapping = NULL;
+ } else {
+ if (remap_swapcache)
+ remove_migration_ptes(page, newpage);
+ page->mapping = NULL;
+ }
+
+ unlock_page(newpage);
+
+ return rc;
+}
+
+static int __unmap_and_move(struct page *page, struct page *newpage,
+ int force, bool offlining, enum migrate_mode mode)
+{
+ int rc = -EAGAIN;
+ int remap_swapcache = 1;
+ int charge = 0;
+ struct mem_cgroup *mem;
+ struct anon_vma *anon_vma = NULL;
+
+ if (!trylock_page(page)) {
+ if (!force || mode == MIGRATE_ASYNC)
+ goto out;
+
+ /*
+ * It's not safe for direct compaction to call lock_page.
+ * For example, during page readahead pages are added locked
+ * to the LRU. Later, when the IO completes the pages are
+ * marked uptodate and unlocked. However, the queueing
+ * could be merging multiple pages for one bio (e.g.
+ * mpage_readpages). If an allocation happens for the
+ * second or third page, the process can end up locking
+ * the same page twice and deadlocking. Rather than
+ * trying to be clever about what pages can be locked,
+ * avoid the use of lock_page for direct compaction
+ * altogether.
+ */
+ if (current->flags & PF_MEMALLOC)
+ goto out;
+
+ lock_page(page);
+ }
+
+ /*
+ * Only memory hotplug's offline_pages() caller has locked out KSM,
+ * and can safely migrate a KSM page. The other cases have skipped
+ * PageKsm along with PageReserved - but it is only now when we have
+ * the page lock that we can be certain it will not go KSM beneath us
+ * (KSM will not upgrade a page from PageAnon to PageKsm when it sees
+ * its pagecount raised, but only here do we take the page lock which
+ * serializes that).
+ */
+ if (PageKsm(page) && !offlining) {
+ rc = -EBUSY;
+ goto unlock;
+ }
+
+ /* charge against new page */
+ charge = mem_cgroup_prepare_migration(page, newpage, &mem, GFP_KERNEL);
+ if (charge == -ENOMEM) {
+ rc = -ENOMEM;
+ goto unlock;
+ }
+ BUG_ON(charge);
+
+ if (PageWriteback(page)) {
+ /*
+ * Only in the case of a full syncronous migration is it
+ * necessary to wait for PageWriteback. In the async case,
+ * the retry loop is too short and in the sync-light case,
+ * the overhead of stalling is too much
+ */
+ if (mode != MIGRATE_SYNC) {
+ rc = -EBUSY;
+ goto uncharge;
+ }
+ if (!force)
+ goto uncharge;
+ wait_on_page_writeback(page);
+ }
+ /*
+ * By try_to_unmap(), page->mapcount goes down to 0 here. In this case,
+ * we cannot notice that anon_vma is freed while we migrates a page.
+ * This get_anon_vma() delays freeing anon_vma pointer until the end
+ * of migration. File cache pages are no problem because of page_lock()
+ * File Caches may use write_page() or lock_page() in migration, then,
+ * just care Anon page here.
+ */
+ if (PageAnon(page)) {
+ /*
+ * Only page_lock_anon_vma() understands the subtleties of
+ * getting a hold on an anon_vma from outside one of its mms.
+ */
+ anon_vma = page_get_anon_vma(page);
+ if (anon_vma) {
+ /*
+ * Anon page
+ */
+ } else if (PageSwapCache(page)) {
+ /*
+ * We cannot be sure that the anon_vma of an unmapped
+ * swapcache page is safe to use because we don't
+ * know in advance if the VMA that this page belonged
+ * to still exists. If the VMA and others sharing the
+ * data have been freed, then the anon_vma could
+ * already be invalid.
+ *
+ * To avoid this possibility, swapcache pages get
+ * migrated but are not remapped when migration
+ * completes
+ */
+ remap_swapcache = 0;
+ } else {
+ goto uncharge;
+ }
+ }
+
+ /*
+ * Corner case handling:
+ * 1. When a new swap-cache page is read into, it is added to the LRU
+ * and treated as swapcache but it has no rmap yet.
+ * Calling try_to_unmap() against a page->mapping==NULL page will
+ * trigger a BUG. So handle it here.
+ * 2. An orphaned page (see truncate_complete_page) might have
+ * fs-private metadata. The page can be picked up due to memory
+ * offlining. Everywhere else except page reclaim, the page is
+ * invisible to the vm, so the page can not be migrated. So try to
+ * free the metadata, so the page can be freed.
+ */
+ if (!page->mapping) {
+ VM_BUG_ON(PageAnon(page));
+ if (page_has_private(page)) {
+ try_to_free_buffers(page);
+ goto uncharge;
+ }
+ goto skip_unmap;
+ }
+
+ /* Establish migration ptes or remove ptes */
+ try_to_unmap(page, TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+
+skip_unmap:
+ if (!page_mapped(page))
+ rc = move_to_new_page(newpage, page, remap_swapcache, mode);
+
+ if (rc && remap_swapcache)
+ remove_migration_ptes(page, page);
+
+ /* Drop an anon_vma reference if we took one */
+ if (anon_vma)
+ put_anon_vma(anon_vma);
+
+uncharge:
+ if (!charge)
+ mem_cgroup_end_migration(mem, page, newpage, rc == 0);
+unlock:
+ unlock_page(page);
+out:
+ return rc;
+}
+
+/*
+ * Obtain the lock on page, remove all ptes and migrate the page
+ * to the newly allocated page in newpage.
+ */
+static int unmap_and_move(new_page_t get_new_page, unsigned long private,
+ struct page *page, int force, bool offlining,
+ enum migrate_mode mode)
+{
+ int rc = 0;
+ int *result = NULL;
+ struct page *newpage = get_new_page(page, private, &result);
+
+ if (!newpage)
+ return -ENOMEM;
+
+ if (page_count(page) == 1) {
+ /* page was freed from under us. So we are done. */
+ goto out;
+ }
+
+ if (unlikely(PageTransHuge(page)))
+ if (unlikely(split_huge_page(page)))
+ goto out;
+
+ rc = __unmap_and_move(page, newpage, force, offlining, mode);
+out:
+ if (rc != -EAGAIN) {
+ /*
+ * A page that has been migrated has all references
+ * removed and will be freed. A page that has not been
+ * migrated will have kepts its references and be
+ * restored.
+ */
+ list_del(&page->lru);
+ dec_zone_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+ putback_lru_page(page);
+ }
+ /*
+ * Move the new page to the LRU. If migration was not successful
+ * then this will free the page.
+ */
+ putback_lru_page(newpage);
+ if (result) {
+ if (rc)
+ *result = rc;
+ else
+ *result = page_to_nid(newpage);
+ }
+ return rc;
+}
+
+/*
+ * Counterpart of unmap_and_move_page() for hugepage migration.
+ *
+ * This function doesn't wait the completion of hugepage I/O
+ * because there is no race between I/O and migration for hugepage.
+ * Note that currently hugepage I/O occurs only in direct I/O
+ * where no lock is held and PG_writeback is irrelevant,
+ * and writeback status of all subpages are counted in the reference
+ * count of the head page (i.e. if all subpages of a 2MB hugepage are
+ * under direct I/O, the reference of the head page is 512 and a bit more.)
+ * This means that when we try to migrate hugepage whose subpages are
+ * doing direct I/O, some references remain after try_to_unmap() and
+ * hugepage migration fails without data corruption.
+ *
+ * There is also no race when direct I/O is issued on the page under migration,
+ * because then pte is replaced with migration swap entry and direct I/O code
+ * will wait in the page fault for migration to complete.
+ */
+static int unmap_and_move_huge_page(new_page_t get_new_page,
+ unsigned long private, struct page *hpage,
+ int force, bool offlining,
+ enum migrate_mode mode)
+{
+ int rc = 0;
+ int *result = NULL;
+ struct page *new_hpage = get_new_page(hpage, private, &result);
+ struct anon_vma *anon_vma = NULL;
+
+ if (!new_hpage)
+ return -ENOMEM;
+
+ rc = -EAGAIN;
+
+ if (!trylock_page(hpage)) {
+ if (!force || mode != MIGRATE_SYNC)
+ goto out;
+ lock_page(hpage);
+ }
+
+ if (PageAnon(hpage))
+ anon_vma = page_get_anon_vma(hpage);
+
+ try_to_unmap(hpage, TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+
+ if (!page_mapped(hpage))
+ rc = move_to_new_page(new_hpage, hpage, 1, mode);
+
+ if (rc)
+ remove_migration_ptes(hpage, hpage);
+
+ if (anon_vma)
+ put_anon_vma(anon_vma);
+ unlock_page(hpage);
+
+out:
+ if (rc != -EAGAIN) {
+ list_del(&hpage->lru);
+ put_page(hpage);
+ }
+
+ put_page(new_hpage);
+
+ if (result) {
+ if (rc)
+ *result = rc;
+ else
+ *result = page_to_nid(new_hpage);
+ }
+ return rc;
+}
+
+/*
+ * migrate_pages
+ *
+ * The function takes one list of pages to migrate and a function
+ * that determines from the page to be migrated and the private data
+ * the target of the move and allocates the page.
+ *
+ * The function returns after 10 attempts or if no pages
+ * are movable anymore because to has become empty
+ * or no retryable pages exist anymore.
+ * Caller should call putback_lru_pages to return pages to the LRU
+ * or free list only if ret != 0.
+ *
+ * Return: Number of pages not migrated or error code.
+ */
+int migrate_pages(struct list_head *from,
+ new_page_t get_new_page, unsigned long private, bool offlining,
+ enum migrate_mode mode)
+{
+ int retry = 1;
+ int nr_failed = 0;
+ int pass = 0;
+ struct page *page;
+ struct page *page2;
+ int swapwrite = current->flags & PF_SWAPWRITE;
+ int rc;
+
+ if (!swapwrite)
+ current->flags |= PF_SWAPWRITE;
+
+ for(pass = 0; pass < 10 && retry; pass++) {
+ retry = 0;
+
+ list_for_each_entry_safe(page, page2, from, lru) {
+ cond_resched();
+
+ rc = unmap_and_move(get_new_page, private,
+ page, pass > 2, offlining,
+ mode);
+
+ switch(rc) {
+ case -ENOMEM:
+ goto out;
+ case -EAGAIN:
+ retry++;
+ break;
+ case 0:
+ break;
+ default:
+ /* Permanent failure */
+ nr_failed++;
+ break;
+ }
+ }
+ }
+ rc = 0;
+out:
+ if (!swapwrite)
+ current->flags &= ~PF_SWAPWRITE;
+
+ if (rc)
+ return rc;
+
+ return nr_failed + retry;
+}
+
+int migrate_huge_pages(struct list_head *from,
+ new_page_t get_new_page, unsigned long private, bool offlining,
+ enum migrate_mode mode)
+{
+ int retry = 1;
+ int nr_failed = 0;
+ int pass = 0;
+ struct page *page;
+ struct page *page2;
+ int rc;
+
+ for (pass = 0; pass < 10 && retry; pass++) {
+ retry = 0;
+
+ list_for_each_entry_safe(page, page2, from, lru) {
+ cond_resched();
+
+ rc = unmap_and_move_huge_page(get_new_page,
+ private, page, pass > 2, offlining,
+ mode);
+
+ switch(rc) {
+ case -ENOMEM:
+ goto out;
+ case -EAGAIN:
+ retry++;
+ break;
+ case 0:
+ break;
+ default:
+ /* Permanent failure */
+ nr_failed++;
+ break;
+ }
+ }
+ }
+ rc = 0;
+out:
+ if (rc)
+ return rc;
+
+ return nr_failed + retry;
+}
+
+#ifdef CONFIG_NUMA
+/*
+ * Move a list of individual pages
+ */
+struct page_to_node {
+ unsigned long addr;
+ struct page *page;
+ int node;
+ int status;
+};
+
+static struct page *new_page_node(struct page *p, unsigned long private,
+ int **result)
+{
+ struct page_to_node *pm = (struct page_to_node *)private;
+
+ while (pm->node != MAX_NUMNODES && pm->page != p)
+ pm++;
+
+ if (pm->node == MAX_NUMNODES)
+ return NULL;
+
+ *result = &pm->status;
+
+ return alloc_pages_exact_node(pm->node,
+ GFP_HIGHUSER_MOVABLE | GFP_THISNODE, 0);
+}
+
+/*
+ * Move a set of pages as indicated in the pm array. The addr
+ * field must be set to the virtual address of the page to be moved
+ * and the node number must contain a valid target node.
+ * The pm array ends with node = MAX_NUMNODES.
+ */
+static int do_move_page_to_node_array(struct mm_struct *mm,
+ struct page_to_node *pm,
+ int migrate_all)
+{
+ int err;
+ struct page_to_node *pp;
+ LIST_HEAD(pagelist);
+
+ down_read(&mm->mmap_sem);
+
+ /*
+ * Build a list of pages to migrate
+ */
+ for (pp = pm; pp->node != MAX_NUMNODES; pp++) {
+ struct vm_area_struct *vma;
+ struct page *page;
+
+ err = -EFAULT;
+ vma = find_vma(mm, pp->addr);
+ if (!vma || pp->addr < vma->vm_start || !vma_migratable(vma))
+ goto set_status;
+
+ page = follow_page(vma, pp->addr, FOLL_GET|FOLL_SPLIT);
+
+ err = PTR_ERR(page);
+ if (IS_ERR(page))
+ goto set_status;
+
+ err = -ENOENT;
+ if (!page)
+ goto set_status;
+
+ /* Use PageReserved to check for zero page */
+ if (PageReserved(page) || PageKsm(page))
+ goto put_and_set;
+
+ pp->page = page;
+ err = page_to_nid(page);
+
+ if (err == pp->node)
+ /*
+ * Node already in the right place
+ */
+ goto put_and_set;
+
+ err = -EACCES;
+ if (page_mapcount(page) > 1 &&
+ !migrate_all)
+ goto put_and_set;
+
+ err = isolate_lru_page(page);
+ if (!err) {
+ list_add_tail(&page->lru, &pagelist);
+ inc_zone_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+ }
+put_and_set:
+ /*
+ * Either remove the duplicate refcount from
+ * isolate_lru_page() or drop the page ref if it was
+ * not isolated.
+ */
+ put_page(page);
+set_status:
+ pp->status = err;
+ }
+
+ err = 0;
+ if (!list_empty(&pagelist)) {
+ err = migrate_pages(&pagelist, new_page_node,
+ (unsigned long)pm, 0, MIGRATE_SYNC);
+ if (err)
+ putback_lru_pages(&pagelist);
+ }
+
+ up_read(&mm->mmap_sem);
+ return err;
+}
+
+/*
+ * Migrate an array of page address onto an array of nodes and fill
+ * the corresponding array of status.
+ */
+static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes,
+ unsigned long nr_pages,
+ const void __user * __user *pages,
+ const int __user *nodes,
+ int __user *status, int flags)
+{
+ struct page_to_node *pm;
+ unsigned long chunk_nr_pages;
+ unsigned long chunk_start;
+ int err;
+
+ err = -ENOMEM;
+ pm = (struct page_to_node *)__get_free_page(GFP_KERNEL);
+ if (!pm)
+ goto out;
+
+ migrate_prep();
+
+ /*
+ * Store a chunk of page_to_node array in a page,
+ * but keep the last one as a marker
+ */
+ chunk_nr_pages = (PAGE_SIZE / sizeof(struct page_to_node)) - 1;
+
+ for (chunk_start = 0;
+ chunk_start < nr_pages;
+ chunk_start += chunk_nr_pages) {
+ int j;
+
+ if (chunk_start + chunk_nr_pages > nr_pages)
+ chunk_nr_pages = nr_pages - chunk_start;
+
+ /* fill the chunk pm with addrs and nodes from user-space */
+ for (j = 0; j < chunk_nr_pages; j++) {
+ const void __user *p;
+ int node;
+
+ err = -EFAULT;
+ if (get_user(p, pages + j + chunk_start))
+ goto out_pm;
+ pm[j].addr = (unsigned long) p;
+
+ if (get_user(node, nodes + j + chunk_start))
+ goto out_pm;
+
+ err = -ENODEV;
+ if (node < 0 || node >= MAX_NUMNODES)
+ goto out_pm;
+
+ if (!node_state(node, N_HIGH_MEMORY))
+ goto out_pm;
+
+ err = -EACCES;
+ if (!node_isset(node, task_nodes))
+ goto out_pm;
+
+ pm[j].node = node;
+ }
+
+ /* End marker for this chunk */
+ pm[chunk_nr_pages].node = MAX_NUMNODES;
+
+ /* Migrate this chunk */
+ err = do_move_page_to_node_array(mm, pm,
+ flags & MPOL_MF_MOVE_ALL);
+ if (err < 0)
+ goto out_pm;
+
+ /* Return status information */
+ for (j = 0; j < chunk_nr_pages; j++)
+ if (put_user(pm[j].status, status + j + chunk_start)) {
+ err = -EFAULT;
+ goto out_pm;
+ }
+ }
+ err = 0;
+
+out_pm:
+ free_page((unsigned long)pm);
+out:
+ return err;
+}
+
+/*
+ * Determine the nodes of an array of pages and store it in an array of status.
+ */
+static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
+ const void __user **pages, int *status)
+{
+ unsigned long i;
+
+ down_read(&mm->mmap_sem);
+
+ for (i = 0; i < nr_pages; i++) {
+ unsigned long addr = (unsigned long)(*pages);
+ struct vm_area_struct *vma;
+ struct page *page;
+ int err = -EFAULT;
+
+ vma = find_vma(mm, addr);
+ if (!vma || addr < vma->vm_start)
+ goto set_status;
+
+ page = follow_page(vma, addr, 0);
+
+ err = PTR_ERR(page);
+ if (IS_ERR(page))
+ goto set_status;
+
+ err = -ENOENT;
+ /* Use PageReserved to check for zero page */
+ if (!page || PageReserved(page) || PageKsm(page))
+ goto set_status;
+
+ err = page_to_nid(page);
+set_status:
+ *status = err;
+
+ pages++;
+ status++;
+ }
+
+ up_read(&mm->mmap_sem);
+}
+
+/*
+ * Determine the nodes of a user array of pages and store it in
+ * a user array of status.
+ */
+static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,
+ const void __user * __user *pages,
+ int __user *status)
+{
+#define DO_PAGES_STAT_CHUNK_NR 16
+ const void __user *chunk_pages[DO_PAGES_STAT_CHUNK_NR];
+ int chunk_status[DO_PAGES_STAT_CHUNK_NR];
+
+ while (nr_pages) {
+ unsigned long chunk_nr;
+
+ chunk_nr = nr_pages;
+ if (chunk_nr > DO_PAGES_STAT_CHUNK_NR)
+ chunk_nr = DO_PAGES_STAT_CHUNK_NR;
+
+ if (copy_from_user(chunk_pages, pages, chunk_nr * sizeof(*chunk_pages)))
+ break;
+
+ do_pages_stat_array(mm, chunk_nr, chunk_pages, chunk_status);
+
+ if (copy_to_user(status, chunk_status, chunk_nr * sizeof(*status)))
+ break;
+
+ pages += chunk_nr;
+ status += chunk_nr;
+ nr_pages -= chunk_nr;
+ }
+ return nr_pages ? -EFAULT : 0;
+}
+
+/*
+ * Move a list of pages in the address space of the currently executing
+ * process.
+ */
+SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages,
+ const void __user * __user *, pages,
+ const int __user *, nodes,
+ int __user *, status, int, flags)
+{
+ const struct cred *cred = current_cred(), *tcred;
+ struct task_struct *task;
+ struct mm_struct *mm;
+ int err;
+ nodemask_t task_nodes;
+
+ /* Check flags */
+ if (flags & ~(MPOL_MF_MOVE|MPOL_MF_MOVE_ALL))
+ return -EINVAL;
+
+ if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
+ return -EPERM;
+
+ /* Find the mm_struct */
+ rcu_read_lock();
+ task = pid ? find_task_by_vpid(pid) : current;
+ if (!task) {
+ rcu_read_unlock();
+ return -ESRCH;
+ }
+ get_task_struct(task);
+
+ /*
+ * Check if this process has the right to modify the specified
+ * process. The right exists if the process has administrative
+ * capabilities, superuser privileges or the same
+ * userid as the target process.
+ */
+ tcred = __task_cred(task);
+ if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
+ cred->uid != tcred->suid && cred->uid != tcred->uid &&
+ !capable(CAP_SYS_NICE)) {
+ rcu_read_unlock();
+ err = -EPERM;
+ goto out;
+ }
+ rcu_read_unlock();
+
+ err = security_task_movememory(task);
+ if (err)
+ goto out;
+
+ task_nodes = cpuset_mems_allowed(task);
+ mm = get_task_mm(task);
+ put_task_struct(task);
+
+ if (!mm)
+ return -EINVAL;
+
+ if (nodes)
+ err = do_pages_move(mm, task_nodes, nr_pages, pages,
+ nodes, status, flags);
+ else
+ err = do_pages_stat(mm, nr_pages, pages, status);
+
+ mmput(mm);
+ return err;
+
+out:
+ put_task_struct(task);
+ return err;
+}
+
+/*
+ * Call migration functions in the vma_ops that may prepare
+ * memory in a vm for migration. migration functions may perform
+ * the migration for vmas that do not have an underlying page struct.
+ */
+int migrate_vmas(struct mm_struct *mm, const nodemask_t *to,
+ const nodemask_t *from, unsigned long flags)
+{
+ struct vm_area_struct *vma;
+ int err = 0;
+
+ for (vma = mm->mmap; vma && !err; vma = vma->vm_next) {
+ if (vma->vm_ops && vma->vm_ops->migrate) {
+ err = vma->vm_ops->migrate(vma, to, from, flags);
+ if (err)
+ break;
+ }
+ }
+ return err;
+}
+#endif
diff --git a/ap/os/linux/linux-3.4.x/mm/mincore.c b/ap/os/linux/linux-3.4.x/mm/mincore.c
new file mode 100644
index 0000000..936b4ce
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mincore.c
@@ -0,0 +1,315 @@
+/*
+ * linux/mm/mincore.c
+ *
+ * Copyright (C) 1994-2006 Linus Torvalds
+ */
+
+/*
+ * The mincore() system call.
+ */
+#include <linux/pagemap.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/syscalls.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/hugetlb.h>
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+
+static void mincore_hugetlb_page_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
+{
+#ifdef CONFIG_HUGETLB_PAGE
+ struct hstate *h;
+
+ h = hstate_vma(vma);
+ while (1) {
+ unsigned char present;
+ pte_t *ptep;
+ /*
+ * Huge pages are always in RAM for now, but
+ * theoretically it needs to be checked.
+ */
+ ptep = huge_pte_offset(current->mm,
+ addr & huge_page_mask(h));
+ present = ptep && !huge_pte_none(huge_ptep_get(ptep));
+ while (1) {
+ *vec = present;
+ vec++;
+ addr += PAGE_SIZE;
+ if (addr == end)
+ return;
+ /* check hugepage border */
+ if (!(addr & ~huge_page_mask(h)))
+ break;
+ }
+ }
+#else
+ BUG();
+#endif
+}
+
+/*
+ * Later we can get more picky about what "in core" means precisely.
+ * For now, simply check to see if the page is in the page cache,
+ * and is up to date; i.e. that no page-in operation would be required
+ * at this time if an application were to map and access this page.
+ */
+static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff)
+{
+ unsigned char present = 0;
+ struct page *page;
+
+ /*
+ * When tmpfs swaps out a page from a file, any process mapping that
+ * file will not get a swp_entry_t in its pte, but rather it is like
+ * any other file mapping (ie. marked !present and faulted in with
+ * tmpfs's .fault). So swapped out tmpfs mappings are tested here.
+ */
+ page = find_get_page(mapping, pgoff);
+#ifdef CONFIG_SWAP
+ /* shmem/tmpfs may return swap: account for swapcache page too. */
+ if (radix_tree_exceptional_entry(page)) {
+ swp_entry_t swap = radix_to_swp_entry(page);
+ page = find_get_page(&swapper_space, swap.val);
+ }
+#endif
+ if (page) {
+ present = PageUptodate(page);
+ page_cache_release(page);
+ }
+
+ return present;
+}
+
+static void mincore_unmapped_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
+{
+ unsigned long nr = (end - addr) >> PAGE_SHIFT;
+ int i;
+
+ if (vma->vm_file) {
+ pgoff_t pgoff;
+
+ pgoff = linear_page_index(vma, addr);
+ for (i = 0; i < nr; i++, pgoff++)
+ vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
+ } else {
+ for (i = 0; i < nr; i++)
+ vec[i] = 0;
+ }
+}
+
+static void mincore_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
+{
+ unsigned long next;
+ spinlock_t *ptl;
+ pte_t *ptep;
+
+ ptep = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ do {
+ pte_t pte = *ptep;
+ pgoff_t pgoff;
+
+ next = addr + PAGE_SIZE;
+ if (pte_none(pte))
+ mincore_unmapped_range(vma, addr, next, vec);
+ else if (pte_present(pte))
+ *vec = 1;
+ else if (pte_file(pte)) {
+ pgoff = pte_to_pgoff(pte);
+ *vec = mincore_page(vma->vm_file->f_mapping, pgoff);
+ } else { /* pte is a swap entry */
+ swp_entry_t entry = pte_to_swp_entry(pte);
+
+ if (is_migration_entry(entry)) {
+ /* migration entries are always uptodate */
+ *vec = 1;
+ } else {
+#ifdef CONFIG_SWAP
+ pgoff = entry.val;
+ *vec = mincore_page(&swapper_space, pgoff);
+#else
+ WARN_ON(1);
+ *vec = 1;
+#endif
+ }
+ }
+ vec++;
+ } while (ptep++, addr = next, addr != end);
+ pte_unmap_unlock(ptep - 1, ptl);
+}
+
+static void mincore_pmd_range(struct vm_area_struct *vma, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
+{
+ unsigned long next;
+ pmd_t *pmd;
+
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_trans_huge(*pmd)) {
+ if (mincore_huge_pmd(vma, pmd, addr, next, vec)) {
+ vec += (next - addr) >> PAGE_SHIFT;
+ continue;
+ }
+ /* fall through */
+ }
+ if (pmd_none_or_trans_huge_or_clear_bad(pmd))
+ mincore_unmapped_range(vma, addr, next, vec);
+ else
+ mincore_pte_range(vma, pmd, addr, next, vec);
+ vec += (next - addr) >> PAGE_SHIFT;
+ } while (pmd++, addr = next, addr != end);
+}
+
+static void mincore_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
+{
+ unsigned long next;
+ pud_t *pud;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ mincore_unmapped_range(vma, addr, next, vec);
+ else
+ mincore_pmd_range(vma, pud, addr, next, vec);
+ vec += (next - addr) >> PAGE_SHIFT;
+ } while (pud++, addr = next, addr != end);
+}
+
+static void mincore_page_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec)
+{
+ unsigned long next;
+ pgd_t *pgd;
+
+ pgd = pgd_offset(vma->vm_mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ mincore_unmapped_range(vma, addr, next, vec);
+ else
+ mincore_pud_range(vma, pgd, addr, next, vec);
+ vec += (next - addr) >> PAGE_SHIFT;
+ } while (pgd++, addr = next, addr != end);
+}
+
+/*
+ * Do a chunk of "sys_mincore()". We've already checked
+ * all the arguments, we hold the mmap semaphore: we should
+ * just return the amount of info we're asked for.
+ */
+static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *vec)
+{
+ struct vm_area_struct *vma;
+ unsigned long end;
+
+ vma = find_vma(current->mm, addr);
+ if (!vma || addr < vma->vm_start)
+ return -ENOMEM;
+
+ end = min(vma->vm_end, addr + (pages << PAGE_SHIFT));
+
+ if (is_vm_hugetlb_page(vma)) {
+ mincore_hugetlb_page_range(vma, addr, end, vec);
+ return (end - addr) >> PAGE_SHIFT;
+ }
+
+ end = pmd_addr_end(addr, end);
+
+ if (is_vm_hugetlb_page(vma))
+ mincore_hugetlb_page_range(vma, addr, end, vec);
+ else
+ mincore_page_range(vma, addr, end, vec);
+
+ return (end - addr) >> PAGE_SHIFT;
+}
+
+/*
+ * The mincore(2) system call.
+ *
+ * mincore() returns the memory residency status of the pages in the
+ * current process's address space specified by [addr, addr + len).
+ * The status is returned in a vector of bytes. The least significant
+ * bit of each byte is 1 if the referenced page is in memory, otherwise
+ * it is zero.
+ *
+ * Because the status of a page can change after mincore() checks it
+ * but before it returns to the application, the returned vector may
+ * contain stale information. Only locked pages are guaranteed to
+ * remain in memory.
+ *
+ * return values:
+ * zero - success
+ * -EFAULT - vec points to an illegal address
+ * -EINVAL - addr is not a multiple of PAGE_CACHE_SIZE
+ * -ENOMEM - Addresses in the range [addr, addr + len] are
+ * invalid for the address space of this process, or
+ * specify one or more pages which are not currently
+ * mapped
+ * -EAGAIN - A kernel resource was temporarily unavailable.
+ */
+SYSCALL_DEFINE3(mincore, unsigned long, start, size_t, len,
+ unsigned char __user *, vec)
+{
+ long retval;
+ unsigned long pages;
+ unsigned char *tmp;
+
+ /* Check the start address: needs to be page-aligned.. */
+ if (start & ~PAGE_CACHE_MASK)
+ return -EINVAL;
+
+ /* ..and we need to be passed a valid user-space range */
+ if (!access_ok(VERIFY_READ, (void __user *) start, len))
+ return -ENOMEM;
+
+ /* This also avoids any overflows on PAGE_CACHE_ALIGN */
+ pages = len >> PAGE_SHIFT;
+ pages += (len & ~PAGE_MASK) != 0;
+
+ if (!access_ok(VERIFY_WRITE, vec, pages))
+ return -EFAULT;
+
+ tmp = (void *) __get_free_page(GFP_USER);
+ if (!tmp)
+ return -EAGAIN;
+
+ retval = 0;
+ while (pages) {
+ /*
+ * Do at most PAGE_SIZE entries per iteration, due to
+ * the temporary buffer size.
+ */
+ down_read(¤t->mm->mmap_sem);
+ retval = do_mincore(start, min(pages, PAGE_SIZE), tmp);
+ up_read(¤t->mm->mmap_sem);
+
+ if (retval <= 0)
+ break;
+ if (copy_to_user(vec, tmp, retval)) {
+ retval = -EFAULT;
+ break;
+ }
+ pages -= retval;
+ vec += retval;
+ start += retval << PAGE_SHIFT;
+ retval = 0;
+ }
+ free_page((unsigned long) tmp);
+ return retval;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/mlock.c b/ap/os/linux/linux-3.4.x/mm/mlock.c
new file mode 100644
index 0000000..7a84dd1
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mlock.c
@@ -0,0 +1,628 @@
+/*
+ * linux/mm/mlock.c
+ *
+ * (C) Copyright 1995 Linus Torvalds
+ * (C) Copyright 2002 Christoph Hellwig
+ */
+
+#include <linux/capability.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/pagemap.h>
+#include <linux/mempolicy.h>
+#include <linux/syscalls.h>
+#include <linux/sched.h>
+#include <linux/export.h>
+#include <linux/rmap.h>
+#include <linux/mmzone.h>
+#include <linux/hugetlb.h>
+
+#include "internal.h"
+
+int can_do_mlock(void)
+{
+ if (capable(CAP_IPC_LOCK))
+ return 1;
+ if (rlimit(RLIMIT_MEMLOCK) != 0)
+ return 1;
+ return 0;
+}
+EXPORT_SYMBOL(can_do_mlock);
+
+/*
+ * Mlocked pages are marked with PageMlocked() flag for efficient testing
+ * in vmscan and, possibly, the fault path; and to support semi-accurate
+ * statistics.
+ *
+ * An mlocked page [PageMlocked(page)] is unevictable. As such, it will
+ * be placed on the LRU "unevictable" list, rather than the [in]active lists.
+ * The unevictable list is an LRU sibling list to the [in]active lists.
+ * PageUnevictable is set to indicate the unevictable state.
+ *
+ * When lazy mlocking via vmscan, it is important to ensure that the
+ * vma's VM_LOCKED status is not concurrently being modified, otherwise we
+ * may have mlocked a page that is being munlocked. So lazy mlock must take
+ * the mmap_sem for read, and verify that the vma really is locked
+ * (see mm/rmap.c).
+ */
+
+/*
+ * LRU accounting for clear_page_mlock()
+ */
+void __clear_page_mlock(struct page *page)
+{
+ VM_BUG_ON(!PageLocked(page));
+
+ if (!page->mapping) { /* truncated ? */
+ return;
+ }
+
+ dec_zone_page_state(page, NR_MLOCK);
+ count_vm_event(UNEVICTABLE_PGCLEARED);
+ if (!isolate_lru_page(page)) {
+ putback_lru_page(page);
+ } else {
+ /*
+ * We lost the race. the page already moved to evictable list.
+ */
+ if (PageUnevictable(page))
+ count_vm_event(UNEVICTABLE_PGSTRANDED);
+ }
+}
+
+/*
+ * Mark page as mlocked if not already.
+ * If page on LRU, isolate and putback to move to unevictable list.
+ */
+void mlock_vma_page(struct page *page)
+{
+ /* Serialize with page migration */
+ BUG_ON(!PageLocked(page));
+
+ if (!TestSetPageMlocked(page)) {
+ inc_zone_page_state(page, NR_MLOCK);
+ count_vm_event(UNEVICTABLE_PGMLOCKED);
+ if (!isolate_lru_page(page))
+ putback_lru_page(page);
+ }
+}
+
+/**
+ * munlock_vma_page - munlock a vma page
+ * @page - page to be unlocked
+ *
+ * called from munlock()/munmap() path with page supposedly on the LRU.
+ * When we munlock a page, because the vma where we found the page is being
+ * munlock()ed or munmap()ed, we want to check whether other vmas hold the
+ * page locked so that we can leave it on the unevictable lru list and not
+ * bother vmscan with it. However, to walk the page's rmap list in
+ * try_to_munlock() we must isolate the page from the LRU. If some other
+ * task has removed the page from the LRU, we won't be able to do that.
+ * So we clear the PageMlocked as we might not get another chance. If we
+ * can't isolate the page, we leave it for putback_lru_page() and vmscan
+ * [page_referenced()/try_to_unmap()] to deal with.
+ */
+void munlock_vma_page(struct page *page)
+{
+ /* For try_to_munlock() and to serialize with page migration */
+ BUG_ON(!PageLocked(page));
+
+ if (TestClearPageMlocked(page)) {
+ dec_zone_page_state(page, NR_MLOCK);
+ if (!isolate_lru_page(page)) {
+ int ret = SWAP_AGAIN;
+
+ /*
+ * Optimization: if the page was mapped just once,
+ * that's our mapping and we don't need to check all the
+ * other vmas.
+ */
+ if (page_mapcount(page) > 1)
+ ret = try_to_munlock(page);
+ /*
+ * did try_to_unlock() succeed or punt?
+ */
+ if (ret != SWAP_MLOCK)
+ count_vm_event(UNEVICTABLE_PGMUNLOCKED);
+
+ putback_lru_page(page);
+ } else {
+ /*
+ * Some other task has removed the page from the LRU.
+ * putback_lru_page() will take care of removing the
+ * page from the unevictable list, if necessary.
+ * vmscan [page_referenced()] will move the page back
+ * to the unevictable list if some other vma has it
+ * mlocked.
+ */
+ if (PageUnevictable(page))
+ count_vm_event(UNEVICTABLE_PGSTRANDED);
+ else
+ count_vm_event(UNEVICTABLE_PGMUNLOCKED);
+ }
+ }
+}
+
+/**
+ * __mlock_vma_pages_range() - mlock a range of pages in the vma.
+ * @vma: target vma
+ * @start: start address
+ * @end: end address
+ *
+ * This takes care of making the pages present too.
+ *
+ * return 0 on success, negative error code on error.
+ *
+ * vma->vm_mm->mmap_sem must be held for at least read.
+ */
+static long __mlock_vma_pages_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end,
+ int *nonblocking)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long addr = start;
+ int nr_pages = (end - start) / PAGE_SIZE;
+ int gup_flags;
+
+ VM_BUG_ON(start & ~PAGE_MASK);
+ VM_BUG_ON(end & ~PAGE_MASK);
+ VM_BUG_ON(start < vma->vm_start);
+ VM_BUG_ON(end > vma->vm_end);
+ VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem));
+
+ gup_flags = FOLL_TOUCH | FOLL_MLOCK;
+ /*
+ * We want to touch writable mappings with a write fault in order
+ * to break COW, except for shared mappings because these don't COW
+ * and we would not want to dirty them for nothing.
+ */
+ if ((vma->vm_flags & (VM_WRITE | VM_SHARED)) == VM_WRITE)
+ gup_flags |= FOLL_WRITE;
+
+ /*
+ * We want mlock to succeed for regions that have any permissions
+ * other than PROT_NONE.
+ */
+ if (vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC))
+ gup_flags |= FOLL_FORCE;
+
+ return __get_user_pages(current, mm, addr, nr_pages, gup_flags,
+ NULL, NULL, nonblocking);
+}
+
+/*
+ * convert get_user_pages() return value to posix mlock() error
+ */
+static int __mlock_posix_error_return(long retval)
+{
+ if (retval == -EFAULT)
+ retval = -ENOMEM;
+ else if (retval == -ENOMEM)
+ retval = -EAGAIN;
+ return retval;
+}
+
+/**
+ * mlock_vma_pages_range() - mlock pages in specified vma range.
+ * @vma - the vma containing the specfied address range
+ * @start - starting address in @vma to mlock
+ * @end - end address [+1] in @vma to mlock
+ *
+ * For mmap()/mremap()/expansion of mlocked vma.
+ *
+ * return 0 on success for "normal" vmas.
+ *
+ * return number of pages [> 0] to be removed from locked_vm on success
+ * of "special" vmas.
+ */
+long mlock_vma_pages_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ int nr_pages = (end - start) / PAGE_SIZE;
+ BUG_ON(!(vma->vm_flags & VM_LOCKED));
+
+ /*
+ * filter unlockable vmas
+ */
+ if (vma->vm_flags & (VM_IO | VM_PFNMAP))
+ goto no_mlock;
+
+ if (!((vma->vm_flags & (VM_DONTEXPAND | VM_RESERVED)) ||
+ is_vm_hugetlb_page(vma) ||
+ vma == get_gate_vma(current->mm))) {
+
+ __mlock_vma_pages_range(vma, start, end, NULL);
+
+ /* Hide errors from mmap() and other callers */
+ return 0;
+ }
+
+ /*
+ * User mapped kernel pages or huge pages:
+ * make these pages present to populate the ptes, but
+ * fall thru' to reset VM_LOCKED--no need to unlock, and
+ * return nr_pages so these don't get counted against task's
+ * locked limit. huge pages are already counted against
+ * locked vm limit.
+ */
+ make_pages_present(start, end);
+
+no_mlock:
+ vma->vm_flags &= ~VM_LOCKED; /* and don't come back! */
+ return nr_pages; /* error or pages NOT mlocked */
+}
+
+/*
+ * munlock_vma_pages_range() - munlock all pages in the vma range.'
+ * @vma - vma containing range to be munlock()ed.
+ * @start - start address in @vma of the range
+ * @end - end of range in @vma.
+ *
+ * For mremap(), munmap() and exit().
+ *
+ * Called with @vma VM_LOCKED.
+ *
+ * Returns with VM_LOCKED cleared. Callers must be prepared to
+ * deal with this.
+ *
+ * We don't save and restore VM_LOCKED here because pages are
+ * still on lru. In unmap path, pages might be scanned by reclaim
+ * and re-mlocked by try_to_{munlock|unmap} before we unmap and
+ * free them. This will result in freeing mlocked pages.
+ */
+void munlock_vma_pages_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ unsigned long addr;
+
+ lru_add_drain();
+ vma->vm_flags &= ~VM_LOCKED;
+
+ for (addr = start; addr < end; addr += PAGE_SIZE) {
+ struct page *page;
+ /*
+ * Although FOLL_DUMP is intended for get_dump_page(),
+ * it just so happens that its special treatment of the
+ * ZERO_PAGE (returning an error instead of doing get_page)
+ * suits munlock very well (and if somehow an abnormal page
+ * has sneaked into the range, we won't oops here: great).
+ */
+ page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP);
+ if (page && !IS_ERR(page)) {
+ lock_page(page);
+ /*
+ * Like in __mlock_vma_pages_range(),
+ * because we lock page here and migration is
+ * blocked by the elevated reference, we need
+ * only check for file-cache page truncation.
+ */
+ if (page->mapping)
+ munlock_vma_page(page);
+ unlock_page(page);
+ put_page(page);
+ }
+ cond_resched();
+ }
+}
+
+/*
+ * mlock_fixup - handle mlock[all]/munlock[all] requests.
+ *
+ * Filters out "special" vmas -- VM_LOCKED never gets set for these, and
+ * munlock is a no-op. However, for some special vmas, we go ahead and
+ * populate the ptes via make_pages_present().
+ *
+ * For vmas that pass the filters, merge/split as appropriate.
+ */
+static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
+ unsigned long start, unsigned long end, vm_flags_t newflags)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pgoff_t pgoff;
+ int nr_pages;
+ int ret = 0;
+ int lock = !!(newflags & VM_LOCKED);
+
+ if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) ||
+ is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm))
+ goto out; /* don't set VM_LOCKED, don't count */
+
+ pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+ *prev = vma_merge(mm, *prev, start, end, newflags, vma->anon_vma,
+ vma->vm_file, pgoff, vma_policy(vma));
+ if (*prev) {
+ vma = *prev;
+ goto success;
+ }
+
+ if (start != vma->vm_start) {
+ ret = split_vma(mm, vma, start, 1);
+ if (ret)
+ goto out;
+ }
+
+ if (end != vma->vm_end) {
+ ret = split_vma(mm, vma, end, 0);
+ if (ret)
+ goto out;
+ }
+
+success:
+ /*
+ * Keep track of amount of locked VM.
+ */
+ nr_pages = (end - start) >> PAGE_SHIFT;
+ if (!lock)
+ nr_pages = -nr_pages;
+ mm->locked_vm += nr_pages;
+
+ /*
+ * vm_flags is protected by the mmap_sem held in write mode.
+ * It's okay if try_to_unmap_one unmaps a page just after we
+ * set VM_LOCKED, __mlock_vma_pages_range will bring it back.
+ */
+
+ if (lock)
+ vma->vm_flags = newflags;
+ else
+ munlock_vma_pages_range(vma, start, end);
+
+out:
+ *prev = vma;
+ return ret;
+}
+
+static int do_mlock(unsigned long start, size_t len, int on)
+{
+ unsigned long nstart, end, tmp;
+ struct vm_area_struct * vma, * prev;
+ int error;
+
+ VM_BUG_ON(start & ~PAGE_MASK);
+ VM_BUG_ON(len != PAGE_ALIGN(len));
+ end = start + len;
+ if (end < start)
+ return -EINVAL;
+ if (end == start)
+ return 0;
+ vma = find_vma(current->mm, start);
+ if (!vma || vma->vm_start > start)
+ return -ENOMEM;
+
+ prev = vma->vm_prev;
+ if (start > vma->vm_start)
+ prev = vma;
+
+ for (nstart = start ; ; ) {
+ vm_flags_t newflags;
+
+ /* Here we know that vma->vm_start <= nstart < vma->vm_end. */
+
+ newflags = vma->vm_flags | VM_LOCKED;
+ if (!on)
+ newflags &= ~VM_LOCKED;
+
+ tmp = vma->vm_end;
+ if (tmp > end)
+ tmp = end;
+ error = mlock_fixup(vma, &prev, nstart, tmp, newflags);
+ if (error)
+ break;
+ nstart = tmp;
+ if (nstart < prev->vm_end)
+ nstart = prev->vm_end;
+ if (nstart >= end)
+ break;
+
+ vma = prev->vm_next;
+ if (!vma || vma->vm_start != nstart) {
+ error = -ENOMEM;
+ break;
+ }
+ }
+ return error;
+}
+
+static int do_mlock_pages(unsigned long start, size_t len, int ignore_errors)
+{
+ struct mm_struct *mm = current->mm;
+ unsigned long end, nstart, nend;
+ struct vm_area_struct *vma = NULL;
+ int locked = 0;
+ int ret = 0;
+
+ VM_BUG_ON(start & ~PAGE_MASK);
+ VM_BUG_ON(len != PAGE_ALIGN(len));
+ end = start + len;
+
+ for (nstart = start; nstart < end; nstart = nend) {
+ /*
+ * We want to fault in pages for [nstart; end) address range.
+ * Find first corresponding VMA.
+ */
+ if (!locked) {
+ locked = 1;
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, nstart);
+ } else if (nstart >= vma->vm_end)
+ vma = vma->vm_next;
+ if (!vma || vma->vm_start >= end)
+ break;
+ /*
+ * Set [nstart; nend) to intersection of desired address
+ * range with the first VMA. Also, skip undesirable VMA types.
+ */
+ nend = min(end, vma->vm_end);
+ if (vma->vm_flags & (VM_IO | VM_PFNMAP))
+ continue;
+ if (nstart < vma->vm_start)
+ nstart = vma->vm_start;
+ /*
+ * Now fault in a range of pages. __mlock_vma_pages_range()
+ * double checks the vma flags, so that it won't mlock pages
+ * if the vma was already munlocked.
+ */
+ ret = __mlock_vma_pages_range(vma, nstart, nend, &locked);
+ if (ret < 0) {
+ if (ignore_errors) {
+ ret = 0;
+ continue; /* continue at next VMA */
+ }
+ ret = __mlock_posix_error_return(ret);
+ break;
+ }
+ nend = nstart + ret * PAGE_SIZE;
+ ret = 0;
+ }
+ if (locked)
+ up_read(&mm->mmap_sem);
+ return ret; /* 0 or negative error code */
+}
+
+SYSCALL_DEFINE2(mlock, unsigned long, start, size_t, len)
+{
+ unsigned long locked;
+ unsigned long lock_limit;
+ int error = -ENOMEM;
+
+ if (!can_do_mlock())
+ return -EPERM;
+
+ lru_add_drain_all(); /* flush pagevec */
+
+ down_write(¤t->mm->mmap_sem);
+ len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
+ start &= PAGE_MASK;
+
+ locked = len >> PAGE_SHIFT;
+ locked += current->mm->locked_vm;
+
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
+ lock_limit >>= PAGE_SHIFT;
+
+ /* check against resource limits */
+ if ((locked <= lock_limit) || capable(CAP_IPC_LOCK))
+ error = do_mlock(start, len, 1);
+ up_write(¤t->mm->mmap_sem);
+ if (!error)
+ error = do_mlock_pages(start, len, 0);
+ return error;
+}
+
+SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len)
+{
+ int ret;
+
+ down_write(¤t->mm->mmap_sem);
+ len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
+ start &= PAGE_MASK;
+ ret = do_mlock(start, len, 0);
+ up_write(¤t->mm->mmap_sem);
+ return ret;
+}
+
+static int do_mlockall(int flags)
+{
+ struct vm_area_struct * vma, * prev = NULL;
+ unsigned int def_flags = 0;
+
+ if (flags & MCL_FUTURE)
+ def_flags = VM_LOCKED;
+ current->mm->def_flags = def_flags;
+ if (flags == MCL_FUTURE)
+ goto out;
+
+ for (vma = current->mm->mmap; vma ; vma = prev->vm_next) {
+ vm_flags_t newflags;
+
+ newflags = vma->vm_flags | VM_LOCKED;
+ if (!(flags & MCL_CURRENT))
+ newflags &= ~VM_LOCKED;
+
+ /* Ignore errors */
+ mlock_fixup(vma, &prev, vma->vm_start, vma->vm_end, newflags);
+ }
+out:
+ return 0;
+}
+
+SYSCALL_DEFINE1(mlockall, int, flags)
+{
+ unsigned long lock_limit;
+ int ret = -EINVAL;
+
+ if (!flags || (flags & ~(MCL_CURRENT | MCL_FUTURE)))
+ goto out;
+
+ ret = -EPERM;
+ if (!can_do_mlock())
+ goto out;
+
+ if (flags & MCL_CURRENT)
+ lru_add_drain_all(); /* flush pagevec */
+
+ down_write(¤t->mm->mmap_sem);
+
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
+ lock_limit >>= PAGE_SHIFT;
+
+ ret = -ENOMEM;
+ if (!(flags & MCL_CURRENT) || (current->mm->total_vm <= lock_limit) ||
+ capable(CAP_IPC_LOCK))
+ ret = do_mlockall(flags);
+ up_write(¤t->mm->mmap_sem);
+ if (!ret && (flags & MCL_CURRENT)) {
+ /* Ignore errors */
+ do_mlock_pages(0, TASK_SIZE, 1);
+ }
+out:
+ return ret;
+}
+
+SYSCALL_DEFINE0(munlockall)
+{
+ int ret;
+
+ down_write(¤t->mm->mmap_sem);
+ ret = do_mlockall(0);
+ up_write(¤t->mm->mmap_sem);
+ return ret;
+}
+
+/*
+ * Objects with different lifetime than processes (SHM_LOCK and SHM_HUGETLB
+ * shm segments) get accounted against the user_struct instead.
+ */
+static DEFINE_SPINLOCK(shmlock_user_lock);
+
+int user_shm_lock(size_t size, struct user_struct *user)
+{
+ unsigned long lock_limit, locked;
+ int allowed = 0;
+
+ locked = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
+ if (lock_limit == RLIM_INFINITY)
+ allowed = 1;
+ lock_limit >>= PAGE_SHIFT;
+ spin_lock(&shmlock_user_lock);
+ if (!allowed &&
+ locked + user->locked_shm > lock_limit && !capable(CAP_IPC_LOCK))
+ goto out;
+ get_uid(user);
+ user->locked_shm += locked;
+ allowed = 1;
+out:
+ spin_unlock(&shmlock_user_lock);
+ return allowed;
+}
+
+void user_shm_unlock(size_t size, struct user_struct *user)
+{
+ spin_lock(&shmlock_user_lock);
+ user->locked_shm -= (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ spin_unlock(&shmlock_user_lock);
+ free_uid(user);
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/mm_init.c b/ap/os/linux/linux-3.4.x/mm/mm_init.c
new file mode 100644
index 0000000..1ffd97a
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mm_init.c
@@ -0,0 +1,152 @@
+/*
+ * mm_init.c - Memory initialisation verification and debugging
+ *
+ * Copyright 2008 IBM Corporation, 2008
+ * Author Mel Gorman <mel@csn.ul.ie>
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/kobject.h>
+#include <linux/export.h>
+#include "internal.h"
+
+#ifdef CONFIG_DEBUG_MEMORY_INIT
+int mminit_loglevel;
+
+#ifndef SECTIONS_SHIFT
+#define SECTIONS_SHIFT 0
+#endif
+
+/* The zonelists are simply reported, validation is manual. */
+void mminit_verify_zonelist(void)
+{
+ int nid;
+
+ if (mminit_loglevel < MMINIT_VERIFY)
+ return;
+
+ for_each_online_node(nid) {
+ pg_data_t *pgdat = NODE_DATA(nid);
+ struct zone *zone;
+ struct zoneref *z;
+ struct zonelist *zonelist;
+ int i, listid, zoneid;
+
+ BUG_ON(MAX_ZONELISTS > 2);
+ for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
+
+ /* Identify the zone and nodelist */
+ zoneid = i % MAX_NR_ZONES;
+ listid = i / MAX_NR_ZONES;
+ zonelist = &pgdat->node_zonelists[listid];
+ zone = &pgdat->node_zones[zoneid];
+ if (!populated_zone(zone))
+ continue;
+
+ /* Print information about the zonelist */
+ printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
+ listid > 0 ? "thisnode" : "general", nid,
+ zone->name);
+
+ /* Iterate the zonelist */
+ for_each_zone_zonelist(zone, z, zonelist, zoneid) {
+#ifdef CONFIG_NUMA
+ printk(KERN_CONT "%d:%s ",
+ zone->node, zone->name);
+#else
+ printk(KERN_CONT "0:%s ", zone->name);
+#endif /* CONFIG_NUMA */
+ }
+ printk(KERN_CONT "\n");
+ }
+ }
+}
+
+void __init mminit_verify_pageflags_layout(void)
+{
+ int shift, width;
+ unsigned long or_mask, add_mask;
+
+ shift = 8 * sizeof(unsigned long);
+ width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH;
+ mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
+ "Section %d Node %d Zone %d Flags %d\n",
+ SECTIONS_WIDTH,
+ NODES_WIDTH,
+ ZONES_WIDTH,
+ NR_PAGEFLAGS);
+ mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
+ "Section %d Node %d Zone %d\n",
+ SECTIONS_SHIFT,
+ NODES_SHIFT,
+ ZONES_SHIFT);
+ mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",
+ "Section %lu Node %lu Zone %lu\n",
+ (unsigned long)SECTIONS_PGSHIFT,
+ (unsigned long)NODES_PGSHIFT,
+ (unsigned long)ZONES_PGSHIFT);
+ mminit_dprintk(MMINIT_TRACE, "pageflags_layout_zoneid",
+ "Zone ID: %lu -> %lu\n",
+ (unsigned long)ZONEID_PGOFF,
+ (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT));
+ mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
+ "location: %d -> %d unused %d -> %d flags %d -> %d\n",
+ shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
+#ifdef NODE_NOT_IN_PAGE_FLAGS
+ mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
+ "Node not in page flags");
+#endif
+
+ if (SECTIONS_WIDTH) {
+ shift -= SECTIONS_WIDTH;
+ BUG_ON(shift != SECTIONS_PGSHIFT);
+ }
+ if (NODES_WIDTH) {
+ shift -= NODES_WIDTH;
+ BUG_ON(shift != NODES_PGSHIFT);
+ }
+ if (ZONES_WIDTH) {
+ shift -= ZONES_WIDTH;
+ BUG_ON(shift != ZONES_PGSHIFT);
+ }
+
+ /* Check for bitmask overlaps */
+ or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
+ (NODES_MASK << NODES_PGSHIFT) |
+ (SECTIONS_MASK << SECTIONS_PGSHIFT);
+ add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
+ (NODES_MASK << NODES_PGSHIFT) +
+ (SECTIONS_MASK << SECTIONS_PGSHIFT);
+ BUG_ON(or_mask != add_mask);
+}
+
+void __meminit mminit_verify_page_links(struct page *page, enum zone_type zone,
+ unsigned long nid, unsigned long pfn)
+{
+ BUG_ON(page_to_nid(page) != nid);
+ BUG_ON(page_zonenum(page) != zone);
+ BUG_ON(page_to_pfn(page) != pfn);
+}
+
+static __init int set_mminit_loglevel(char *str)
+{
+ get_option(&str, &mminit_loglevel);
+ return 0;
+}
+early_param("mminit_loglevel", set_mminit_loglevel);
+#endif /* CONFIG_DEBUG_MEMORY_INIT */
+
+struct kobject *mm_kobj;
+EXPORT_SYMBOL_GPL(mm_kobj);
+
+static int __init mm_sysfs_init(void)
+{
+ mm_kobj = kobject_create_and_add("mm", kernel_kobj);
+ if (!mm_kobj)
+ return -ENOMEM;
+
+ return 0;
+}
+
+__initcall(mm_sysfs_init);
diff --git a/ap/os/linux/linux-3.4.x/mm/mmap.c b/ap/os/linux/linux-3.4.x/mm/mmap.c
new file mode 100644
index 0000000..cb6456d
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mmap.c
@@ -0,0 +1,2800 @@
+/*
+ * mm/mmap.c
+ *
+ * Written by obz.
+ *
+ * Address space accounting code <alan@lxorguk.ukuu.org.uk>
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/backing-dev.h>
+#include <linux/mm.h>
+#include <linux/shm.h>
+#include <linux/mman.h>
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+#include <linux/syscalls.h>
+#include <linux/capability.h>
+#include <linux/init.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/personality.h>
+#include <linux/security.h>
+#include <linux/hugetlb.h>
+#include <linux/profile.h>
+#include <linux/export.h>
+#include <linux/mount.h>
+#include <linux/mempolicy.h>
+#include <linux/rmap.h>
+#include <linux/mmu_notifier.h>
+#include <linux/perf_event.h>
+#include <linux/audit.h>
+#include <linux/khugepaged.h>
+
+#include <asm/uaccess.h>
+#include <asm/cacheflush.h>
+#include <asm/tlb.h>
+#include <asm/mmu_context.h>
+
+#include "internal.h"
+
+#ifndef arch_mmap_check
+#define arch_mmap_check(addr, len, flags) (0)
+#endif
+
+#ifndef arch_rebalance_pgtables
+#define arch_rebalance_pgtables(addr, len) (addr)
+#endif
+
+static void unmap_region(struct mm_struct *mm,
+ struct vm_area_struct *vma, struct vm_area_struct *prev,
+ unsigned long start, unsigned long end);
+
+/*
+ * WARNING: the debugging will use recursive algorithms so never enable this
+ * unless you know what you are doing.
+ */
+#undef DEBUG_MM_RB
+
+/* description of effects of mapping type and prot in current implementation.
+ * this is due to the limited x86 page protection hardware. The expected
+ * behavior is in parens:
+ *
+ * map_type prot
+ * PROT_NONE PROT_READ PROT_WRITE PROT_EXEC
+ * MAP_SHARED r: (no) no r: (yes) yes r: (no) yes r: (no) yes
+ * w: (no) no w: (no) no w: (yes) yes w: (no) no
+ * x: (no) no x: (no) yes x: (no) yes x: (yes) yes
+ *
+ * MAP_PRIVATE r: (no) no r: (yes) yes r: (no) yes r: (no) yes
+ * w: (no) no w: (no) no w: (copy) copy w: (no) no
+ * x: (no) no x: (no) yes x: (no) yes x: (yes) yes
+ *
+ */
+pgprot_t protection_map[16] = {
+ __P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111,
+ __S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
+};
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+ return __pgprot(pgprot_val(protection_map[vm_flags &
+ (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
+ pgprot_val(arch_vm_get_page_prot(vm_flags)));
+}
+EXPORT_SYMBOL(vm_get_page_prot);
+
+int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS; /* heuristic overcommit */
+int sysctl_overcommit_ratio __read_mostly = 50; /* default is 50% */
+int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
+/*
+ * Make sure vm_committed_as in one cacheline and not cacheline shared with
+ * other variables. It can be updated by several CPUs frequently.
+ */
+struct percpu_counter vm_committed_as ____cacheline_aligned_in_smp;
+
+/*
+ * Check that a process has enough memory to allocate a new virtual
+ * mapping. 0 means there is enough memory for the allocation to
+ * succeed and -ENOMEM implies there is not.
+ *
+ * We currently support three overcommit policies, which are set via the
+ * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting
+ *
+ * Strict overcommit modes added 2002 Feb 26 by Alan Cox.
+ * Additional code 2002 Jul 20 by Robert Love.
+ *
+ * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise.
+ *
+ * Note this is a helper function intended to be used by LSMs which
+ * wish to use this logic.
+ */
+int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
+{
+ long free, allowed;
+
+ vm_acct_memory(pages);
+
+ /*
+ * Sometimes we want to use more memory than we have
+ */
+ if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS)
+ return 0;
+
+ if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) {
+ free = global_page_state(NR_FREE_PAGES);
+ free += global_page_state(NR_FILE_PAGES);
+
+ /*
+ * shmem pages shouldn't be counted as free in this
+ * case, they can't be purged, only swapped out, and
+ * that won't affect the overall amount of available
+ * memory in the system.
+ */
+ free -= global_page_state(NR_SHMEM);
+
+ free += nr_swap_pages;
+
+ /*
+ * Any slabs which are created with the
+ * SLAB_RECLAIM_ACCOUNT flag claim to have contents
+ * which are reclaimable, under pressure. The dentry
+ * cache and most inode caches should fall into this
+ */
+ free += global_page_state(NR_SLAB_RECLAIMABLE);
+
+ /*
+ * Leave reserved pages. The pages are not for anonymous pages.
+ */
+ if (free <= totalreserve_pages)
+ goto error;
+ else
+ free -= totalreserve_pages;
+
+ /*
+ * Leave the last 3% for root
+ */
+ if (!cap_sys_admin)
+ free -= free / 32;
+
+ if (free > pages)
+ return 0;
+
+ goto error;
+ }
+
+ allowed = (totalram_pages - hugetlb_total_pages())
+ * sysctl_overcommit_ratio / 100;
+ /*
+ * Leave the last 3% for root
+ */
+ if (!cap_sys_admin)
+ allowed -= allowed / 32;
+ allowed += total_swap_pages;
+
+ /* Don't let a single process grow too big:
+ leave 3% of the size of this process for other processes */
+ if (mm)
+ allowed -= mm->total_vm / 32;
+
+ if (percpu_counter_read_positive(&vm_committed_as) < allowed)
+ return 0;
+error:
+ vm_unacct_memory(pages);
+
+ return -ENOMEM;
+}
+
+/*
+ * Requires inode->i_mapping->i_mmap_mutex
+ */
+static void __remove_shared_vm_struct(struct vm_area_struct *vma,
+ struct file *file, struct address_space *mapping)
+{
+ if (vma->vm_flags & VM_DENYWRITE)
+ atomic_inc(&file->f_path.dentry->d_inode->i_writecount);
+ if (vma->vm_flags & VM_SHARED)
+ mapping->i_mmap_writable--;
+
+ flush_dcache_mmap_lock(mapping);
+ if (unlikely(vma->vm_flags & VM_NONLINEAR))
+ list_del_init(&vma->shared.vm_set.list);
+ else
+ vma_prio_tree_remove(vma, &mapping->i_mmap);
+ flush_dcache_mmap_unlock(mapping);
+}
+
+/*
+ * Unlink a file-based vm structure from its prio_tree, to hide
+ * vma from rmap and vmtruncate before freeing its page tables.
+ */
+void unlink_file_vma(struct vm_area_struct *vma)
+{
+ struct file *file = vma->vm_file;
+
+ if (file) {
+ struct address_space *mapping = file->f_mapping;
+ mutex_lock(&mapping->i_mmap_mutex);
+ __remove_shared_vm_struct(vma, file, mapping);
+ mutex_unlock(&mapping->i_mmap_mutex);
+ }
+}
+
+/*
+ * Close a vm structure and free it, returning the next.
+ */
+static struct vm_area_struct *remove_vma(struct vm_area_struct *vma)
+{
+ struct vm_area_struct *next = vma->vm_next;
+
+ might_sleep();
+ if (vma->vm_ops && vma->vm_ops->close)
+ vma->vm_ops->close(vma);
+ if (vma->vm_file) {
+ fput(vma->vm_file);
+ if (vma->vm_flags & VM_EXECUTABLE)
+ removed_exe_file_vma(vma->vm_mm);
+ }
+ mpol_put(vma_policy(vma));
+ kmem_cache_free(vm_area_cachep, vma);
+ return next;
+}
+
+static unsigned long do_brk(unsigned long addr, unsigned long len);
+
+SYSCALL_DEFINE1(brk, unsigned long, brk)
+{
+ unsigned long rlim, retval;
+ unsigned long newbrk, oldbrk;
+ struct mm_struct *mm = current->mm;
+ unsigned long min_brk;
+
+ down_write(&mm->mmap_sem);
+
+#ifdef CONFIG_COMPAT_BRK
+ /*
+ * CONFIG_COMPAT_BRK can still be overridden by setting
+ * randomize_va_space to 2, which will still cause mm->start_brk
+ * to be arbitrarily shifted
+ */
+ if (current->brk_randomized)
+ min_brk = mm->start_brk;
+ else
+ min_brk = mm->end_data;
+#else
+ min_brk = mm->start_brk;
+#endif
+ if (brk < min_brk)
+ goto out;
+
+ /*
+ * Check against rlimit here. If this check is done later after the test
+ * of oldbrk with newbrk then it can escape the test and let the data
+ * segment grow beyond its set limit the in case where the limit is
+ * not page aligned -Ram Gupta
+ */
+ rlim = rlimit(RLIMIT_DATA);
+ if (rlim < RLIM_INFINITY && (brk - mm->start_brk) +
+ (mm->end_data - mm->start_data) > rlim)
+ goto out;
+
+ newbrk = PAGE_ALIGN(brk);
+ oldbrk = PAGE_ALIGN(mm->brk);
+ if (oldbrk == newbrk)
+ goto set_brk;
+
+ /* Always allow shrinking brk. */
+ if (brk <= mm->brk) {
+ if (!do_munmap(mm, newbrk, oldbrk-newbrk))
+ goto set_brk;
+ goto out;
+ }
+
+ /* Check against existing mmap mappings. */
+ if (find_vma_intersection(mm, oldbrk, newbrk+PAGE_SIZE))
+ goto out;
+
+ /* Ok, looks good - let it rip. */
+ if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk)
+ goto out;
+set_brk:
+ mm->brk = brk;
+out:
+ retval = mm->brk;
+ up_write(&mm->mmap_sem);
+ return retval;
+}
+
+#ifdef DEBUG_MM_RB
+static int browse_rb(struct rb_root *root)
+{
+ int i = 0, j;
+ struct rb_node *nd, *pn = NULL;
+ unsigned long prev = 0, pend = 0;
+
+ for (nd = rb_first(root); nd; nd = rb_next(nd)) {
+ struct vm_area_struct *vma;
+ vma = rb_entry(nd, struct vm_area_struct, vm_rb);
+ if (vma->vm_start < prev)
+ printk("vm_start %lx prev %lx\n", vma->vm_start, prev), i = -1;
+ if (vma->vm_start < pend)
+ printk("vm_start %lx pend %lx\n", vma->vm_start, pend);
+ if (vma->vm_start > vma->vm_end)
+ printk("vm_end %lx < vm_start %lx\n", vma->vm_end, vma->vm_start);
+ i++;
+ pn = nd;
+ prev = vma->vm_start;
+ pend = vma->vm_end;
+ }
+ j = 0;
+ for (nd = pn; nd; nd = rb_prev(nd)) {
+ j++;
+ }
+ if (i != j)
+ printk("backwards %d, forwards %d\n", j, i), i = 0;
+ return i;
+}
+
+void validate_mm(struct mm_struct *mm)
+{
+ int bug = 0;
+ int i = 0;
+ struct vm_area_struct *tmp = mm->mmap;
+ while (tmp) {
+ tmp = tmp->vm_next;
+ i++;
+ }
+ if (i != mm->map_count)
+ printk("map_count %d vm_next %d\n", mm->map_count, i), bug = 1;
+ i = browse_rb(&mm->mm_rb);
+ if (i != mm->map_count)
+ printk("map_count %d rb %d\n", mm->map_count, i), bug = 1;
+ BUG_ON(bug);
+}
+#else
+#define validate_mm(mm) do { } while (0)
+#endif
+
+static struct vm_area_struct *
+find_vma_prepare(struct mm_struct *mm, unsigned long addr,
+ struct vm_area_struct **pprev, struct rb_node ***rb_link,
+ struct rb_node ** rb_parent)
+{
+ struct vm_area_struct * vma;
+ struct rb_node ** __rb_link, * __rb_parent, * rb_prev;
+
+ __rb_link = &mm->mm_rb.rb_node;
+ rb_prev = __rb_parent = NULL;
+ vma = NULL;
+
+ while (*__rb_link) {
+ struct vm_area_struct *vma_tmp;
+
+ __rb_parent = *__rb_link;
+ vma_tmp = rb_entry(__rb_parent, struct vm_area_struct, vm_rb);
+
+ if (vma_tmp->vm_end > addr) {
+ vma = vma_tmp;
+ if (vma_tmp->vm_start <= addr)
+ break;
+ __rb_link = &__rb_parent->rb_left;
+ } else {
+ rb_prev = __rb_parent;
+ __rb_link = &__rb_parent->rb_right;
+ }
+ }
+
+ *pprev = NULL;
+ if (rb_prev)
+ *pprev = rb_entry(rb_prev, struct vm_area_struct, vm_rb);
+ *rb_link = __rb_link;
+ *rb_parent = __rb_parent;
+ return vma;
+}
+
+static unsigned long count_vma_pages_range(struct mm_struct *mm,
+ unsigned long addr, unsigned long end)
+{
+ unsigned long nr_pages = 0;
+ struct vm_area_struct *vma;
+
+ /* Find first overlaping mapping */
+ vma = find_vma_intersection(mm, addr, end);
+ if (!vma)
+ return 0;
+
+ nr_pages = (min(end, vma->vm_end) -
+ max(addr, vma->vm_start)) >> PAGE_SHIFT;
+
+ /* Iterate over the rest of the overlaps */
+ for (vma = vma->vm_next; vma; vma = vma->vm_next) {
+ unsigned long overlap_len;
+
+ if (vma->vm_start > end)
+ break;
+
+ overlap_len = min(end, vma->vm_end) - vma->vm_start;
+ nr_pages += overlap_len >> PAGE_SHIFT;
+ }
+
+ return nr_pages;
+}
+
+void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct rb_node **rb_link, struct rb_node *rb_parent)
+{
+ rb_link_node(&vma->vm_rb, rb_parent, rb_link);
+ rb_insert_color(&vma->vm_rb, &mm->mm_rb);
+}
+
+static void __vma_link_file(struct vm_area_struct *vma)
+{
+ struct file *file;
+
+ file = vma->vm_file;
+ if (file) {
+ struct address_space *mapping = file->f_mapping;
+
+ if (vma->vm_flags & VM_DENYWRITE)
+ atomic_dec(&file->f_path.dentry->d_inode->i_writecount);
+ if (vma->vm_flags & VM_SHARED)
+ mapping->i_mmap_writable++;
+
+ flush_dcache_mmap_lock(mapping);
+ if (unlikely(vma->vm_flags & VM_NONLINEAR))
+ vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
+ else
+ vma_prio_tree_insert(vma, &mapping->i_mmap);
+ flush_dcache_mmap_unlock(mapping);
+ }
+}
+
+static void
+__vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct vm_area_struct *prev, struct rb_node **rb_link,
+ struct rb_node *rb_parent)
+{
+ __vma_link_list(mm, vma, prev, rb_parent);
+ __vma_link_rb(mm, vma, rb_link, rb_parent);
+}
+
+static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct vm_area_struct *prev, struct rb_node **rb_link,
+ struct rb_node *rb_parent)
+{
+ struct address_space *mapping = NULL;
+
+ if (vma->vm_file)
+ mapping = vma->vm_file->f_mapping;
+
+ if (mapping)
+ mutex_lock(&mapping->i_mmap_mutex);
+
+ __vma_link(mm, vma, prev, rb_link, rb_parent);
+ __vma_link_file(vma);
+
+ if (mapping)
+ mutex_unlock(&mapping->i_mmap_mutex);
+
+ mm->map_count++;
+ validate_mm(mm);
+}
+
+/*
+ * Helper for vma_adjust() in the split_vma insert case: insert a vma into the
+ * mm's list and rbtree. It has already been inserted into the prio_tree.
+ */
+static void __insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
+{
+ struct vm_area_struct *__vma, *prev;
+ struct rb_node **rb_link, *rb_parent;
+
+ __vma = find_vma_prepare(mm, vma->vm_start,&prev, &rb_link, &rb_parent);
+ BUG_ON(__vma && __vma->vm_start < vma->vm_end);
+ __vma_link(mm, vma, prev, rb_link, rb_parent);
+ mm->map_count++;
+}
+
+static inline void
+__vma_unlink(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct vm_area_struct *prev)
+{
+ struct vm_area_struct *next = vma->vm_next;
+
+ prev->vm_next = next;
+ if (next)
+ next->vm_prev = prev;
+ rb_erase(&vma->vm_rb, &mm->mm_rb);
+ if (mm->mmap_cache == vma)
+ mm->mmap_cache = prev;
+}
+
+/*
+ * We cannot adjust vm_start, vm_end, vm_pgoff fields of a vma that
+ * is already present in an i_mmap tree without adjusting the tree.
+ * The following helper function should be used when such adjustments
+ * are necessary. The "insert" vma (if any) is to be inserted
+ * before we drop the necessary locks.
+ */
+int vma_adjust(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ struct vm_area_struct *next = vma->vm_next;
+ struct vm_area_struct *importer = NULL;
+ struct address_space *mapping = NULL;
+ struct prio_tree_root *root = NULL;
+ struct anon_vma *anon_vma = NULL;
+ struct file *file = vma->vm_file;
+ long adjust_next = 0;
+ int remove_next = 0;
+
+ if (next && !insert) {
+ struct vm_area_struct *exporter = NULL;
+
+ if (end >= next->vm_end) {
+ /*
+ * vma expands, overlapping all the next, and
+ * perhaps the one after too (mprotect case 6).
+ */
+again: remove_next = 1 + (end > next->vm_end);
+ end = next->vm_end;
+ exporter = next;
+ importer = vma;
+ } else if (end > next->vm_start) {
+ /*
+ * vma expands, overlapping part of the next:
+ * mprotect case 5 shifting the boundary up.
+ */
+ adjust_next = (end - next->vm_start) >> PAGE_SHIFT;
+ exporter = next;
+ importer = vma;
+ } else if (end < vma->vm_end) {
+ /*
+ * vma shrinks, and !insert tells it's not
+ * split_vma inserting another: so it must be
+ * mprotect case 4 shifting the boundary down.
+ */
+ adjust_next = - ((vma->vm_end - end) >> PAGE_SHIFT);
+ exporter = vma;
+ importer = next;
+ }
+
+ /*
+ * Easily overlooked: when mprotect shifts the boundary,
+ * make sure the expanding vma has anon_vma set if the
+ * shrinking vma had, to cover any anon pages imported.
+ */
+ if (exporter && exporter->anon_vma && !importer->anon_vma) {
+ int error;
+
+ importer->anon_vma = exporter->anon_vma;
+ error = anon_vma_clone(importer, exporter);
+ if (error)
+ return error;
+ }
+ }
+
+ if (file) {
+ mapping = file->f_mapping;
+ if (!(vma->vm_flags & VM_NONLINEAR))
+ root = &mapping->i_mmap;
+ mutex_lock(&mapping->i_mmap_mutex);
+ if (insert) {
+ /*
+ * Put into prio_tree now, so instantiated pages
+ * are visible to arm/parisc __flush_dcache_page
+ * throughout; but we cannot insert into address
+ * space until vma start or end is updated.
+ */
+ __vma_link_file(insert);
+ }
+ }
+
+ vma_adjust_trans_huge(vma, start, end, adjust_next);
+
+ /*
+ * When changing only vma->vm_end, we don't really need anon_vma
+ * lock. This is a fairly rare case by itself, but the anon_vma
+ * lock may be shared between many sibling processes. Skipping
+ * the lock for brk adjustments makes a difference sometimes.
+ */
+ if (vma->anon_vma && (importer || start != vma->vm_start)) {
+ anon_vma = vma->anon_vma;
+ anon_vma_lock(anon_vma);
+ }
+
+ if (root) {
+ flush_dcache_mmap_lock(mapping);
+ vma_prio_tree_remove(vma, root);
+ if (adjust_next)
+ vma_prio_tree_remove(next, root);
+ }
+
+ vma->vm_start = start;
+ vma->vm_end = end;
+ vma->vm_pgoff = pgoff;
+ if (adjust_next) {
+ next->vm_start += adjust_next << PAGE_SHIFT;
+ next->vm_pgoff += adjust_next;
+ }
+
+ if (root) {
+ if (adjust_next)
+ vma_prio_tree_insert(next, root);
+ vma_prio_tree_insert(vma, root);
+ flush_dcache_mmap_unlock(mapping);
+ }
+
+ if (remove_next) {
+ /*
+ * vma_merge has merged next into vma, and needs
+ * us to remove next before dropping the locks.
+ */
+ __vma_unlink(mm, next, vma);
+ if (file)
+ __remove_shared_vm_struct(next, file, mapping);
+ } else if (insert) {
+ /*
+ * split_vma has split insert from vma, and needs
+ * us to insert it before dropping the locks
+ * (it may either follow vma or precede it).
+ */
+ __insert_vm_struct(mm, insert);
+ }
+
+ if (anon_vma)
+ anon_vma_unlock(anon_vma);
+ if (mapping)
+ mutex_unlock(&mapping->i_mmap_mutex);
+
+ if (remove_next) {
+ if (file) {
+ fput(file);
+ if (next->vm_flags & VM_EXECUTABLE)
+ removed_exe_file_vma(mm);
+ }
+ if (next->anon_vma)
+ anon_vma_merge(vma, next);
+ mm->map_count--;
+ mpol_put(vma_policy(next));
+ kmem_cache_free(vm_area_cachep, next);
+ /*
+ * In mprotect's case 6 (see comments on vma_merge),
+ * we must remove another next too. It would clutter
+ * up the code too much to do both in one go.
+ */
+ if (remove_next == 2) {
+ next = vma->vm_next;
+ goto again;
+ }
+ }
+
+ validate_mm(mm);
+
+ return 0;
+}
+
+/*
+ * If the vma has a ->close operation then the driver probably needs to release
+ * per-vma resources, so we don't attempt to merge those.
+ */
+static inline int is_mergeable_vma(struct vm_area_struct *vma,
+ struct file *file, unsigned long vm_flags)
+{
+ /* VM_CAN_NONLINEAR may get set later by f_op->mmap() */
+ if ((vma->vm_flags ^ vm_flags) & ~VM_CAN_NONLINEAR)
+ return 0;
+ if (vma->vm_file != file)
+ return 0;
+ if (vma->vm_ops && vma->vm_ops->close)
+ return 0;
+ return 1;
+}
+
+static inline int is_mergeable_anon_vma(struct anon_vma *anon_vma1,
+ struct anon_vma *anon_vma2,
+ struct vm_area_struct *vma)
+{
+ /*
+ * The list_is_singular() test is to avoid merging VMA cloned from
+ * parents. This can improve scalability caused by anon_vma lock.
+ */
+ if ((!anon_vma1 || !anon_vma2) && (!vma ||
+ list_is_singular(&vma->anon_vma_chain)))
+ return 1;
+ return anon_vma1 == anon_vma2;
+}
+
+/*
+ * Return true if we can merge this (vm_flags,anon_vma,file,vm_pgoff)
+ * in front of (at a lower virtual address and file offset than) the vma.
+ *
+ * We cannot merge two vmas if they have differently assigned (non-NULL)
+ * anon_vmas, nor if same anon_vma is assigned but offsets incompatible.
+ *
+ * We don't check here for the merged mmap wrapping around the end of pagecache
+ * indices (16TB on ia32) because do_mmap_pgoff() does not permit mmap's which
+ * wrap, nor mmaps which cover the final page at index -1UL.
+ */
+static int
+can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
+ struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff)
+{
+ if (is_mergeable_vma(vma, file, vm_flags) &&
+ is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
+ if (vma->vm_pgoff == vm_pgoff)
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * Return true if we can merge this (vm_flags,anon_vma,file,vm_pgoff)
+ * beyond (at a higher virtual address and file offset than) the vma.
+ *
+ * We cannot merge two vmas if they have differently assigned (non-NULL)
+ * anon_vmas, nor if same anon_vma is assigned but offsets incompatible.
+ */
+static int
+can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
+ struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff)
+{
+ if (is_mergeable_vma(vma, file, vm_flags) &&
+ is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
+ pgoff_t vm_pglen;
+ vm_pglen = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+ if (vma->vm_pgoff + vm_pglen == vm_pgoff)
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * Given a mapping request (addr,end,vm_flags,file,pgoff), figure out
+ * whether that can be merged with its predecessor or its successor.
+ * Or both (it neatly fills a hole).
+ *
+ * In most cases - when called for mmap, brk or mremap - [addr,end) is
+ * certain not to be mapped by the time vma_merge is called; but when
+ * called for mprotect, it is certain to be already mapped (either at
+ * an offset within prev, or at the start of next), and the flags of
+ * this area are about to be changed to vm_flags - and the no-change
+ * case has already been eliminated.
+ *
+ * The following mprotect cases have to be considered, where AAAA is
+ * the area passed down from mprotect_fixup, never extending beyond one
+ * vma, PPPPPP is the prev vma specified, and NNNNNN the next vma after:
+ *
+ * AAAA AAAA AAAA AAAA
+ * PPPPPPNNNNNN PPPPPPNNNNNN PPPPPPNNNNNN PPPPNNNNXXXX
+ * cannot merge might become might become might become
+ * PPNNNNNNNNNN PPPPPPPPPPNN PPPPPPPPPPPP 6 or
+ * mmap, brk or case 4 below case 5 below PPPPPPPPXXXX 7 or
+ * mremap move: PPPPNNNNNNNN 8
+ * AAAA
+ * PPPP NNNN PPPPPPPPPPPP PPPPPPPPNNNN PPPPNNNNNNNN
+ * might become case 1 below case 2 below case 3 below
+ *
+ * Odd one out? Case 8, because it extends NNNN but needs flags of XXXX:
+ * mprotect_fixup updates vm_flags & vm_page_prot on successful return.
+ */
+struct vm_area_struct *vma_merge(struct mm_struct *mm,
+ struct vm_area_struct *prev, unsigned long addr,
+ unsigned long end, unsigned long vm_flags,
+ struct anon_vma *anon_vma, struct file *file,
+ pgoff_t pgoff, struct mempolicy *policy)
+{
+ pgoff_t pglen = (end - addr) >> PAGE_SHIFT;
+ struct vm_area_struct *area, *next;
+ int err;
+
+ /*
+ * We later require that vma->vm_flags == vm_flags,
+ * so this tests vma->vm_flags & VM_SPECIAL, too.
+ */
+ if (vm_flags & VM_SPECIAL)
+ return NULL;
+
+ if (prev)
+ next = prev->vm_next;
+ else
+ next = mm->mmap;
+ area = next;
+ if (next && next->vm_end == end) /* cases 6, 7, 8 */
+ next = next->vm_next;
+
+ /*
+ * Can it merge with the predecessor?
+ */
+ if (prev && prev->vm_end == addr &&
+ mpol_equal(vma_policy(prev), policy) &&
+ can_vma_merge_after(prev, vm_flags,
+ anon_vma, file, pgoff)) {
+ /*
+ * OK, it can. Can we now merge in the successor as well?
+ */
+ if (next && end == next->vm_start &&
+ mpol_equal(policy, vma_policy(next)) &&
+ can_vma_merge_before(next, vm_flags,
+ anon_vma, file, pgoff+pglen) &&
+ is_mergeable_anon_vma(prev->anon_vma,
+ next->anon_vma, NULL)) {
+ /* cases 1, 6 */
+ err = vma_adjust(prev, prev->vm_start,
+ next->vm_end, prev->vm_pgoff, NULL);
+ } else /* cases 2, 5, 7 */
+ err = vma_adjust(prev, prev->vm_start,
+ end, prev->vm_pgoff, NULL);
+ if (err)
+ return NULL;
+ khugepaged_enter_vma_merge(prev, vm_flags);
+ return prev;
+ }
+
+ /*
+ * Can this new request be merged in front of next?
+ */
+ if (next && end == next->vm_start &&
+ mpol_equal(policy, vma_policy(next)) &&
+ can_vma_merge_before(next, vm_flags,
+ anon_vma, file, pgoff+pglen)) {
+ if (prev && addr < prev->vm_end) /* case 4 */
+ err = vma_adjust(prev, prev->vm_start,
+ addr, prev->vm_pgoff, NULL);
+ else /* cases 3, 8 */
+ err = vma_adjust(area, addr, next->vm_end,
+ next->vm_pgoff - pglen, NULL);
+ if (err)
+ return NULL;
+ khugepaged_enter_vma_merge(area, vm_flags);
+ return area;
+ }
+
+ return NULL;
+}
+
+/*
+ * Rough compatbility check to quickly see if it's even worth looking
+ * at sharing an anon_vma.
+ *
+ * They need to have the same vm_file, and the flags can only differ
+ * in things that mprotect may change.
+ *
+ * NOTE! The fact that we share an anon_vma doesn't _have_ to mean that
+ * we can merge the two vma's. For example, we refuse to merge a vma if
+ * there is a vm_ops->close() function, because that indicates that the
+ * driver is doing some kind of reference counting. But that doesn't
+ * really matter for the anon_vma sharing case.
+ */
+static int anon_vma_compatible(struct vm_area_struct *a, struct vm_area_struct *b)
+{
+ return a->vm_end == b->vm_start &&
+ mpol_equal(vma_policy(a), vma_policy(b)) &&
+ a->vm_file == b->vm_file &&
+ !((a->vm_flags ^ b->vm_flags) & ~(VM_READ|VM_WRITE|VM_EXEC)) &&
+ b->vm_pgoff == a->vm_pgoff + ((b->vm_start - a->vm_start) >> PAGE_SHIFT);
+}
+
+/*
+ * Do some basic sanity checking to see if we can re-use the anon_vma
+ * from 'old'. The 'a'/'b' vma's are in VM order - one of them will be
+ * the same as 'old', the other will be the new one that is trying
+ * to share the anon_vma.
+ *
+ * NOTE! This runs with mm_sem held for reading, so it is possible that
+ * the anon_vma of 'old' is concurrently in the process of being set up
+ * by another page fault trying to merge _that_. But that's ok: if it
+ * is being set up, that automatically means that it will be a singleton
+ * acceptable for merging, so we can do all of this optimistically. But
+ * we do that ACCESS_ONCE() to make sure that we never re-load the pointer.
+ *
+ * IOW: that the "list_is_singular()" test on the anon_vma_chain only
+ * matters for the 'stable anon_vma' case (ie the thing we want to avoid
+ * is to return an anon_vma that is "complex" due to having gone through
+ * a fork).
+ *
+ * We also make sure that the two vma's are compatible (adjacent,
+ * and with the same memory policies). That's all stable, even with just
+ * a read lock on the mm_sem.
+ */
+static struct anon_vma *reusable_anon_vma(struct vm_area_struct *old, struct vm_area_struct *a, struct vm_area_struct *b)
+{
+ if (anon_vma_compatible(a, b)) {
+ struct anon_vma *anon_vma = ACCESS_ONCE(old->anon_vma);
+
+ if (anon_vma && list_is_singular(&old->anon_vma_chain))
+ return anon_vma;
+ }
+ return NULL;
+}
+
+/*
+ * find_mergeable_anon_vma is used by anon_vma_prepare, to check
+ * neighbouring vmas for a suitable anon_vma, before it goes off
+ * to allocate a new anon_vma. It checks because a repetitive
+ * sequence of mprotects and faults may otherwise lead to distinct
+ * anon_vmas being allocated, preventing vma merge in subsequent
+ * mprotect.
+ */
+struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *vma)
+{
+ struct anon_vma *anon_vma;
+ struct vm_area_struct *near;
+
+ near = vma->vm_next;
+ if (!near)
+ goto try_prev;
+
+ anon_vma = reusable_anon_vma(near, vma, near);
+ if (anon_vma)
+ return anon_vma;
+try_prev:
+ near = vma->vm_prev;
+ if (!near)
+ goto none;
+
+ anon_vma = reusable_anon_vma(near, near, vma);
+ if (anon_vma)
+ return anon_vma;
+none:
+ /*
+ * There's no absolute need to look only at touching neighbours:
+ * we could search further afield for "compatible" anon_vmas.
+ * But it would probably just be a waste of time searching,
+ * or lead to too many vmas hanging off the same anon_vma.
+ * We're trying to allow mprotect remerging later on,
+ * not trying to minimize memory used for anon_vmas.
+ */
+ return NULL;
+}
+
+#ifdef CONFIG_PROC_FS
+void vm_stat_account(struct mm_struct *mm, unsigned long flags,
+ struct file *file, long pages)
+{
+ const unsigned long stack_flags
+ = VM_STACK_FLAGS & (VM_GROWSUP|VM_GROWSDOWN);
+
+ if (file) {
+ mm->shared_vm += pages;
+ if ((flags & (VM_EXEC|VM_WRITE)) == VM_EXEC)
+ mm->exec_vm += pages;
+ } else if (flags & stack_flags)
+ mm->stack_vm += pages;
+ if (flags & (VM_RESERVED|VM_IO))
+ mm->reserved_vm += pages;
+}
+#endif /* CONFIG_PROC_FS */
+
+/*
+ * If a hint addr is less than mmap_min_addr change hint to be as
+ * low as possible but still greater than mmap_min_addr
+ */
+static inline unsigned long round_hint_to_min(unsigned long hint)
+{
+ hint &= PAGE_MASK;
+ if (((void *)hint != NULL) &&
+ (hint < mmap_min_addr))
+ return PAGE_ALIGN(mmap_min_addr);
+ return hint;
+}
+
+/*
+ * The caller must hold down_write(¤t->mm->mmap_sem).
+ */
+
+static unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flags, unsigned long pgoff)
+{
+ struct mm_struct * mm = current->mm;
+ struct inode *inode;
+ vm_flags_t vm_flags;
+ int error;
+ unsigned long reqprot = prot;
+
+ /*
+ * Does the application expect PROT_READ to imply PROT_EXEC?
+ *
+ * (the exception is when the underlying filesystem is noexec
+ * mounted, in which case we dont add PROT_EXEC.)
+ */
+ if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
+ if (!(file && (file->f_path.mnt->mnt_flags & MNT_NOEXEC)))
+ prot |= PROT_EXEC;
+
+ if (!len)
+ return -EINVAL;
+
+ if (!(flags & MAP_FIXED))
+ addr = round_hint_to_min(addr);
+
+ /* Careful about overflows.. */
+ len = PAGE_ALIGN(len);
+ if (!len)
+ return -ENOMEM;
+
+ /* offset overflow? */
+ if ((pgoff + (len >> PAGE_SHIFT)) < pgoff)
+ return -EOVERFLOW;
+
+ /* Too many mappings? */
+ if (mm->map_count > sysctl_max_map_count)
+ return -ENOMEM;
+
+ /* Obtain the address to map to. we verify (or select) it and ensure
+ * that it represents a valid section of the address space.
+ */
+ addr = get_unmapped_area(file, addr, len, pgoff, flags);
+ if (addr & ~PAGE_MASK)
+ return addr;
+
+ /* Do simple checking here so the lower-level routines won't have
+ * to. we assume access permissions have been handled by the open
+ * of the memory object, so we don't do any here.
+ */
+ vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags) |
+ mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
+
+ if (flags & MAP_LOCKED)
+ if (!can_do_mlock())
+ return -EPERM;
+
+ /* mlock MCL_FUTURE? */
+ if (vm_flags & VM_LOCKED) {
+ unsigned long locked, lock_limit;
+ locked = len >> PAGE_SHIFT;
+ locked += mm->locked_vm;
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
+ lock_limit >>= PAGE_SHIFT;
+ if (locked > lock_limit && !capable(CAP_IPC_LOCK))
+ return -EAGAIN;
+ }
+
+ inode = file ? file->f_path.dentry->d_inode : NULL;
+
+ if (file) {
+ switch (flags & MAP_TYPE) {
+ case MAP_SHARED:
+ if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
+ return -EACCES;
+
+ /*
+ * Make sure we don't allow writing to an append-only
+ * file..
+ */
+ if (IS_APPEND(inode) && (file->f_mode & FMODE_WRITE))
+ return -EACCES;
+
+ /*
+ * Make sure there are no mandatory locks on the file.
+ */
+ if (locks_verify_locked(inode))
+ return -EAGAIN;
+
+ vm_flags |= VM_SHARED | VM_MAYSHARE;
+ if (!(file->f_mode & FMODE_WRITE))
+ vm_flags &= ~(VM_MAYWRITE | VM_SHARED);
+
+ /* fall through */
+ case MAP_PRIVATE:
+ if (!(file->f_mode & FMODE_READ))
+ return -EACCES;
+ if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) {
+ if (vm_flags & VM_EXEC)
+ return -EPERM;
+ vm_flags &= ~VM_MAYEXEC;
+ }
+
+ if (!file->f_op || !file->f_op->mmap)
+ return -ENODEV;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ } else {
+ switch (flags & MAP_TYPE) {
+ case MAP_SHARED:
+ /*
+ * Ignore pgoff.
+ */
+ pgoff = 0;
+ vm_flags |= VM_SHARED | VM_MAYSHARE;
+ break;
+ case MAP_PRIVATE:
+ /*
+ * Set pgoff according to addr for anon_vma.
+ */
+ pgoff = addr >> PAGE_SHIFT;
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+
+ error = security_file_mmap(file, reqprot, prot, flags, addr, 0);
+ if (error)
+ return error;
+
+ return mmap_region(file, addr, len, flags, vm_flags, pgoff);
+}
+
+unsigned long do_mmap(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flag, unsigned long offset)
+{
+ if (unlikely(offset + PAGE_ALIGN(len) < offset))
+ return -EINVAL;
+ if (unlikely(offset & ~PAGE_MASK))
+ return -EINVAL;
+ return do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
+}
+EXPORT_SYMBOL(do_mmap);
+
+unsigned long vm_mmap(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flag, unsigned long offset)
+{
+ unsigned long ret;
+ struct mm_struct *mm = current->mm;
+
+ down_write(&mm->mmap_sem);
+ ret = do_mmap(file, addr, len, prot, flag, offset);
+ up_write(&mm->mmap_sem);
+ return ret;
+}
+EXPORT_SYMBOL(vm_mmap);
+
+SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
+ unsigned long, prot, unsigned long, flags,
+ unsigned long, fd, unsigned long, pgoff)
+{
+ struct file *file = NULL;
+ unsigned long retval = -EBADF;
+
+ if (!(flags & MAP_ANONYMOUS)) {
+ audit_mmap_fd(fd, flags);
+ if (unlikely(flags & MAP_HUGETLB))
+ return -EINVAL;
+ file = fget(fd);
+ if (!file)
+ goto out;
+ if (is_file_hugepages(file))
+ len = ALIGN(len, huge_page_size(hstate_file(file)));
+ } else if (flags & MAP_HUGETLB) {
+ struct user_struct *user = NULL;
+
+ len = ALIGN(len, huge_page_size(&default_hstate));
+ /*
+ * VM_NORESERVE is used because the reservations will be
+ * taken when vm_ops->mmap() is called
+ * A dummy user value is used because we are not locking
+ * memory so no accounting is necessary
+ */
+ file = hugetlb_file_setup(HUGETLB_ANON_FILE, len,
+ VM_NORESERVE, &user,
+ HUGETLB_ANONHUGE_INODE);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+ }
+
+ flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
+
+ down_write(¤t->mm->mmap_sem);
+ retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
+ up_write(¤t->mm->mmap_sem);
+
+ if (file)
+ fput(file);
+out:
+ return retval;
+}
+
+#ifdef __ARCH_WANT_SYS_OLD_MMAP
+struct mmap_arg_struct {
+ unsigned long addr;
+ unsigned long len;
+ unsigned long prot;
+ unsigned long flags;
+ unsigned long fd;
+ unsigned long offset;
+};
+
+SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg)
+{
+ struct mmap_arg_struct a;
+
+ if (copy_from_user(&a, arg, sizeof(a)))
+ return -EFAULT;
+ if (a.offset & ~PAGE_MASK)
+ return -EINVAL;
+
+ return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
+ a.offset >> PAGE_SHIFT);
+}
+#endif /* __ARCH_WANT_SYS_OLD_MMAP */
+
+/*
+ * Some shared mappigns will want the pages marked read-only
+ * to track write events. If so, we'll downgrade vm_page_prot
+ * to the private version (using protection_map[] without the
+ * VM_SHARED bit).
+ */
+int vma_wants_writenotify(struct vm_area_struct *vma)
+{
+ vm_flags_t vm_flags = vma->vm_flags;
+
+ /* If it was private or non-writable, the write bit is already clear */
+ if ((vm_flags & (VM_WRITE|VM_SHARED)) != ((VM_WRITE|VM_SHARED)))
+ return 0;
+
+ /* The backer wishes to know when pages are first written to? */
+ if (vma->vm_ops && vma->vm_ops->page_mkwrite)
+ return 1;
+
+ /* The open routine did something to the protections already? */
+ if (pgprot_val(vma->vm_page_prot) !=
+ pgprot_val(vm_get_page_prot(vm_flags)))
+ return 0;
+
+ /* Specialty mapping? */
+ if (vm_flags & (VM_PFNMAP|VM_INSERTPAGE))
+ return 0;
+
+ /* Can the mapping track the dirty pages? */
+ return vma->vm_file && vma->vm_file->f_mapping &&
+ mapping_cap_account_dirty(vma->vm_file->f_mapping);
+}
+
+/*
+ * We account for memory if it's a private writeable mapping,
+ * not hugepages and VM_NORESERVE wasn't set.
+ */
+static inline int accountable_mapping(struct file *file, vm_flags_t vm_flags)
+{
+ /*
+ * hugetlb has its own accounting separate from the core VM
+ * VM_HUGETLB may not be set yet so we cannot check for that flag.
+ */
+ if (file && is_file_hugepages(file))
+ return 0;
+
+ return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE;
+}
+
+unsigned long mmap_region(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long flags,
+ vm_flags_t vm_flags, unsigned long pgoff)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma, *prev;
+ int correct_wcount = 0;
+ int error;
+ struct rb_node **rb_link, *rb_parent;
+ unsigned long charged = 0;
+ struct inode *inode = file ? file->f_path.dentry->d_inode : NULL;
+
+ /* Check against address space limit. */
+ if (!may_expand_vm(mm, len >> PAGE_SHIFT)) {
+ unsigned long nr_pages;
+
+ /*
+ * MAP_FIXED may remove pages of mappings that intersects with
+ * requested mapping. Account for the pages it would unmap.
+ */
+ if (!(vm_flags & MAP_FIXED))
+ return -ENOMEM;
+
+ nr_pages = count_vma_pages_range(mm, addr, addr + len);
+
+ if (!may_expand_vm(mm, (len >> PAGE_SHIFT) - nr_pages))
+ return -ENOMEM;
+ }
+
+ /* Clear old maps */
+ error = -ENOMEM;
+munmap_back:
+ vma = find_vma_prepare(mm, addr, &prev, &rb_link, &rb_parent);
+ if (vma && vma->vm_start < addr + len) {
+ if (do_munmap(mm, addr, len))
+ return -ENOMEM;
+ goto munmap_back;
+ }
+
+ /*
+ * Set 'VM_NORESERVE' if we should not account for the
+ * memory use of this mapping.
+ */
+ if ((flags & MAP_NORESERVE)) {
+ /* We honor MAP_NORESERVE if allowed to overcommit */
+ if (sysctl_overcommit_memory != OVERCOMMIT_NEVER)
+ vm_flags |= VM_NORESERVE;
+
+ /* hugetlb applies strict overcommit unless MAP_NORESERVE */
+ if (file && is_file_hugepages(file))
+ vm_flags |= VM_NORESERVE;
+ }
+
+ /*
+ * Private writable mapping: check memory availability
+ */
+ if (accountable_mapping(file, vm_flags)) {
+ charged = len >> PAGE_SHIFT;
+ if (security_vm_enough_memory_mm(mm, charged))
+ return -ENOMEM;
+ vm_flags |= VM_ACCOUNT;
+ }
+
+ /*
+ * Can we just expand an old mapping?
+ */
+ vma = vma_merge(mm, prev, addr, addr + len, vm_flags, NULL, file, pgoff, NULL);
+ if (vma)
+ goto out;
+
+ /*
+ * Determine the object being mapped and call the appropriate
+ * specific mapper. the address has already been validated, but
+ * not unmapped, but the maps are removed from the list.
+ */
+ vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
+ if (!vma) {
+ error = -ENOMEM;
+ goto unacct_error;
+ }
+
+ vma->vm_mm = mm;
+ vma->vm_start = addr;
+ vma->vm_end = addr + len;
+ vma->vm_flags = vm_flags;
+ vma->vm_page_prot = vm_get_page_prot(vm_flags);
+ vma->vm_pgoff = pgoff;
+ INIT_LIST_HEAD(&vma->anon_vma_chain);
+
+ error = -EINVAL; /* when rejecting VM_GROWSDOWN|VM_GROWSUP */
+
+ if (file) {
+ if (vm_flags & (VM_GROWSDOWN|VM_GROWSUP))
+ goto free_vma;
+ if (vm_flags & VM_DENYWRITE) {
+ error = deny_write_access(file);
+ if (error)
+ goto free_vma;
+ correct_wcount = 1;
+ }
+ vma->vm_file = file;
+ get_file(file);
+ error = file->f_op->mmap(file, vma);
+ if (error)
+ goto unmap_and_free_vma;
+ if (vm_flags & VM_EXECUTABLE)
+ added_exe_file_vma(mm);
+
+ /* Can addr have changed??
+ *
+ * Answer: Yes, several device drivers can do it in their
+ * f_op->mmap method. -DaveM
+ */
+ addr = vma->vm_start;
+ pgoff = vma->vm_pgoff;
+ vm_flags = vma->vm_flags;
+ } else if (vm_flags & VM_SHARED) {
+ if (unlikely(vm_flags & (VM_GROWSDOWN|VM_GROWSUP)))
+ goto free_vma;
+ error = shmem_zero_setup(vma);
+ if (error)
+ goto free_vma;
+ }
+
+ if (vma_wants_writenotify(vma)) {
+ pgprot_t pprot = vma->vm_page_prot;
+
+ /* Can vma->vm_page_prot have changed??
+ *
+ * Answer: Yes, drivers may have changed it in their
+ * f_op->mmap method.
+ *
+ * Ensures that vmas marked as uncached stay that way.
+ */
+ vma->vm_page_prot = vm_get_page_prot(vm_flags & ~VM_SHARED);
+ if (pgprot_val(pprot) == pgprot_val(pgprot_noncached(pprot)))
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+ }
+
+ vma_link(mm, vma, prev, rb_link, rb_parent);
+ file = vma->vm_file;
+
+ /* Once vma denies write, undo our temporary denial count */
+ if (correct_wcount)
+ atomic_inc(&inode->i_writecount);
+out:
+ perf_event_mmap(vma);
+
+ mm->total_vm += len >> PAGE_SHIFT;
+ vm_stat_account(mm, vm_flags, file, len >> PAGE_SHIFT);
+ if (vm_flags & VM_LOCKED) {
+ if (!mlock_vma_pages_range(vma, addr, addr + len))
+ mm->locked_vm += (len >> PAGE_SHIFT);
+ } else if ((flags & MAP_POPULATE) && !(flags & MAP_NONBLOCK))
+ make_pages_present(addr, addr + len);
+ return addr;
+
+unmap_and_free_vma:
+ if (correct_wcount)
+ atomic_inc(&inode->i_writecount);
+ vma->vm_file = NULL;
+ fput(file);
+
+ /* Undo any partial mapping done by a device driver. */
+ unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end);
+ charged = 0;
+free_vma:
+ kmem_cache_free(vm_area_cachep, vma);
+unacct_error:
+ if (charged)
+ vm_unacct_memory(charged);
+ return error;
+}
+
+/* Get an address range which is currently unmapped.
+ * For shmat() with addr=0.
+ *
+ * Ugly calling convention alert:
+ * Return value with the low bits set means error value,
+ * ie
+ * if (ret & ~PAGE_MASK)
+ * error = ret;
+ *
+ * This function "knows" that -ENOMEM has the bits set.
+ */
+#ifndef HAVE_ARCH_UNMAPPED_AREA
+unsigned long
+arch_get_unmapped_area(struct file *filp, unsigned long addr,
+ unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long start_addr;
+
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ if (flags & MAP_FIXED)
+ return addr;
+
+ if (addr) {
+ addr = PAGE_ALIGN(addr);
+ vma = find_vma(mm, addr);
+ if (TASK_SIZE - len >= addr &&
+ (!vma || addr + len <= vma->vm_start))
+ return addr;
+ }
+ if (len > mm->cached_hole_size) {
+ start_addr = addr = mm->free_area_cache;
+ } else {
+ start_addr = addr = TASK_UNMAPPED_BASE;
+ mm->cached_hole_size = 0;
+ }
+
+full_search:
+ for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
+ /* At this point: (!vma || addr < vma->vm_end). */
+ if (TASK_SIZE - len < addr) {
+ /*
+ * Start a new search - just in case we missed
+ * some holes.
+ */
+ if (start_addr != TASK_UNMAPPED_BASE) {
+ addr = TASK_UNMAPPED_BASE;
+ start_addr = addr;
+ mm->cached_hole_size = 0;
+ goto full_search;
+ }
+ return -ENOMEM;
+ }
+ if (!vma || addr + len <= vma->vm_start) {
+ /*
+ * Remember the place where we stopped the search:
+ */
+ mm->free_area_cache = addr + len;
+ return addr;
+ }
+ if (addr + mm->cached_hole_size < vma->vm_start)
+ mm->cached_hole_size = vma->vm_start - addr;
+ addr = vma->vm_end;
+ }
+}
+#endif
+
+void arch_unmap_area(struct mm_struct *mm, unsigned long addr)
+{
+ /*
+ * Is this a new hole at the lowest possible address?
+ */
+ if (addr >= TASK_UNMAPPED_BASE && addr < mm->free_area_cache)
+ mm->free_area_cache = addr;
+}
+
+/*
+ * This mmap-allocator allocates new areas top-down from below the
+ * stack's low limit (the base):
+ */
+#ifndef HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
+unsigned long
+arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
+ const unsigned long len, const unsigned long pgoff,
+ const unsigned long flags)
+{
+ struct vm_area_struct *vma;
+ struct mm_struct *mm = current->mm;
+ unsigned long addr = addr0, start_addr;
+
+ /* requested length too big for entire address space */
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ if (flags & MAP_FIXED)
+ return addr;
+
+ /* requesting a specific address */
+ if (addr) {
+ addr = PAGE_ALIGN(addr);
+ vma = find_vma(mm, addr);
+ if (TASK_SIZE - len >= addr &&
+ (!vma || addr + len <= vma->vm_start))
+ return addr;
+ }
+
+ /* check if free_area_cache is useful for us */
+ if (len <= mm->cached_hole_size) {
+ mm->cached_hole_size = 0;
+ mm->free_area_cache = mm->mmap_base;
+ }
+
+try_again:
+ /* either no address requested or can't fit in requested address hole */
+ start_addr = addr = mm->free_area_cache;
+
+ if (addr < len)
+ goto fail;
+
+ addr -= len;
+ do {
+ /*
+ * Lookup failure means no vma is above this address,
+ * else if new region fits below vma->vm_start,
+ * return with success:
+ */
+ vma = find_vma(mm, addr);
+ if (!vma || addr+len <= vma->vm_start)
+ /* remember the address as a hint for next time */
+ return (mm->free_area_cache = addr);
+
+ /* remember the largest hole we saw so far */
+ if (addr + mm->cached_hole_size < vma->vm_start)
+ mm->cached_hole_size = vma->vm_start - addr;
+
+ /* try just below the current vma->vm_start */
+ addr = vma->vm_start-len;
+ } while (len < vma->vm_start);
+
+fail:
+ /*
+ * if hint left us with no space for the requested
+ * mapping then try again:
+ *
+ * Note: this is different with the case of bottomup
+ * which does the fully line-search, but we use find_vma
+ * here that causes some holes skipped.
+ */
+ if (start_addr != mm->mmap_base) {
+ mm->free_area_cache = mm->mmap_base;
+ mm->cached_hole_size = 0;
+ goto try_again;
+ }
+
+ /*
+ * A failed mmap() very likely causes application failure,
+ * so fall back to the bottom-up function here. This scenario
+ * can happen with large stack limits and large mmap()
+ * allocations.
+ */
+ mm->cached_hole_size = ~0UL;
+ mm->free_area_cache = TASK_UNMAPPED_BASE;
+ addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
+ /*
+ * Restore the topdown base:
+ */
+ mm->free_area_cache = mm->mmap_base;
+ mm->cached_hole_size = ~0UL;
+
+ return addr;
+}
+#endif
+
+void arch_unmap_area_topdown(struct mm_struct *mm, unsigned long addr)
+{
+ /*
+ * Is this a new hole at the highest possible address?
+ */
+ if (addr > mm->free_area_cache)
+ mm->free_area_cache = addr;
+
+ /* dont allow allocations above current base */
+ if (mm->free_area_cache > mm->mmap_base)
+ mm->free_area_cache = mm->mmap_base;
+}
+
+unsigned long
+get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
+ unsigned long pgoff, unsigned long flags)
+{
+ unsigned long (*get_area)(struct file *, unsigned long,
+ unsigned long, unsigned long, unsigned long);
+
+ unsigned long error = arch_mmap_check(addr, len, flags);
+ if (error)
+ return error;
+
+ /* Careful about overflows.. */
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ get_area = current->mm->get_unmapped_area;
+ if (file && file->f_op && file->f_op->get_unmapped_area)
+ get_area = file->f_op->get_unmapped_area;
+ addr = get_area(file, addr, len, pgoff, flags);
+ if (IS_ERR_VALUE(addr))
+ return addr;
+
+ if (addr > TASK_SIZE - len)
+ return -ENOMEM;
+ if (addr & ~PAGE_MASK)
+ return -EINVAL;
+
+ return arch_rebalance_pgtables(addr, len);
+}
+
+EXPORT_SYMBOL(get_unmapped_area);
+
+/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
+struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
+{
+ struct vm_area_struct *vma = NULL;
+
+ if (mm) {
+ /* Check the cache first. */
+ /* (Cache hit rate is typically around 35%.) */
+ vma = ACCESS_ONCE(mm->mmap_cache);
+ if (!(vma && vma->vm_end > addr && vma->vm_start <= addr)) {
+ struct rb_node * rb_node;
+
+ rb_node = mm->mm_rb.rb_node;
+ vma = NULL;
+
+ while (rb_node) {
+ struct vm_area_struct * vma_tmp;
+
+ vma_tmp = rb_entry(rb_node,
+ struct vm_area_struct, vm_rb);
+
+ if (vma_tmp->vm_end > addr) {
+ vma = vma_tmp;
+ if (vma_tmp->vm_start <= addr)
+ break;
+ rb_node = rb_node->rb_left;
+ } else
+ rb_node = rb_node->rb_right;
+ }
+ if (vma)
+ mm->mmap_cache = vma;
+ }
+ }
+ return vma;
+}
+
+EXPORT_SYMBOL(find_vma);
+
+/*
+ * Same as find_vma, but also return a pointer to the previous VMA in *pprev.
+ */
+struct vm_area_struct *
+find_vma_prev(struct mm_struct *mm, unsigned long addr,
+ struct vm_area_struct **pprev)
+{
+ struct vm_area_struct *vma;
+
+ vma = find_vma(mm, addr);
+ if (vma) {
+ *pprev = vma->vm_prev;
+ } else {
+ struct rb_node *rb_node = mm->mm_rb.rb_node;
+ *pprev = NULL;
+ while (rb_node) {
+ *pprev = rb_entry(rb_node, struct vm_area_struct, vm_rb);
+ rb_node = rb_node->rb_right;
+ }
+ }
+ return vma;
+}
+
+/*
+ * Verify that the stack growth is acceptable and
+ * update accounting. This is shared with both the
+ * grow-up and grow-down cases.
+ */
+static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, unsigned long grow)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ struct rlimit *rlim = current->signal->rlim;
+ unsigned long new_start, actual_size;
+
+ /* address space limit tests */
+ if (!may_expand_vm(mm, grow))
+ return -ENOMEM;
+
+ /* Stack limit test */
+ actual_size = size;
+ if (size && (vma->vm_flags & (VM_GROWSUP | VM_GROWSDOWN)))
+ actual_size -= PAGE_SIZE;
+ if (actual_size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur))
+ return -ENOMEM;
+
+ /* mlock limit tests */
+ if (vma->vm_flags & VM_LOCKED) {
+ unsigned long locked;
+ unsigned long limit;
+ locked = mm->locked_vm + grow;
+ limit = ACCESS_ONCE(rlim[RLIMIT_MEMLOCK].rlim_cur);
+ limit >>= PAGE_SHIFT;
+ if (locked > limit && !capable(CAP_IPC_LOCK))
+ return -ENOMEM;
+ }
+
+ /* Check to ensure the stack will not grow into a hugetlb-only region */
+ new_start = (vma->vm_flags & VM_GROWSUP) ? vma->vm_start :
+ vma->vm_end - size;
+ if (is_hugepage_only_range(vma->vm_mm, new_start, size))
+ return -EFAULT;
+
+ /*
+ * Overcommit.. This must be the final test, as it will
+ * update security statistics.
+ */
+ if (security_vm_enough_memory_mm(mm, grow))
+ return -ENOMEM;
+
+ /* Ok, everything looks good - let it rip */
+ mm->total_vm += grow;
+ if (vma->vm_flags & VM_LOCKED)
+ mm->locked_vm += grow;
+ vm_stat_account(mm, vma->vm_flags, vma->vm_file, grow);
+ return 0;
+}
+
+#if defined(CONFIG_STACK_GROWSUP) || defined(CONFIG_IA64)
+/*
+ * PA-RISC uses this for its stack; IA64 for its Register Backing Store.
+ * vma is the last one with address > vma->vm_end. Have to extend vma.
+ */
+int expand_upwards(struct vm_area_struct *vma, unsigned long address)
+{
+ int error;
+
+ if (!(vma->vm_flags & VM_GROWSUP))
+ return -EFAULT;
+
+ /*
+ * We must make sure the anon_vma is allocated
+ * so that the anon_vma locking is not a noop.
+ */
+ if (unlikely(anon_vma_prepare(vma)))
+ return -ENOMEM;
+ vma_lock_anon_vma(vma);
+
+ /*
+ * vma->vm_start/vm_end cannot change under us because the caller
+ * is required to hold the mmap_sem in read mode. We need the
+ * anon_vma lock to serialize against concurrent expand_stacks.
+ * Also guard against wrapping around to address 0.
+ */
+ if (address < PAGE_ALIGN(address+4))
+ address = PAGE_ALIGN(address+4);
+ else {
+ vma_unlock_anon_vma(vma);
+ return -ENOMEM;
+ }
+ error = 0;
+
+ /* Somebody else might have raced and expanded it already */
+ if (address > vma->vm_end) {
+ unsigned long size, grow;
+
+ size = address - vma->vm_start;
+ grow = (address - vma->vm_end) >> PAGE_SHIFT;
+
+ error = -ENOMEM;
+ if (vma->vm_pgoff + (size >> PAGE_SHIFT) >= vma->vm_pgoff) {
+ error = acct_stack_growth(vma, size, grow);
+ if (!error) {
+ vma->vm_end = address;
+ perf_event_mmap(vma);
+ }
+ }
+ }
+ vma_unlock_anon_vma(vma);
+ khugepaged_enter_vma_merge(vma, vma->vm_flags);
+ return error;
+}
+#endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */
+
+/*
+ * vma is the first one with address < vma->vm_start. Have to extend vma.
+ */
+int expand_downwards(struct vm_area_struct *vma,
+ unsigned long address)
+{
+ int error;
+
+ /*
+ * We must make sure the anon_vma is allocated
+ * so that the anon_vma locking is not a noop.
+ */
+ if (unlikely(anon_vma_prepare(vma)))
+ return -ENOMEM;
+
+ address &= PAGE_MASK;
+ error = security_file_mmap(NULL, 0, 0, 0, address, 1);
+ if (error)
+ return error;
+
+ vma_lock_anon_vma(vma);
+
+ /*
+ * vma->vm_start/vm_end cannot change under us because the caller
+ * is required to hold the mmap_sem in read mode. We need the
+ * anon_vma lock to serialize against concurrent expand_stacks.
+ */
+
+ /* Somebody else might have raced and expanded it already */
+ if (address < vma->vm_start) {
+ unsigned long size, grow;
+
+ size = vma->vm_end - address;
+ grow = (vma->vm_start - address) >> PAGE_SHIFT;
+
+ error = -ENOMEM;
+ if (grow <= vma->vm_pgoff) {
+ error = acct_stack_growth(vma, size, grow);
+ if (!error) {
+ vma->vm_start = address;
+ vma->vm_pgoff -= grow;
+ perf_event_mmap(vma);
+ }
+ }
+ }
+ vma_unlock_anon_vma(vma);
+ khugepaged_enter_vma_merge(vma, vma->vm_flags);
+ return error;
+}
+
+/*
+ * Note how expand_stack() refuses to expand the stack all the way to
+ * abut the next virtual mapping, *unless* that mapping itself is also
+ * a stack mapping. We want to leave room for a guard page, after all
+ * (the guard page itself is not added here, that is done by the
+ * actual page faulting logic)
+ *
+ * This matches the behavior of the guard page logic (see mm/memory.c:
+ * check_stack_guard_page()), which only allows the guard page to be
+ * removed under these circumstances.
+ */
+#ifdef CONFIG_STACK_GROWSUP
+int expand_stack(struct vm_area_struct *vma, unsigned long address)
+{
+ struct vm_area_struct *next;
+
+ address &= PAGE_MASK;
+ next = vma->vm_next;
+ if (next && next->vm_start == address + PAGE_SIZE) {
+ if (!(next->vm_flags & VM_GROWSUP))
+ return -ENOMEM;
+ }
+ return expand_upwards(vma, address);
+}
+
+struct vm_area_struct *
+find_extend_vma(struct mm_struct *mm, unsigned long addr)
+{
+ struct vm_area_struct *vma, *prev;
+
+ addr &= PAGE_MASK;
+ vma = find_vma_prev(mm, addr, &prev);
+ if (vma && (vma->vm_start <= addr))
+ return vma;
+ if (!prev || expand_stack(prev, addr))
+ return NULL;
+ if (prev->vm_flags & VM_LOCKED) {
+ mlock_vma_pages_range(prev, addr, prev->vm_end);
+ }
+ return prev;
+}
+#else
+int expand_stack(struct vm_area_struct *vma, unsigned long address)
+{
+ struct vm_area_struct *prev;
+
+ address &= PAGE_MASK;
+ prev = vma->vm_prev;
+ if (prev && prev->vm_end == address) {
+ if (!(prev->vm_flags & VM_GROWSDOWN))
+ return -ENOMEM;
+ }
+ return expand_downwards(vma, address);
+}
+
+struct vm_area_struct *
+find_extend_vma(struct mm_struct * mm, unsigned long addr)
+{
+ struct vm_area_struct * vma;
+ unsigned long start;
+
+ addr &= PAGE_MASK;
+ vma = find_vma(mm,addr);
+ if (!vma)
+ return NULL;
+ if (vma->vm_start <= addr)
+ return vma;
+ if (!(vma->vm_flags & VM_GROWSDOWN))
+ return NULL;
+ start = vma->vm_start;
+ if (expand_stack(vma, addr))
+ return NULL;
+ if (vma->vm_flags & VM_LOCKED) {
+ mlock_vma_pages_range(vma, addr, start);
+ }
+ return vma;
+}
+#endif
+
+/*
+ * Ok - we have the memory areas we should free on the vma list,
+ * so release them, and do the vma updates.
+ *
+ * Called with the mm semaphore held.
+ */
+static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma)
+{
+ /* Update high watermark before we lower total_vm */
+ update_hiwater_vm(mm);
+ do {
+ long nrpages = vma_pages(vma);
+
+ mm->total_vm -= nrpages;
+ vm_stat_account(mm, vma->vm_flags, vma->vm_file, -nrpages);
+ vma = remove_vma(vma);
+ } while (vma);
+ validate_mm(mm);
+}
+
+/*
+ * Get rid of page table information in the indicated region.
+ *
+ * Called with the mm semaphore held.
+ */
+static void unmap_region(struct mm_struct *mm,
+ struct vm_area_struct *vma, struct vm_area_struct *prev,
+ unsigned long start, unsigned long end)
+{
+ struct vm_area_struct *next = prev? prev->vm_next: mm->mmap;
+ struct mmu_gather tlb;
+ unsigned long nr_accounted = 0;
+
+ lru_add_drain();
+ tlb_gather_mmu(&tlb, mm, 0);
+ update_hiwater_rss(mm);
+ unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL);
+ vm_unacct_memory(nr_accounted);
+ free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS,
+ next ? next->vm_start : USER_PGTABLES_CEILING);
+ tlb_finish_mmu(&tlb, start, end);
+}
+
+/*
+ * Create a list of vma's touched by the unmap, removing them from the mm's
+ * vma list as we go..
+ */
+static void
+detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct vm_area_struct *prev, unsigned long end)
+{
+ struct vm_area_struct **insertion_point;
+ struct vm_area_struct *tail_vma = NULL;
+ unsigned long addr;
+
+ insertion_point = (prev ? &prev->vm_next : &mm->mmap);
+ vma->vm_prev = NULL;
+ do {
+ rb_erase(&vma->vm_rb, &mm->mm_rb);
+ mm->map_count--;
+ tail_vma = vma;
+ vma = vma->vm_next;
+ } while (vma && vma->vm_start < end);
+ *insertion_point = vma;
+ if (vma)
+ vma->vm_prev = prev;
+ tail_vma->vm_next = NULL;
+ if (mm->unmap_area == arch_unmap_area)
+ addr = prev ? prev->vm_end : mm->mmap_base;
+ else
+ addr = vma ? vma->vm_start : mm->mmap_base;
+ mm->unmap_area(mm, addr);
+ mm->mmap_cache = NULL; /* Kill the cache. */
+}
+
+/*
+ * __split_vma() bypasses sysctl_max_map_count checking. We use this on the
+ * munmap path where it doesn't make sense to fail.
+ */
+static int __split_vma(struct mm_struct * mm, struct vm_area_struct * vma,
+ unsigned long addr, int new_below)
+{
+ struct mempolicy *pol;
+ struct vm_area_struct *new;
+ int err = -ENOMEM;
+
+ if (is_vm_hugetlb_page(vma) && (addr &
+ ~(huge_page_mask(hstate_vma(vma)))))
+ return -EINVAL;
+
+ new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
+ if (!new)
+ goto out_err;
+
+ /* most fields are the same, copy all, and then fixup */
+ *new = *vma;
+
+ INIT_LIST_HEAD(&new->anon_vma_chain);
+
+ if (new_below)
+ new->vm_end = addr;
+ else {
+ new->vm_start = addr;
+ new->vm_pgoff += ((addr - vma->vm_start) >> PAGE_SHIFT);
+ }
+
+ pol = mpol_dup(vma_policy(vma));
+ if (IS_ERR(pol)) {
+ err = PTR_ERR(pol);
+ goto out_free_vma;
+ }
+ vma_set_policy(new, pol);
+
+ if (anon_vma_clone(new, vma))
+ goto out_free_mpol;
+
+ if (new->vm_file) {
+ get_file(new->vm_file);
+ if (vma->vm_flags & VM_EXECUTABLE)
+ added_exe_file_vma(mm);
+ }
+
+ if (new->vm_ops && new->vm_ops->open)
+ new->vm_ops->open(new);
+
+ if (new_below)
+ err = vma_adjust(vma, addr, vma->vm_end, vma->vm_pgoff +
+ ((addr - new->vm_start) >> PAGE_SHIFT), new);
+ else
+ err = vma_adjust(vma, vma->vm_start, addr, vma->vm_pgoff, new);
+
+ /* Success. */
+ if (!err)
+ return 0;
+
+ /* Clean everything up if vma_adjust failed. */
+ if (new->vm_ops && new->vm_ops->close)
+ new->vm_ops->close(new);
+ if (new->vm_file) {
+ if (vma->vm_flags & VM_EXECUTABLE)
+ removed_exe_file_vma(mm);
+ fput(new->vm_file);
+ }
+ unlink_anon_vmas(new);
+ out_free_mpol:
+ mpol_put(pol);
+ out_free_vma:
+ kmem_cache_free(vm_area_cachep, new);
+ out_err:
+ return err;
+}
+
+/*
+ * Split a vma into two pieces at address 'addr', a new vma is allocated
+ * either for the first part or the tail.
+ */
+int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, int new_below)
+{
+ if (mm->map_count >= sysctl_max_map_count)
+ return -ENOMEM;
+
+ return __split_vma(mm, vma, addr, new_below);
+}
+
+/* Munmap is split into 2 main parts -- this part which finds
+ * what needs doing, and the areas themselves, which do the
+ * work. This now handles partial unmappings.
+ * Jeremy Fitzhardinge <jeremy@goop.org>
+ */
+int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
+{
+ unsigned long end;
+ struct vm_area_struct *vma, *prev, *last;
+
+ if ((start & ~PAGE_MASK) || start > TASK_SIZE || len > TASK_SIZE-start)
+ return -EINVAL;
+
+ if ((len = PAGE_ALIGN(len)) == 0)
+ return -EINVAL;
+
+ /* Find the first overlapping VMA */
+ vma = find_vma(mm, start);
+ if (!vma)
+ return 0;
+ prev = vma->vm_prev;
+ /* we have start < vma->vm_end */
+
+ /* if it doesn't overlap, we have nothing.. */
+ end = start + len;
+ if (vma->vm_start >= end)
+ return 0;
+
+ /*
+ * If we need to split any vma, do it now to save pain later.
+ *
+ * Note: mremap's move_vma VM_ACCOUNT handling assumes a partially
+ * unmapped vm_area_struct will remain in use: so lower split_vma
+ * places tmp vma above, and higher split_vma places tmp vma below.
+ */
+ if (start > vma->vm_start) {
+ int error;
+
+ /*
+ * Make sure that map_count on return from munmap() will
+ * not exceed its limit; but let map_count go just above
+ * its limit temporarily, to help free resources as expected.
+ */
+ if (end < vma->vm_end && mm->map_count >= sysctl_max_map_count)
+ return -ENOMEM;
+
+ error = __split_vma(mm, vma, start, 0);
+ if (error)
+ return error;
+ prev = vma;
+ }
+
+ /* Does it split the last one? */
+ last = find_vma(mm, end);
+ if (last && end > last->vm_start) {
+ int error = __split_vma(mm, last, end, 1);
+ if (error)
+ return error;
+ }
+ vma = prev? prev->vm_next: mm->mmap;
+
+ /*
+ * unlock any mlock()ed ranges before detaching vmas
+ */
+ if (mm->locked_vm) {
+ struct vm_area_struct *tmp = vma;
+ while (tmp && tmp->vm_start < end) {
+ if (tmp->vm_flags & VM_LOCKED) {
+ mm->locked_vm -= vma_pages(tmp);
+ munlock_vma_pages_all(tmp);
+ }
+ tmp = tmp->vm_next;
+ }
+ }
+
+ /*
+ * Remove the vma's, and unmap the actual pages
+ */
+ detach_vmas_to_be_unmapped(mm, vma, prev, end);
+ unmap_region(mm, vma, prev, start, end);
+
+ /* Fix up all other VM information */
+ remove_vma_list(mm, vma);
+
+ return 0;
+}
+EXPORT_SYMBOL(do_munmap);
+
+int vm_munmap(unsigned long start, size_t len)
+{
+ int ret;
+ struct mm_struct *mm = current->mm;
+
+ down_write(&mm->mmap_sem);
+ ret = do_munmap(mm, start, len);
+ up_write(&mm->mmap_sem);
+ return ret;
+}
+EXPORT_SYMBOL(vm_munmap);
+
+SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
+{
+ profile_munmap(addr);
+ return vm_munmap(addr, len);
+}
+
+static inline void verify_mm_writelocked(struct mm_struct *mm)
+{
+#ifdef CONFIG_DEBUG_VM
+ if (unlikely(down_read_trylock(&mm->mmap_sem))) {
+ WARN_ON(1);
+ up_read(&mm->mmap_sem);
+ }
+#endif
+}
+
+/*
+ * this is really a simplified "do_mmap". it only handles
+ * anonymous maps. eventually we may be able to do some
+ * brk-specific accounting here.
+ */
+static unsigned long do_brk(unsigned long addr, unsigned long len)
+{
+ struct mm_struct * mm = current->mm;
+ struct vm_area_struct * vma, * prev;
+ unsigned long flags;
+ struct rb_node ** rb_link, * rb_parent;
+ pgoff_t pgoff = addr >> PAGE_SHIFT;
+ int error;
+
+ len = PAGE_ALIGN(len);
+ if (!len)
+ return addr;
+
+ error = security_file_mmap(NULL, 0, 0, 0, addr, 1);
+ if (error)
+ return error;
+
+ flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
+
+ error = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED);
+ if (error & ~PAGE_MASK)
+ return error;
+
+ /*
+ * mlock MCL_FUTURE?
+ */
+ if (mm->def_flags & VM_LOCKED) {
+ unsigned long locked, lock_limit;
+ locked = len >> PAGE_SHIFT;
+ locked += mm->locked_vm;
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
+ lock_limit >>= PAGE_SHIFT;
+ if (locked > lock_limit && !capable(CAP_IPC_LOCK))
+ return -EAGAIN;
+ }
+
+ /*
+ * mm->mmap_sem is required to protect against another thread
+ * changing the mappings in case we sleep.
+ */
+ verify_mm_writelocked(mm);
+
+ /*
+ * Clear old maps. this also does some error checking for us
+ */
+ munmap_back:
+ vma = find_vma_prepare(mm, addr, &prev, &rb_link, &rb_parent);
+ if (vma && vma->vm_start < addr + len) {
+ if (do_munmap(mm, addr, len))
+ return -ENOMEM;
+ goto munmap_back;
+ }
+
+ /* Check against address space limits *after* clearing old maps... */
+ if (!may_expand_vm(mm, len >> PAGE_SHIFT))
+ return -ENOMEM;
+
+ if (mm->map_count > sysctl_max_map_count)
+ return -ENOMEM;
+
+ if (security_vm_enough_memory_mm(mm, len >> PAGE_SHIFT))
+ return -ENOMEM;
+
+ /* Can we just expand an old private anonymous mapping? */
+ vma = vma_merge(mm, prev, addr, addr + len, flags,
+ NULL, NULL, pgoff, NULL);
+ if (vma)
+ goto out;
+
+ /*
+ * create a vma struct for an anonymous mapping
+ */
+ vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
+ if (!vma) {
+ vm_unacct_memory(len >> PAGE_SHIFT);
+ return -ENOMEM;
+ }
+
+ INIT_LIST_HEAD(&vma->anon_vma_chain);
+ vma->vm_mm = mm;
+ vma->vm_start = addr;
+ vma->vm_end = addr + len;
+ vma->vm_pgoff = pgoff;
+ vma->vm_flags = flags;
+ vma->vm_page_prot = vm_get_page_prot(flags);
+ vma_link(mm, vma, prev, rb_link, rb_parent);
+out:
+ perf_event_mmap(vma);
+ mm->total_vm += len >> PAGE_SHIFT;
+ if (flags & VM_LOCKED) {
+ if (!mlock_vma_pages_range(vma, addr, addr + len))
+ mm->locked_vm += (len >> PAGE_SHIFT);
+ }
+ return addr;
+}
+
+unsigned long vm_brk(unsigned long addr, unsigned long len)
+{
+ struct mm_struct *mm = current->mm;
+ unsigned long ret;
+
+ down_write(&mm->mmap_sem);
+ ret = do_brk(addr, len);
+ up_write(&mm->mmap_sem);
+ return ret;
+}
+EXPORT_SYMBOL(vm_brk);
+
+/* Release all mmaps. */
+void exit_mmap(struct mm_struct *mm)
+{
+ struct mmu_gather tlb;
+ struct vm_area_struct *vma;
+ unsigned long nr_accounted = 0;
+
+ /* mm's last user has gone, and its about to be pulled down */
+ mmu_notifier_release(mm);
+
+ if (mm->locked_vm) {
+ vma = mm->mmap;
+ while (vma) {
+ if (vma->vm_flags & VM_LOCKED)
+ munlock_vma_pages_all(vma);
+ vma = vma->vm_next;
+ }
+ }
+
+ arch_exit_mmap(mm);
+
+ vma = mm->mmap;
+ if (!vma) /* Can happen if dup_mmap() received an OOM */
+ return;
+
+ lru_add_drain();
+ flush_cache_mm(mm);
+ tlb_gather_mmu(&tlb, mm, 1);
+ /* update_hiwater_rss(mm) here? but nobody should be looking */
+ /* Use -1 here to ensure all VMAs in the mm are unmapped */
+ unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);
+ vm_unacct_memory(nr_accounted);
+
+ free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, USER_PGTABLES_CEILING);
+ tlb_finish_mmu(&tlb, 0, -1);
+
+ /*
+ * Walk the list again, actually closing and freeing it,
+ * with preemption enabled, without holding any MM locks.
+ */
+ while (vma)
+ vma = remove_vma(vma);
+
+ BUG_ON(mm->nr_ptes > (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT);
+}
+
+/* Insert vm structure into process list sorted by address
+ * and into the inode's i_mmap tree. If vm_file is non-NULL
+ * then i_mmap_mutex is taken here.
+ */
+int insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma)
+{
+ struct vm_area_struct * __vma, * prev;
+ struct rb_node ** rb_link, * rb_parent;
+
+ /*
+ * The vm_pgoff of a purely anonymous vma should be irrelevant
+ * until its first write fault, when page's anon_vma and index
+ * are set. But now set the vm_pgoff it will almost certainly
+ * end up with (unless mremap moves it elsewhere before that
+ * first wfault), so /proc/pid/maps tells a consistent story.
+ *
+ * By setting it to reflect the virtual start address of the
+ * vma, merges and splits can happen in a seamless way, just
+ * using the existing file pgoff checks and manipulations.
+ * Similarly in do_mmap_pgoff and in do_brk.
+ */
+ if (!vma->vm_file) {
+ BUG_ON(vma->anon_vma);
+ vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
+ }
+ __vma = find_vma_prepare(mm,vma->vm_start,&prev,&rb_link,&rb_parent);
+ if (__vma && __vma->vm_start < vma->vm_end)
+ return -ENOMEM;
+ if ((vma->vm_flags & VM_ACCOUNT) &&
+ security_vm_enough_memory_mm(mm, vma_pages(vma)))
+ return -ENOMEM;
+ vma_link(mm, vma, prev, rb_link, rb_parent);
+ return 0;
+}
+
+/*
+ * Copy the vma structure to a new location in the same mm,
+ * prior to moving page table entries, to effect an mremap move.
+ */
+struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
+ unsigned long addr, unsigned long len, pgoff_t pgoff)
+{
+ struct vm_area_struct *vma = *vmap;
+ unsigned long vma_start = vma->vm_start;
+ struct mm_struct *mm = vma->vm_mm;
+ struct vm_area_struct *new_vma, *prev;
+ struct rb_node **rb_link, *rb_parent;
+ struct mempolicy *pol;
+ bool faulted_in_anon_vma = true;
+
+ /*
+ * If anonymous vma has not yet been faulted, update new pgoff
+ * to match new location, to increase its chance of merging.
+ */
+ if (unlikely(!vma->vm_file && !vma->anon_vma)) {
+ pgoff = addr >> PAGE_SHIFT;
+ faulted_in_anon_vma = false;
+ }
+
+ find_vma_prepare(mm, addr, &prev, &rb_link, &rb_parent);
+ new_vma = vma_merge(mm, prev, addr, addr + len, vma->vm_flags,
+ vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma));
+ if (new_vma) {
+ /*
+ * Source vma may have been merged into new_vma
+ */
+ if (unlikely(vma_start >= new_vma->vm_start &&
+ vma_start < new_vma->vm_end)) {
+ /*
+ * The only way we can get a vma_merge with
+ * self during an mremap is if the vma hasn't
+ * been faulted in yet and we were allowed to
+ * reset the dst vma->vm_pgoff to the
+ * destination address of the mremap to allow
+ * the merge to happen. mremap must change the
+ * vm_pgoff linearity between src and dst vmas
+ * (in turn preventing a vma_merge) to be
+ * safe. It is only safe to keep the vm_pgoff
+ * linear if there are no pages mapped yet.
+ */
+ VM_BUG_ON(faulted_in_anon_vma);
+ *vmap = new_vma;
+ } else
+ anon_vma_moveto_tail(new_vma);
+ } else {
+ new_vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
+ if (new_vma) {
+ *new_vma = *vma;
+ pol = mpol_dup(vma_policy(vma));
+ if (IS_ERR(pol))
+ goto out_free_vma;
+ INIT_LIST_HEAD(&new_vma->anon_vma_chain);
+ if (anon_vma_clone(new_vma, vma))
+ goto out_free_mempol;
+ vma_set_policy(new_vma, pol);
+ new_vma->vm_start = addr;
+ new_vma->vm_end = addr + len;
+ new_vma->vm_pgoff = pgoff;
+ if (new_vma->vm_file) {
+ get_file(new_vma->vm_file);
+ if (vma->vm_flags & VM_EXECUTABLE)
+ added_exe_file_vma(mm);
+ }
+ if (new_vma->vm_ops && new_vma->vm_ops->open)
+ new_vma->vm_ops->open(new_vma);
+ vma_link(mm, new_vma, prev, rb_link, rb_parent);
+ }
+ }
+ return new_vma;
+
+ out_free_mempol:
+ mpol_put(pol);
+ out_free_vma:
+ kmem_cache_free(vm_area_cachep, new_vma);
+ return NULL;
+}
+
+/*
+ * Return true if the calling process may expand its vm space by the passed
+ * number of pages
+ */
+int may_expand_vm(struct mm_struct *mm, unsigned long npages)
+{
+ unsigned long cur = mm->total_vm; /* pages */
+ unsigned long lim;
+
+ lim = rlimit(RLIMIT_AS) >> PAGE_SHIFT;
+
+ if (cur + npages > lim)
+ return 0;
+ return 1;
+}
+
+
+static int special_mapping_fault(struct vm_area_struct *vma,
+ struct vm_fault *vmf)
+{
+ pgoff_t pgoff;
+ struct page **pages;
+
+ /*
+ * special mappings have no vm_file, and in that case, the mm
+ * uses vm_pgoff internally. So we have to subtract it from here.
+ * We are allowed to do this because we are the mm; do not copy
+ * this code into drivers!
+ */
+ pgoff = vmf->pgoff - vma->vm_pgoff;
+
+ for (pages = vma->vm_private_data; pgoff && *pages; ++pages)
+ pgoff--;
+
+ if (*pages) {
+ struct page *page = *pages;
+ get_page(page);
+ vmf->page = page;
+ return 0;
+ }
+
+ return VM_FAULT_SIGBUS;
+}
+
+/*
+ * Having a close hook prevents vma merging regardless of flags.
+ */
+static void special_mapping_close(struct vm_area_struct *vma)
+{
+}
+
+static const struct vm_operations_struct special_mapping_vmops = {
+ .close = special_mapping_close,
+ .fault = special_mapping_fault,
+};
+
+/*
+ * Called with mm->mmap_sem held for writing.
+ * Insert a new vma covering the given region, with the given flags.
+ * Its pages are supplied by the given array of struct page *.
+ * The array can be shorter than len >> PAGE_SHIFT if it's null-terminated.
+ * The region past the last page supplied will always produce SIGBUS.
+ * The array pointer and the pages it points to are assumed to stay alive
+ * for as long as this mapping might exist.
+ */
+int install_special_mapping(struct mm_struct *mm,
+ unsigned long addr, unsigned long len,
+ unsigned long vm_flags, struct page **pages)
+{
+ int ret;
+ struct vm_area_struct *vma;
+
+ vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
+ if (unlikely(vma == NULL))
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&vma->anon_vma_chain);
+ vma->vm_mm = mm;
+ vma->vm_start = addr;
+ vma->vm_end = addr + len;
+
+ vma->vm_flags = vm_flags | mm->def_flags | VM_DONTEXPAND;
+ vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+
+ vma->vm_ops = &special_mapping_vmops;
+ vma->vm_private_data = pages;
+
+ ret = security_file_mmap(NULL, 0, 0, 0, vma->vm_start, 1);
+ if (ret)
+ goto out;
+
+ ret = insert_vm_struct(mm, vma);
+ if (ret)
+ goto out;
+
+ mm->total_vm += len >> PAGE_SHIFT;
+
+ perf_event_mmap(vma);
+
+ return 0;
+
+out:
+ kmem_cache_free(vm_area_cachep, vma);
+ return ret;
+}
+
+static DEFINE_MUTEX(mm_all_locks_mutex);
+
+static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma)
+{
+ if (!test_bit(0, (unsigned long *) &anon_vma->root->head.next)) {
+ /*
+ * The LSB of head.next can't change from under us
+ * because we hold the mm_all_locks_mutex.
+ */
+ mutex_lock_nest_lock(&anon_vma->root->mutex, &mm->mmap_sem);
+ /*
+ * We can safely modify head.next after taking the
+ * anon_vma->root->mutex. If some other vma in this mm shares
+ * the same anon_vma we won't take it again.
+ *
+ * No need of atomic instructions here, head.next
+ * can't change from under us thanks to the
+ * anon_vma->root->mutex.
+ */
+ if (__test_and_set_bit(0, (unsigned long *)
+ &anon_vma->root->head.next))
+ BUG();
+ }
+}
+
+static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping)
+{
+ if (!test_bit(AS_MM_ALL_LOCKS, &mapping->flags)) {
+ /*
+ * AS_MM_ALL_LOCKS can't change from under us because
+ * we hold the mm_all_locks_mutex.
+ *
+ * Operations on ->flags have to be atomic because
+ * even if AS_MM_ALL_LOCKS is stable thanks to the
+ * mm_all_locks_mutex, there may be other cpus
+ * changing other bitflags in parallel to us.
+ */
+ if (test_and_set_bit(AS_MM_ALL_LOCKS, &mapping->flags))
+ BUG();
+ mutex_lock_nest_lock(&mapping->i_mmap_mutex, &mm->mmap_sem);
+ }
+}
+
+/*
+ * This operation locks against the VM for all pte/vma/mm related
+ * operations that could ever happen on a certain mm. This includes
+ * vmtruncate, try_to_unmap, and all page faults.
+ *
+ * The caller must take the mmap_sem in write mode before calling
+ * mm_take_all_locks(). The caller isn't allowed to release the
+ * mmap_sem until mm_drop_all_locks() returns.
+ *
+ * mmap_sem in write mode is required in order to block all operations
+ * that could modify pagetables and free pages without need of
+ * altering the vma layout (for example populate_range() with
+ * nonlinear vmas). It's also needed in write mode to avoid new
+ * anon_vmas to be associated with existing vmas.
+ *
+ * A single task can't take more than one mm_take_all_locks() in a row
+ * or it would deadlock.
+ *
+ * The LSB in anon_vma->head.next and the AS_MM_ALL_LOCKS bitflag in
+ * mapping->flags avoid to take the same lock twice, if more than one
+ * vma in this mm is backed by the same anon_vma or address_space.
+ *
+ * We can take all the locks in random order because the VM code
+ * taking i_mmap_mutex or anon_vma->mutex outside the mmap_sem never
+ * takes more than one of them in a row. Secondly we're protected
+ * against a concurrent mm_take_all_locks() by the mm_all_locks_mutex.
+ *
+ * mm_take_all_locks() and mm_drop_all_locks are expensive operations
+ * that may have to take thousand of locks.
+ *
+ * mm_take_all_locks() can fail if it's interrupted by signals.
+ */
+int mm_take_all_locks(struct mm_struct *mm)
+{
+ struct vm_area_struct *vma;
+ struct anon_vma_chain *avc;
+
+ BUG_ON(down_read_trylock(&mm->mmap_sem));
+
+ mutex_lock(&mm_all_locks_mutex);
+
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (signal_pending(current))
+ goto out_unlock;
+ if (vma->vm_file && vma->vm_file->f_mapping)
+ vm_lock_mapping(mm, vma->vm_file->f_mapping);
+ }
+
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (signal_pending(current))
+ goto out_unlock;
+ if (vma->anon_vma)
+ list_for_each_entry(avc, &vma->anon_vma_chain, same_vma)
+ vm_lock_anon_vma(mm, avc->anon_vma);
+ }
+
+ return 0;
+
+out_unlock:
+ mm_drop_all_locks(mm);
+ return -EINTR;
+}
+
+static void vm_unlock_anon_vma(struct anon_vma *anon_vma)
+{
+ if (test_bit(0, (unsigned long *) &anon_vma->root->head.next)) {
+ /*
+ * The LSB of head.next can't change to 0 from under
+ * us because we hold the mm_all_locks_mutex.
+ *
+ * We must however clear the bitflag before unlocking
+ * the vma so the users using the anon_vma->head will
+ * never see our bitflag.
+ *
+ * No need of atomic instructions here, head.next
+ * can't change from under us until we release the
+ * anon_vma->root->mutex.
+ */
+ if (!__test_and_clear_bit(0, (unsigned long *)
+ &anon_vma->root->head.next))
+ BUG();
+ anon_vma_unlock(anon_vma);
+ }
+}
+
+static void vm_unlock_mapping(struct address_space *mapping)
+{
+ if (test_bit(AS_MM_ALL_LOCKS, &mapping->flags)) {
+ /*
+ * AS_MM_ALL_LOCKS can't change to 0 from under us
+ * because we hold the mm_all_locks_mutex.
+ */
+ mutex_unlock(&mapping->i_mmap_mutex);
+ if (!test_and_clear_bit(AS_MM_ALL_LOCKS,
+ &mapping->flags))
+ BUG();
+ }
+}
+
+/*
+ * The mmap_sem cannot be released by the caller until
+ * mm_drop_all_locks() returns.
+ */
+void mm_drop_all_locks(struct mm_struct *mm)
+{
+ struct vm_area_struct *vma;
+ struct anon_vma_chain *avc;
+
+ BUG_ON(down_read_trylock(&mm->mmap_sem));
+ BUG_ON(!mutex_is_locked(&mm_all_locks_mutex));
+
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (vma->anon_vma)
+ list_for_each_entry(avc, &vma->anon_vma_chain, same_vma)
+ vm_unlock_anon_vma(avc->anon_vma);
+ if (vma->vm_file && vma->vm_file->f_mapping)
+ vm_unlock_mapping(vma->vm_file->f_mapping);
+ }
+
+ mutex_unlock(&mm_all_locks_mutex);
+}
+
+/*
+ * initialise the VMA slab
+ */
+void __init mmap_init(void)
+{
+ int ret;
+
+ ret = percpu_counter_init(&vm_committed_as, 0);
+ VM_BUG_ON(ret);
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/mmu_context.c b/ap/os/linux/linux-3.4.x/mm/mmu_context.c
new file mode 100644
index 0000000..1385e48
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mmu_context.c
@@ -0,0 +1,64 @@
+/* Copyright (C) 2009 Red Hat, Inc.
+ *
+ * See ../COPYING for licensing terms.
+ */
+
+#include <linux/mm.h>
+#include <linux/mmu_context.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+
+#include <asm/mmu_context.h>
+
+/*
+ * use_mm
+ * Makes the calling kernel thread take on the specified
+ * mm context.
+ * Called by the retry thread execute retries within the
+ * iocb issuer's mm context, so that copy_from/to_user
+ * operations work seamlessly for aio.
+ * (Note: this routine is intended to be called only
+ * from a kernel thread context)
+ */
+void use_mm(struct mm_struct *mm)
+{
+ struct mm_struct *active_mm;
+ struct task_struct *tsk = current;
+
+ task_lock(tsk);
+ preempt_disable_rt();
+ active_mm = tsk->active_mm;
+ if (active_mm != mm) {
+ atomic_inc(&mm->mm_count);
+ tsk->active_mm = mm;
+ }
+ tsk->mm = mm;
+ switch_mm(active_mm, mm, tsk);
+ preempt_enable_rt();
+ task_unlock(tsk);
+
+ if (active_mm != mm)
+ mmdrop(active_mm);
+}
+EXPORT_SYMBOL_GPL(use_mm);
+
+/*
+ * unuse_mm
+ * Reverses the effect of use_mm, i.e. releases the
+ * specified mm context which was earlier taken on
+ * by the calling kernel thread
+ * (Note: this routine is intended to be called only
+ * from a kernel thread context)
+ */
+void unuse_mm(struct mm_struct *mm)
+{
+ struct task_struct *tsk = current;
+
+ task_lock(tsk);
+ sync_mm_rss(mm);
+ tsk->mm = NULL;
+ /* active_mm is still 'mm' */
+ enter_lazy_tlb(mm, tsk);
+ task_unlock(tsk);
+}
+EXPORT_SYMBOL_GPL(unuse_mm);
diff --git a/ap/os/linux/linux-3.4.x/mm/mmu_notifier.c b/ap/os/linux/linux-3.4.x/mm/mmu_notifier.c
new file mode 100644
index 0000000..c1f947b
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mmu_notifier.c
@@ -0,0 +1,344 @@
+/*
+ * linux/mm/mmu_notifier.c
+ *
+ * Copyright (C) 2008 Qumranet, Inc.
+ * Copyright (C) 2008 SGI
+ * Christoph Lameter <clameter@sgi.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+
+#include <linux/rculist.h>
+#include <linux/mmu_notifier.h>
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/err.h>
+#include <linux/srcu.h>
+#include <linux/rcupdate.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+/* global SRCU for all MMs */
+static struct srcu_struct srcu;
+
+/*
+ * This function can't run concurrently against mmu_notifier_register
+ * because mm->mm_users > 0 during mmu_notifier_register and exit_mmap
+ * runs with mm_users == 0. Other tasks may still invoke mmu notifiers
+ * in parallel despite there being no task using this mm any more,
+ * through the vmas outside of the exit_mmap context, such as with
+ * vmtruncate. This serializes against mmu_notifier_unregister with
+ * the mmu_notifier_mm->lock in addition to SRCU and it serializes
+ * against the other mmu notifiers with SRCU. struct mmu_notifier_mm
+ * can't go away from under us as exit_mmap holds an mm_count pin
+ * itself.
+ */
+void __mmu_notifier_release(struct mm_struct *mm)
+{
+ struct mmu_notifier *mn;
+ struct hlist_node *node;
+ int id;
+
+ /*
+ * SRCU here will block mmu_notifier_unregister until
+ * ->release returns.
+ */
+ id = srcu_read_lock(&srcu);
+ hlist_for_each_entry_rcu(mn, node, &mm->mmu_notifier_mm->list, hlist)
+ /*
+ * If ->release runs before mmu_notifier_unregister it must be
+ * handled, as it's the only way for the driver to flush all
+ * existing sptes and stop the driver from establishing any more
+ * sptes before all the pages in the mm are freed.
+ */
+ if (mn->ops->release)
+ mn->ops->release(mn, mm);
+ srcu_read_unlock(&srcu, id);
+
+ spin_lock(&mm->mmu_notifier_mm->lock);
+ while (unlikely(!hlist_empty(&mm->mmu_notifier_mm->list))) {
+ mn = hlist_entry(mm->mmu_notifier_mm->list.first,
+ struct mmu_notifier,
+ hlist);
+ /*
+ * We arrived before mmu_notifier_unregister so
+ * mmu_notifier_unregister will do nothing other than to wait
+ * for ->release to finish and for mmu_notifier_unregister to
+ * return.
+ */
+ hlist_del_init_rcu(&mn->hlist);
+ }
+ spin_unlock(&mm->mmu_notifier_mm->lock);
+
+ /*
+ * synchronize_srcu here prevents mmu_notifier_release from returning to
+ * exit_mmap (which would proceed with freeing all pages in the mm)
+ * until the ->release method returns, if it was invoked by
+ * mmu_notifier_unregister.
+ *
+ * The mmu_notifier_mm can't go away from under us because one mm_count
+ * is held by exit_mmap.
+ */
+ synchronize_srcu(&srcu);
+}
+
+/*
+ * If no young bitflag is supported by the hardware, ->clear_flush_young can
+ * unmap the address and return 1 or 0 depending if the mapping previously
+ * existed or not.
+ */
+int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
+ unsigned long address)
+{
+ struct mmu_notifier *mn;
+ struct hlist_node *n;
+ int young = 0, id;
+
+ id = srcu_read_lock(&srcu);
+ hlist_for_each_entry_rcu(mn, n, &mm->mmu_notifier_mm->list, hlist) {
+ if (mn->ops->clear_flush_young)
+ young |= mn->ops->clear_flush_young(mn, mm, address);
+ }
+ srcu_read_unlock(&srcu, id);
+
+ return young;
+}
+
+int __mmu_notifier_test_young(struct mm_struct *mm,
+ unsigned long address)
+{
+ struct mmu_notifier *mn;
+ struct hlist_node *n;
+ int young = 0, id;
+
+ id = srcu_read_lock(&srcu);
+ hlist_for_each_entry_rcu(mn, n, &mm->mmu_notifier_mm->list, hlist) {
+ if (mn->ops->test_young) {
+ young = mn->ops->test_young(mn, mm, address);
+ if (young)
+ break;
+ }
+ }
+ srcu_read_unlock(&srcu, id);
+
+ return young;
+}
+
+void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
+ pte_t pte)
+{
+ struct mmu_notifier *mn;
+ struct hlist_node *n;
+ int id;
+
+ id = srcu_read_lock(&srcu);
+ hlist_for_each_entry_rcu(mn, n, &mm->mmu_notifier_mm->list, hlist) {
+ if (mn->ops->change_pte)
+ mn->ops->change_pte(mn, mm, address, pte);
+ /*
+ * Some drivers don't have change_pte,
+ * so we must call invalidate_page in that case.
+ */
+ else if (mn->ops->invalidate_page)
+ mn->ops->invalidate_page(mn, mm, address);
+ }
+ srcu_read_unlock(&srcu, id);
+}
+
+void __mmu_notifier_invalidate_page(struct mm_struct *mm,
+ unsigned long address)
+{
+ struct mmu_notifier *mn;
+ struct hlist_node *n;
+ int id;
+
+ id = srcu_read_lock(&srcu);
+ hlist_for_each_entry_rcu(mn, n, &mm->mmu_notifier_mm->list, hlist) {
+ if (mn->ops->invalidate_page)
+ mn->ops->invalidate_page(mn, mm, address);
+ }
+ srcu_read_unlock(&srcu, id);
+}
+
+void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
+{
+ struct mmu_notifier *mn;
+ struct hlist_node *n;
+ int id;
+
+ id = srcu_read_lock(&srcu);
+ hlist_for_each_entry_rcu(mn, n, &mm->mmu_notifier_mm->list, hlist) {
+ if (mn->ops->invalidate_range_start)
+ mn->ops->invalidate_range_start(mn, mm, start, end);
+ }
+ srcu_read_unlock(&srcu, id);
+}
+
+void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
+{
+ struct mmu_notifier *mn;
+ struct hlist_node *n;
+ int id;
+
+ id = srcu_read_lock(&srcu);
+ hlist_for_each_entry_rcu(mn, n, &mm->mmu_notifier_mm->list, hlist) {
+ if (mn->ops->invalidate_range_end)
+ mn->ops->invalidate_range_end(mn, mm, start, end);
+ }
+ srcu_read_unlock(&srcu, id);
+}
+
+static int do_mmu_notifier_register(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ int take_mmap_sem)
+{
+ struct mmu_notifier_mm *mmu_notifier_mm;
+ int ret;
+
+ BUG_ON(atomic_read(&mm->mm_users) <= 0);
+
+ /*
+ * Verify that mmu_notifier_init() already run and the global srcu is
+ * initialized.
+ */
+ BUG_ON(!srcu.per_cpu_ref);
+
+ ret = -ENOMEM;
+ mmu_notifier_mm = kmalloc(sizeof(struct mmu_notifier_mm), GFP_KERNEL);
+ if (unlikely(!mmu_notifier_mm))
+ goto out;
+
+ if (take_mmap_sem)
+ down_write(&mm->mmap_sem);
+ ret = mm_take_all_locks(mm);
+ if (unlikely(ret))
+ goto out_cleanup;
+
+ if (!mm_has_notifiers(mm)) {
+ INIT_HLIST_HEAD(&mmu_notifier_mm->list);
+ spin_lock_init(&mmu_notifier_mm->lock);
+ mm->mmu_notifier_mm = mmu_notifier_mm;
+ mmu_notifier_mm = NULL;
+ }
+ atomic_inc(&mm->mm_count);
+
+ /*
+ * Serialize the update against mmu_notifier_unregister. A
+ * side note: mmu_notifier_release can't run concurrently with
+ * us because we hold the mm_users pin (either implicitly as
+ * current->mm or explicitly with get_task_mm() or similar).
+ * We can't race against any other mmu notifier method either
+ * thanks to mm_take_all_locks().
+ */
+ spin_lock(&mm->mmu_notifier_mm->lock);
+ hlist_add_head(&mn->hlist, &mm->mmu_notifier_mm->list);
+ spin_unlock(&mm->mmu_notifier_mm->lock);
+
+ mm_drop_all_locks(mm);
+out_cleanup:
+ if (take_mmap_sem)
+ up_write(&mm->mmap_sem);
+ /* kfree() does nothing if mmu_notifier_mm is NULL */
+ kfree(mmu_notifier_mm);
+out:
+ BUG_ON(atomic_read(&mm->mm_users) <= 0);
+ return ret;
+}
+
+/*
+ * Must not hold mmap_sem nor any other VM related lock when calling
+ * this registration function. Must also ensure mm_users can't go down
+ * to zero while this runs to avoid races with mmu_notifier_release,
+ * so mm has to be current->mm or the mm should be pinned safely such
+ * as with get_task_mm(). If the mm is not current->mm, the mm_users
+ * pin should be released by calling mmput after mmu_notifier_register
+ * returns. mmu_notifier_unregister must be always called to
+ * unregister the notifier. mm_count is automatically pinned to allow
+ * mmu_notifier_unregister to safely run at any time later, before or
+ * after exit_mmap. ->release will always be called before exit_mmap
+ * frees the pages.
+ */
+int mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
+{
+ return do_mmu_notifier_register(mn, mm, 1);
+}
+EXPORT_SYMBOL_GPL(mmu_notifier_register);
+
+/*
+ * Same as mmu_notifier_register but here the caller must hold the
+ * mmap_sem in write mode.
+ */
+int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
+{
+ return do_mmu_notifier_register(mn, mm, 0);
+}
+EXPORT_SYMBOL_GPL(__mmu_notifier_register);
+
+/* this is called after the last mmu_notifier_unregister() returned */
+void __mmu_notifier_mm_destroy(struct mm_struct *mm)
+{
+ BUG_ON(!hlist_empty(&mm->mmu_notifier_mm->list));
+ kfree(mm->mmu_notifier_mm);
+ mm->mmu_notifier_mm = LIST_POISON1; /* debug */
+}
+
+/*
+ * This releases the mm_count pin automatically and frees the mm
+ * structure if it was the last user of it. It serializes against
+ * running mmu notifiers with SRCU and against mmu_notifier_unregister
+ * with the unregister lock + SRCU. All sptes must be dropped before
+ * calling mmu_notifier_unregister. ->release or any other notifier
+ * method may be invoked concurrently with mmu_notifier_unregister,
+ * and only after mmu_notifier_unregister returned we're guaranteed
+ * that ->release or any other method can't run anymore.
+ */
+void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm)
+{
+ BUG_ON(atomic_read(&mm->mm_count) <= 0);
+
+ if (!hlist_unhashed(&mn->hlist)) {
+ /*
+ * SRCU here will force exit_mmap to wait for ->release to
+ * finish before freeing the pages.
+ */
+ int id;
+
+ id = srcu_read_lock(&srcu);
+ /*
+ * exit_mmap will block in mmu_notifier_release to guarantee
+ * that ->release is called before freeing the pages.
+ */
+ if (mn->ops->release)
+ mn->ops->release(mn, mm);
+ srcu_read_unlock(&srcu, id);
+
+ spin_lock(&mm->mmu_notifier_mm->lock);
+ /*
+ * Can not use list_del_rcu() since __mmu_notifier_release
+ * can delete it before we hold the lock.
+ */
+ hlist_del_init_rcu(&mn->hlist);
+ spin_unlock(&mm->mmu_notifier_mm->lock);
+ }
+
+ /*
+ * Wait for any running method to finish, of course including
+ * ->release if it was run by mmu_notifier_relase instead of us.
+ */
+ synchronize_srcu(&srcu);
+
+ BUG_ON(atomic_read(&mm->mm_count) <= 0);
+
+ mmdrop(mm);
+}
+EXPORT_SYMBOL_GPL(mmu_notifier_unregister);
+
+static int __init mmu_notifier_init(void)
+{
+ return init_srcu_struct(&srcu);
+}
+
+module_init(mmu_notifier_init);
diff --git a/ap/os/linux/linux-3.4.x/mm/mmzone.c b/ap/os/linux/linux-3.4.x/mm/mmzone.c
new file mode 100644
index 0000000..7cf7b7d
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mmzone.c
@@ -0,0 +1,88 @@
+/*
+ * linux/mm/mmzone.c
+ *
+ * management codes for pgdats and zones.
+ */
+
+
+#include <linux/stddef.h>
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+
+struct pglist_data *first_online_pgdat(void)
+{
+ return NODE_DATA(first_online_node);
+}
+
+struct pglist_data *next_online_pgdat(struct pglist_data *pgdat)
+{
+ int nid = next_online_node(pgdat->node_id);
+
+ if (nid == MAX_NUMNODES)
+ return NULL;
+ return NODE_DATA(nid);
+}
+
+/*
+ * next_zone - helper magic for for_each_zone()
+ */
+struct zone *next_zone(struct zone *zone)
+{
+ pg_data_t *pgdat = zone->zone_pgdat;
+
+ if (zone < pgdat->node_zones + MAX_NR_ZONES - 1)
+ zone++;
+ else {
+ pgdat = next_online_pgdat(pgdat);
+ if (pgdat)
+ zone = pgdat->node_zones;
+ else
+ zone = NULL;
+ }
+ return zone;
+}
+
+static inline int zref_in_nodemask(struct zoneref *zref, nodemask_t *nodes)
+{
+#ifdef CONFIG_NUMA
+ return node_isset(zonelist_node_idx(zref), *nodes);
+#else
+ return 1;
+#endif /* CONFIG_NUMA */
+}
+
+/* Returns the next zone at or below highest_zoneidx in a zonelist */
+struct zoneref *next_zones_zonelist(struct zoneref *z,
+ enum zone_type highest_zoneidx,
+ nodemask_t *nodes,
+ struct zone **zone)
+{
+ /*
+ * Find the next suitable zone to use for the allocation.
+ * Only filter based on nodemask if it's set
+ */
+ if (likely(nodes == NULL))
+ while (zonelist_zone_idx(z) > highest_zoneidx)
+ z++;
+ else
+ while (zonelist_zone_idx(z) > highest_zoneidx ||
+ (z->zone && !zref_in_nodemask(z, nodes)))
+ z++;
+
+ *zone = zonelist_zone(z);
+ return z;
+}
+
+#ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
+int memmap_valid_within(unsigned long pfn,
+ struct page *page, struct zone *zone)
+{
+ if (page_to_pfn(page) != pfn)
+ return 0;
+
+ if (page_zone(page) != zone)
+ return 0;
+
+ return 1;
+}
+#endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
diff --git a/ap/os/linux/linux-3.4.x/mm/mprotect.c b/ap/os/linux/linux-3.4.x/mm/mprotect.c
new file mode 100644
index 0000000..a409926
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mprotect.c
@@ -0,0 +1,330 @@
+/*
+ * mm/mprotect.c
+ *
+ * (C) Copyright 1994 Linus Torvalds
+ * (C) Copyright 2002 Christoph Hellwig
+ *
+ * Address space accounting code <alan@lxorguk.ukuu.org.uk>
+ * (C) Copyright 2002 Red Hat Inc, All Rights Reserved
+ */
+
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/shm.h>
+#include <linux/mman.h>
+#include <linux/fs.h>
+#include <linux/highmem.h>
+#include <linux/security.h>
+#include <linux/mempolicy.h>
+#include <linux/personality.h>
+#include <linux/syscalls.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/mmu_notifier.h>
+#include <linux/migrate.h>
+#include <linux/perf_event.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+
+#ifndef pgprot_modify
+static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
+{
+ return newprot;
+}
+#endif
+
+static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
+ unsigned long addr, unsigned long end, pgprot_t newprot,
+ int dirty_accountable)
+{
+ pte_t *pte, oldpte;
+ spinlock_t *ptl;
+
+ pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
+ arch_enter_lazy_mmu_mode();
+ do {
+ oldpte = *pte;
+ if (pte_present(oldpte)) {
+ pte_t ptent;
+
+ ptent = ptep_modify_prot_start(mm, addr, pte);
+ ptent = pte_modify(ptent, newprot);
+
+ /*
+ * Avoid taking write faults for pages we know to be
+ * dirty.
+ */
+ if (dirty_accountable && pte_dirty(ptent))
+ ptent = pte_mkwrite(ptent);
+
+ ptep_modify_prot_commit(mm, addr, pte, ptent);
+ } else if (IS_ENABLED(CONFIG_MIGRATION) && !pte_file(oldpte)) {
+ swp_entry_t entry = pte_to_swp_entry(oldpte);
+
+ if (is_write_migration_entry(entry)) {
+ /*
+ * A protection check is difficult so
+ * just be safe and disable write
+ */
+ make_migration_entry_read(&entry);
+ set_pte_at(mm, addr, pte,
+ swp_entry_to_pte(entry));
+ }
+ }
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ arch_leave_lazy_mmu_mode();
+ pte_unmap_unlock(pte - 1, ptl);
+}
+
+static inline void change_pmd_range(struct vm_area_struct *vma, pud_t *pud,
+ unsigned long addr, unsigned long end, pgprot_t newprot,
+ int dirty_accountable)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_trans_huge(*pmd)) {
+ if (next - addr != HPAGE_PMD_SIZE)
+ split_huge_page_pmd(vma->vm_mm, pmd);
+ else if (change_huge_pmd(vma, pmd, addr, newprot))
+ continue;
+ /* fall through */
+ }
+ if (pmd_none_or_clear_bad(pmd))
+ continue;
+ change_pte_range(vma->vm_mm, pmd, addr, next, newprot,
+ dirty_accountable);
+ } while (pmd++, addr = next, addr != end);
+}
+
+static inline void change_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
+ unsigned long addr, unsigned long end, pgprot_t newprot,
+ int dirty_accountable)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ change_pmd_range(vma, pud, addr, next, newprot,
+ dirty_accountable);
+ } while (pud++, addr = next, addr != end);
+}
+
+static void change_protection(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end, pgprot_t newprot,
+ int dirty_accountable)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pgd_t *pgd;
+ unsigned long next;
+ unsigned long start = addr;
+
+ BUG_ON(addr >= end);
+ pgd = pgd_offset(mm, addr);
+ flush_cache_range(vma, addr, end);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ change_pud_range(vma, pgd, addr, next, newprot,
+ dirty_accountable);
+ } while (pgd++, addr = next, addr != end);
+ flush_tlb_range(vma, start, end);
+}
+
+int
+mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
+ unsigned long start, unsigned long end, unsigned long newflags)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long oldflags = vma->vm_flags;
+ long nrpages = (end - start) >> PAGE_SHIFT;
+ unsigned long charged = 0;
+ pgoff_t pgoff;
+ int error;
+ int dirty_accountable = 0;
+
+ if (newflags == oldflags) {
+ *pprev = vma;
+ return 0;
+ }
+
+ /*
+ * If we make a private mapping writable we increase our commit;
+ * but (without finer accounting) cannot reduce our commit if we
+ * make it unwritable again. hugetlb mapping were accounted for
+ * even if read-only so there is no need to account for them here
+ */
+ if (newflags & VM_WRITE) {
+ if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB|
+ VM_SHARED|VM_NORESERVE))) {
+ charged = nrpages;
+ if (security_vm_enough_memory_mm(mm, charged))
+ return -ENOMEM;
+ newflags |= VM_ACCOUNT;
+ }
+ }
+
+ /*
+ * First try to merge with previous and/or next vma.
+ */
+ pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+ *pprev = vma_merge(mm, *pprev, start, end, newflags,
+ vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma));
+ if (*pprev) {
+ vma = *pprev;
+ goto success;
+ }
+
+ *pprev = vma;
+
+ if (start != vma->vm_start) {
+ error = split_vma(mm, vma, start, 1);
+ if (error)
+ goto fail;
+ }
+
+ if (end != vma->vm_end) {
+ error = split_vma(mm, vma, end, 0);
+ if (error)
+ goto fail;
+ }
+
+success:
+ /*
+ * vm_flags and vm_page_prot are protected by the mmap_sem
+ * held in write mode.
+ */
+ vma->vm_flags = newflags;
+ vma->vm_page_prot = pgprot_modify(vma->vm_page_prot,
+ vm_get_page_prot(newflags));
+
+ if (vma_wants_writenotify(vma)) {
+ vma->vm_page_prot = vm_get_page_prot(newflags & ~VM_SHARED);
+ dirty_accountable = 1;
+ }
+
+ mmu_notifier_invalidate_range_start(mm, start, end);
+ if (is_vm_hugetlb_page(vma))
+ hugetlb_change_protection(vma, start, end, vma->vm_page_prot);
+ else
+ change_protection(vma, start, end, vma->vm_page_prot, dirty_accountable);
+ mmu_notifier_invalidate_range_end(mm, start, end);
+ vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
+ vm_stat_account(mm, newflags, vma->vm_file, nrpages);
+ perf_event_mmap(vma);
+ return 0;
+
+fail:
+ vm_unacct_memory(charged);
+ return error;
+}
+
+SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
+ unsigned long, prot)
+{
+ unsigned long vm_flags, nstart, end, tmp, reqprot;
+ struct vm_area_struct *vma, *prev;
+ int error = -EINVAL;
+ const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP);
+ prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP);
+ if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */
+ return -EINVAL;
+
+ if (start & ~PAGE_MASK)
+ return -EINVAL;
+ if (!len)
+ return 0;
+ len = PAGE_ALIGN(len);
+ end = start + len;
+ if (end <= start)
+ return -ENOMEM;
+ if (!arch_validate_prot(prot))
+ return -EINVAL;
+
+ reqprot = prot;
+ /*
+ * Does the application expect PROT_READ to imply PROT_EXEC:
+ */
+ if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
+ prot |= PROT_EXEC;
+
+ vm_flags = calc_vm_prot_bits(prot);
+
+ down_write(¤t->mm->mmap_sem);
+
+ vma = find_vma(current->mm, start);
+ error = -ENOMEM;
+ if (!vma)
+ goto out;
+ prev = vma->vm_prev;
+ if (unlikely(grows & PROT_GROWSDOWN)) {
+ if (vma->vm_start >= end)
+ goto out;
+ start = vma->vm_start;
+ error = -EINVAL;
+ if (!(vma->vm_flags & VM_GROWSDOWN))
+ goto out;
+ }
+ else {
+ if (vma->vm_start > start)
+ goto out;
+ if (unlikely(grows & PROT_GROWSUP)) {
+ end = vma->vm_end;
+ error = -EINVAL;
+ if (!(vma->vm_flags & VM_GROWSUP))
+ goto out;
+ }
+ }
+ if (start > vma->vm_start)
+ prev = vma;
+
+ for (nstart = start ; ; ) {
+ unsigned long newflags;
+
+ /* Here we know that vma->vm_start <= nstart < vma->vm_end. */
+
+ newflags = vm_flags | (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
+
+ /* newflags >> 4 shift VM_MAY% in place of VM_% */
+ if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) {
+ error = -EACCES;
+ goto out;
+ }
+
+ error = security_file_mprotect(vma, reqprot, prot);
+ if (error)
+ goto out;
+
+ tmp = vma->vm_end;
+ if (tmp > end)
+ tmp = end;
+ error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
+ if (error)
+ goto out;
+ nstart = tmp;
+
+ if (nstart < prev->vm_end)
+ nstart = prev->vm_end;
+ if (nstart >= end)
+ goto out;
+
+ vma = prev->vm_next;
+ if (!vma || vma->vm_start != nstart) {
+ error = -ENOMEM;
+ goto out;
+ }
+ }
+out:
+ up_write(¤t->mm->mmap_sem);
+ return error;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/mremap.c b/ap/os/linux/linux-3.4.x/mm/mremap.c
new file mode 100755
index 0000000..860755d
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/mremap.c
@@ -0,0 +1,558 @@
+/*
+ * mm/mremap.c
+ *
+ * (C) Copyright 1996 Linus Torvalds
+ *
+ * Address space accounting code <alan@lxorguk.ukuu.org.uk>
+ * (C) Copyright 2002 Red Hat Inc, All Rights Reserved
+ */
+
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/shm.h>
+#include <linux/ksm.h>
+#include <linux/mman.h>
+#include <linux/swap.h>
+#include <linux/capability.h>
+#include <linux/fs.h>
+#include <linux/highmem.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/mmu_notifier.h>
+
+#include <asm/uaccess.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+
+#include "internal.h"
+
+static pmd_t *get_old_pmd(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ pgd = pgd_offset(mm, addr);
+ if (pgd_none_or_clear_bad(pgd))
+ return NULL;
+
+ pud = pud_offset(pgd, addr);
+ if (pud_none_or_clear_bad(pud))
+ return NULL;
+
+ pmd = pmd_offset(pud, addr);
+ if (pmd_none(*pmd))
+ return NULL;
+
+ return pmd;
+}
+
+static pmd_t *alloc_new_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ pgd = pgd_offset(mm, addr);
+ pud = pud_alloc(mm, pgd, addr);
+ if (!pud)
+ return NULL;
+
+ pmd = pmd_alloc(mm, pud, addr);
+ if (!pmd)
+ return NULL;
+
+ VM_BUG_ON(pmd_trans_huge(*pmd));
+
+ return pmd;
+}
+
+static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
+ unsigned long old_addr, unsigned long old_end,
+ struct vm_area_struct *new_vma, pmd_t *new_pmd,
+ unsigned long new_addr)
+{
+ struct address_space *mapping = NULL;
+ struct mm_struct *mm = vma->vm_mm;
+ pte_t *old_pte, *new_pte, pte;
+ spinlock_t *old_ptl, *new_ptl;
+ bool force_flush = false;
+ unsigned long len = old_end - old_addr;
+ if (vma->vm_file) {
+ /*
+ * Subtle point from Rajesh Venkatasubramanian: before
+ * moving file-based ptes, we must lock truncate_pagecache
+ * out, since it might clean the dst vma before the src vma,
+ * and we propagate stale pages into the dst afterward.
+ */
+ mapping = vma->vm_file->f_mapping;
+ mutex_lock(&mapping->i_mmap_mutex);
+ }
+
+ /*
+ * We don't have to worry about the ordering of src and dst
+ * pte locks because exclusive mmap_sem prevents deadlock.
+ */
+ old_pte = pte_offset_map_lock(mm, old_pmd, old_addr, &old_ptl);
+ new_pte = pte_offset_map(new_pmd, new_addr);
+ new_ptl = pte_lockptr(mm, new_pmd);
+ if (new_ptl != old_ptl)
+ spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING);
+ arch_enter_lazy_mmu_mode();
+
+ for (; old_addr < old_end; old_pte++, old_addr += PAGE_SIZE,
+ new_pte++, new_addr += PAGE_SIZE) {
+ if (pte_none(*old_pte))
+ continue;
+ pte = ptep_get_and_clear(mm, old_addr, old_pte);
+
+ /*fix for hub CVE-2018-18281*/
+ if (pte_present(pte))
+ force_flush = true;
+ pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
+ set_pte_at(mm, new_addr, new_pte, pte);
+ }
+
+ arch_leave_lazy_mmu_mode();
+ /*fix for hub CVE-2018-18281*/
+ if (force_flush)
+ flush_tlb_range(vma, old_end - len, old_end);
+ if (new_ptl != old_ptl)
+ spin_unlock(new_ptl);
+ pte_unmap(new_pte - 1);
+ pte_unmap_unlock(old_pte - 1, old_ptl);
+ if (mapping)
+ mutex_unlock(&mapping->i_mmap_mutex);
+}
+
+#define LATENCY_LIMIT (64 * PAGE_SIZE)
+
+unsigned long move_page_tables(struct vm_area_struct *vma,
+ unsigned long old_addr, struct vm_area_struct *new_vma,
+ unsigned long new_addr, unsigned long len)
+{
+ unsigned long extent, next, old_end;
+ pmd_t *old_pmd, *new_pmd;
+
+ old_end = old_addr + len;
+ flush_cache_range(vma, old_addr, old_end);
+
+ mmu_notifier_invalidate_range_start(vma->vm_mm, old_addr, old_end);
+
+ for (; old_addr < old_end; old_addr += extent, new_addr += extent) {
+ cond_resched();
+ next = (old_addr + PMD_SIZE) & PMD_MASK;
+ /* even if next overflowed, extent below will be ok */
+ extent = next - old_addr;
+ if (extent > old_end - old_addr)
+ extent = old_end - old_addr;
+ old_pmd = get_old_pmd(vma->vm_mm, old_addr);
+ if (!old_pmd)
+ continue;
+ new_pmd = alloc_new_pmd(vma->vm_mm, vma, new_addr);
+ if (!new_pmd)
+ break;
+ if (pmd_trans_huge(*old_pmd)) {
+ int err = 0;
+ if (extent == HPAGE_PMD_SIZE)
+ err = move_huge_pmd(vma, new_vma, old_addr,
+ new_addr, old_end,
+ old_pmd, new_pmd);
+ if (err > 0) {
+ continue;
+ } else if (!err) {
+ split_huge_page_pmd(vma->vm_mm, old_pmd);
+ }
+ VM_BUG_ON(pmd_trans_huge(*old_pmd));
+ }
+ if (pmd_none(*new_pmd) && __pte_alloc(new_vma->vm_mm, new_vma,
+ new_pmd, new_addr))
+ break;
+ next = (new_addr + PMD_SIZE) & PMD_MASK;
+ if (extent > next - new_addr)
+ extent = next - new_addr;
+ if (extent > LATENCY_LIMIT)
+ extent = LATENCY_LIMIT;
+ move_ptes(vma, old_pmd, old_addr, old_addr + extent,
+ new_vma, new_pmd, new_addr);
+ }
+
+
+ mmu_notifier_invalidate_range_end(vma->vm_mm, old_end-len, old_end);
+
+ return len + old_addr - old_end; /* how much done */
+}
+
+static unsigned long move_vma(struct vm_area_struct *vma,
+ unsigned long old_addr, unsigned long old_len,
+ unsigned long new_len, unsigned long new_addr)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ struct vm_area_struct *new_vma;
+ unsigned long vm_flags = vma->vm_flags;
+ unsigned long new_pgoff;
+ unsigned long moved_len;
+ unsigned long excess = 0;
+ unsigned long hiwater_vm;
+ int split = 0;
+ int err;
+
+ /*
+ * We'd prefer to avoid failure later on in do_munmap:
+ * which may split one vma into three before unmapping.
+ */
+ if (mm->map_count >= sysctl_max_map_count - 3)
+ return -ENOMEM;
+
+ /*
+ * Advise KSM to break any KSM pages in the area to be moved:
+ * it would be confusing if they were to turn up at the new
+ * location, where they happen to coincide with different KSM
+ * pages recently unmapped. But leave vma->vm_flags as it was,
+ * so KSM can come around to merge on vma and new_vma afterwards.
+ */
+ err = ksm_madvise(vma, old_addr, old_addr + old_len,
+ MADV_UNMERGEABLE, &vm_flags);
+ if (err)
+ return err;
+
+ new_pgoff = vma->vm_pgoff + ((old_addr - vma->vm_start) >> PAGE_SHIFT);
+ new_vma = copy_vma(&vma, new_addr, new_len, new_pgoff);
+ if (!new_vma)
+ return -ENOMEM;
+
+ moved_len = move_page_tables(vma, old_addr, new_vma, new_addr, old_len);
+ if (moved_len < old_len) {
+ /*
+ * Before moving the page tables from the new vma to
+ * the old vma, we need to be sure the old vma is
+ * queued after new vma in the same_anon_vma list to
+ * prevent SMP races with rmap_walk (that could lead
+ * rmap_walk to miss some page table).
+ */
+ anon_vma_moveto_tail(vma);
+
+ /*
+ * On error, move entries back from new area to old,
+ * which will succeed since page tables still there,
+ * and then proceed to unmap new area instead of old.
+ */
+ move_page_tables(new_vma, new_addr, vma, old_addr, moved_len);
+ vma = new_vma;
+ old_len = new_len;
+ old_addr = new_addr;
+ new_addr = -ENOMEM;
+ }
+
+ /* Conceal VM_ACCOUNT so old reservation is not undone */
+ if (vm_flags & VM_ACCOUNT) {
+ vma->vm_flags &= ~VM_ACCOUNT;
+ excess = vma->vm_end - vma->vm_start - old_len;
+ if (old_addr > vma->vm_start &&
+ old_addr + old_len < vma->vm_end)
+ split = 1;
+ }
+
+ /*
+ * If we failed to move page tables we still do total_vm increment
+ * since do_munmap() will decrement it by old_len == new_len.
+ *
+ * Since total_vm is about to be raised artificially high for a
+ * moment, we need to restore high watermark afterwards: if stats
+ * are taken meanwhile, total_vm and hiwater_vm appear too high.
+ * If this were a serious issue, we'd add a flag to do_munmap().
+ */
+ hiwater_vm = mm->hiwater_vm;
+ mm->total_vm += new_len >> PAGE_SHIFT;
+ vm_stat_account(mm, vma->vm_flags, vma->vm_file, new_len>>PAGE_SHIFT);
+
+ if (do_munmap(mm, old_addr, old_len) < 0) {
+ /* OOM: unable to split vma, just get accounts right */
+ vm_unacct_memory(excess >> PAGE_SHIFT);
+ excess = 0;
+ }
+ mm->hiwater_vm = hiwater_vm;
+
+ /* Restore VM_ACCOUNT if one or two pieces of vma left */
+ if (excess) {
+ vma->vm_flags |= VM_ACCOUNT;
+ if (split)
+ vma->vm_next->vm_flags |= VM_ACCOUNT;
+ }
+
+ if (vm_flags & VM_LOCKED) {
+ mm->locked_vm += new_len >> PAGE_SHIFT;
+ if (new_len > old_len)
+ mlock_vma_pages_range(new_vma, new_addr + old_len,
+ new_addr + new_len);
+ }
+
+ return new_addr;
+}
+
+static struct vm_area_struct *vma_to_resize(unsigned long addr,
+ unsigned long old_len, unsigned long new_len, unsigned long *p)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma = find_vma(mm, addr);
+
+ if (!vma || vma->vm_start > addr)
+ goto Efault;
+
+ if (is_vm_hugetlb_page(vma))
+ goto Einval;
+
+ /* We can't remap across vm area boundaries */
+ if (old_len > vma->vm_end - addr)
+ goto Efault;
+
+ /* Need to be careful about a growing mapping */
+ if (new_len > old_len) {
+ unsigned long pgoff;
+
+ if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP))
+ goto Efault;
+ pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
+ pgoff += vma->vm_pgoff;
+ if (pgoff + (new_len >> PAGE_SHIFT) < pgoff)
+ goto Einval;
+ }
+
+ if (vma->vm_flags & VM_LOCKED) {
+ unsigned long locked, lock_limit;
+ locked = mm->locked_vm << PAGE_SHIFT;
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
+ locked += new_len - old_len;
+ if (locked > lock_limit && !capable(CAP_IPC_LOCK))
+ goto Eagain;
+ }
+
+ if (!may_expand_vm(mm, (new_len - old_len) >> PAGE_SHIFT))
+ goto Enomem;
+
+ if (vma->vm_flags & VM_ACCOUNT) {
+ unsigned long charged = (new_len - old_len) >> PAGE_SHIFT;
+ if (security_vm_enough_memory_mm(mm, charged))
+ goto Efault;
+ *p = charged;
+ }
+
+ return vma;
+
+Efault: /* very odd choice for most of the cases, but... */
+ return ERR_PTR(-EFAULT);
+Einval:
+ return ERR_PTR(-EINVAL);
+Enomem:
+ return ERR_PTR(-ENOMEM);
+Eagain:
+ return ERR_PTR(-EAGAIN);
+}
+
+static unsigned long mremap_to(unsigned long addr,
+ unsigned long old_len, unsigned long new_addr,
+ unsigned long new_len)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long ret = -EINVAL;
+ unsigned long charged = 0;
+ unsigned long map_flags;
+
+ if (new_addr & ~PAGE_MASK)
+ goto out;
+
+ if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len)
+ goto out;
+
+ /* Check if the location we're moving into overlaps the
+ * old location at all, and fail if it does.
+ */
+ if ((new_addr <= addr) && (new_addr+new_len) > addr)
+ goto out;
+
+ if ((addr <= new_addr) && (addr+old_len) > new_addr)
+ goto out;
+
+ ret = security_file_mmap(NULL, 0, 0, 0, new_addr, 1);
+ if (ret)
+ goto out;
+
+ ret = do_munmap(mm, new_addr, new_len);
+ if (ret)
+ goto out;
+
+ if (old_len >= new_len) {
+ ret = do_munmap(mm, addr+new_len, old_len - new_len);
+ if (ret && old_len != new_len)
+ goto out;
+ old_len = new_len;
+ }
+
+ vma = vma_to_resize(addr, old_len, new_len, &charged);
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
+ goto out;
+ }
+
+ map_flags = MAP_FIXED;
+ if (vma->vm_flags & VM_MAYSHARE)
+ map_flags |= MAP_SHARED;
+
+ ret = get_unmapped_area(vma->vm_file, new_addr, new_len, vma->vm_pgoff +
+ ((addr - vma->vm_start) >> PAGE_SHIFT),
+ map_flags);
+ if (ret & ~PAGE_MASK)
+ goto out1;
+
+ ret = move_vma(vma, addr, old_len, new_len, new_addr);
+ if (!(ret & ~PAGE_MASK))
+ goto out;
+out1:
+ vm_unacct_memory(charged);
+
+out:
+ return ret;
+}
+
+static int vma_expandable(struct vm_area_struct *vma, unsigned long delta)
+{
+ unsigned long end = vma->vm_end + delta;
+ if (end < vma->vm_end) /* overflow */
+ return 0;
+ if (vma->vm_next && vma->vm_next->vm_start < end) /* intersection */
+ return 0;
+ if (get_unmapped_area(NULL, vma->vm_start, end - vma->vm_start,
+ 0, MAP_FIXED) & ~PAGE_MASK)
+ return 0;
+ return 1;
+}
+
+/*
+ * Expand (or shrink) an existing mapping, potentially moving it at the
+ * same time (controlled by the MREMAP_MAYMOVE flag and available VM space)
+ *
+ * MREMAP_FIXED option added 5-Dec-1999 by Benjamin LaHaise
+ * This option implies MREMAP_MAYMOVE.
+ */
+unsigned long do_mremap(unsigned long addr,
+ unsigned long old_len, unsigned long new_len,
+ unsigned long flags, unsigned long new_addr)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long ret = -EINVAL;
+ unsigned long charged = 0;
+
+ if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE))
+ goto out;
+
+ if (addr & ~PAGE_MASK)
+ goto out;
+
+ old_len = PAGE_ALIGN(old_len);
+ new_len = PAGE_ALIGN(new_len);
+
+ /*
+ * We allow a zero old-len as a special case
+ * for DOS-emu "duplicate shm area" thing. But
+ * a zero new-len is nonsensical.
+ */
+ if (!new_len)
+ goto out;
+
+ if (flags & MREMAP_FIXED) {
+ if (flags & MREMAP_MAYMOVE)
+ ret = mremap_to(addr, old_len, new_addr, new_len);
+ goto out;
+ }
+
+ /*
+ * Always allow a shrinking remap: that just unmaps
+ * the unnecessary pages..
+ * do_munmap does all the needed commit accounting
+ */
+ if (old_len >= new_len) {
+ ret = do_munmap(mm, addr+new_len, old_len - new_len);
+ if (ret && old_len != new_len)
+ goto out;
+ ret = addr;
+ goto out;
+ }
+
+ /*
+ * Ok, we need to grow..
+ */
+ vma = vma_to_resize(addr, old_len, new_len, &charged);
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
+ goto out;
+ }
+
+ /* old_len exactly to the end of the area..
+ */
+ if (old_len == vma->vm_end - addr) {
+ /* can we just expand the current mapping? */
+ if (vma_expandable(vma, new_len - old_len)) {
+ int pages = (new_len - old_len) >> PAGE_SHIFT;
+
+ if (vma_adjust(vma, vma->vm_start, addr + new_len,
+ vma->vm_pgoff, NULL)) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ mm->total_vm += pages;
+ vm_stat_account(mm, vma->vm_flags, vma->vm_file, pages);
+ if (vma->vm_flags & VM_LOCKED) {
+ mm->locked_vm += pages;
+ mlock_vma_pages_range(vma, addr + old_len,
+ addr + new_len);
+ }
+ ret = addr;
+ goto out;
+ }
+ }
+
+ /*
+ * We weren't able to just expand or shrink the area,
+ * we need to create a new one and move it..
+ */
+ ret = -ENOMEM;
+ if (flags & MREMAP_MAYMOVE) {
+ unsigned long map_flags = 0;
+ if (vma->vm_flags & VM_MAYSHARE)
+ map_flags |= MAP_SHARED;
+
+ new_addr = get_unmapped_area(vma->vm_file, 0, new_len,
+ vma->vm_pgoff +
+ ((addr - vma->vm_start) >> PAGE_SHIFT),
+ map_flags);
+ if (new_addr & ~PAGE_MASK) {
+ ret = new_addr;
+ goto out;
+ }
+
+ ret = security_file_mmap(NULL, 0, 0, 0, new_addr, 1);
+ if (ret)
+ goto out;
+ ret = move_vma(vma, addr, old_len, new_len, new_addr);
+ }
+out:
+ if (ret & ~PAGE_MASK)
+ vm_unacct_memory(charged);
+ return ret;
+}
+
+SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
+ unsigned long, new_len, unsigned long, flags,
+ unsigned long, new_addr)
+{
+ unsigned long ret;
+
+ down_write(¤t->mm->mmap_sem);
+ ret = do_mremap(addr, old_len, new_len, flags, new_addr);
+ up_write(¤t->mm->mmap_sem);
+ return ret;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/msync.c b/ap/os/linux/linux-3.4.x/mm/msync.c
new file mode 100644
index 0000000..632df45
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/msync.c
@@ -0,0 +1,103 @@
+/*
+ * linux/mm/msync.c
+ *
+ * Copyright (C) 1994-1999 Linus Torvalds
+ */
+
+/*
+ * The msync() system call.
+ */
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/file.h>
+#include <linux/syscalls.h>
+#include <linux/sched.h>
+
+/*
+ * MS_SYNC syncs the entire file - including mappings.
+ *
+ * MS_ASYNC does not start I/O (it used to, up to 2.5.67).
+ * Nor does it marks the relevant pages dirty (it used to up to 2.6.17).
+ * Now it doesn't do anything, since dirty pages are properly tracked.
+ *
+ * The application may now run fsync() to
+ * write out the dirty pages and wait on the writeout and check the result.
+ * Or the application may run fadvise(FADV_DONTNEED) against the fd to start
+ * async writeout immediately.
+ * So by _not_ starting I/O in MS_ASYNC we provide complete flexibility to
+ * applications.
+ */
+SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
+{
+ unsigned long end;
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ int unmapped_error = 0;
+ int error = -EINVAL;
+
+ if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC))
+ goto out;
+ if (start & ~PAGE_MASK)
+ goto out;
+ if ((flags & MS_ASYNC) && (flags & MS_SYNC))
+ goto out;
+ error = -ENOMEM;
+ len = (len + ~PAGE_MASK) & PAGE_MASK;
+ end = start + len;
+ if (end < start)
+ goto out;
+ error = 0;
+ if (end == start)
+ goto out;
+ /*
+ * If the interval [start,end) covers some unmapped address ranges,
+ * just ignore them, but return -ENOMEM at the end.
+ */
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, start);
+ for (;;) {
+ struct file *file;
+
+ /* Still start < end. */
+ error = -ENOMEM;
+ if (!vma)
+ goto out_unlock;
+ /* Here start < vma->vm_end. */
+ if (start < vma->vm_start) {
+ start = vma->vm_start;
+ if (start >= end)
+ goto out_unlock;
+ unmapped_error = -ENOMEM;
+ }
+ /* Here vma->vm_start <= start < vma->vm_end. */
+ if ((flags & MS_INVALIDATE) &&
+ (vma->vm_flags & VM_LOCKED)) {
+ error = -EBUSY;
+ goto out_unlock;
+ }
+ file = vma->vm_file;
+ start = vma->vm_end;
+ if ((flags & MS_SYNC) && file &&
+ (vma->vm_flags & VM_SHARED)) {
+ get_file(file);
+ up_read(&mm->mmap_sem);
+ error = vfs_fsync(file, 0);
+ fput(file);
+ if (error || start >= end)
+ goto out;
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, start);
+ } else {
+ if (start >= end) {
+ error = 0;
+ goto out_unlock;
+ }
+ vma = vma->vm_next;
+ }
+ }
+out_unlock:
+ up_read(&mm->mmap_sem);
+out:
+ return error ? : unmapped_error;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/nobootmem.c b/ap/os/linux/linux-3.4.x/mm/nobootmem.c
new file mode 100644
index 0000000..218e6f9
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/nobootmem.c
@@ -0,0 +1,420 @@
+/*
+ * bootmem - A boot-time physical memory allocator and configurator
+ *
+ * Copyright (C) 1999 Ingo Molnar
+ * 1999 Kanoj Sarcar, SGI
+ * 2008 Johannes Weiner
+ *
+ * Access to this subsystem has to be serialized externally (which is true
+ * for the boot process anyway).
+ */
+#include <linux/init.h>
+#include <linux/pfn.h>
+#include <linux/slab.h>
+#include <linux/bootmem.h>
+#include <linux/export.h>
+#include <linux/kmemleak.h>
+#include <linux/range.h>
+#include <linux/memblock.h>
+
+#include <asm/bug.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+
+#include "internal.h"
+
+#ifndef CONFIG_NEED_MULTIPLE_NODES
+struct pglist_data __refdata contig_page_data;
+EXPORT_SYMBOL(contig_page_data);
+#endif
+
+unsigned long max_low_pfn;
+unsigned long min_low_pfn;
+unsigned long max_pfn;
+
+static void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
+ u64 goal, u64 limit)
+{
+ void *ptr;
+ u64 addr;
+
+ if (limit > memblock.current_limit)
+ limit = memblock.current_limit;
+
+ addr = memblock_find_in_range_node(goal, limit, size, align, nid);
+ if (!addr)
+ return NULL;
+
+ ptr = phys_to_virt(addr);
+ memset(ptr, 0, size);
+ memblock_reserve(addr, size);
+ /*
+ * The min_count is set to 0 so that bootmem allocated blocks
+ * are never reported as leaks.
+ */
+ kmemleak_alloc(ptr, size, 0, 0);
+ return ptr;
+}
+
+/*
+ * free_bootmem_late - free bootmem pages directly to page allocator
+ * @addr: starting address of the range
+ * @size: size of the range in bytes
+ *
+ * This is only useful when the bootmem allocator has already been torn
+ * down, but we are still initializing the system. Pages are given directly
+ * to the page allocator, no bootmem metadata is updated because it is gone.
+ */
+void __init free_bootmem_late(unsigned long addr, unsigned long size)
+{
+ unsigned long cursor, end;
+
+ kmemleak_free_part(__va(addr), size);
+
+ cursor = PFN_UP(addr);
+ end = PFN_DOWN(addr + size);
+
+ for (; cursor < end; cursor++) {
+ __free_pages_bootmem(pfn_to_page(cursor), 0);
+ totalram_pages++;
+ }
+}
+
+static void __init __free_pages_memory(unsigned long start, unsigned long end)
+{
+ unsigned long i, start_aligned, end_aligned;
+ int order = ilog2(BITS_PER_LONG);
+
+ start_aligned = (start + (BITS_PER_LONG - 1)) & ~(BITS_PER_LONG - 1);
+ end_aligned = end & ~(BITS_PER_LONG - 1);
+
+ if (end_aligned <= start_aligned) {
+ for (i = start; i < end; i++)
+ __free_pages_bootmem(pfn_to_page(i), 0);
+
+ return;
+ }
+
+ for (i = start; i < start_aligned; i++)
+ __free_pages_bootmem(pfn_to_page(i), 0);
+
+ for (i = start_aligned; i < end_aligned; i += BITS_PER_LONG)
+ __free_pages_bootmem(pfn_to_page(i), order);
+
+ for (i = end_aligned; i < end; i++)
+ __free_pages_bootmem(pfn_to_page(i), 0);
+}
+
+static unsigned long __init __free_memory_core(phys_addr_t start,
+ phys_addr_t end)
+{
+ unsigned long start_pfn = PFN_UP(start);
+ unsigned long end_pfn = min_t(unsigned long,
+ PFN_DOWN(end), max_low_pfn);
+
+ if (start_pfn > end_pfn)
+ return 0;
+
+ __free_pages_memory(start_pfn, end_pfn);
+
+ return end_pfn - start_pfn;
+}
+
+unsigned long __init free_low_memory_core_early(int nodeid)
+{
+ unsigned long count = 0;
+ phys_addr_t start, end, size;
+ u64 i;
+
+ for_each_free_mem_range(i, MAX_NUMNODES, &start, &end, NULL)
+ count += __free_memory_core(start, end);
+
+ /* free range that is used for reserved array if we allocate it */
+ size = get_allocated_memblock_reserved_regions_info(&start);
+ if (size)
+ count += __free_memory_core(start, start + size);
+
+ return count;
+}
+
+/**
+ * free_all_bootmem_node - release a node's free pages to the buddy allocator
+ * @pgdat: node to be released
+ *
+ * Returns the number of pages actually released.
+ */
+unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
+{
+ register_page_bootmem_info_node(pgdat);
+
+ /* free_low_memory_core_early(MAX_NUMNODES) will be called later */
+ return 0;
+}
+
+/**
+ * free_all_bootmem - release free pages to the buddy allocator
+ *
+ * Returns the number of pages actually released.
+ */
+unsigned long __init free_all_bootmem(void)
+{
+ /*
+ * We need to use MAX_NUMNODES instead of NODE_DATA(0)->node_id
+ * because in some case like Node0 doesn't have RAM installed
+ * low ram will be on Node1
+ * Use MAX_NUMNODES will make sure all ranges in early_node_map[]
+ * will be used instead of only Node0 related
+ */
+ return free_low_memory_core_early(MAX_NUMNODES);
+}
+
+/**
+ * free_bootmem_node - mark a page range as usable
+ * @pgdat: node the range resides on
+ * @physaddr: starting address of the range
+ * @size: size of the range in bytes
+ *
+ * Partial pages will be considered reserved and left as they are.
+ *
+ * The range must reside completely on the specified node.
+ */
+void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
+ unsigned long size)
+{
+ kmemleak_free_part(__va(physaddr), size);
+ memblock_free(physaddr, size);
+}
+
+/**
+ * free_bootmem - mark a page range as usable
+ * @addr: starting address of the range
+ * @size: size of the range in bytes
+ *
+ * Partial pages will be considered reserved and left as they are.
+ *
+ * The range must be contiguous but may span node boundaries.
+ */
+void __init free_bootmem(unsigned long addr, unsigned long size)
+{
+ kmemleak_free_part(__va(addr), size);
+ memblock_free(addr, size);
+}
+
+static void * __init ___alloc_bootmem_nopanic(unsigned long size,
+ unsigned long align,
+ unsigned long goal,
+ unsigned long limit)
+{
+ void *ptr;
+
+ if (WARN_ON_ONCE(slab_is_available()))
+ return kzalloc(size, GFP_NOWAIT);
+
+restart:
+
+ ptr = __alloc_memory_core_early(MAX_NUMNODES, size, align, goal, limit);
+
+ if (ptr)
+ return ptr;
+
+ if (goal != 0) {
+ goal = 0;
+ goto restart;
+ }
+
+ return NULL;
+}
+
+/**
+ * __alloc_bootmem_nopanic - allocate boot memory without panicking
+ * @size: size of the request in bytes
+ * @align: alignment of the region
+ * @goal: preferred starting address of the region
+ *
+ * The goal is dropped if it can not be satisfied and the allocation will
+ * fall back to memory below @goal.
+ *
+ * Allocation may happen on any node in the system.
+ *
+ * Returns NULL on failure.
+ */
+void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
+ unsigned long goal)
+{
+ unsigned long limit = -1UL;
+
+ return ___alloc_bootmem_nopanic(size, align, goal, limit);
+}
+
+static void * __init ___alloc_bootmem(unsigned long size, unsigned long align,
+ unsigned long goal, unsigned long limit)
+{
+ void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit);
+
+ if (mem)
+ return mem;
+ /*
+ * Whoops, we cannot satisfy the allocation request.
+ */
+ printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
+ panic("Out of memory");
+ return NULL;
+}
+
+/**
+ * __alloc_bootmem - allocate boot memory
+ * @size: size of the request in bytes
+ * @align: alignment of the region
+ * @goal: preferred starting address of the region
+ *
+ * The goal is dropped if it can not be satisfied and the allocation will
+ * fall back to memory below @goal.
+ *
+ * Allocation may happen on any node in the system.
+ *
+ * The function panics if the request can not be satisfied.
+ */
+void * __init __alloc_bootmem(unsigned long size, unsigned long align,
+ unsigned long goal)
+{
+ unsigned long limit = -1UL;
+
+ return ___alloc_bootmem(size, align, goal, limit);
+}
+
+/**
+ * __alloc_bootmem_node - allocate boot memory from a specific node
+ * @pgdat: node to allocate from
+ * @size: size of the request in bytes
+ * @align: alignment of the region
+ * @goal: preferred starting address of the region
+ *
+ * The goal is dropped if it can not be satisfied and the allocation will
+ * fall back to memory below @goal.
+ *
+ * Allocation may fall back to any node in the system if the specified node
+ * can not hold the requested memory.
+ *
+ * The function panics if the request can not be satisfied.
+ */
+void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
+ unsigned long align, unsigned long goal)
+{
+ void *ptr;
+
+ if (WARN_ON_ONCE(slab_is_available()))
+ return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
+
+again:
+ ptr = __alloc_memory_core_early(pgdat->node_id, size, align,
+ goal, -1ULL);
+ if (ptr)
+ return ptr;
+
+ ptr = __alloc_memory_core_early(MAX_NUMNODES, size, align,
+ goal, -1ULL);
+ if (!ptr && goal) {
+ goal = 0;
+ goto again;
+ }
+ return ptr;
+}
+
+void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
+ unsigned long align, unsigned long goal)
+{
+ return __alloc_bootmem_node(pgdat, size, align, goal);
+}
+
+#ifdef CONFIG_SPARSEMEM
+/**
+ * alloc_bootmem_section - allocate boot memory from a specific section
+ * @size: size of the request in bytes
+ * @section_nr: sparse map section to allocate from
+ *
+ * Return NULL on failure.
+ */
+void * __init alloc_bootmem_section(unsigned long size,
+ unsigned long section_nr)
+{
+ unsigned long pfn, goal, limit;
+
+ pfn = section_nr_to_pfn(section_nr);
+ goal = pfn << PAGE_SHIFT;
+ limit = section_nr_to_pfn(section_nr + 1) << PAGE_SHIFT;
+
+ return __alloc_memory_core_early(early_pfn_to_nid(pfn), size,
+ SMP_CACHE_BYTES, goal, limit);
+}
+#endif
+
+void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size,
+ unsigned long align, unsigned long goal)
+{
+ void *ptr;
+
+ if (WARN_ON_ONCE(slab_is_available()))
+ return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
+
+ ptr = __alloc_memory_core_early(pgdat->node_id, size, align,
+ goal, -1ULL);
+ if (ptr)
+ return ptr;
+
+ return __alloc_bootmem_nopanic(size, align, goal);
+}
+
+#ifndef ARCH_LOW_ADDRESS_LIMIT
+#define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
+#endif
+
+/**
+ * __alloc_bootmem_low - allocate low boot memory
+ * @size: size of the request in bytes
+ * @align: alignment of the region
+ * @goal: preferred starting address of the region
+ *
+ * The goal is dropped if it can not be satisfied and the allocation will
+ * fall back to memory below @goal.
+ *
+ * Allocation may happen on any node in the system.
+ *
+ * The function panics if the request can not be satisfied.
+ */
+void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
+ unsigned long goal)
+{
+ return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
+}
+
+/**
+ * __alloc_bootmem_low_node - allocate low boot memory from a specific node
+ * @pgdat: node to allocate from
+ * @size: size of the request in bytes
+ * @align: alignment of the region
+ * @goal: preferred starting address of the region
+ *
+ * The goal is dropped if it can not be satisfied and the allocation will
+ * fall back to memory below @goal.
+ *
+ * Allocation may fall back to any node in the system if the specified node
+ * can not hold the requested memory.
+ *
+ * The function panics if the request can not be satisfied.
+ */
+void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
+ unsigned long align, unsigned long goal)
+{
+ void *ptr;
+
+ if (WARN_ON_ONCE(slab_is_available()))
+ return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
+
+ ptr = __alloc_memory_core_early(pgdat->node_id, size, align,
+ goal, ARCH_LOW_ADDRESS_LIMIT);
+ if (ptr)
+ return ptr;
+
+ return __alloc_memory_core_early(MAX_NUMNODES, size, align,
+ goal, ARCH_LOW_ADDRESS_LIMIT);
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/nommu.c b/ap/os/linux/linux-3.4.x/mm/nommu.c
new file mode 100644
index 0000000..3f282f9
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/nommu.c
@@ -0,0 +1,2137 @@
+/*
+ * linux/mm/nommu.c
+ *
+ * Replacement code for mm functions to support CPU's that don't
+ * have any form of memory management unit (thus no virtual memory).
+ *
+ * See Documentation/nommu-mmap.txt
+ *
+ * Copyright (c) 2004-2008 David Howells <dhowells@redhat.com>
+ * Copyright (c) 2000-2003 David McCullough <davidm@snapgear.com>
+ * Copyright (c) 2000-2001 D Jeff Dionne <jeff@uClinux.org>
+ * Copyright (c) 2002 Greg Ungerer <gerg@snapgear.com>
+ * Copyright (c) 2007-2010 Paul Mundt <lethal@linux-sh.org>
+ */
+
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/swap.h>
+#include <linux/file.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <linux/mount.h>
+#include <linux/personality.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/audit.h>
+
+#include <asm/uaccess.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+#include "internal.h"
+
+#if 0
+#define kenter(FMT, ...) \
+ printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+ printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
+#define kdebug(FMT, ...) \
+ printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__)
+#else
+#define kenter(FMT, ...) \
+ no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+ no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
+#define kdebug(FMT, ...) \
+ no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
+#endif
+
+void *high_memory;
+struct page *mem_map;
+unsigned long max_mapnr;
+unsigned long num_physpages;
+unsigned long highest_memmap_pfn;
+struct percpu_counter vm_committed_as;
+int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
+int sysctl_overcommit_ratio = 50; /* default is 50% */
+int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT;
+int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS;
+int heap_stack_gap = 0;
+
+atomic_long_t mmap_pages_allocated;
+
+EXPORT_SYMBOL(mem_map);
+EXPORT_SYMBOL(num_physpages);
+
+/* list of mapped, potentially shareable regions */
+static struct kmem_cache *vm_region_jar;
+struct rb_root nommu_region_tree = RB_ROOT;
+DECLARE_RWSEM(nommu_region_sem);
+
+const struct vm_operations_struct generic_file_vm_ops = {
+};
+
+/*
+ * Return the total memory allocated for this pointer, not
+ * just what the caller asked for.
+ *
+ * Doesn't have to be accurate, i.e. may have races.
+ */
+unsigned int kobjsize(const void *objp)
+{
+ struct page *page;
+
+ /*
+ * If the object we have should not have ksize performed on it,
+ * return size of 0
+ */
+ if (!objp || !virt_addr_valid(objp))
+ return 0;
+
+ page = virt_to_head_page(objp);
+
+ /*
+ * If the allocator sets PageSlab, we know the pointer came from
+ * kmalloc().
+ */
+ if (PageSlab(page))
+ return ksize(objp);
+
+ /*
+ * If it's not a compound page, see if we have a matching VMA
+ * region. This test is intentionally done in reverse order,
+ * so if there's no VMA, we still fall through and hand back
+ * PAGE_SIZE for 0-order pages.
+ */
+ if (!PageCompound(page)) {
+ struct vm_area_struct *vma;
+
+ vma = find_vma(current->mm, (unsigned long)objp);
+ if (vma)
+ return vma->vm_end - vma->vm_start;
+ }
+
+ /*
+ * The ksize() function is only guaranteed to work for pointers
+ * returned by kmalloc(). So handle arbitrary pointers here.
+ */
+ return PAGE_SIZE << compound_order(page);
+}
+
+int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long start, int nr_pages, unsigned int foll_flags,
+ struct page **pages, struct vm_area_struct **vmas,
+ int *retry)
+{
+ struct vm_area_struct *vma;
+ unsigned long vm_flags;
+ int i;
+
+ /* calculate required read or write permissions.
+ * If FOLL_FORCE is set, we only require the "MAY" flags.
+ */
+ vm_flags = (foll_flags & FOLL_WRITE) ?
+ (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
+ vm_flags &= (foll_flags & FOLL_FORCE) ?
+ (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
+
+ for (i = 0; i < nr_pages; i++) {
+ vma = find_vma(mm, start);
+ if (!vma)
+ goto finish_or_fault;
+
+ /* protect what we can, including chardevs */
+ if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
+ !(vm_flags & vma->vm_flags))
+ goto finish_or_fault;
+
+ if (pages) {
+ pages[i] = virt_to_page(start);
+ if (pages[i])
+ page_cache_get(pages[i]);
+ }
+ if (vmas)
+ vmas[i] = vma;
+ start = (start + PAGE_SIZE) & PAGE_MASK;
+ }
+
+ return i;
+
+finish_or_fault:
+ return i ? : -EFAULT;
+}
+
+/*
+ * get a list of pages in an address range belonging to the specified process
+ * and indicate the VMA that covers each page
+ * - this is potentially dodgy as we may end incrementing the page count of a
+ * slab page or a secondary page from a compound page
+ * - don't permit access to VMAs that don't support it, such as I/O mappings
+ */
+int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long start, int nr_pages, int write, int force,
+ struct page **pages, struct vm_area_struct **vmas)
+{
+ int flags = 0;
+
+ if (write)
+ flags |= FOLL_WRITE;
+ if (force)
+ flags |= FOLL_FORCE;
+
+ return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas,
+ NULL);
+}
+EXPORT_SYMBOL(get_user_pages);
+
+/**
+ * follow_pfn - look up PFN at a user virtual address
+ * @vma: memory mapping
+ * @address: user virtual address
+ * @pfn: location to store found PFN
+ *
+ * Only IO mappings and raw PFN mappings are allowed.
+ *
+ * Returns zero and the pfn at @pfn on success, -ve otherwise.
+ */
+int follow_pfn(struct vm_area_struct *vma, unsigned long address,
+ unsigned long *pfn)
+{
+ if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
+ return -EINVAL;
+
+ *pfn = address >> PAGE_SHIFT;
+ return 0;
+}
+EXPORT_SYMBOL(follow_pfn);
+
+DEFINE_RWLOCK(vmlist_lock);
+struct vm_struct *vmlist;
+
+void vfree(const void *addr)
+{
+ kfree(addr);
+}
+EXPORT_SYMBOL(vfree);
+
+void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
+{
+ /*
+ * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc()
+ * returns only a logical address.
+ */
+ return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM);
+}
+EXPORT_SYMBOL(__vmalloc);
+
+void *vmalloc_user(unsigned long size)
+{
+ void *ret;
+
+ ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
+ PAGE_KERNEL);
+ if (ret) {
+ struct vm_area_struct *vma;
+
+ down_write(¤t->mm->mmap_sem);
+ vma = find_vma(current->mm, (unsigned long)ret);
+ if (vma)
+ vma->vm_flags |= VM_USERMAP;
+ up_write(¤t->mm->mmap_sem);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(vmalloc_user);
+
+struct page *vmalloc_to_page(const void *addr)
+{
+ return virt_to_page(addr);
+}
+EXPORT_SYMBOL(vmalloc_to_page);
+
+unsigned long vmalloc_to_pfn(const void *addr)
+{
+ return page_to_pfn(virt_to_page(addr));
+}
+EXPORT_SYMBOL(vmalloc_to_pfn);
+
+long vread(char *buf, char *addr, unsigned long count)
+{
+ memcpy(buf, addr, count);
+ return count;
+}
+
+long vwrite(char *buf, char *addr, unsigned long count)
+{
+ /* Don't allow overflow */
+ if ((unsigned long) addr + count < count)
+ count = -(unsigned long) addr;
+
+ memcpy(addr, buf, count);
+ return(count);
+}
+
+/*
+ * vmalloc - allocate virtually continguos memory
+ *
+ * @size: allocation size
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into continguos kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+void *vmalloc(unsigned long size)
+{
+ return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL);
+}
+EXPORT_SYMBOL(vmalloc);
+
+/*
+ * vzalloc - allocate virtually continguos memory with zero fill
+ *
+ * @size: allocation size
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into continguos kernel virtual space.
+ * The memory allocated is set to zero.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+void *vzalloc(unsigned long size)
+{
+ return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
+ PAGE_KERNEL);
+}
+EXPORT_SYMBOL(vzalloc);
+
+/**
+ * vmalloc_node - allocate memory on a specific node
+ * @size: allocation size
+ * @node: numa node
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+void *vmalloc_node(unsigned long size, int node)
+{
+ return vmalloc(size);
+}
+EXPORT_SYMBOL(vmalloc_node);
+
+/**
+ * vzalloc_node - allocate memory on a specific node with zero fill
+ * @size: allocation size
+ * @node: numa node
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ * The memory allocated is set to zero.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+void *vzalloc_node(unsigned long size, int node)
+{
+ return vzalloc(size);
+}
+EXPORT_SYMBOL(vzalloc_node);
+
+#ifndef PAGE_KERNEL_EXEC
+# define PAGE_KERNEL_EXEC PAGE_KERNEL
+#endif
+
+/**
+ * vmalloc_exec - allocate virtually contiguous, executable memory
+ * @size: allocation size
+ *
+ * Kernel-internal function to allocate enough pages to cover @size
+ * the page level allocator and map them into contiguous and
+ * executable kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+
+void *vmalloc_exec(unsigned long size)
+{
+ return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC);
+}
+
+/**
+ * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
+ * @size: allocation size
+ *
+ * Allocate enough 32bit PA addressable pages to cover @size from the
+ * page level allocator and map them into continguos kernel virtual space.
+ */
+void *vmalloc_32(unsigned long size)
+{
+ return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL);
+}
+EXPORT_SYMBOL(vmalloc_32);
+
+/**
+ * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
+ * @size: allocation size
+ *
+ * The resulting memory area is 32bit addressable and zeroed so it can be
+ * mapped to userspace without leaking data.
+ *
+ * VM_USERMAP is set on the corresponding VMA so that subsequent calls to
+ * remap_vmalloc_range() are permissible.
+ */
+void *vmalloc_32_user(unsigned long size)
+{
+ /*
+ * We'll have to sort out the ZONE_DMA bits for 64-bit,
+ * but for now this can simply use vmalloc_user() directly.
+ */
+ return vmalloc_user(size);
+}
+EXPORT_SYMBOL(vmalloc_32_user);
+
+void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot)
+{
+ BUG();
+ return NULL;
+}
+EXPORT_SYMBOL(vmap);
+
+void vunmap(const void *addr)
+{
+ BUG();
+}
+EXPORT_SYMBOL(vunmap);
+
+void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
+{
+ BUG();
+ return NULL;
+}
+EXPORT_SYMBOL(vm_map_ram);
+
+void vm_unmap_ram(const void *mem, unsigned int count)
+{
+ BUG();
+}
+EXPORT_SYMBOL(vm_unmap_ram);
+
+void vm_unmap_aliases(void)
+{
+}
+EXPORT_SYMBOL_GPL(vm_unmap_aliases);
+
+/*
+ * Implement a stub for vmalloc_sync_all() if the architecture chose not to
+ * have one.
+ */
+void __attribute__((weak)) vmalloc_sync_all(void)
+{
+}
+
+/**
+ * alloc_vm_area - allocate a range of kernel address space
+ * @size: size of the area
+ *
+ * Returns: NULL on failure, vm_struct on success
+ *
+ * This function reserves a range of kernel address space, and
+ * allocates pagetables to map that range. No actual mappings
+ * are created. If the kernel address space is not shared
+ * between processes, it syncs the pagetable across all
+ * processes.
+ */
+struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
+{
+ BUG();
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(alloc_vm_area);
+
+void free_vm_area(struct vm_struct *area)
+{
+ BUG();
+}
+EXPORT_SYMBOL_GPL(free_vm_area);
+
+int vm_insert_page(struct vm_area_struct *vma, unsigned long addr,
+ struct page *page)
+{
+ return -EINVAL;
+}
+EXPORT_SYMBOL(vm_insert_page);
+
+/*
+ * sys_brk() for the most part doesn't need the global kernel
+ * lock, except when an application is doing something nasty
+ * like trying to un-brk an area that has already been mapped
+ * to a regular file. in this case, the unmapping will need
+ * to invoke file system routines that need the global lock.
+ */
+SYSCALL_DEFINE1(brk, unsigned long, brk)
+{
+ struct mm_struct *mm = current->mm;
+
+ if (brk < mm->start_brk || brk > mm->context.end_brk)
+ return mm->brk;
+
+ if (mm->brk == brk)
+ return mm->brk;
+
+ /*
+ * Always allow shrinking brk
+ */
+ if (brk <= mm->brk) {
+ mm->brk = brk;
+ return brk;
+ }
+
+ /*
+ * Ok, looks good - let it rip.
+ */
+ flush_icache_range(mm->brk, brk);
+ return mm->brk = brk;
+}
+
+/*
+ * initialise the VMA and region record slabs
+ */
+void __init mmap_init(void)
+{
+ int ret;
+
+ ret = percpu_counter_init(&vm_committed_as, 0);
+ VM_BUG_ON(ret);
+ vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC);
+}
+
+/*
+ * validate the region tree
+ * - the caller must hold the region lock
+ */
+#ifdef CONFIG_DEBUG_NOMMU_REGIONS
+static noinline void validate_nommu_regions(void)
+{
+ struct vm_region *region, *last;
+ struct rb_node *p, *lastp;
+
+ lastp = rb_first(&nommu_region_tree);
+ if (!lastp)
+ return;
+
+ last = rb_entry(lastp, struct vm_region, vm_rb);
+ BUG_ON(unlikely(last->vm_end <= last->vm_start));
+ BUG_ON(unlikely(last->vm_top < last->vm_end));
+
+ while ((p = rb_next(lastp))) {
+ region = rb_entry(p, struct vm_region, vm_rb);
+ last = rb_entry(lastp, struct vm_region, vm_rb);
+
+ BUG_ON(unlikely(region->vm_end <= region->vm_start));
+ BUG_ON(unlikely(region->vm_top < region->vm_end));
+ BUG_ON(unlikely(region->vm_start < last->vm_top));
+
+ lastp = p;
+ }
+}
+#else
+static void validate_nommu_regions(void)
+{
+}
+#endif
+
+/*
+ * add a region into the global tree
+ */
+static void add_nommu_region(struct vm_region *region)
+{
+ struct vm_region *pregion;
+ struct rb_node **p, *parent;
+
+ validate_nommu_regions();
+
+ parent = NULL;
+ p = &nommu_region_tree.rb_node;
+ while (*p) {
+ parent = *p;
+ pregion = rb_entry(parent, struct vm_region, vm_rb);
+ if (region->vm_start < pregion->vm_start)
+ p = &(*p)->rb_left;
+ else if (region->vm_start > pregion->vm_start)
+ p = &(*p)->rb_right;
+ else if (pregion == region)
+ return;
+ else
+ BUG();
+ }
+
+ rb_link_node(®ion->vm_rb, parent, p);
+ rb_insert_color(®ion->vm_rb, &nommu_region_tree);
+
+ validate_nommu_regions();
+}
+
+/*
+ * delete a region from the global tree
+ */
+static void delete_nommu_region(struct vm_region *region)
+{
+ BUG_ON(!nommu_region_tree.rb_node);
+
+ validate_nommu_regions();
+ rb_erase(®ion->vm_rb, &nommu_region_tree);
+ validate_nommu_regions();
+}
+
+/*
+ * free a contiguous series of pages
+ */
+static void free_page_series(unsigned long from, unsigned long to)
+{
+ for (; from < to; from += PAGE_SIZE) {
+ struct page *page = virt_to_page(from);
+
+ kdebug("- free %lx", from);
+ atomic_long_dec(&mmap_pages_allocated);
+ if (page_count(page) != 1)
+ kdebug("free page %p: refcount not one: %d",
+ page, page_count(page));
+ put_page(page);
+ }
+}
+
+/*
+ * release a reference to a region
+ * - the caller must hold the region semaphore for writing, which this releases
+ * - the region may not have been added to the tree yet, in which case vm_top
+ * will equal vm_start
+ */
+static void __put_nommu_region(struct vm_region *region)
+ __releases(nommu_region_sem)
+{
+ kenter("%p{%d}", region, region->vm_usage);
+
+ BUG_ON(!nommu_region_tree.rb_node);
+
+ if (--region->vm_usage == 0) {
+ if (region->vm_top > region->vm_start)
+ delete_nommu_region(region);
+ up_write(&nommu_region_sem);
+
+ if (region->vm_file)
+ fput(region->vm_file);
+
+ /* IO memory and memory shared directly out of the pagecache
+ * from ramfs/tmpfs mustn't be released here */
+ if (region->vm_flags & VM_MAPPED_COPY) {
+ kdebug("free series");
+ free_page_series(region->vm_start, region->vm_top);
+ }
+ kmem_cache_free(vm_region_jar, region);
+ } else {
+ up_write(&nommu_region_sem);
+ }
+}
+
+/*
+ * release a reference to a region
+ */
+static void put_nommu_region(struct vm_region *region)
+{
+ down_write(&nommu_region_sem);
+ __put_nommu_region(region);
+}
+
+/*
+ * update protection on a vma
+ */
+static void protect_vma(struct vm_area_struct *vma, unsigned long flags)
+{
+#ifdef CONFIG_MPU
+ struct mm_struct *mm = vma->vm_mm;
+ long start = vma->vm_start & PAGE_MASK;
+ while (start < vma->vm_end) {
+ protect_page(mm, start, flags);
+ start += PAGE_SIZE;
+ }
+ update_protections(mm);
+#endif
+}
+
+/*
+ * add a VMA into a process's mm_struct in the appropriate place in the list
+ * and tree and add to the address space's page tree also if not an anonymous
+ * page
+ * - should be called with mm->mmap_sem held writelocked
+ */
+static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
+{
+ struct vm_area_struct *pvma, *prev;
+ struct address_space *mapping;
+ struct rb_node **p, *parent, *rb_prev;
+
+ kenter(",%p", vma);
+
+ BUG_ON(!vma->vm_region);
+
+ mm->map_count++;
+ vma->vm_mm = mm;
+
+ protect_vma(vma, vma->vm_flags);
+
+ /* add the VMA to the mapping */
+ if (vma->vm_file) {
+ mapping = vma->vm_file->f_mapping;
+
+ mutex_lock(&mapping->i_mmap_mutex);
+ flush_dcache_mmap_lock(mapping);
+ vma_prio_tree_insert(vma, &mapping->i_mmap);
+ flush_dcache_mmap_unlock(mapping);
+ mutex_unlock(&mapping->i_mmap_mutex);
+ }
+
+ /* add the VMA to the tree */
+ parent = rb_prev = NULL;
+ p = &mm->mm_rb.rb_node;
+ while (*p) {
+ parent = *p;
+ pvma = rb_entry(parent, struct vm_area_struct, vm_rb);
+
+ /* sort by: start addr, end addr, VMA struct addr in that order
+ * (the latter is necessary as we may get identical VMAs) */
+ if (vma->vm_start < pvma->vm_start)
+ p = &(*p)->rb_left;
+ else if (vma->vm_start > pvma->vm_start) {
+ rb_prev = parent;
+ p = &(*p)->rb_right;
+ } else if (vma->vm_end < pvma->vm_end)
+ p = &(*p)->rb_left;
+ else if (vma->vm_end > pvma->vm_end) {
+ rb_prev = parent;
+ p = &(*p)->rb_right;
+ } else if (vma < pvma)
+ p = &(*p)->rb_left;
+ else if (vma > pvma) {
+ rb_prev = parent;
+ p = &(*p)->rb_right;
+ } else
+ BUG();
+ }
+
+ rb_link_node(&vma->vm_rb, parent, p);
+ rb_insert_color(&vma->vm_rb, &mm->mm_rb);
+
+ /* add VMA to the VMA list also */
+ prev = NULL;
+ if (rb_prev)
+ prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb);
+
+ __vma_link_list(mm, vma, prev, parent);
+}
+
+/*
+ * delete a VMA from its owning mm_struct and address space
+ */
+static void delete_vma_from_mm(struct vm_area_struct *vma)
+{
+ struct address_space *mapping;
+ struct mm_struct *mm = vma->vm_mm;
+
+ kenter("%p", vma);
+
+ protect_vma(vma, 0);
+
+ mm->map_count--;
+ if (mm->mmap_cache == vma)
+ mm->mmap_cache = NULL;
+
+ /* remove the VMA from the mapping */
+ if (vma->vm_file) {
+ mapping = vma->vm_file->f_mapping;
+
+ mutex_lock(&mapping->i_mmap_mutex);
+ flush_dcache_mmap_lock(mapping);
+ vma_prio_tree_remove(vma, &mapping->i_mmap);
+ flush_dcache_mmap_unlock(mapping);
+ mutex_unlock(&mapping->i_mmap_mutex);
+ }
+
+ /* remove from the MM's tree and list */
+ rb_erase(&vma->vm_rb, &mm->mm_rb);
+
+ if (vma->vm_prev)
+ vma->vm_prev->vm_next = vma->vm_next;
+ else
+ mm->mmap = vma->vm_next;
+
+ if (vma->vm_next)
+ vma->vm_next->vm_prev = vma->vm_prev;
+}
+
+/*
+ * destroy a VMA record
+ */
+static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma)
+{
+ kenter("%p", vma);
+ if (vma->vm_ops && vma->vm_ops->close)
+ vma->vm_ops->close(vma);
+ if (vma->vm_file) {
+ fput(vma->vm_file);
+ if (vma->vm_flags & VM_EXECUTABLE)
+ removed_exe_file_vma(mm);
+ }
+ put_nommu_region(vma->vm_region);
+ kmem_cache_free(vm_area_cachep, vma);
+}
+
+/*
+ * look up the first VMA in which addr resides, NULL if none
+ * - should be called with mm->mmap_sem at least held readlocked
+ */
+struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
+{
+ struct vm_area_struct *vma;
+
+ /* check the cache first */
+ vma = ACCESS_ONCE(mm->mmap_cache);
+ if (vma && vma->vm_start <= addr && vma->vm_end > addr)
+ return vma;
+
+ /* trawl the list (there may be multiple mappings in which addr
+ * resides) */
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (vma->vm_start > addr)
+ return NULL;
+ if (vma->vm_end > addr) {
+ mm->mmap_cache = vma;
+ return vma;
+ }
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL(find_vma);
+
+/*
+ * find a VMA
+ * - we don't extend stack VMAs under NOMMU conditions
+ */
+struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
+{
+ return find_vma(mm, addr);
+}
+
+/*
+ * expand a stack to a given address
+ * - not supported under NOMMU conditions
+ */
+int expand_stack(struct vm_area_struct *vma, unsigned long address)
+{
+ return -ENOMEM;
+}
+
+/*
+ * look up the first VMA exactly that exactly matches addr
+ * - should be called with mm->mmap_sem at least held readlocked
+ */
+static struct vm_area_struct *find_vma_exact(struct mm_struct *mm,
+ unsigned long addr,
+ unsigned long len)
+{
+ struct vm_area_struct *vma;
+ unsigned long end = addr + len;
+
+ /* check the cache first */
+ vma = mm->mmap_cache;
+ if (vma && vma->vm_start == addr && vma->vm_end == end)
+ return vma;
+
+ /* trawl the list (there may be multiple mappings in which addr
+ * resides) */
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (vma->vm_start < addr)
+ continue;
+ if (vma->vm_start > addr)
+ return NULL;
+ if (vma->vm_end == end) {
+ mm->mmap_cache = vma;
+ return vma;
+ }
+ }
+
+ return NULL;
+}
+
+/*
+ * determine whether a mapping should be permitted and, if so, what sort of
+ * mapping we're capable of supporting
+ */
+static int validate_mmap_request(struct file *file,
+ unsigned long addr,
+ unsigned long len,
+ unsigned long prot,
+ unsigned long flags,
+ unsigned long pgoff,
+ unsigned long *_capabilities)
+{
+ unsigned long capabilities, rlen;
+ unsigned long reqprot = prot;
+ int ret;
+
+ /* do the simple checks first */
+ if (flags & MAP_FIXED) {
+ printk(KERN_DEBUG
+ "%d: Can't do fixed-address/overlay mmap of RAM\n",
+ current->pid);
+ return -EINVAL;
+ }
+
+ if ((flags & MAP_TYPE) != MAP_PRIVATE &&
+ (flags & MAP_TYPE) != MAP_SHARED)
+ return -EINVAL;
+
+ if (!len)
+ return -EINVAL;
+
+ /* Careful about overflows.. */
+ rlen = PAGE_ALIGN(len);
+ if (!rlen || rlen > TASK_SIZE)
+ return -ENOMEM;
+
+ /* offset overflow? */
+ if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff)
+ return -EOVERFLOW;
+
+ if (file) {
+ /* validate file mapping requests */
+ struct address_space *mapping;
+
+ /* files must support mmap */
+ if (!file->f_op || !file->f_op->mmap)
+ return -ENODEV;
+
+ /* work out if what we've got could possibly be shared
+ * - we support chardevs that provide their own "memory"
+ * - we support files/blockdevs that are memory backed
+ */
+ mapping = file->f_mapping;
+ if (!mapping)
+ mapping = file->f_path.dentry->d_inode->i_mapping;
+
+ capabilities = 0;
+ if (mapping && mapping->backing_dev_info)
+ capabilities = mapping->backing_dev_info->capabilities;
+
+ if (!capabilities) {
+ /* no explicit capabilities set, so assume some
+ * defaults */
+ switch (file->f_path.dentry->d_inode->i_mode & S_IFMT) {
+ case S_IFREG:
+ case S_IFBLK:
+ capabilities = BDI_CAP_MAP_COPY;
+ break;
+
+ case S_IFCHR:
+ capabilities =
+ BDI_CAP_MAP_DIRECT |
+ BDI_CAP_READ_MAP |
+ BDI_CAP_WRITE_MAP;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ }
+
+ /* eliminate any capabilities that we can't support on this
+ * device */
+ if (!file->f_op->get_unmapped_area)
+ capabilities &= ~BDI_CAP_MAP_DIRECT;
+ if (!file->f_op->read)
+ capabilities &= ~BDI_CAP_MAP_COPY;
+
+ /* The file shall have been opened with read permission. */
+ if (!(file->f_mode & FMODE_READ))
+ return -EACCES;
+
+ if (flags & MAP_SHARED) {
+ /* do checks for writing, appending and locking */
+ if ((prot & PROT_WRITE) &&
+ !(file->f_mode & FMODE_WRITE))
+ return -EACCES;
+
+ if (IS_APPEND(file->f_path.dentry->d_inode) &&
+ (file->f_mode & FMODE_WRITE))
+ return -EACCES;
+
+ if (locks_verify_locked(file->f_path.dentry->d_inode))
+ return -EAGAIN;
+
+ if (!(capabilities & BDI_CAP_MAP_DIRECT))
+ return -ENODEV;
+
+ /* we mustn't privatise shared mappings */
+ capabilities &= ~BDI_CAP_MAP_COPY;
+ }
+ else {
+ /* we're going to read the file into private memory we
+ * allocate */
+ if (!(capabilities & BDI_CAP_MAP_COPY))
+ return -ENODEV;
+
+ /* we don't permit a private writable mapping to be
+ * shared with the backing device */
+ if (prot & PROT_WRITE)
+ capabilities &= ~BDI_CAP_MAP_DIRECT;
+ }
+
+ if (capabilities & BDI_CAP_MAP_DIRECT) {
+ if (((prot & PROT_READ) && !(capabilities & BDI_CAP_READ_MAP)) ||
+ ((prot & PROT_WRITE) && !(capabilities & BDI_CAP_WRITE_MAP)) ||
+ ((prot & PROT_EXEC) && !(capabilities & BDI_CAP_EXEC_MAP))
+ ) {
+ capabilities &= ~BDI_CAP_MAP_DIRECT;
+ if (flags & MAP_SHARED) {
+ printk(KERN_WARNING
+ "MAP_SHARED not completely supported on !MMU\n");
+ return -EINVAL;
+ }
+ }
+ }
+
+ /* handle executable mappings and implied executable
+ * mappings */
+ if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) {
+ if (prot & PROT_EXEC)
+ return -EPERM;
+ }
+ else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) {
+ /* handle implication of PROT_EXEC by PROT_READ */
+ if (current->personality & READ_IMPLIES_EXEC) {
+ if (capabilities & BDI_CAP_EXEC_MAP)
+ prot |= PROT_EXEC;
+ }
+ }
+ else if ((prot & PROT_READ) &&
+ (prot & PROT_EXEC) &&
+ !(capabilities & BDI_CAP_EXEC_MAP)
+ ) {
+ /* backing file is not executable, try to copy */
+ capabilities &= ~BDI_CAP_MAP_DIRECT;
+ }
+ }
+ else {
+ /* anonymous mappings are always memory backed and can be
+ * privately mapped
+ */
+ capabilities = BDI_CAP_MAP_COPY;
+
+ /* handle PROT_EXEC implication by PROT_READ */
+ if ((prot & PROT_READ) &&
+ (current->personality & READ_IMPLIES_EXEC))
+ prot |= PROT_EXEC;
+ }
+
+ /* allow the security API to have its say */
+ ret = security_file_mmap(file, reqprot, prot, flags, addr, 0);
+ if (ret < 0)
+ return ret;
+
+ /* looks okay */
+ *_capabilities = capabilities;
+ return 0;
+}
+
+/*
+ * we've determined that we can make the mapping, now translate what we
+ * now know into VMA flags
+ */
+static unsigned long determine_vm_flags(struct file *file,
+ unsigned long prot,
+ unsigned long flags,
+ unsigned long capabilities)
+{
+ unsigned long vm_flags;
+
+ vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags);
+ /* vm_flags |= mm->def_flags; */
+
+ if (!(capabilities & BDI_CAP_MAP_DIRECT)) {
+ /* attempt to share read-only copies of mapped file chunks */
+ vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
+ if (file && !(prot & PROT_WRITE))
+ vm_flags |= VM_MAYSHARE;
+ } else {
+ /* overlay a shareable mapping on the backing device or inode
+ * if possible - used for chardevs, ramfs/tmpfs/shmfs and
+ * romfs/cramfs */
+ vm_flags |= VM_MAYSHARE | (capabilities & BDI_CAP_VMFLAGS);
+ if (flags & MAP_SHARED)
+ vm_flags |= VM_SHARED;
+ }
+
+ /* refuse to let anyone share private mappings with this process if
+ * it's being traced - otherwise breakpoints set in it may interfere
+ * with another untraced process
+ */
+ if ((flags & MAP_PRIVATE) && current->ptrace)
+ vm_flags &= ~VM_MAYSHARE;
+
+ return vm_flags;
+}
+
+/*
+ * set up a shared mapping on a file (the driver or filesystem provides and
+ * pins the storage)
+ */
+static int do_mmap_shared_file(struct vm_area_struct *vma)
+{
+ int ret;
+
+ ret = vma->vm_file->f_op->mmap(vma->vm_file, vma);
+ if (ret == 0) {
+ vma->vm_region->vm_top = vma->vm_region->vm_end;
+ return 0;
+ }
+ if (ret != -ENOSYS)
+ return ret;
+
+ /* getting -ENOSYS indicates that direct mmap isn't possible (as
+ * opposed to tried but failed) so we can only give a suitable error as
+ * it's not possible to make a private copy if MAP_SHARED was given */
+ return -ENODEV;
+}
+
+/*
+ * set up a private mapping or an anonymous shared mapping
+ */
+static int do_mmap_private(struct vm_area_struct *vma,
+ struct vm_region *region,
+ unsigned long len,
+ unsigned long capabilities)
+{
+ struct page *pages;
+ unsigned long total, point, n;
+ void *base;
+ int ret, order;
+
+ /* invoke the file's mapping function so that it can keep track of
+ * shared mappings on devices or memory
+ * - VM_MAYSHARE will be set if it may attempt to share
+ */
+ if (capabilities & BDI_CAP_MAP_DIRECT) {
+ ret = vma->vm_file->f_op->mmap(vma->vm_file, vma);
+ if (ret == 0) {
+ /* shouldn't return success if we're not sharing */
+ BUG_ON(!(vma->vm_flags & VM_MAYSHARE));
+ vma->vm_region->vm_top = vma->vm_region->vm_end;
+ return 0;
+ }
+ if (ret != -ENOSYS)
+ return ret;
+
+ /* getting an ENOSYS error indicates that direct mmap isn't
+ * possible (as opposed to tried but failed) so we'll try to
+ * make a private copy of the data and map that instead */
+ }
+
+
+ /* allocate some memory to hold the mapping
+ * - note that this may not return a page-aligned address if the object
+ * we're allocating is smaller than a page
+ */
+ order = get_order(len);
+ kdebug("alloc order %d for %lx", order, len);
+
+ pages = alloc_pages(GFP_KERNEL, order);
+ if (!pages)
+ goto enomem;
+
+ total = 1 << order;
+ atomic_long_add(total, &mmap_pages_allocated);
+
+ point = len >> PAGE_SHIFT;
+
+ /* we allocated a power-of-2 sized page set, so we may want to trim off
+ * the excess */
+ if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) {
+ while (total > point) {
+ order = ilog2(total - point);
+ n = 1 << order;
+ kdebug("shave %lu/%lu @%lu", n, total - point, total);
+ atomic_long_sub(n, &mmap_pages_allocated);
+ total -= n;
+ set_page_refcounted(pages + total);
+ __free_pages(pages + total, order);
+ }
+ }
+
+ for (point = 1; point < total; point++)
+ set_page_refcounted(&pages[point]);
+
+ base = page_address(pages);
+ region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY;
+ region->vm_start = (unsigned long) base;
+ region->vm_end = region->vm_start + len;
+ region->vm_top = region->vm_start + (total << PAGE_SHIFT);
+
+ vma->vm_start = region->vm_start;
+ vma->vm_end = region->vm_start + len;
+
+ if (vma->vm_file) {
+ /* read the contents of a file into the copy */
+ mm_segment_t old_fs;
+ loff_t fpos;
+
+ fpos = vma->vm_pgoff;
+ fpos <<= PAGE_SHIFT;
+
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ ret = vma->vm_file->f_op->read(vma->vm_file, base, len, &fpos);
+ set_fs(old_fs);
+
+ if (ret < 0)
+ goto error_free;
+
+ /* clear the last little bit */
+ if (ret < len)
+ memset(base + ret, 0, len - ret);
+
+ }
+
+ return 0;
+
+error_free:
+ free_page_series(region->vm_start, region->vm_top);
+ region->vm_start = vma->vm_start = 0;
+ region->vm_end = vma->vm_end = 0;
+ region->vm_top = 0;
+ return ret;
+
+enomem:
+ printk("Allocation of length %lu from process %d (%s) failed\n",
+ len, current->pid, current->comm);
+ show_free_areas(0);
+ return -ENOMEM;
+}
+
+/*
+ * handle mapping creation for uClinux
+ */
+static unsigned long do_mmap_pgoff(struct file *file,
+ unsigned long addr,
+ unsigned long len,
+ unsigned long prot,
+ unsigned long flags,
+ unsigned long pgoff)
+{
+ struct vm_area_struct *vma;
+ struct vm_region *region;
+ struct rb_node *rb;
+ unsigned long capabilities, vm_flags, result;
+ int ret;
+
+ kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff);
+
+ /* decide whether we should attempt the mapping, and if so what sort of
+ * mapping */
+ ret = validate_mmap_request(file, addr, len, prot, flags, pgoff,
+ &capabilities);
+ if (ret < 0) {
+ kleave(" = %d [val]", ret);
+ return ret;
+ }
+
+ /* we ignore the address hint */
+ addr = 0;
+ len = PAGE_ALIGN(len);
+
+ /* we've determined that we can make the mapping, now translate what we
+ * now know into VMA flags */
+ vm_flags = determine_vm_flags(file, prot, flags, capabilities);
+
+ /* we're going to need to record the mapping */
+ region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL);
+ if (!region)
+ goto error_getting_region;
+
+ vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
+ if (!vma)
+ goto error_getting_vma;
+
+ region->vm_usage = 1;
+ region->vm_flags = vm_flags;
+ region->vm_pgoff = pgoff;
+
+ INIT_LIST_HEAD(&vma->anon_vma_chain);
+ vma->vm_flags = vm_flags;
+ vma->vm_pgoff = pgoff;
+
+ if (file) {
+ region->vm_file = file;
+ get_file(file);
+ vma->vm_file = file;
+ get_file(file);
+ if (vm_flags & VM_EXECUTABLE) {
+ added_exe_file_vma(current->mm);
+ vma->vm_mm = current->mm;
+ }
+ }
+
+ down_write(&nommu_region_sem);
+
+ /* if we want to share, we need to check for regions created by other
+ * mmap() calls that overlap with our proposed mapping
+ * - we can only share with a superset match on most regular files
+ * - shared mappings on character devices and memory backed files are
+ * permitted to overlap inexactly as far as we are concerned for in
+ * these cases, sharing is handled in the driver or filesystem rather
+ * than here
+ */
+ if (vm_flags & VM_MAYSHARE) {
+ struct vm_region *pregion;
+ unsigned long pglen, rpglen, pgend, rpgend, start;
+
+ pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ pgend = pgoff + pglen;
+
+ for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) {
+ pregion = rb_entry(rb, struct vm_region, vm_rb);
+
+ if (!(pregion->vm_flags & VM_MAYSHARE))
+ continue;
+
+ /* search for overlapping mappings on the same file */
+ if (pregion->vm_file->f_path.dentry->d_inode !=
+ file->f_path.dentry->d_inode)
+ continue;
+
+ if (pregion->vm_pgoff >= pgend)
+ continue;
+
+ rpglen = pregion->vm_end - pregion->vm_start;
+ rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ rpgend = pregion->vm_pgoff + rpglen;
+ if (pgoff >= rpgend)
+ continue;
+
+ /* handle inexactly overlapping matches between
+ * mappings */
+ if ((pregion->vm_pgoff != pgoff || rpglen != pglen) &&
+ !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) {
+ /* new mapping is not a subset of the region */
+ if (!(capabilities & BDI_CAP_MAP_DIRECT))
+ goto sharing_violation;
+ continue;
+ }
+
+ /* we've found a region we can share */
+ pregion->vm_usage++;
+ vma->vm_region = pregion;
+ start = pregion->vm_start;
+ start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT;
+ vma->vm_start = start;
+ vma->vm_end = start + len;
+
+ if (pregion->vm_flags & VM_MAPPED_COPY) {
+ kdebug("share copy");
+ vma->vm_flags |= VM_MAPPED_COPY;
+ } else {
+ kdebug("share mmap");
+ ret = do_mmap_shared_file(vma);
+ if (ret < 0) {
+ vma->vm_region = NULL;
+ vma->vm_start = 0;
+ vma->vm_end = 0;
+ pregion->vm_usage--;
+ pregion = NULL;
+ goto error_just_free;
+ }
+ }
+ fput(region->vm_file);
+ kmem_cache_free(vm_region_jar, region);
+ region = pregion;
+ result = start;
+ goto share;
+ }
+
+ /* obtain the address at which to make a shared mapping
+ * - this is the hook for quasi-memory character devices to
+ * tell us the location of a shared mapping
+ */
+ if (capabilities & BDI_CAP_MAP_DIRECT) {
+ addr = file->f_op->get_unmapped_area(file, addr, len,
+ pgoff, flags);
+ if (IS_ERR_VALUE(addr)) {
+ ret = addr;
+ if (ret != -ENOSYS)
+ goto error_just_free;
+
+ /* the driver refused to tell us where to site
+ * the mapping so we'll have to attempt to copy
+ * it */
+ ret = -ENODEV;
+ if (!(capabilities & BDI_CAP_MAP_COPY))
+ goto error_just_free;
+
+ capabilities &= ~BDI_CAP_MAP_DIRECT;
+ } else {
+ vma->vm_start = region->vm_start = addr;
+ vma->vm_end = region->vm_end = addr + len;
+ }
+ }
+ }
+
+ vma->vm_region = region;
+
+ /* set up the mapping
+ * - the region is filled in if BDI_CAP_MAP_DIRECT is still set
+ */
+ if (file && vma->vm_flags & VM_SHARED)
+ ret = do_mmap_shared_file(vma);
+ else
+ ret = do_mmap_private(vma, region, len, capabilities);
+ if (ret < 0)
+ goto error_just_free;
+ add_nommu_region(region);
+
+ /* clear anonymous mappings that don't ask for uninitialized data */
+ if (!vma->vm_file && !(flags & MAP_UNINITIALIZED))
+ memset((void *)region->vm_start, 0,
+ region->vm_end - region->vm_start);
+
+ /* okay... we have a mapping; now we have to register it */
+ result = vma->vm_start;
+
+ current->mm->total_vm += len >> PAGE_SHIFT;
+
+share:
+ add_vma_to_mm(current->mm, vma);
+
+ /* we flush the region from the icache only when the first executable
+ * mapping of it is made */
+ if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) {
+ flush_icache_range(region->vm_start, region->vm_end);
+ region->vm_icache_flushed = true;
+ }
+
+ up_write(&nommu_region_sem);
+
+ kleave(" = %lx", result);
+ return result;
+
+error_just_free:
+ up_write(&nommu_region_sem);
+error:
+ if (region->vm_file)
+ fput(region->vm_file);
+ kmem_cache_free(vm_region_jar, region);
+ if (vma->vm_file)
+ fput(vma->vm_file);
+ if (vma->vm_flags & VM_EXECUTABLE)
+ removed_exe_file_vma(vma->vm_mm);
+ kmem_cache_free(vm_area_cachep, vma);
+ kleave(" = %d", ret);
+ return ret;
+
+sharing_violation:
+ up_write(&nommu_region_sem);
+ printk(KERN_WARNING "Attempt to share mismatched mappings\n");
+ ret = -EINVAL;
+ goto error;
+
+error_getting_vma:
+ kmem_cache_free(vm_region_jar, region);
+ printk(KERN_WARNING "Allocation of vma for %lu byte allocation"
+ " from process %d failed\n",
+ len, current->pid);
+ show_free_areas(0);
+ return -ENOMEM;
+
+error_getting_region:
+ printk(KERN_WARNING "Allocation of vm region for %lu byte allocation"
+ " from process %d failed\n",
+ len, current->pid);
+ show_free_areas(0);
+ return -ENOMEM;
+}
+
+unsigned long do_mmap(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flag, unsigned long offset)
+{
+ if (unlikely(offset + PAGE_ALIGN(len) < offset))
+ return -EINVAL;
+ if (unlikely(offset & ~PAGE_MASK))
+ return -EINVAL;
+ return do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
+}
+EXPORT_SYMBOL(do_mmap);
+
+unsigned long vm_mmap(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flag, unsigned long offset)
+{
+ unsigned long ret;
+ struct mm_struct *mm = current->mm;
+
+ down_write(&mm->mmap_sem);
+ ret = do_mmap(file, addr, len, prot, flag, offset);
+ up_write(&mm->mmap_sem);
+ return ret;
+}
+EXPORT_SYMBOL(vm_mmap);
+
+SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
+ unsigned long, prot, unsigned long, flags,
+ unsigned long, fd, unsigned long, pgoff)
+{
+ struct file *file = NULL;
+ unsigned long retval = -EBADF;
+
+ audit_mmap_fd(fd, flags);
+ if (!(flags & MAP_ANONYMOUS)) {
+ file = fget(fd);
+ if (!file)
+ goto out;
+ }
+
+ flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
+
+ down_write(¤t->mm->mmap_sem);
+ retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
+ up_write(¤t->mm->mmap_sem);
+
+ if (file)
+ fput(file);
+out:
+ return retval;
+}
+
+#ifdef __ARCH_WANT_SYS_OLD_MMAP
+struct mmap_arg_struct {
+ unsigned long addr;
+ unsigned long len;
+ unsigned long prot;
+ unsigned long flags;
+ unsigned long fd;
+ unsigned long offset;
+};
+
+SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg)
+{
+ struct mmap_arg_struct a;
+
+ if (copy_from_user(&a, arg, sizeof(a)))
+ return -EFAULT;
+ if (a.offset & ~PAGE_MASK)
+ return -EINVAL;
+
+ return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
+ a.offset >> PAGE_SHIFT);
+}
+#endif /* __ARCH_WANT_SYS_OLD_MMAP */
+
+/*
+ * split a vma into two pieces at address 'addr', a new vma is allocated either
+ * for the first part or the tail.
+ */
+int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, int new_below)
+{
+ struct vm_area_struct *new;
+ struct vm_region *region;
+ unsigned long npages;
+
+ kenter("");
+
+ /* we're only permitted to split anonymous regions (these should have
+ * only a single usage on the region) */
+ if (vma->vm_file)
+ return -ENOMEM;
+
+ if (mm->map_count >= sysctl_max_map_count)
+ return -ENOMEM;
+
+ region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL);
+ if (!region)
+ return -ENOMEM;
+
+ new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
+ if (!new) {
+ kmem_cache_free(vm_region_jar, region);
+ return -ENOMEM;
+ }
+
+ /* most fields are the same, copy all, and then fixup */
+ *new = *vma;
+ *region = *vma->vm_region;
+ new->vm_region = region;
+
+ npages = (addr - vma->vm_start) >> PAGE_SHIFT;
+
+ if (new_below) {
+ region->vm_top = region->vm_end = new->vm_end = addr;
+ } else {
+ region->vm_start = new->vm_start = addr;
+ region->vm_pgoff = new->vm_pgoff += npages;
+ }
+
+ if (new->vm_ops && new->vm_ops->open)
+ new->vm_ops->open(new);
+
+ delete_vma_from_mm(vma);
+ down_write(&nommu_region_sem);
+ delete_nommu_region(vma->vm_region);
+ if (new_below) {
+ vma->vm_region->vm_start = vma->vm_start = addr;
+ vma->vm_region->vm_pgoff = vma->vm_pgoff += npages;
+ } else {
+ vma->vm_region->vm_end = vma->vm_end = addr;
+ vma->vm_region->vm_top = addr;
+ }
+ add_nommu_region(vma->vm_region);
+ add_nommu_region(new->vm_region);
+ up_write(&nommu_region_sem);
+ add_vma_to_mm(mm, vma);
+ add_vma_to_mm(mm, new);
+ return 0;
+}
+
+/*
+ * shrink a VMA by removing the specified chunk from either the beginning or
+ * the end
+ */
+static int shrink_vma(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long from, unsigned long to)
+{
+ struct vm_region *region;
+
+ kenter("");
+
+ /* adjust the VMA's pointers, which may reposition it in the MM's tree
+ * and list */
+ delete_vma_from_mm(vma);
+ if (from > vma->vm_start)
+ vma->vm_end = from;
+ else
+ vma->vm_start = to;
+ add_vma_to_mm(mm, vma);
+
+ /* cut the backing region down to size */
+ region = vma->vm_region;
+ BUG_ON(region->vm_usage != 1);
+
+ down_write(&nommu_region_sem);
+ delete_nommu_region(region);
+ if (from > region->vm_start) {
+ to = region->vm_top;
+ region->vm_top = region->vm_end = from;
+ } else {
+ region->vm_start = to;
+ }
+ add_nommu_region(region);
+ up_write(&nommu_region_sem);
+
+ free_page_series(from, to);
+ return 0;
+}
+
+/*
+ * release a mapping
+ * - under NOMMU conditions the chunk to be unmapped must be backed by a single
+ * VMA, though it need not cover the whole VMA
+ */
+int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
+{
+ struct vm_area_struct *vma;
+ unsigned long end;
+ int ret;
+
+ kenter(",%lx,%zx", start, len);
+
+ len = PAGE_ALIGN(len);
+ if (len == 0)
+ return -EINVAL;
+
+ end = start + len;
+
+ /* find the first potentially overlapping VMA */
+ vma = find_vma(mm, start);
+ if (!vma) {
+ static int limit = 0;
+ if (limit < 5) {
+ printk(KERN_WARNING
+ "munmap of memory not mmapped by process %d"
+ " (%s): 0x%lx-0x%lx\n",
+ current->pid, current->comm,
+ start, start + len - 1);
+ limit++;
+ }
+ return -EINVAL;
+ }
+
+ /* we're allowed to split an anonymous VMA but not a file-backed one */
+ if (vma->vm_file) {
+ do {
+ if (start > vma->vm_start) {
+ kleave(" = -EINVAL [miss]");
+ return -EINVAL;
+ }
+ if (end == vma->vm_end)
+ goto erase_whole_vma;
+ vma = vma->vm_next;
+ } while (vma);
+ kleave(" = -EINVAL [split file]");
+ return -EINVAL;
+ } else {
+ /* the chunk must be a subset of the VMA found */
+ if (start == vma->vm_start && end == vma->vm_end)
+ goto erase_whole_vma;
+ if (start < vma->vm_start || end > vma->vm_end) {
+ kleave(" = -EINVAL [superset]");
+ return -EINVAL;
+ }
+ if (start & ~PAGE_MASK) {
+ kleave(" = -EINVAL [unaligned start]");
+ return -EINVAL;
+ }
+ if (end != vma->vm_end && end & ~PAGE_MASK) {
+ kleave(" = -EINVAL [unaligned split]");
+ return -EINVAL;
+ }
+ if (start != vma->vm_start && end != vma->vm_end) {
+ ret = split_vma(mm, vma, start, 1);
+ if (ret < 0) {
+ kleave(" = %d [split]", ret);
+ return ret;
+ }
+ }
+ return shrink_vma(mm, vma, start, end);
+ }
+
+erase_whole_vma:
+ delete_vma_from_mm(vma);
+ delete_vma(mm, vma);
+ kleave(" = 0");
+ return 0;
+}
+EXPORT_SYMBOL(do_munmap);
+
+int vm_munmap(unsigned long addr, size_t len)
+{
+ struct mm_struct *mm = current->mm;
+ int ret;
+
+ down_write(&mm->mmap_sem);
+ ret = do_munmap(mm, addr, len);
+ up_write(&mm->mmap_sem);
+ return ret;
+}
+EXPORT_SYMBOL(vm_munmap);
+
+SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
+{
+ return vm_munmap(addr, len);
+}
+
+/*
+ * release all the mappings made in a process's VM space
+ */
+void exit_mmap(struct mm_struct *mm)
+{
+ struct vm_area_struct *vma;
+
+ if (!mm)
+ return;
+
+ kenter("");
+
+ mm->total_vm = 0;
+
+ while ((vma = mm->mmap)) {
+ mm->mmap = vma->vm_next;
+ delete_vma_from_mm(vma);
+ delete_vma(mm, vma);
+ cond_resched();
+ }
+
+ kleave("");
+}
+
+unsigned long vm_brk(unsigned long addr, unsigned long len)
+{
+ return -ENOMEM;
+}
+
+/*
+ * expand (or shrink) an existing mapping, potentially moving it at the same
+ * time (controlled by the MREMAP_MAYMOVE flag and available VM space)
+ *
+ * under NOMMU conditions, we only permit changing a mapping's size, and only
+ * as long as it stays within the region allocated by do_mmap_private() and the
+ * block is not shareable
+ *
+ * MREMAP_FIXED is not supported under NOMMU conditions
+ */
+unsigned long do_mremap(unsigned long addr,
+ unsigned long old_len, unsigned long new_len,
+ unsigned long flags, unsigned long new_addr)
+{
+ struct vm_area_struct *vma;
+
+ /* insanity checks first */
+ old_len = PAGE_ALIGN(old_len);
+ new_len = PAGE_ALIGN(new_len);
+ if (old_len == 0 || new_len == 0)
+ return (unsigned long) -EINVAL;
+
+ if (addr & ~PAGE_MASK)
+ return -EINVAL;
+
+ if (flags & MREMAP_FIXED && new_addr != addr)
+ return (unsigned long) -EINVAL;
+
+ vma = find_vma_exact(current->mm, addr, old_len);
+ if (!vma)
+ return (unsigned long) -EINVAL;
+
+ if (vma->vm_end != vma->vm_start + old_len)
+ return (unsigned long) -EFAULT;
+
+ if (vma->vm_flags & VM_MAYSHARE)
+ return (unsigned long) -EPERM;
+
+ if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start)
+ return (unsigned long) -ENOMEM;
+
+ /* all checks complete - do it */
+ vma->vm_end = vma->vm_start + new_len;
+ return vma->vm_start;
+}
+EXPORT_SYMBOL(do_mremap);
+
+SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
+ unsigned long, new_len, unsigned long, flags,
+ unsigned long, new_addr)
+{
+ unsigned long ret;
+
+ down_write(¤t->mm->mmap_sem);
+ ret = do_mremap(addr, old_len, new_len, flags, new_addr);
+ up_write(¤t->mm->mmap_sem);
+ return ret;
+}
+
+struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
+ unsigned int foll_flags)
+{
+ return NULL;
+}
+
+int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn, unsigned long size, pgprot_t prot)
+{
+ if (addr != (pfn << PAGE_SHIFT))
+ return -EINVAL;
+
+ vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
+ return 0;
+}
+EXPORT_SYMBOL(remap_pfn_range);
+
+int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len)
+{
+ unsigned long pfn = start >> PAGE_SHIFT;
+ unsigned long vm_len = vma->vm_end - vma->vm_start;
+
+ pfn += vma->vm_pgoff;
+ return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len, vma->vm_page_prot);
+}
+EXPORT_SYMBOL(vm_iomap_memory);
+
+int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
+ unsigned long pgoff)
+{
+ unsigned int size = vma->vm_end - vma->vm_start;
+
+ if (!(vma->vm_flags & VM_USERMAP))
+ return -EINVAL;
+
+ vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT));
+ vma->vm_end = vma->vm_start + size;
+
+ return 0;
+}
+EXPORT_SYMBOL(remap_vmalloc_range);
+
+unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+ return -ENOMEM;
+}
+
+void arch_unmap_area(struct mm_struct *mm, unsigned long addr)
+{
+}
+
+void unmap_mapping_range(struct address_space *mapping,
+ loff_t const holebegin, loff_t const holelen,
+ int even_cows)
+{
+}
+EXPORT_SYMBOL(unmap_mapping_range);
+
+/*
+ * Check that a process has enough memory to allocate a new virtual
+ * mapping. 0 means there is enough memory for the allocation to
+ * succeed and -ENOMEM implies there is not.
+ *
+ * We currently support three overcommit policies, which are set via the
+ * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting
+ *
+ * Strict overcommit modes added 2002 Feb 26 by Alan Cox.
+ * Additional code 2002 Jul 20 by Robert Love.
+ *
+ * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise.
+ *
+ * Note this is a helper function intended to be used by LSMs which
+ * wish to use this logic.
+ */
+int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
+{
+ long free, allowed;
+
+ vm_acct_memory(pages);
+
+ /*
+ * Sometimes we want to use more memory than we have
+ */
+ if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS)
+ return 0;
+
+ if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) {
+ free = global_page_state(NR_FREE_PAGES);
+ free += global_page_state(NR_FILE_PAGES);
+
+ /*
+ * shmem pages shouldn't be counted as free in this
+ * case, they can't be purged, only swapped out, and
+ * that won't affect the overall amount of available
+ * memory in the system.
+ */
+ free -= global_page_state(NR_SHMEM);
+
+ free += nr_swap_pages;
+
+ /*
+ * Any slabs which are created with the
+ * SLAB_RECLAIM_ACCOUNT flag claim to have contents
+ * which are reclaimable, under pressure. The dentry
+ * cache and most inode caches should fall into this
+ */
+ free += global_page_state(NR_SLAB_RECLAIMABLE);
+
+ /*
+ * Leave reserved pages. The pages are not for anonymous pages.
+ */
+ if (free <= totalreserve_pages)
+ goto error;
+ else
+ free -= totalreserve_pages;
+
+ /*
+ * Leave the last 3% for root
+ */
+ if (!cap_sys_admin)
+ free -= free / 32;
+
+ if (free > pages)
+ return 0;
+
+ goto error;
+ }
+
+ allowed = totalram_pages * sysctl_overcommit_ratio / 100;
+ /*
+ * Leave the last 3% for root
+ */
+ if (!cap_sys_admin)
+ allowed -= allowed / 32;
+ allowed += total_swap_pages;
+
+ /* Don't let a single process grow too big:
+ leave 3% of the size of this process for other processes */
+ if (mm)
+ allowed -= mm->total_vm / 32;
+
+ if (percpu_counter_read_positive(&vm_committed_as) < allowed)
+ return 0;
+
+error:
+ vm_unacct_memory(pages);
+
+ return -ENOMEM;
+}
+
+int in_gate_area_no_mm(unsigned long addr)
+{
+ return 0;
+}
+
+int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ BUG();
+ return 0;
+}
+EXPORT_SYMBOL(filemap_fault);
+
+static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long addr, void *buf, int len, int write)
+{
+ struct vm_area_struct *vma;
+
+ down_read(&mm->mmap_sem);
+
+ /* the access must start within one of the target process's mappings */
+ vma = find_vma(mm, addr);
+ if (vma) {
+ /* don't overrun this mapping */
+ if (addr + len >= vma->vm_end)
+ len = vma->vm_end - addr;
+
+ /* only read or write mappings where it is permitted */
+ if (write && vma->vm_flags & VM_MAYWRITE)
+ copy_to_user_page(vma, NULL, addr,
+ (void *) addr, buf, len);
+ else if (!write && vma->vm_flags & VM_MAYREAD)
+ copy_from_user_page(vma, NULL, addr,
+ buf, (void *) addr, len);
+ else
+ len = 0;
+ } else {
+ len = 0;
+ }
+
+ up_read(&mm->mmap_sem);
+
+ return len;
+}
+
+/**
+ * @access_remote_vm - access another process' address space
+ * @mm: the mm_struct of the target address space
+ * @addr: start address to access
+ * @buf: source or destination buffer
+ * @len: number of bytes to transfer
+ * @write: whether the access is a write
+ *
+ * The caller must hold a reference on @mm.
+ */
+int access_remote_vm(struct mm_struct *mm, unsigned long addr,
+ void *buf, int len, int write)
+{
+ return __access_remote_vm(NULL, mm, addr, buf, len, write);
+}
+
+/*
+ * Access another process' address space.
+ * - source/target buffer must be kernel space
+ */
+int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write)
+{
+ struct mm_struct *mm;
+
+ if (addr + len < addr)
+ return 0;
+
+ mm = get_task_mm(tsk);
+ if (!mm)
+ return 0;
+
+ len = __access_remote_vm(tsk, mm, addr, buf, len, write);
+
+ mmput(mm);
+ return len;
+}
+
+/**
+ * nommu_shrink_inode_mappings - Shrink the shared mappings on an inode
+ * @inode: The inode to check
+ * @size: The current filesize of the inode
+ * @newsize: The proposed filesize of the inode
+ *
+ * Check the shared mappings on an inode on behalf of a shrinking truncate to
+ * make sure that that any outstanding VMAs aren't broken and then shrink the
+ * vm_regions that extend that beyond so that do_mmap_pgoff() doesn't
+ * automatically grant mappings that are too large.
+ */
+int nommu_shrink_inode_mappings(struct inode *inode, size_t size,
+ size_t newsize)
+{
+ struct vm_area_struct *vma;
+ struct prio_tree_iter iter;
+ struct vm_region *region;
+ pgoff_t low, high;
+ size_t r_size, r_top;
+
+ low = newsize >> PAGE_SHIFT;
+ high = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+ down_write(&nommu_region_sem);
+ mutex_lock(&inode->i_mapping->i_mmap_mutex);
+
+ /* search for VMAs that fall within the dead zone */
+ vma_prio_tree_foreach(vma, &iter, &inode->i_mapping->i_mmap,
+ low, high) {
+ /* found one - only interested if it's shared out of the page
+ * cache */
+ if (vma->vm_flags & VM_SHARED) {
+ mutex_unlock(&inode->i_mapping->i_mmap_mutex);
+ up_write(&nommu_region_sem);
+ return -ETXTBSY; /* not quite true, but near enough */
+ }
+ }
+
+ /* reduce any regions that overlap the dead zone - if in existence,
+ * these will be pointed to by VMAs that don't overlap the dead zone
+ *
+ * we don't check for any regions that start beyond the EOF as there
+ * shouldn't be any
+ */
+ vma_prio_tree_foreach(vma, &iter, &inode->i_mapping->i_mmap,
+ 0, ULONG_MAX) {
+ if (!(vma->vm_flags & VM_SHARED))
+ continue;
+
+ region = vma->vm_region;
+ r_size = region->vm_top - region->vm_start;
+ r_top = (region->vm_pgoff << PAGE_SHIFT) + r_size;
+
+ if (r_top > newsize) {
+ region->vm_top -= r_top - newsize;
+ if (region->vm_end > region->vm_top)
+ region->vm_end = region->vm_top;
+ }
+ }
+
+ mutex_unlock(&inode->i_mapping->i_mmap_mutex);
+ up_write(&nommu_region_sem);
+ return 0;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/oom_kill.c b/ap/os/linux/linux-3.4.x/mm/oom_kill.c
new file mode 100644
index 0000000..b72c880
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/oom_kill.c
@@ -0,0 +1,801 @@
+/*
+ * linux/mm/oom_kill.c
+ *
+ * Copyright (C) 1998,2000 Rik van Riel
+ * Thanks go out to Claus Fischer for some serious inspiration and
+ * for goading me into coding this file...
+ * Copyright (C) 2010 Google, Inc.
+ * Rewritten by David Rientjes
+ *
+ * The routines in this file are used to kill a process when
+ * we're seriously out of memory. This gets called from __alloc_pages()
+ * in mm/page_alloc.c when we really run out of memory.
+ *
+ * Since we won't call these routines often (on a well-configured
+ * machine) this file will double as a 'coding guide' and a signpost
+ * for newbie kernel hackers. It features several pointers to major
+ * kernel subsystems and hints as to where to find out what things do.
+ */
+
+#include <linux/oom.h>
+#include <linux/mm.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/sched.h>
+#include <linux/swap.h>
+#include <linux/timex.h>
+#include <linux/jiffies.h>
+#include <linux/cpuset.h>
+#include <linux/export.h>
+#include <linux/notifier.h>
+#include <linux/memcontrol.h>
+#include <linux/mempolicy.h>
+#include <linux/security.h>
+#include <linux/ptrace.h>
+#include <linux/freezer.h>
+#include <linux/ftrace.h>
+#include <linux/ratelimit.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/oom.h>
+
+int sysctl_panic_on_oom;
+int sysctl_oom_kill_allocating_task;
+int sysctl_oom_dump_tasks = 1;
+static DEFINE_SPINLOCK(zone_scan_lock);
+
+/*
+ * compare_swap_oom_score_adj() - compare and swap current's oom_score_adj
+ * @old_val: old oom_score_adj for compare
+ * @new_val: new oom_score_adj for swap
+ *
+ * Sets the oom_score_adj value for current to @new_val iff its present value is
+ * @old_val. Usually used to reinstate a previous value to prevent racing with
+ * userspacing tuning the value in the interim.
+ */
+void compare_swap_oom_score_adj(int old_val, int new_val)
+{
+ struct sighand_struct *sighand = current->sighand;
+
+ spin_lock_irq(&sighand->siglock);
+ if (current->signal->oom_score_adj == old_val)
+ current->signal->oom_score_adj = new_val;
+ trace_oom_score_adj_update(current);
+ spin_unlock_irq(&sighand->siglock);
+}
+
+/**
+ * test_set_oom_score_adj() - set current's oom_score_adj and return old value
+ * @new_val: new oom_score_adj value
+ *
+ * Sets the oom_score_adj value for current to @new_val with proper
+ * synchronization and returns the old value. Usually used to temporarily
+ * set a value, save the old value in the caller, and then reinstate it later.
+ */
+int test_set_oom_score_adj(int new_val)
+{
+ struct sighand_struct *sighand = current->sighand;
+ int old_val;
+
+ spin_lock_irq(&sighand->siglock);
+ old_val = current->signal->oom_score_adj;
+ current->signal->oom_score_adj = new_val;
+ trace_oom_score_adj_update(current);
+ spin_unlock_irq(&sighand->siglock);
+
+ return old_val;
+}
+
+#ifdef CONFIG_NUMA
+/**
+ * has_intersects_mems_allowed() - check task eligiblity for kill
+ * @tsk: task struct of which task to consider
+ * @mask: nodemask passed to page allocator for mempolicy ooms
+ *
+ * Task eligibility is determined by whether or not a candidate task, @tsk,
+ * shares the same mempolicy nodes as current if it is bound by such a policy
+ * and whether or not it has the same set of allowed cpuset nodes.
+ */
+static bool has_intersects_mems_allowed(struct task_struct *tsk,
+ const nodemask_t *mask)
+{
+ struct task_struct *start = tsk;
+
+ do {
+ if (mask) {
+ /*
+ * If this is a mempolicy constrained oom, tsk's
+ * cpuset is irrelevant. Only return true if its
+ * mempolicy intersects current, otherwise it may be
+ * needlessly killed.
+ */
+ if (mempolicy_nodemask_intersects(tsk, mask))
+ return true;
+ } else {
+ /*
+ * This is not a mempolicy constrained oom, so only
+ * check the mems of tsk's cpuset.
+ */
+ if (cpuset_mems_allowed_intersects(current, tsk))
+ return true;
+ }
+ } while_each_thread(start, tsk);
+
+ return false;
+}
+#else
+static bool has_intersects_mems_allowed(struct task_struct *tsk,
+ const nodemask_t *mask)
+{
+ return true;
+}
+#endif /* CONFIG_NUMA */
+
+/*
+ * The process p may have detached its own ->mm while exiting or through
+ * use_mm(), but one or more of its subthreads may still have a valid
+ * pointer. Return p, or any of its subthreads with a valid ->mm, with
+ * task_lock() held.
+ */
+struct task_struct *find_lock_task_mm(struct task_struct *p)
+{
+ struct task_struct *t = p;
+
+ do {
+ task_lock(t);
+ if (likely(t->mm))
+ return t;
+ task_unlock(t);
+ } while_each_thread(p, t);
+
+ return NULL;
+}
+
+/* return true if the task is not adequate as candidate victim task. */
+static bool oom_unkillable_task(struct task_struct *p,
+ const struct mem_cgroup *memcg, const nodemask_t *nodemask)
+{
+ if (is_global_init(p))
+ return true;
+ if (p->flags & PF_KTHREAD)
+ return true;
+
+ /* When mem_cgroup_out_of_memory() and p is not member of the group */
+ if (memcg && !task_in_mem_cgroup(p, memcg))
+ return true;
+
+ /* p may not have freeable memory in nodemask */
+ if (!has_intersects_mems_allowed(p, nodemask))
+ return true;
+
+ return false;
+}
+
+/**
+ * oom_badness - heuristic function to determine which candidate task to kill
+ * @p: task struct of which task we should calculate
+ * @totalpages: total present RAM allowed for page allocation
+ *
+ * The heuristic for determining which task to kill is made to be as simple and
+ * predictable as possible. The goal is to return the highest value for the
+ * task consuming the most memory to avoid subsequent oom failures.
+ */
+unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *memcg,
+ const nodemask_t *nodemask, unsigned long totalpages)
+{
+ long points;
+
+ if (oom_unkillable_task(p, memcg, nodemask))
+ return 0;
+
+ p = find_lock_task_mm(p);
+ if (!p)
+ return 0;
+
+ if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) {
+ task_unlock(p);
+ return 0;
+ }
+
+ /*
+ * The memory controller may have a limit of 0 bytes, so avoid a divide
+ * by zero, if necessary.
+ */
+ if (!totalpages)
+ totalpages = 1;
+
+ /*
+ * The baseline for the badness score is the proportion of RAM that each
+ * task's rss, pagetable and swap space use.
+ */
+ points = get_mm_rss(p->mm) + p->mm->nr_ptes;
+ points += get_mm_counter(p->mm, MM_SWAPENTS);
+
+ points *= 1000;
+ points /= totalpages;
+ task_unlock(p);
+
+ /*
+ * Root processes get 3% bonus, just like the __vm_enough_memory()
+ * implementation used by LSMs.
+ */
+ if (has_capability_noaudit(p, CAP_SYS_ADMIN))
+ points -= 30;
+
+ /*
+ * /proc/pid/oom_score_adj ranges from -1000 to +1000 such that it may
+ * either completely disable oom killing or always prefer a certain
+ * task.
+ */
+ points += p->signal->oom_score_adj;
+
+ /*
+ * Never return 0 for an eligible task that may be killed since it's
+ * possible that no single user task uses more than 0.1% of memory and
+ * no single admin tasks uses more than 3.0%.
+ */
+ if (points <= 0)
+ return 1;
+ return (points < 1000) ? points : 1000;
+}
+
+/*
+ * Determine the type of allocation constraint.
+ */
+#ifdef CONFIG_NUMA
+static enum oom_constraint constrained_alloc(struct zonelist *zonelist,
+ gfp_t gfp_mask, nodemask_t *nodemask,
+ unsigned long *totalpages)
+{
+ struct zone *zone;
+ struct zoneref *z;
+ enum zone_type high_zoneidx = gfp_zone(gfp_mask);
+ bool cpuset_limited = false;
+ int nid;
+
+ /* Default to all available memory */
+ *totalpages = totalram_pages + total_swap_pages;
+
+ if (!zonelist)
+ return CONSTRAINT_NONE;
+ /*
+ * Reach here only when __GFP_NOFAIL is used. So, we should avoid
+ * to kill current.We have to random task kill in this case.
+ * Hopefully, CONSTRAINT_THISNODE...but no way to handle it, now.
+ */
+ if (gfp_mask & __GFP_THISNODE)
+ return CONSTRAINT_NONE;
+
+ /*
+ * This is not a __GFP_THISNODE allocation, so a truncated nodemask in
+ * the page allocator means a mempolicy is in effect. Cpuset policy
+ * is enforced in get_page_from_freelist().
+ */
+ if (nodemask && !nodes_subset(node_states[N_HIGH_MEMORY], *nodemask)) {
+ *totalpages = total_swap_pages;
+ for_each_node_mask(nid, *nodemask)
+ *totalpages += node_spanned_pages(nid);
+ return CONSTRAINT_MEMORY_POLICY;
+ }
+
+ /* Check this allocation failure is caused by cpuset's wall function */
+ for_each_zone_zonelist_nodemask(zone, z, zonelist,
+ high_zoneidx, nodemask)
+ if (!cpuset_zone_allowed_softwall(zone, gfp_mask))
+ cpuset_limited = true;
+
+ if (cpuset_limited) {
+ *totalpages = total_swap_pages;
+ for_each_node_mask(nid, cpuset_current_mems_allowed)
+ *totalpages += node_spanned_pages(nid);
+ return CONSTRAINT_CPUSET;
+ }
+ return CONSTRAINT_NONE;
+}
+#else
+static enum oom_constraint constrained_alloc(struct zonelist *zonelist,
+ gfp_t gfp_mask, nodemask_t *nodemask,
+ unsigned long *totalpages)
+{
+ *totalpages = totalram_pages + total_swap_pages;
+ return CONSTRAINT_NONE;
+}
+#endif
+
+/*
+ * Simple selection loop. We chose the process with the highest
+ * number of 'points'. We expect the caller will lock the tasklist.
+ *
+ * (not docbooked, we don't want this one cluttering up the manual)
+ */
+static struct task_struct *select_bad_process(unsigned int *ppoints,
+ unsigned long totalpages, struct mem_cgroup *memcg,
+ const nodemask_t *nodemask, bool force_kill)
+{
+ struct task_struct *g, *p;
+ struct task_struct *chosen = NULL;
+ *ppoints = 0;
+
+ do_each_thread(g, p) {
+ unsigned int points;
+
+ if (p->exit_state)
+ continue;
+ if (oom_unkillable_task(p, memcg, nodemask))
+ continue;
+
+ /*
+ * This task already has access to memory reserves and is
+ * being killed. Don't allow any other task access to the
+ * memory reserve.
+ *
+ * Note: this may have a chance of deadlock if it gets
+ * blocked waiting for another task which itself is waiting
+ * for memory. Is there a better alternative?
+ */
+ if (test_tsk_thread_flag(p, TIF_MEMDIE)) {
+ if (unlikely(frozen(p)))
+ __thaw_task(p);
+ if (!force_kill)
+ return ERR_PTR(-1UL);
+ }
+ if (!p->mm)
+ continue;
+
+ if (p->flags & PF_EXITING) {
+ /*
+ * If p is the current task and is in the process of
+ * releasing memory, we allow the "kill" to set
+ * TIF_MEMDIE, which will allow it to gain access to
+ * memory reserves. Otherwise, it may stall forever.
+ *
+ * The loop isn't broken here, however, in case other
+ * threads are found to have already been oom killed.
+ */
+ if (p == current) {
+ chosen = p;
+ *ppoints = 1000;
+ } else if (!force_kill) {
+ /*
+ * If this task is not being ptraced on exit,
+ * then wait for it to finish before killing
+ * some other task unnecessarily.
+ */
+ if (!(p->group_leader->ptrace & PT_TRACE_EXIT))
+ return ERR_PTR(-1UL);
+ }
+ }
+
+ points = oom_badness(p, memcg, nodemask, totalpages);
+ if (points > *ppoints) {
+ chosen = p;
+ *ppoints = points;
+ }
+ } while_each_thread(g, p);
+
+ return chosen;
+}
+
+/**
+ * dump_tasks - dump current memory state of all system tasks
+ * @mem: current's memory controller, if constrained
+ * @nodemask: nodemask passed to page allocator for mempolicy ooms
+ *
+ * Dumps the current memory state of all eligible tasks. Tasks not in the same
+ * memcg, not in the same cpuset, or bound to a disjoint set of mempolicy nodes
+ * are not shown.
+ * State information includes task's pid, uid, tgid, vm size, rss, cpu, oom_adj
+ * value, oom_score_adj value, and name.
+ *
+ * Call with tasklist_lock read-locked.
+ */
+static void dump_tasks(const struct mem_cgroup *memcg, const nodemask_t *nodemask)
+{
+ struct task_struct *p;
+ struct task_struct *task;
+
+ pr_info("[ pid ] uid tgid total_vm rss cpu oom_adj oom_score_adj name\n");
+ for_each_process(p) {
+ if (oom_unkillable_task(p, memcg, nodemask))
+ continue;
+
+ task = find_lock_task_mm(p);
+ if (!task) {
+ /*
+ * This is a kthread or all of p's threads have already
+ * detached their mm's. There's no need to report
+ * them; they can't be oom killed anyway.
+ */
+ continue;
+ }
+
+ pr_info("[%5d] %5d %5d %8lu %8lu %3u %3d %5d %s\n",
+ task->pid, task_uid(task), task->tgid,
+ task->mm->total_vm, get_mm_rss(task->mm),
+ task_cpu(task), task->signal->oom_adj,
+ task->signal->oom_score_adj, task->comm);
+ task_unlock(task);
+ }
+}
+
+static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
+ struct mem_cgroup *memcg, const nodemask_t *nodemask)
+{
+ task_lock(current);
+ pr_warning("%s invoked oom-killer: gfp_mask=0x%x, order=%d, "
+ "oom_adj=%d, oom_score_adj=%d\n",
+ current->comm, gfp_mask, order, current->signal->oom_adj,
+ current->signal->oom_score_adj);
+ cpuset_print_task_mems_allowed(current);
+ task_unlock(current);
+ dump_stack();
+ mem_cgroup_print_oom_info(memcg, p);
+ show_mem(SHOW_MEM_FILTER_NODES);
+ if (sysctl_oom_dump_tasks)
+ dump_tasks(memcg, nodemask);
+}
+
+/*
+ * Number of OOM killer invocations (including memcg OOM killer).
+ * Primarily used by PM freezer to check for potential races with
+ * OOM killed frozen task.
+ */
+static atomic_t oom_kills = ATOMIC_INIT(0);
+
+int oom_kills_count(void)
+{
+ return atomic_read(&oom_kills);
+}
+
+void note_oom_kill(void)
+{
+ atomic_inc(&oom_kills);
+}
+
+#define K(x) ((x) << (PAGE_SHIFT-10))
+static void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
+ unsigned int points, unsigned long totalpages,
+ struct mem_cgroup *memcg, nodemask_t *nodemask,
+ const char *message)
+{
+ struct task_struct *victim = p;
+ struct task_struct *child;
+ struct task_struct *t = p;
+ struct mm_struct *mm;
+ unsigned int victim_points = 0;
+ static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+ /*
+ * If the task is already exiting, don't alarm the sysadmin or kill
+ * its children or threads, just set TIF_MEMDIE so it can die quickly
+ */
+ if (p->flags & PF_EXITING) {
+ set_tsk_thread_flag(p, TIF_MEMDIE);
+ return;
+ }
+
+ if (__ratelimit(&oom_rs))
+ dump_header(p, gfp_mask, order, memcg, nodemask);
+
+ task_lock(p);
+ pr_err("%s: Kill process %d (%s) score %d or sacrifice child\n",
+ message, task_pid_nr(p), p->comm, points);
+ task_unlock(p);
+
+ /*
+ * If any of p's children has a different mm and is eligible for kill,
+ * the one with the highest oom_badness() score is sacrificed for its
+ * parent. This attempts to lose the minimal amount of work done while
+ * still freeing memory.
+ */
+ do {
+ list_for_each_entry(child, &t->children, sibling) {
+ unsigned int child_points;
+
+ if (child->mm == p->mm)
+ continue;
+ /*
+ * oom_badness() returns 0 if the thread is unkillable
+ */
+ child_points = oom_badness(child, memcg, nodemask,
+ totalpages);
+ if (child_points > victim_points) {
+ victim = child;
+ victim_points = child_points;
+ }
+ }
+ } while_each_thread(p, t);
+
+ victim = find_lock_task_mm(victim);
+ if (!victim)
+ return;
+
+ /* mm cannot safely be dereferenced after task_unlock(victim) */
+ mm = victim->mm;
+ pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n",
+ task_pid_nr(victim), victim->comm, K(victim->mm->total_vm),
+ K(get_mm_counter(victim->mm, MM_ANONPAGES)),
+ K(get_mm_counter(victim->mm, MM_FILEPAGES)));
+ task_unlock(victim);
+
+ /*
+ * Kill all user processes sharing victim->mm in other thread groups, if
+ * any. They don't get access to memory reserves, though, to avoid
+ * depletion of all memory. This prevents mm->mmap_sem livelock when an
+ * oom killed thread cannot exit because it requires the semaphore and
+ * its contended by another thread trying to allocate memory itself.
+ * That thread will now get access to memory reserves since it has a
+ * pending fatal signal.
+ */
+ for_each_process(p)
+ if (p->mm == mm && !same_thread_group(p, victim) &&
+ !(p->flags & PF_KTHREAD)) {
+ if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
+ continue;
+
+ task_lock(p); /* Protect ->comm from prctl() */
+ pr_err("Kill process %d (%s) sharing same memory\n",
+ task_pid_nr(p), p->comm);
+ task_unlock(p);
+ do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);
+ }
+
+ set_tsk_thread_flag(victim, TIF_MEMDIE);
+ do_send_sig_info(SIGKILL, SEND_SIG_FORCED, victim, true);
+}
+#undef K
+
+/*
+ * Determines whether the kernel must panic because of the panic_on_oom sysctl.
+ */
+static void check_panic_on_oom(enum oom_constraint constraint, gfp_t gfp_mask,
+ int order, const nodemask_t *nodemask)
+{
+ if (likely(!sysctl_panic_on_oom))
+ return;
+
+ sysctl_panic_on_oom = 2;
+ if (sysctl_panic_on_oom != 2) {
+ /*
+ * panic_on_oom == 1 only affects CONSTRAINT_NONE, the kernel
+ * does not panic for cpuset, mempolicy, or memcg allocation
+ * failures.
+ */
+ if (constraint != CONSTRAINT_NONE)
+ return;
+ }
+ read_lock(&tasklist_lock);
+ dump_header(NULL, gfp_mask, order, NULL, nodemask);
+ read_unlock(&tasklist_lock);
+ panic("[zx297510]Out of memory: %s panic_on_oom is enabled\n",
+ sysctl_panic_on_oom == 2 ? "compulsory" : "system-wide");
+}
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
+ int order)
+{
+ unsigned long limit;
+ unsigned int points = 0;
+ struct task_struct *p;
+
+ /*
+ * If current has a pending SIGKILL or is exiting, then automatically
+ * select it. The goal is to allow it to allocate so that it may
+ * quickly exit and free its memory.
+ */
+ if (fatal_signal_pending(current) || current->flags & PF_EXITING) {
+ set_thread_flag(TIF_MEMDIE);
+ return;
+ }
+
+ check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL);
+ limit = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT;
+ read_lock(&tasklist_lock);
+ p = select_bad_process(&points, limit, memcg, NULL, false);
+ if (p && PTR_ERR(p) != -1UL)
+ oom_kill_process(p, gfp_mask, order, points, limit, memcg, NULL,
+ "Memory cgroup out of memory");
+ read_unlock(&tasklist_lock);
+}
+#endif
+
+static BLOCKING_NOTIFIER_HEAD(oom_notify_list);
+
+int register_oom_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&oom_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(register_oom_notifier);
+
+int unregister_oom_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&oom_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_oom_notifier);
+
+/*
+ * Try to acquire the OOM killer lock for the zones in zonelist. Returns zero
+ * if a parallel OOM killing is already taking place that includes a zone in
+ * the zonelist. Otherwise, locks all zones in the zonelist and returns 1.
+ */
+int try_set_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_mask)
+{
+ struct zoneref *z;
+ struct zone *zone;
+ int ret = 1;
+
+ spin_lock(&zone_scan_lock);
+ for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask)) {
+ if (zone_is_oom_locked(zone)) {
+ ret = 0;
+ goto out;
+ }
+ }
+
+ for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask)) {
+ /*
+ * Lock each zone in the zonelist under zone_scan_lock so a
+ * parallel invocation of try_set_zonelist_oom() doesn't succeed
+ * when it shouldn't.
+ */
+ zone_set_flag(zone, ZONE_OOM_LOCKED);
+ }
+
+out:
+ spin_unlock(&zone_scan_lock);
+ return ret;
+}
+
+/*
+ * Clears the ZONE_OOM_LOCKED flag for all zones in the zonelist so that failed
+ * allocation attempts with zonelists containing them may now recall the OOM
+ * killer, if necessary.
+ */
+void clear_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_mask)
+{
+ struct zoneref *z;
+ struct zone *zone;
+
+ spin_lock(&zone_scan_lock);
+ for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask)) {
+ zone_clear_flag(zone, ZONE_OOM_LOCKED);
+ }
+ spin_unlock(&zone_scan_lock);
+}
+
+/*
+ * Try to acquire the oom killer lock for all system zones. Returns zero if a
+ * parallel oom killing is taking place, otherwise locks all zones and returns
+ * non-zero.
+ */
+static int try_set_system_oom(void)
+{
+ struct zone *zone;
+ int ret = 1;
+
+ spin_lock(&zone_scan_lock);
+ for_each_populated_zone(zone)
+ if (zone_is_oom_locked(zone)) {
+ ret = 0;
+ goto out;
+ }
+ for_each_populated_zone(zone)
+ zone_set_flag(zone, ZONE_OOM_LOCKED);
+out:
+ spin_unlock(&zone_scan_lock);
+ return ret;
+}
+
+/*
+ * Clears ZONE_OOM_LOCKED for all system zones so that failed allocation
+ * attempts or page faults may now recall the oom killer, if necessary.
+ */
+static void clear_system_oom(void)
+{
+ struct zone *zone;
+
+ spin_lock(&zone_scan_lock);
+ for_each_populated_zone(zone)
+ zone_clear_flag(zone, ZONE_OOM_LOCKED);
+ spin_unlock(&zone_scan_lock);
+}
+
+/**
+ * out_of_memory - kill the "best" process when we run out of memory
+ * @zonelist: zonelist pointer
+ * @gfp_mask: memory allocation flags
+ * @order: amount of memory being requested as a power of 2
+ * @nodemask: nodemask passed to page allocator
+ * @force_kill: true if a task must be killed, even if others are exiting
+ *
+ * If we run out of memory, we have the choice between either
+ * killing a random task (bad), letting the system crash (worse)
+ * OR try to be smart about which process to kill. Note that we
+ * don't have to be perfect here, we just have to be good.
+ */
+void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
+ int order, nodemask_t *nodemask, bool force_kill)
+{
+ const nodemask_t *mpol_mask;
+ struct task_struct *p;
+ unsigned long totalpages;
+ unsigned long freed = 0;
+ unsigned int points;
+ enum oom_constraint constraint = CONSTRAINT_NONE;
+ int killed = 0;
+
+ blocking_notifier_call_chain(&oom_notify_list, 0, &freed);
+ if (freed > 0)
+ /* Got some memory back in the last second. */
+ return;
+
+ /*
+ * If current has a pending SIGKILL, then automatically select it. The
+ * goal is to allow it to allocate so that it may quickly exit and free
+ * its memory.
+ */
+ if (fatal_signal_pending(current)) {
+ set_thread_flag(TIF_MEMDIE);
+ return;
+ }
+
+ /*
+ * Check if there were limitations on the allocation (only relevant for
+ * NUMA) that may require different handling.
+ */
+ constraint = constrained_alloc(zonelist, gfp_mask, nodemask,
+ &totalpages);
+ mpol_mask = (constraint == CONSTRAINT_MEMORY_POLICY) ? nodemask : NULL;
+ check_panic_on_oom(constraint, gfp_mask, order, mpol_mask);
+
+ read_lock(&tasklist_lock);
+ if (sysctl_oom_kill_allocating_task &&
+ !oom_unkillable_task(current, NULL, nodemask) &&
+ current->mm) {
+ oom_kill_process(current, gfp_mask, order, 0, totalpages, NULL,
+ nodemask,
+ "Out of memory (oom_kill_allocating_task)");
+ goto out;
+ }
+
+ p = select_bad_process(&points, totalpages, NULL, mpol_mask,
+ force_kill);
+ /* Found nothing?!?! Either we hang forever, or we panic. */
+ if (!p) {
+ dump_header(NULL, gfp_mask, order, NULL, mpol_mask);
+ read_unlock(&tasklist_lock);
+ panic("Out of memory and no killable processes...\n");
+ }
+ if (PTR_ERR(p) != -1UL) {
+ oom_kill_process(p, gfp_mask, order, points, totalpages, NULL,
+ nodemask, "Out of memory");
+ killed = 1;
+ }
+out:
+ read_unlock(&tasklist_lock);
+
+ /*
+ * Give "p" a good chance of killing itself before we
+ * retry to allocate memory unless "p" is current
+ */
+ if (killed && !test_thread_flag(TIF_MEMDIE))
+ schedule_timeout_uninterruptible(1);
+}
+
+/*
+ * The pagefault handler calls here because it is out of memory, so kill a
+ * memory-hogging task. If a populated zone has ZONE_OOM_LOCKED set, a parallel
+ * oom killing is already in progress so do nothing. If a task is found with
+ * TIF_MEMDIE set, it has been killed so do nothing and allow it to exit.
+ */
+void pagefault_out_of_memory(void)
+{
+ if (try_set_system_oom()) {
+ out_of_memory(NULL, 0, 0, NULL, false);
+ clear_system_oom();
+ }
+ if (!test_thread_flag(TIF_MEMDIE))
+ schedule_timeout_uninterruptible(1);
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/page-writeback.c b/ap/os/linux/linux-3.4.x/mm/page-writeback.c
new file mode 100644
index 0000000..ecd1c4c
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/page-writeback.c
@@ -0,0 +1,2244 @@
+/*
+ * mm/page-writeback.c
+ *
+ * Copyright (C) 2002, Linus Torvalds.
+ * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *
+ * Contains functions related to writing back dirty pages at the
+ * address_space level.
+ *
+ * 10Apr2002 Andrew Morton
+ * Initial version
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/spinlock.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/writeback.h>
+#include <linux/init.h>
+#include <linux/backing-dev.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/blkdev.h>
+#include <linux/mpage.h>
+#include <linux/rmap.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/smp.h>
+#include <linux/sysctl.h>
+#include <linux/cpu.h>
+#include <linux/syscalls.h>
+#include <linux/buffer_head.h> /* __set_page_dirty_buffers */
+#include <linux/pagevec.h>
+#include <trace/events/writeback.h>
+
+/*
+ * Sleep at most 200ms at a time in balance_dirty_pages().
+ */
+#define MAX_PAUSE max(HZ/5, 1)
+
+/*
+ * Try to keep balance_dirty_pages() call intervals higher than this many pages
+ * by raising pause time to max_pause when falls below it.
+ */
+#define DIRTY_POLL_THRESH (128 >> (PAGE_SHIFT - 10))
+
+/*
+ * Estimate write bandwidth at 200ms intervals.
+ */
+#define BANDWIDTH_INTERVAL max(HZ/5, 1)
+
+#define RATELIMIT_CALC_SHIFT 10
+
+/*
+ * After a CPU has dirtied this many pages, balance_dirty_pages_ratelimited
+ * will look to see if it needs to force writeback or throttling.
+ */
+static long ratelimit_pages = 32;
+
+/* The following parameters are exported via /proc/sys/vm */
+
+/*
+ * Start background writeback (via writeback threads) at this percentage
+ */
+int dirty_background_ratio = 10;
+
+/*
+ * dirty_background_bytes starts at 0 (disabled) so that it is a function of
+ * dirty_background_ratio * the amount of dirtyable memory
+ */
+unsigned long dirty_background_bytes;
+
+/*
+ * free highmem will not be subtracted from the total free memory
+ * for calculating free ratios if vm_highmem_is_dirtyable is true
+ */
+int vm_highmem_is_dirtyable;
+
+/*
+ * The generator of dirty data starts writeback at this percentage
+ */
+int vm_dirty_ratio = 20;
+
+/*
+ * vm_dirty_bytes starts at 0 (disabled) so that it is a function of
+ * vm_dirty_ratio * the amount of dirtyable memory
+ */
+unsigned long vm_dirty_bytes;
+
+/*
+ * The interval between `kupdate'-style writebacks
+ */
+unsigned int dirty_writeback_interval = 5 * 100; /* centiseconds */
+
+EXPORT_SYMBOL_GPL(dirty_writeback_interval);
+
+/*
+ * The longest time for which data is allowed to remain dirty
+ */
+unsigned int dirty_expire_interval = 30 * 100; /* centiseconds */
+
+/*
+ * Flag that makes the machine dump writes/reads and block dirtyings.
+ */
+int block_dump;
+
+/*
+ * Flag that puts the machine in "laptop mode". Doubles as a timeout in jiffies:
+ * a full sync is triggered after this time elapses without any disk activity.
+ */
+int laptop_mode;
+
+EXPORT_SYMBOL(laptop_mode);
+
+/* End of sysctl-exported parameters */
+
+unsigned long global_dirty_limit;
+
+/*
+ * Scale the writeback cache size proportional to the relative writeout speeds.
+ *
+ * We do this by keeping a floating proportion between BDIs, based on page
+ * writeback completions [end_page_writeback()]. Those devices that write out
+ * pages fastest will get the larger share, while the slower will get a smaller
+ * share.
+ *
+ * We use page writeout completions because we are interested in getting rid of
+ * dirty pages. Having them written out is the primary goal.
+ *
+ * We introduce a concept of time, a period over which we measure these events,
+ * because demand can/will vary over time. The length of this period itself is
+ * measured in page writeback completions.
+ *
+ */
+static struct prop_descriptor vm_completions;
+
+/*
+ * Work out the current dirty-memory clamping and background writeout
+ * thresholds.
+ *
+ * The main aim here is to lower them aggressively if there is a lot of mapped
+ * memory around. To avoid stressing page reclaim with lots of unreclaimable
+ * pages. It is better to clamp down on writers than to start swapping, and
+ * performing lots of scanning.
+ *
+ * We only allow 1/2 of the currently-unmapped memory to be dirtied.
+ *
+ * We don't permit the clamping level to fall below 5% - that is getting rather
+ * excessive.
+ *
+ * We make sure that the background writeout level is below the adjusted
+ * clamping level.
+ */
+
+/*
+ * In a memory zone, there is a certain amount of pages we consider
+ * available for the page cache, which is essentially the number of
+ * free and reclaimable pages, minus some zone reserves to protect
+ * lowmem and the ability to uphold the zone's watermarks without
+ * requiring writeback.
+ *
+ * This number of dirtyable pages is the base value of which the
+ * user-configurable dirty ratio is the effictive number of pages that
+ * are allowed to be actually dirtied. Per individual zone, or
+ * globally by using the sum of dirtyable pages over all zones.
+ *
+ * Because the user is allowed to specify the dirty limit globally as
+ * absolute number of bytes, calculating the per-zone dirty limit can
+ * require translating the configured limit into a percentage of
+ * global dirtyable memory first.
+ */
+
+static unsigned long highmem_dirtyable_memory(unsigned long total)
+{
+#ifdef CONFIG_HIGHMEM
+ int node;
+ unsigned long x = 0;
+
+ for_each_node_state(node, N_HIGH_MEMORY) {
+ struct zone *z =
+ &NODE_DATA(node)->node_zones[ZONE_HIGHMEM];
+
+ x += zone_page_state(z, NR_FREE_PAGES) +
+ zone_reclaimable_pages(z) - z->dirty_balance_reserve;
+ }
+ /*
+ * Unreclaimable memory (kernel memory or anonymous memory
+ * without swap) can bring down the dirtyable pages below
+ * the zone's dirty balance reserve and the above calculation
+ * will underflow. However we still want to add in nodes
+ * which are below threshold (negative values) to get a more
+ * accurate calculation but make sure that the total never
+ * underflows.
+ */
+ if ((long)x < 0)
+ x = 0;
+
+ /*
+ * Make sure that the number of highmem pages is never larger
+ * than the number of the total dirtyable memory. This can only
+ * occur in very strange VM situations but we want to make sure
+ * that this does not occur.
+ */
+ return min(x, total);
+#else
+ return 0;
+#endif
+}
+
+/**
+ * global_dirtyable_memory - number of globally dirtyable pages
+ *
+ * Returns the global number of pages potentially available for dirty
+ * page cache. This is the base value for the global dirty limits.
+ */
+unsigned long global_dirtyable_memory(void)
+{
+ unsigned long x;
+
+ x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages();
+ x -= min(x, dirty_balance_reserve);
+
+ if (!vm_highmem_is_dirtyable)
+ x -= highmem_dirtyable_memory(x);
+
+ return x + 1; /* Ensure that we never return 0 */
+}
+
+/*
+ * global_dirty_limits - background-writeback and dirty-throttling thresholds
+ *
+ * Calculate the dirty thresholds based on sysctl parameters
+ * - vm.dirty_background_ratio or vm.dirty_background_bytes
+ * - vm.dirty_ratio or vm.dirty_bytes
+ * The dirty limits will be lifted by 1/4 for PF_LESS_THROTTLE (ie. nfsd) and
+ * real-time tasks.
+ */
+void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty)
+{
+ unsigned long background;
+ unsigned long dirty;
+ unsigned long uninitialized_var(available_memory);
+ struct task_struct *tsk;
+
+ if (!vm_dirty_bytes || !dirty_background_bytes)
+ available_memory = global_dirtyable_memory();
+
+ if (vm_dirty_bytes)
+ dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE);
+ else
+ dirty = (vm_dirty_ratio * available_memory) / 100;
+
+ if (dirty_background_bytes)
+ background = DIV_ROUND_UP(dirty_background_bytes, PAGE_SIZE);
+ else
+ background = (dirty_background_ratio * available_memory) / 100;
+
+ if (background >= dirty)
+ background = dirty / 2;
+ tsk = current;
+ if (tsk->flags & PF_LESS_THROTTLE || rt_task(tsk)) {
+ background += background / 4;
+ dirty += dirty / 4;
+ }
+ *pbackground = background;
+ *pdirty = dirty;
+ trace_global_dirty_state(background, dirty);
+}
+
+/**
+ * zone_dirtyable_memory - number of dirtyable pages in a zone
+ * @zone: the zone
+ *
+ * Returns the zone's number of pages potentially available for dirty
+ * page cache. This is the base value for the per-zone dirty limits.
+ */
+static unsigned long zone_dirtyable_memory(struct zone *zone)
+{
+ /*
+ * The effective global number of dirtyable pages may exclude
+ * highmem as a big-picture measure to keep the ratio between
+ * dirty memory and lowmem reasonable.
+ *
+ * But this function is purely about the individual zone and a
+ * highmem zone can hold its share of dirty pages, so we don't
+ * care about vm_highmem_is_dirtyable here.
+ */
+ unsigned long nr_pages = zone_page_state(zone, NR_FREE_PAGES) +
+ zone_reclaimable_pages(zone);
+
+ /* don't allow this to underflow */
+ nr_pages -= min(nr_pages, zone->dirty_balance_reserve);
+ return nr_pages;
+}
+
+/**
+ * zone_dirty_limit - maximum number of dirty pages allowed in a zone
+ * @zone: the zone
+ *
+ * Returns the maximum number of dirty pages allowed in a zone, based
+ * on the zone's dirtyable memory.
+ */
+static unsigned long zone_dirty_limit(struct zone *zone)
+{
+ unsigned long zone_memory = zone_dirtyable_memory(zone);
+ struct task_struct *tsk = current;
+ unsigned long dirty;
+
+ if (vm_dirty_bytes)
+ dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE) *
+ zone_memory / global_dirtyable_memory();
+ else
+ dirty = vm_dirty_ratio * zone_memory / 100;
+
+ if (tsk->flags & PF_LESS_THROTTLE || rt_task(tsk))
+ dirty += dirty / 4;
+
+ return dirty;
+}
+
+/**
+ * zone_dirty_ok - tells whether a zone is within its dirty limits
+ * @zone: the zone to check
+ *
+ * Returns %true when the dirty pages in @zone are within the zone's
+ * dirty limit, %false if the limit is exceeded.
+ */
+bool zone_dirty_ok(struct zone *zone)
+{
+ unsigned long limit = zone_dirty_limit(zone);
+
+ return zone_page_state(zone, NR_FILE_DIRTY) +
+ zone_page_state(zone, NR_UNSTABLE_NFS) +
+ zone_page_state(zone, NR_WRITEBACK) <= limit;
+}
+
+/*
+ * couple the period to the dirty_ratio:
+ *
+ * period/2 ~ roundup_pow_of_two(dirty limit)
+ */
+static int calc_period_shift(void)
+{
+ unsigned long dirty_total;
+
+ if (vm_dirty_bytes)
+ dirty_total = vm_dirty_bytes / PAGE_SIZE;
+ else
+ dirty_total = (vm_dirty_ratio * global_dirtyable_memory()) /
+ 100;
+ return 2 + ilog2(dirty_total - 1);
+}
+
+/*
+ * update the period when the dirty threshold changes.
+ */
+static void update_completion_period(void)
+{
+ int shift = calc_period_shift();
+ prop_change_shift(&vm_completions, shift);
+
+ writeback_set_ratelimit();
+}
+
+int dirty_background_ratio_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int ret;
+
+ ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+ if (ret == 0 && write)
+ dirty_background_bytes = 0;
+ return ret;
+}
+
+int dirty_background_bytes_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int ret;
+
+ ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
+ if (ret == 0 && write)
+ dirty_background_ratio = 0;
+ return ret;
+}
+
+int dirty_ratio_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int old_ratio = vm_dirty_ratio;
+ int ret;
+
+ ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+ if (ret == 0 && write && vm_dirty_ratio != old_ratio) {
+ update_completion_period();
+ vm_dirty_bytes = 0;
+ }
+ return ret;
+}
+
+int dirty_bytes_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ unsigned long old_bytes = vm_dirty_bytes;
+ int ret;
+
+ ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
+ if (ret == 0 && write && vm_dirty_bytes != old_bytes) {
+ update_completion_period();
+ vm_dirty_ratio = 0;
+ }
+ return ret;
+}
+
+/*
+ * Increment the BDI's writeout completion count and the global writeout
+ * completion count. Called from test_clear_page_writeback().
+ */
+static inline void __bdi_writeout_inc(struct backing_dev_info *bdi)
+{
+ __inc_bdi_stat(bdi, BDI_WRITTEN);
+ __prop_inc_percpu_max(&vm_completions, &bdi->completions,
+ bdi->max_prop_frac);
+}
+
+void bdi_writeout_inc(struct backing_dev_info *bdi)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __bdi_writeout_inc(bdi);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(bdi_writeout_inc);
+
+/*
+ * Obtain an accurate fraction of the BDI's portion.
+ */
+static void bdi_writeout_fraction(struct backing_dev_info *bdi,
+ long *numerator, long *denominator)
+{
+ prop_fraction_percpu(&vm_completions, &bdi->completions,
+ numerator, denominator);
+}
+
+/*
+ * bdi_min_ratio keeps the sum of the minimum dirty shares of all
+ * registered backing devices, which, for obvious reasons, can not
+ * exceed 100%.
+ */
+static unsigned int bdi_min_ratio;
+
+int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio)
+{
+ int ret = 0;
+
+ spin_lock_bh(&bdi_lock);
+ if (min_ratio > bdi->max_ratio) {
+ ret = -EINVAL;
+ } else {
+ min_ratio -= bdi->min_ratio;
+ if (bdi_min_ratio + min_ratio < 100) {
+ bdi_min_ratio += min_ratio;
+ bdi->min_ratio += min_ratio;
+ } else {
+ ret = -EINVAL;
+ }
+ }
+ spin_unlock_bh(&bdi_lock);
+
+ return ret;
+}
+
+int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio)
+{
+ int ret = 0;
+
+ if (max_ratio > 100)
+ return -EINVAL;
+
+ spin_lock_bh(&bdi_lock);
+ if (bdi->min_ratio > max_ratio) {
+ ret = -EINVAL;
+ } else {
+ bdi->max_ratio = max_ratio;
+ bdi->max_prop_frac = (PROP_FRAC_BASE * max_ratio) / 100;
+ }
+ spin_unlock_bh(&bdi_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(bdi_set_max_ratio);
+
+static unsigned long dirty_freerun_ceiling(unsigned long thresh,
+ unsigned long bg_thresh)
+{
+ return (thresh + bg_thresh) / 2;
+}
+
+static unsigned long hard_dirty_limit(unsigned long thresh)
+{
+ return max(thresh, global_dirty_limit);
+}
+
+/**
+ * bdi_dirty_limit - @bdi's share of dirty throttling threshold
+ * @bdi: the backing_dev_info to query
+ * @dirty: global dirty limit in pages
+ *
+ * Returns @bdi's dirty limit in pages. The term "dirty" in the context of
+ * dirty balancing includes all PG_dirty, PG_writeback and NFS unstable pages.
+ *
+ * Note that balance_dirty_pages() will only seriously take it as a hard limit
+ * when sleeping max_pause per page is not enough to keep the dirty pages under
+ * control. For example, when the device is completely stalled due to some error
+ * conditions, or when there are 1000 dd tasks writing to a slow 10MB/s USB key.
+ * In the other normal situations, it acts more gently by throttling the tasks
+ * more (rather than completely block them) when the bdi dirty pages go high.
+ *
+ * It allocates high/low dirty limits to fast/slow devices, in order to prevent
+ * - starving fast devices
+ * - piling up dirty pages (that will take long time to sync) on slow devices
+ *
+ * The bdi's share of dirty limit will be adapting to its throughput and
+ * bounded by the bdi->min_ratio and/or bdi->max_ratio parameters, if set.
+ */
+unsigned long bdi_dirty_limit(struct backing_dev_info *bdi, unsigned long dirty)
+{
+ u64 bdi_dirty;
+ long numerator, denominator;
+
+ /*
+ * Calculate this BDI's share of the dirty ratio.
+ */
+ bdi_writeout_fraction(bdi, &numerator, &denominator);
+
+ bdi_dirty = (dirty * (100 - bdi_min_ratio)) / 100;
+ bdi_dirty *= numerator;
+ do_div(bdi_dirty, denominator);
+
+ bdi_dirty += (dirty * bdi->min_ratio) / 100;
+ if (bdi_dirty > (dirty * bdi->max_ratio) / 100)
+ bdi_dirty = dirty * bdi->max_ratio / 100;
+
+ return bdi_dirty;
+}
+
+/*
+ * Dirty position control.
+ *
+ * (o) global/bdi setpoints
+ *
+ * We want the dirty pages be balanced around the global/bdi setpoints.
+ * When the number of dirty pages is higher/lower than the setpoint, the
+ * dirty position control ratio (and hence task dirty ratelimit) will be
+ * decreased/increased to bring the dirty pages back to the setpoint.
+ *
+ * pos_ratio = 1 << RATELIMIT_CALC_SHIFT
+ *
+ * if (dirty < setpoint) scale up pos_ratio
+ * if (dirty > setpoint) scale down pos_ratio
+ *
+ * if (bdi_dirty < bdi_setpoint) scale up pos_ratio
+ * if (bdi_dirty > bdi_setpoint) scale down pos_ratio
+ *
+ * task_ratelimit = dirty_ratelimit * pos_ratio >> RATELIMIT_CALC_SHIFT
+ *
+ * (o) global control line
+ *
+ * ^ pos_ratio
+ * |
+ * | |<===== global dirty control scope ======>|
+ * 2.0 .............*
+ * | .*
+ * | . *
+ * | . *
+ * | . *
+ * | . *
+ * | . *
+ * 1.0 ................................*
+ * | . . *
+ * | . . *
+ * | . . *
+ * | . . *
+ * | . . *
+ * 0 +------------.------------------.----------------------*------------->
+ * freerun^ setpoint^ limit^ dirty pages
+ *
+ * (o) bdi control line
+ *
+ * ^ pos_ratio
+ * |
+ * | *
+ * | *
+ * | *
+ * | *
+ * | * |<=========== span ============>|
+ * 1.0 .......................*
+ * | . *
+ * | . *
+ * | . *
+ * | . *
+ * | . *
+ * | . *
+ * | . *
+ * | . *
+ * | . *
+ * | . *
+ * | . *
+ * 1/4 ...............................................* * * * * * * * * * * *
+ * | . .
+ * | . .
+ * | . .
+ * 0 +----------------------.-------------------------------.------------->
+ * bdi_setpoint^ x_intercept^
+ *
+ * The bdi control line won't drop below pos_ratio=1/4, so that bdi_dirty can
+ * be smoothly throttled down to normal if it starts high in situations like
+ * - start writing to a slow SD card and a fast disk at the same time. The SD
+ * card's bdi_dirty may rush to many times higher than bdi_setpoint.
+ * - the bdi dirty thresh drops quickly due to change of JBOD workload
+ */
+static unsigned long bdi_position_ratio(struct backing_dev_info *bdi,
+ unsigned long thresh,
+ unsigned long bg_thresh,
+ unsigned long dirty,
+ unsigned long bdi_thresh,
+ unsigned long bdi_dirty)
+{
+ unsigned long write_bw = bdi->avg_write_bandwidth;
+ unsigned long freerun = dirty_freerun_ceiling(thresh, bg_thresh);
+ unsigned long limit = hard_dirty_limit(thresh);
+ unsigned long x_intercept;
+ unsigned long setpoint; /* dirty pages' target balance point */
+ unsigned long bdi_setpoint;
+ unsigned long span;
+ long long pos_ratio; /* for scaling up/down the rate limit */
+ long x;
+
+ if (unlikely(dirty >= limit))
+ return 0;
+
+ /*
+ * global setpoint
+ *
+ * setpoint - dirty 3
+ * f(dirty) := 1.0 + (----------------)
+ * limit - setpoint
+ *
+ * it's a 3rd order polynomial that subjects to
+ *
+ * (1) f(freerun) = 2.0 => rampup dirty_ratelimit reasonably fast
+ * (2) f(setpoint) = 1.0 => the balance point
+ * (3) f(limit) = 0 => the hard limit
+ * (4) df/dx <= 0 => negative feedback control
+ * (5) the closer to setpoint, the smaller |df/dx| (and the reverse)
+ * => fast response on large errors; small oscillation near setpoint
+ */
+ setpoint = (freerun + limit) / 2;
+ x = div_s64((setpoint - dirty) << RATELIMIT_CALC_SHIFT,
+ limit - setpoint + 1);
+ pos_ratio = x;
+ pos_ratio = pos_ratio * x >> RATELIMIT_CALC_SHIFT;
+ pos_ratio = pos_ratio * x >> RATELIMIT_CALC_SHIFT;
+ pos_ratio += 1 << RATELIMIT_CALC_SHIFT;
+
+ /*
+ * We have computed basic pos_ratio above based on global situation. If
+ * the bdi is over/under its share of dirty pages, we want to scale
+ * pos_ratio further down/up. That is done by the following mechanism.
+ */
+
+ /*
+ * bdi setpoint
+ *
+ * f(bdi_dirty) := 1.0 + k * (bdi_dirty - bdi_setpoint)
+ *
+ * x_intercept - bdi_dirty
+ * := --------------------------
+ * x_intercept - bdi_setpoint
+ *
+ * The main bdi control line is a linear function that subjects to
+ *
+ * (1) f(bdi_setpoint) = 1.0
+ * (2) k = - 1 / (8 * write_bw) (in single bdi case)
+ * or equally: x_intercept = bdi_setpoint + 8 * write_bw
+ *
+ * For single bdi case, the dirty pages are observed to fluctuate
+ * regularly within range
+ * [bdi_setpoint - write_bw/2, bdi_setpoint + write_bw/2]
+ * for various filesystems, where (2) can yield in a reasonable 12.5%
+ * fluctuation range for pos_ratio.
+ *
+ * For JBOD case, bdi_thresh (not bdi_dirty!) could fluctuate up to its
+ * own size, so move the slope over accordingly and choose a slope that
+ * yields 100% pos_ratio fluctuation on suddenly doubled bdi_thresh.
+ */
+ if (unlikely(bdi_thresh > thresh))
+ bdi_thresh = thresh;
+ /*
+ * It's very possible that bdi_thresh is close to 0 not because the
+ * device is slow, but that it has remained inactive for long time.
+ * Honour such devices a reasonable good (hopefully IO efficient)
+ * threshold, so that the occasional writes won't be blocked and active
+ * writes can rampup the threshold quickly.
+ */
+ bdi_thresh = max(bdi_thresh, (limit - dirty) / 8);
+ /*
+ * scale global setpoint to bdi's:
+ * bdi_setpoint = setpoint * bdi_thresh / thresh
+ */
+ x = div_u64((u64)bdi_thresh << 16, thresh | 1);
+ bdi_setpoint = setpoint * (u64)x >> 16;
+ /*
+ * Use span=(8*write_bw) in single bdi case as indicated by
+ * (thresh - bdi_thresh ~= 0) and transit to bdi_thresh in JBOD case.
+ *
+ * bdi_thresh thresh - bdi_thresh
+ * span = ---------- * (8 * write_bw) + ------------------- * bdi_thresh
+ * thresh thresh
+ */
+ span = (thresh - bdi_thresh + 8 * write_bw) * (u64)x >> 16;
+ x_intercept = bdi_setpoint + span;
+
+ if (bdi_dirty < x_intercept - span / 4) {
+ pos_ratio = div_u64(pos_ratio * (x_intercept - bdi_dirty),
+ x_intercept - bdi_setpoint + 1);
+ } else
+ pos_ratio /= 4;
+
+ /*
+ * bdi reserve area, safeguard against dirty pool underrun and disk idle
+ * It may push the desired control point of global dirty pages higher
+ * than setpoint.
+ */
+ x_intercept = bdi_thresh / 2;
+ if (bdi_dirty < x_intercept) {
+ if (bdi_dirty > x_intercept / 8)
+ pos_ratio = div_u64(pos_ratio * x_intercept, bdi_dirty);
+ else
+ pos_ratio *= 8;
+ }
+
+ return pos_ratio;
+}
+
+static void bdi_update_write_bandwidth(struct backing_dev_info *bdi,
+ unsigned long elapsed,
+ unsigned long written)
+{
+ const unsigned long period = roundup_pow_of_two(3 * HZ);
+ unsigned long avg = bdi->avg_write_bandwidth;
+ unsigned long old = bdi->write_bandwidth;
+ u64 bw;
+
+ /*
+ * bw = written * HZ / elapsed
+ *
+ * bw * elapsed + write_bandwidth * (period - elapsed)
+ * write_bandwidth = ---------------------------------------------------
+ * period
+ *
+ * @written may have decreased due to account_page_redirty().
+ * Avoid underflowing @bw calculation.
+ */
+ bw = written - min(written, bdi->written_stamp);
+ bw *= HZ;
+ if (unlikely(elapsed > period)) {
+ do_div(bw, elapsed);
+ avg = bw;
+ goto out;
+ }
+ bw += (u64)bdi->write_bandwidth * (period - elapsed);
+ bw >>= ilog2(period);
+
+ /*
+ * one more level of smoothing, for filtering out sudden spikes
+ */
+ if (avg > old && old >= (unsigned long)bw)
+ avg -= (avg - old) >> 3;
+
+ if (avg < old && old <= (unsigned long)bw)
+ avg += (old - avg) >> 3;
+
+out:
+ bdi->write_bandwidth = bw;
+ bdi->avg_write_bandwidth = avg;
+}
+
+/*
+ * The global dirtyable memory and dirty threshold could be suddenly knocked
+ * down by a large amount (eg. on the startup of KVM in a swapless system).
+ * This may throw the system into deep dirty exceeded state and throttle
+ * heavy/light dirtiers alike. To retain good responsiveness, maintain
+ * global_dirty_limit for tracking slowly down to the knocked down dirty
+ * threshold.
+ */
+static void update_dirty_limit(unsigned long thresh, unsigned long dirty)
+{
+ unsigned long limit = global_dirty_limit;
+
+ /*
+ * Follow up in one step.
+ */
+ if (limit < thresh) {
+ limit = thresh;
+ goto update;
+ }
+
+ /*
+ * Follow down slowly. Use the higher one as the target, because thresh
+ * may drop below dirty. This is exactly the reason to introduce
+ * global_dirty_limit which is guaranteed to lie above the dirty pages.
+ */
+ thresh = max(thresh, dirty);
+ if (limit > thresh) {
+ limit -= (limit - thresh) >> 5;
+ goto update;
+ }
+ return;
+update:
+ global_dirty_limit = limit;
+}
+
+static void global_update_bandwidth(unsigned long thresh,
+ unsigned long dirty,
+ unsigned long now)
+{
+ static DEFINE_SPINLOCK(dirty_lock);
+ static unsigned long update_time = INITIAL_JIFFIES;
+
+ /*
+ * check locklessly first to optimize away locking for the most time
+ */
+ if (time_before(now, update_time + BANDWIDTH_INTERVAL))
+ return;
+
+ spin_lock(&dirty_lock);
+ if (time_after_eq(now, update_time + BANDWIDTH_INTERVAL)) {
+ update_dirty_limit(thresh, dirty);
+ update_time = now;
+ }
+ spin_unlock(&dirty_lock);
+}
+
+/*
+ * Maintain bdi->dirty_ratelimit, the base dirty throttle rate.
+ *
+ * Normal bdi tasks will be curbed at or below it in long term.
+ * Obviously it should be around (write_bw / N) when there are N dd tasks.
+ */
+static void bdi_update_dirty_ratelimit(struct backing_dev_info *bdi,
+ unsigned long thresh,
+ unsigned long bg_thresh,
+ unsigned long dirty,
+ unsigned long bdi_thresh,
+ unsigned long bdi_dirty,
+ unsigned long dirtied,
+ unsigned long elapsed)
+{
+ unsigned long freerun = dirty_freerun_ceiling(thresh, bg_thresh);
+ unsigned long limit = hard_dirty_limit(thresh);
+ unsigned long setpoint = (freerun + limit) / 2;
+ unsigned long write_bw = bdi->avg_write_bandwidth;
+ unsigned long dirty_ratelimit = bdi->dirty_ratelimit;
+ unsigned long dirty_rate;
+ unsigned long task_ratelimit;
+ unsigned long balanced_dirty_ratelimit;
+ unsigned long pos_ratio;
+ unsigned long step;
+ unsigned long x;
+
+ /*
+ * The dirty rate will match the writeout rate in long term, except
+ * when dirty pages are truncated by userspace or re-dirtied by FS.
+ */
+ dirty_rate = (dirtied - bdi->dirtied_stamp) * HZ / elapsed;
+
+ pos_ratio = bdi_position_ratio(bdi, thresh, bg_thresh, dirty,
+ bdi_thresh, bdi_dirty);
+ /*
+ * task_ratelimit reflects each dd's dirty rate for the past 200ms.
+ */
+ task_ratelimit = (u64)dirty_ratelimit *
+ pos_ratio >> RATELIMIT_CALC_SHIFT;
+ task_ratelimit++; /* it helps rampup dirty_ratelimit from tiny values */
+
+ /*
+ * A linear estimation of the "balanced" throttle rate. The theory is,
+ * if there are N dd tasks, each throttled at task_ratelimit, the bdi's
+ * dirty_rate will be measured to be (N * task_ratelimit). So the below
+ * formula will yield the balanced rate limit (write_bw / N).
+ *
+ * Note that the expanded form is not a pure rate feedback:
+ * rate_(i+1) = rate_(i) * (write_bw / dirty_rate) (1)
+ * but also takes pos_ratio into account:
+ * rate_(i+1) = rate_(i) * (write_bw / dirty_rate) * pos_ratio (2)
+ *
+ * (1) is not realistic because pos_ratio also takes part in balancing
+ * the dirty rate. Consider the state
+ * pos_ratio = 0.5 (3)
+ * rate = 2 * (write_bw / N) (4)
+ * If (1) is used, it will stuck in that state! Because each dd will
+ * be throttled at
+ * task_ratelimit = pos_ratio * rate = (write_bw / N) (5)
+ * yielding
+ * dirty_rate = N * task_ratelimit = write_bw (6)
+ * put (6) into (1) we get
+ * rate_(i+1) = rate_(i) (7)
+ *
+ * So we end up using (2) to always keep
+ * rate_(i+1) ~= (write_bw / N) (8)
+ * regardless of the value of pos_ratio. As long as (8) is satisfied,
+ * pos_ratio is able to drive itself to 1.0, which is not only where
+ * the dirty count meet the setpoint, but also where the slope of
+ * pos_ratio is most flat and hence task_ratelimit is least fluctuated.
+ */
+ balanced_dirty_ratelimit = div_u64((u64)task_ratelimit * write_bw,
+ dirty_rate | 1);
+ /*
+ * balanced_dirty_ratelimit ~= (write_bw / N) <= write_bw
+ */
+ if (unlikely(balanced_dirty_ratelimit > write_bw))
+ balanced_dirty_ratelimit = write_bw;
+
+ /*
+ * We could safely do this and return immediately:
+ *
+ * bdi->dirty_ratelimit = balanced_dirty_ratelimit;
+ *
+ * However to get a more stable dirty_ratelimit, the below elaborated
+ * code makes use of task_ratelimit to filter out sigular points and
+ * limit the step size.
+ *
+ * The below code essentially only uses the relative value of
+ *
+ * task_ratelimit - dirty_ratelimit
+ * = (pos_ratio - 1) * dirty_ratelimit
+ *
+ * which reflects the direction and size of dirty position error.
+ */
+
+ /*
+ * dirty_ratelimit will follow balanced_dirty_ratelimit iff
+ * task_ratelimit is on the same side of dirty_ratelimit, too.
+ * For example, when
+ * - dirty_ratelimit > balanced_dirty_ratelimit
+ * - dirty_ratelimit > task_ratelimit (dirty pages are above setpoint)
+ * lowering dirty_ratelimit will help meet both the position and rate
+ * control targets. Otherwise, don't update dirty_ratelimit if it will
+ * only help meet the rate target. After all, what the users ultimately
+ * feel and care are stable dirty rate and small position error.
+ *
+ * |task_ratelimit - dirty_ratelimit| is used to limit the step size
+ * and filter out the sigular points of balanced_dirty_ratelimit. Which
+ * keeps jumping around randomly and can even leap far away at times
+ * due to the small 200ms estimation period of dirty_rate (we want to
+ * keep that period small to reduce time lags).
+ */
+ step = 0;
+ if (dirty < setpoint) {
+ x = min(bdi->balanced_dirty_ratelimit,
+ min(balanced_dirty_ratelimit, task_ratelimit));
+ if (dirty_ratelimit < x)
+ step = x - dirty_ratelimit;
+ } else {
+ x = max(bdi->balanced_dirty_ratelimit,
+ max(balanced_dirty_ratelimit, task_ratelimit));
+ if (dirty_ratelimit > x)
+ step = dirty_ratelimit - x;
+ }
+
+ /*
+ * Don't pursue 100% rate matching. It's impossible since the balanced
+ * rate itself is constantly fluctuating. So decrease the track speed
+ * when it gets close to the target. Helps eliminate pointless tremors.
+ */
+ step >>= dirty_ratelimit / (2 * step + 1);
+ /*
+ * Limit the tracking speed to avoid overshooting.
+ */
+ step = (step + 7) / 8;
+
+ if (dirty_ratelimit < balanced_dirty_ratelimit)
+ dirty_ratelimit += step;
+ else
+ dirty_ratelimit -= step;
+
+ bdi->dirty_ratelimit = max(dirty_ratelimit, 1UL);
+ bdi->balanced_dirty_ratelimit = balanced_dirty_ratelimit;
+
+ trace_bdi_dirty_ratelimit(bdi, dirty_rate, task_ratelimit);
+}
+
+void __bdi_update_bandwidth(struct backing_dev_info *bdi,
+ unsigned long thresh,
+ unsigned long bg_thresh,
+ unsigned long dirty,
+ unsigned long bdi_thresh,
+ unsigned long bdi_dirty,
+ unsigned long start_time)
+{
+ unsigned long now = jiffies;
+ unsigned long elapsed = now - bdi->bw_time_stamp;
+ unsigned long dirtied;
+ unsigned long written;
+
+ /*
+ * rate-limit, only update once every 200ms.
+ */
+ if (elapsed < BANDWIDTH_INTERVAL)
+ return;
+
+ dirtied = percpu_counter_read(&bdi->bdi_stat[BDI_DIRTIED]);
+ written = percpu_counter_read(&bdi->bdi_stat[BDI_WRITTEN]);
+
+ /*
+ * Skip quiet periods when disk bandwidth is under-utilized.
+ * (at least 1s idle time between two flusher runs)
+ */
+ if (elapsed > HZ && time_before(bdi->bw_time_stamp, start_time))
+ goto snapshot;
+
+ if (thresh) {
+ global_update_bandwidth(thresh, dirty, now);
+ bdi_update_dirty_ratelimit(bdi, thresh, bg_thresh, dirty,
+ bdi_thresh, bdi_dirty,
+ dirtied, elapsed);
+ }
+ bdi_update_write_bandwidth(bdi, elapsed, written);
+
+snapshot:
+ bdi->dirtied_stamp = dirtied;
+ bdi->written_stamp = written;
+ bdi->bw_time_stamp = now;
+}
+
+static void bdi_update_bandwidth(struct backing_dev_info *bdi,
+ unsigned long thresh,
+ unsigned long bg_thresh,
+ unsigned long dirty,
+ unsigned long bdi_thresh,
+ unsigned long bdi_dirty,
+ unsigned long start_time)
+{
+ if (time_is_after_eq_jiffies(bdi->bw_time_stamp + BANDWIDTH_INTERVAL))
+ return;
+ spin_lock(&bdi->wb.list_lock);
+ __bdi_update_bandwidth(bdi, thresh, bg_thresh, dirty,
+ bdi_thresh, bdi_dirty, start_time);
+ spin_unlock(&bdi->wb.list_lock);
+}
+
+/*
+ * After a task dirtied this many pages, balance_dirty_pages_ratelimited_nr()
+ * will look to see if it needs to start dirty throttling.
+ *
+ * If dirty_poll_interval is too low, big NUMA machines will call the expensive
+ * global_page_state() too often. So scale it near-sqrt to the safety margin
+ * (the number of pages we may dirty without exceeding the dirty limits).
+ */
+static unsigned long dirty_poll_interval(unsigned long dirty,
+ unsigned long thresh)
+{
+ if (thresh > dirty)
+ return 1UL << (ilog2(thresh - dirty) >> 1);
+
+ return 1;
+}
+
+static unsigned long bdi_max_pause(struct backing_dev_info *bdi,
+ unsigned long bdi_dirty)
+{
+ unsigned long bw = bdi->avg_write_bandwidth;
+ unsigned long t;
+
+ /*
+ * Limit pause time for small memory systems. If sleeping for too long
+ * time, a small pool of dirty/writeback pages may go empty and disk go
+ * idle.
+ *
+ * 8 serves as the safety ratio.
+ */
+ t = bdi_dirty / (1 + bw / roundup_pow_of_two(1 + HZ / 8));
+ t++;
+
+ return min_t(unsigned long, t, MAX_PAUSE);
+}
+
+static long bdi_min_pause(struct backing_dev_info *bdi,
+ long max_pause,
+ unsigned long task_ratelimit,
+ unsigned long dirty_ratelimit,
+ int *nr_dirtied_pause)
+{
+ long hi = ilog2(bdi->avg_write_bandwidth);
+ long lo = ilog2(bdi->dirty_ratelimit);
+ long t; /* target pause */
+ long pause; /* estimated next pause */
+ int pages; /* target nr_dirtied_pause */
+
+ /* target for 10ms pause on 1-dd case */
+ t = max(1, HZ / 100);
+
+ /*
+ * Scale up pause time for concurrent dirtiers in order to reduce CPU
+ * overheads.
+ *
+ * (N * 10ms) on 2^N concurrent tasks.
+ */
+ if (hi > lo)
+ t += (hi - lo) * (10 * HZ) / 1024;
+
+ /*
+ * This is a bit convoluted. We try to base the next nr_dirtied_pause
+ * on the much more stable dirty_ratelimit. However the next pause time
+ * will be computed based on task_ratelimit and the two rate limits may
+ * depart considerably at some time. Especially if task_ratelimit goes
+ * below dirty_ratelimit/2 and the target pause is max_pause, the next
+ * pause time will be max_pause*2 _trimmed down_ to max_pause. As a
+ * result task_ratelimit won't be executed faithfully, which could
+ * eventually bring down dirty_ratelimit.
+ *
+ * We apply two rules to fix it up:
+ * 1) try to estimate the next pause time and if necessary, use a lower
+ * nr_dirtied_pause so as not to exceed max_pause. When this happens,
+ * nr_dirtied_pause will be "dancing" with task_ratelimit.
+ * 2) limit the target pause time to max_pause/2, so that the normal
+ * small fluctuations of task_ratelimit won't trigger rule (1) and
+ * nr_dirtied_pause will remain as stable as dirty_ratelimit.
+ */
+ t = min(t, 1 + max_pause / 2);
+ pages = dirty_ratelimit * t / roundup_pow_of_two(HZ);
+
+ /*
+ * Tiny nr_dirtied_pause is found to hurt I/O performance in the test
+ * case fio-mmap-randwrite-64k, which does 16*{sync read, async write}.
+ * When the 16 consecutive reads are often interrupted by some dirty
+ * throttling pause during the async writes, cfq will go into idles
+ * (deadline is fine). So push nr_dirtied_pause as high as possible
+ * until reaches DIRTY_POLL_THRESH=32 pages.
+ */
+ if (pages < DIRTY_POLL_THRESH) {
+ t = max_pause;
+ pages = dirty_ratelimit * t / roundup_pow_of_two(HZ);
+ if (pages > DIRTY_POLL_THRESH) {
+ pages = DIRTY_POLL_THRESH;
+ t = HZ * DIRTY_POLL_THRESH / dirty_ratelimit;
+ }
+ }
+
+ pause = HZ * pages / (task_ratelimit + 1);
+ if (pause > max_pause) {
+ t = max_pause;
+ pages = task_ratelimit * t / roundup_pow_of_two(HZ);
+ }
+
+ *nr_dirtied_pause = pages;
+ /*
+ * The minimal pause time will normally be half the target pause time.
+ */
+ return pages >= DIRTY_POLL_THRESH ? 1 + t / 2 : t;
+}
+
+/*
+ * balance_dirty_pages() must be called by processes which are generating dirty
+ * data. It looks at the number of dirty pages in the machine and will force
+ * the caller to wait once crossing the (background_thresh + dirty_thresh) / 2.
+ * If we're over `background_thresh' then the writeback threads are woken to
+ * perform some writeout.
+ */
+static void balance_dirty_pages(struct address_space *mapping,
+ unsigned long pages_dirtied)
+{
+ unsigned long nr_reclaimable; /* = file_dirty + unstable_nfs */
+ unsigned long bdi_reclaimable;
+ unsigned long nr_dirty; /* = file_dirty + writeback + unstable_nfs */
+ unsigned long bdi_dirty;
+ unsigned long freerun;
+ unsigned long background_thresh;
+ unsigned long dirty_thresh;
+ unsigned long bdi_thresh;
+ long period;
+ long pause;
+ long max_pause;
+ long min_pause;
+ int nr_dirtied_pause;
+ bool dirty_exceeded = false;
+ unsigned long task_ratelimit;
+ unsigned long dirty_ratelimit;
+ unsigned long pos_ratio;
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
+ unsigned long start_time = jiffies;
+
+ for (;;) {
+ unsigned long now = jiffies;
+
+ /*
+ * Unstable writes are a feature of certain networked
+ * filesystems (i.e. NFS) in which data may have been
+ * written to the server's write cache, but has not yet
+ * been flushed to permanent storage.
+ */
+ nr_reclaimable = global_page_state(NR_FILE_DIRTY) +
+ global_page_state(NR_UNSTABLE_NFS);
+ nr_dirty = nr_reclaimable + global_page_state(NR_WRITEBACK);
+
+ global_dirty_limits(&background_thresh, &dirty_thresh);
+
+ /*
+ * Throttle it only when the background writeback cannot
+ * catch-up. This avoids (excessively) small writeouts
+ * when the bdi limits are ramping up.
+ */
+ freerun = dirty_freerun_ceiling(dirty_thresh,
+ background_thresh);
+ if (nr_dirty <= freerun) {
+ current->dirty_paused_when = now;
+ current->nr_dirtied = 0;
+ current->nr_dirtied_pause =
+ dirty_poll_interval(nr_dirty, dirty_thresh);
+ break;
+ }
+
+ if (unlikely(!writeback_in_progress(bdi)))
+ bdi_start_background_writeback(bdi);
+
+ /*
+ * bdi_thresh is not treated as some limiting factor as
+ * dirty_thresh, due to reasons
+ * - in JBOD setup, bdi_thresh can fluctuate a lot
+ * - in a system with HDD and USB key, the USB key may somehow
+ * go into state (bdi_dirty >> bdi_thresh) either because
+ * bdi_dirty starts high, or because bdi_thresh drops low.
+ * In this case we don't want to hard throttle the USB key
+ * dirtiers for 100 seconds until bdi_dirty drops under
+ * bdi_thresh. Instead the auxiliary bdi control line in
+ * bdi_position_ratio() will let the dirtier task progress
+ * at some rate <= (write_bw / 2) for bringing down bdi_dirty.
+ */
+ bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh);
+
+ /*
+ * In order to avoid the stacked BDI deadlock we need
+ * to ensure we accurately count the 'dirty' pages when
+ * the threshold is low.
+ *
+ * Otherwise it would be possible to get thresh+n pages
+ * reported dirty, even though there are thresh-m pages
+ * actually dirty; with m+n sitting in the percpu
+ * deltas.
+ */
+ if (bdi_thresh < 2 * bdi_stat_error(bdi)) {
+ bdi_reclaimable = bdi_stat_sum(bdi, BDI_RECLAIMABLE);
+ bdi_dirty = bdi_reclaimable +
+ bdi_stat_sum(bdi, BDI_WRITEBACK);
+ } else {
+ bdi_reclaimable = bdi_stat(bdi, BDI_RECLAIMABLE);
+ bdi_dirty = bdi_reclaimable +
+ bdi_stat(bdi, BDI_WRITEBACK);
+ }
+
+ dirty_exceeded = (bdi_dirty > bdi_thresh) &&
+ (nr_dirty > dirty_thresh);
+ if (dirty_exceeded && !bdi->dirty_exceeded)
+ bdi->dirty_exceeded = 1;
+
+ bdi_update_bandwidth(bdi, dirty_thresh, background_thresh,
+ nr_dirty, bdi_thresh, bdi_dirty,
+ start_time);
+
+ dirty_ratelimit = bdi->dirty_ratelimit;
+ pos_ratio = bdi_position_ratio(bdi, dirty_thresh,
+ background_thresh, nr_dirty,
+ bdi_thresh, bdi_dirty);
+ task_ratelimit = ((u64)dirty_ratelimit * pos_ratio) >>
+ RATELIMIT_CALC_SHIFT;
+ max_pause = bdi_max_pause(bdi, bdi_dirty);
+ min_pause = bdi_min_pause(bdi, max_pause,
+ task_ratelimit, dirty_ratelimit,
+ &nr_dirtied_pause);
+
+ if (unlikely(task_ratelimit == 0)) {
+ period = max_pause;
+ pause = max_pause;
+ goto pause;
+ }
+ period = HZ * pages_dirtied / task_ratelimit;
+ pause = period;
+ if (current->dirty_paused_when)
+ pause -= now - current->dirty_paused_when;
+ /*
+ * For less than 1s think time (ext3/4 may block the dirtier
+ * for up to 800ms from time to time on 1-HDD; so does xfs,
+ * however at much less frequency), try to compensate it in
+ * future periods by updating the virtual time; otherwise just
+ * do a reset, as it may be a light dirtier.
+ */
+ if (pause < min_pause) {
+ trace_balance_dirty_pages(bdi,
+ dirty_thresh,
+ background_thresh,
+ nr_dirty,
+ bdi_thresh,
+ bdi_dirty,
+ dirty_ratelimit,
+ task_ratelimit,
+ pages_dirtied,
+ period,
+ min(pause, 0L),
+ start_time);
+ if (pause < -HZ) {
+ current->dirty_paused_when = now;
+ current->nr_dirtied = 0;
+ } else if (period) {
+ current->dirty_paused_when += period;
+ current->nr_dirtied = 0;
+ } else if (current->nr_dirtied_pause <= pages_dirtied)
+ current->nr_dirtied_pause += pages_dirtied;
+ break;
+ }
+ if (unlikely(pause > max_pause)) {
+ /* for occasional dropped task_ratelimit */
+ now += min(pause - max_pause, max_pause);
+ pause = max_pause;
+ }
+
+pause:
+ trace_balance_dirty_pages(bdi,
+ dirty_thresh,
+ background_thresh,
+ nr_dirty,
+ bdi_thresh,
+ bdi_dirty,
+ dirty_ratelimit,
+ task_ratelimit,
+ pages_dirtied,
+ period,
+ pause,
+ start_time);
+ __set_current_state(TASK_KILLABLE);
+ io_schedule_timeout(pause);
+
+ current->dirty_paused_when = now + pause;
+ current->nr_dirtied = 0;
+ current->nr_dirtied_pause = nr_dirtied_pause;
+
+ /*
+ * This is typically equal to (nr_dirty < dirty_thresh) and can
+ * also keep "1000+ dd on a slow USB stick" under control.
+ */
+ if (task_ratelimit)
+ break;
+
+ /*
+ * In the case of an unresponding NFS server and the NFS dirty
+ * pages exceeds dirty_thresh, give the other good bdi's a pipe
+ * to go through, so that tasks on them still remain responsive.
+ *
+ * In theory 1 page is enough to keep the comsumer-producer
+ * pipe going: the flusher cleans 1 page => the task dirties 1
+ * more page. However bdi_dirty has accounting errors. So use
+ * the larger and more IO friendly bdi_stat_error.
+ */
+ if (bdi_dirty <= bdi_stat_error(bdi))
+ break;
+
+ if (fatal_signal_pending(current))
+ break;
+ }
+
+ if (!dirty_exceeded && bdi->dirty_exceeded)
+ bdi->dirty_exceeded = 0;
+
+ if (writeback_in_progress(bdi))
+ return;
+
+ /*
+ * In laptop mode, we wait until hitting the higher threshold before
+ * starting background writeout, and then write out all the way down
+ * to the lower threshold. So slow writers cause minimal disk activity.
+ *
+ * In normal mode, we start background writeout at the lower
+ * background_thresh, to keep the amount of dirty memory low.
+ */
+ if (laptop_mode)
+ return;
+
+ if (nr_reclaimable > background_thresh)
+ bdi_start_background_writeback(bdi);
+}
+
+static DEFINE_PER_CPU(int, bdp_ratelimits);
+
+/*
+ * Normal tasks are throttled by
+ * loop {
+ * dirty tsk->nr_dirtied_pause pages;
+ * take a snap in balance_dirty_pages();
+ * }
+ * However there is a worst case. If every task exit immediately when dirtied
+ * (tsk->nr_dirtied_pause - 1) pages, balance_dirty_pages() will never be
+ * called to throttle the page dirties. The solution is to save the not yet
+ * throttled page dirties in dirty_throttle_leaks on task exit and charge them
+ * randomly into the running tasks. This works well for the above worst case,
+ * as the new task will pick up and accumulate the old task's leaked dirty
+ * count and eventually get throttled.
+ */
+DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0;
+
+/**
+ * balance_dirty_pages_ratelimited_nr - balance dirty memory state
+ * @mapping: address_space which was dirtied
+ * @nr_pages_dirtied: number of pages which the caller has just dirtied
+ *
+ * Processes which are dirtying memory should call in here once for each page
+ * which was newly dirtied. The function will periodically check the system's
+ * dirty state and will initiate writeback if needed.
+ *
+ * On really big machines, get_writeback_state is expensive, so try to avoid
+ * calling it too often (ratelimiting). But once we're over the dirty memory
+ * limit we decrease the ratelimiting by a lot, to prevent individual processes
+ * from overshooting the limit by (ratelimit_pages) each.
+ */
+void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
+ unsigned long nr_pages_dirtied)
+{
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
+ int ratelimit;
+ int *p;
+
+ if (!bdi_cap_account_dirty(bdi))
+ return;
+
+ ratelimit = current->nr_dirtied_pause;
+ if (bdi->dirty_exceeded)
+ ratelimit = min(ratelimit, 32 >> (PAGE_SHIFT - 10));
+
+ preempt_disable();
+ /*
+ * This prevents one CPU to accumulate too many dirtied pages without
+ * calling into balance_dirty_pages(), which can happen when there are
+ * 1000+ tasks, all of them start dirtying pages at exactly the same
+ * time, hence all honoured too large initial task->nr_dirtied_pause.
+ */
+ p = &__get_cpu_var(bdp_ratelimits);
+ if (unlikely(current->nr_dirtied >= ratelimit))
+ *p = 0;
+ else if (unlikely(*p >= ratelimit_pages)) {
+ *p = 0;
+ ratelimit = 0;
+ }
+ /*
+ * Pick up the dirtied pages by the exited tasks. This avoids lots of
+ * short-lived tasks (eg. gcc invocations in a kernel build) escaping
+ * the dirty throttling and livelock other long-run dirtiers.
+ */
+ p = &__get_cpu_var(dirty_throttle_leaks);
+ if (*p > 0 && current->nr_dirtied < ratelimit) {
+ nr_pages_dirtied = min(*p, ratelimit - current->nr_dirtied);
+ *p -= nr_pages_dirtied;
+ current->nr_dirtied += nr_pages_dirtied;
+ }
+ preempt_enable();
+
+ if (unlikely(current->nr_dirtied >= ratelimit))
+ balance_dirty_pages(mapping, current->nr_dirtied);
+}
+EXPORT_SYMBOL(balance_dirty_pages_ratelimited_nr);
+
+void throttle_vm_writeout(gfp_t gfp_mask)
+{
+ unsigned long background_thresh;
+ unsigned long dirty_thresh;
+
+ for ( ; ; ) {
+ global_dirty_limits(&background_thresh, &dirty_thresh);
+ dirty_thresh = hard_dirty_limit(dirty_thresh);
+
+ /*
+ * Boost the allowable dirty threshold a bit for page
+ * allocators so they don't get DoS'ed by heavy writers
+ */
+ dirty_thresh += dirty_thresh / 10; /* wheeee... */
+
+ if (global_page_state(NR_UNSTABLE_NFS) +
+ global_page_state(NR_WRITEBACK) <= dirty_thresh)
+ break;
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+
+ /*
+ * The caller might hold locks which can prevent IO completion
+ * or progress in the filesystem. So we cannot just sit here
+ * waiting for IO to complete.
+ */
+ if ((gfp_mask & (__GFP_FS|__GFP_IO)) != (__GFP_FS|__GFP_IO))
+ break;
+ }
+}
+
+/*
+ * sysctl handler for /proc/sys/vm/dirty_writeback_centisecs
+ */
+int dirty_writeback_centisecs_handler(ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ proc_dointvec(table, write, buffer, length, ppos);
+ bdi_arm_supers_timer();
+ return 0;
+}
+
+#ifdef CONFIG_BLOCK
+void laptop_mode_timer_fn(unsigned long data)
+{
+ struct request_queue *q = (struct request_queue *)data;
+ int nr_pages = global_page_state(NR_FILE_DIRTY) +
+ global_page_state(NR_UNSTABLE_NFS);
+
+ /*
+ * We want to write everything out, not just down to the dirty
+ * threshold
+ */
+ if (bdi_has_dirty_io(&q->backing_dev_info))
+ bdi_start_writeback(&q->backing_dev_info, nr_pages,
+ WB_REASON_LAPTOP_TIMER);
+}
+
+/*
+ * We've spun up the disk and we're in laptop mode: schedule writeback
+ * of all dirty data a few seconds from now. If the flush is already scheduled
+ * then push it back - the user is still using the disk.
+ */
+void laptop_io_completion(struct backing_dev_info *info)
+{
+ mod_timer(&info->laptop_mode_wb_timer, jiffies + laptop_mode);
+}
+
+/*
+ * We're in laptop mode and we've just synced. The sync's writes will have
+ * caused another writeback to be scheduled by laptop_io_completion.
+ * Nothing needs to be written back anymore, so we unschedule the writeback.
+ */
+void laptop_sync_completion(void)
+{
+ struct backing_dev_info *bdi;
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(bdi, &bdi_list, bdi_list)
+ del_timer(&bdi->laptop_mode_wb_timer);
+
+ rcu_read_unlock();
+}
+#endif
+
+/*
+ * If ratelimit_pages is too high then we can get into dirty-data overload
+ * if a large number of processes all perform writes at the same time.
+ * If it is too low then SMP machines will call the (expensive)
+ * get_writeback_state too often.
+ *
+ * Here we set ratelimit_pages to a level which ensures that when all CPUs are
+ * dirtying in parallel, we cannot go more than 3% (1/32) over the dirty memory
+ * thresholds.
+ */
+
+void writeback_set_ratelimit(void)
+{
+ unsigned long background_thresh;
+ unsigned long dirty_thresh;
+ global_dirty_limits(&background_thresh, &dirty_thresh);
+ ratelimit_pages = dirty_thresh / (num_online_cpus() * 32);
+ if (ratelimit_pages < 16)
+ ratelimit_pages = 16;
+}
+
+static int __cpuinit
+ratelimit_handler(struct notifier_block *self, unsigned long u, void *v)
+{
+ writeback_set_ratelimit();
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block __cpuinitdata ratelimit_nb = {
+ .notifier_call = ratelimit_handler,
+ .next = NULL,
+};
+
+/*
+ * Called early on to tune the page writeback dirty limits.
+ *
+ * We used to scale dirty pages according to how total memory
+ * related to pages that could be allocated for buffers (by
+ * comparing nr_free_buffer_pages() to vm_total_pages.
+ *
+ * However, that was when we used "dirty_ratio" to scale with
+ * all memory, and we don't do that any more. "dirty_ratio"
+ * is now applied to total non-HIGHPAGE memory (by subtracting
+ * totalhigh_pages from vm_total_pages), and as such we can't
+ * get into the old insane situation any more where we had
+ * large amounts of dirty pages compared to a small amount of
+ * non-HIGHMEM memory.
+ *
+ * But we might still want to scale the dirty_ratio by how
+ * much memory the box has..
+ */
+void __init page_writeback_init(void)
+{
+ int shift;
+
+ writeback_set_ratelimit();
+ register_cpu_notifier(&ratelimit_nb);
+
+ shift = calc_period_shift();
+ prop_descriptor_init(&vm_completions, shift);
+}
+
+/**
+ * tag_pages_for_writeback - tag pages to be written by write_cache_pages
+ * @mapping: address space structure to write
+ * @start: starting page index
+ * @end: ending page index (inclusive)
+ *
+ * This function scans the page range from @start to @end (inclusive) and tags
+ * all pages that have DIRTY tag set with a special TOWRITE tag. The idea is
+ * that write_cache_pages (or whoever calls this function) will then use
+ * TOWRITE tag to identify pages eligible for writeback. This mechanism is
+ * used to avoid livelocking of writeback by a process steadily creating new
+ * dirty pages in the file (thus it is important for this function to be quick
+ * so that it can tag pages faster than a dirtying process can create them).
+ */
+/*
+ * We tag pages in batches of WRITEBACK_TAG_BATCH to reduce tree_lock latency.
+ */
+void tag_pages_for_writeback(struct address_space *mapping,
+ pgoff_t start, pgoff_t end)
+{
+#define WRITEBACK_TAG_BATCH 4096
+ unsigned long tagged;
+
+ do {
+ spin_lock_irq(&mapping->tree_lock);
+ tagged = radix_tree_range_tag_if_tagged(&mapping->page_tree,
+ &start, end, WRITEBACK_TAG_BATCH,
+ PAGECACHE_TAG_DIRTY, PAGECACHE_TAG_TOWRITE);
+ spin_unlock_irq(&mapping->tree_lock);
+ WARN_ON_ONCE(tagged > WRITEBACK_TAG_BATCH);
+ cond_resched();
+ /* We check 'start' to handle wrapping when end == ~0UL */
+ } while (tagged >= WRITEBACK_TAG_BATCH && start);
+}
+EXPORT_SYMBOL(tag_pages_for_writeback);
+
+/**
+ * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
+ * @mapping: address space structure to write
+ * @wbc: subtract the number of written pages from *@wbc->nr_to_write
+ * @writepage: function called for each page
+ * @data: data passed to writepage function
+ *
+ * If a page is already under I/O, write_cache_pages() skips it, even
+ * if it's dirty. This is desirable behaviour for memory-cleaning writeback,
+ * but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
+ * and msync() need to guarantee that all the data which was dirty at the time
+ * the call was made get new I/O started against them. If wbc->sync_mode is
+ * WB_SYNC_ALL then we were called for data integrity and we must wait for
+ * existing IO to complete.
+ *
+ * To avoid livelocks (when other process dirties new pages), we first tag
+ * pages which should be written back with TOWRITE tag and only then start
+ * writing them. For data-integrity sync we have to be careful so that we do
+ * not miss some pages (e.g., because some other process has cleared TOWRITE
+ * tag we set). The rule we follow is that TOWRITE tag can be cleared only
+ * by the process clearing the DIRTY tag (and submitting the page for IO).
+ */
+int write_cache_pages(struct address_space *mapping,
+ struct writeback_control *wbc, writepage_t writepage,
+ void *data)
+{
+ int ret = 0;
+ int done = 0;
+ struct pagevec pvec;
+ int nr_pages;
+ pgoff_t uninitialized_var(writeback_index);
+ pgoff_t index;
+ pgoff_t end; /* Inclusive */
+ pgoff_t done_index;
+ int cycled;
+ int range_whole = 0;
+ int tag;
+
+ pagevec_init(&pvec, 0);
+ if (wbc->range_cyclic) {
+ writeback_index = mapping->writeback_index; /* prev offset */
+ index = writeback_index;
+ if (index == 0)
+ cycled = 1;
+ else
+ cycled = 0;
+ end = -1;
+ } else {
+ index = wbc->range_start >> PAGE_CACHE_SHIFT;
+ end = wbc->range_end >> PAGE_CACHE_SHIFT;
+ if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
+ range_whole = 1;
+ cycled = 1; /* ignore range_cyclic tests */
+ }
+ if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
+ tag = PAGECACHE_TAG_TOWRITE;
+ else
+ tag = PAGECACHE_TAG_DIRTY;
+retry:
+ if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
+ tag_pages_for_writeback(mapping, index, end);
+ done_index = index;
+ while (!done && (index <= end)) {
+ int i;
+
+ nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+ if (nr_pages == 0)
+ break;
+
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page = pvec.pages[i];
+
+ /*
+ * At this point, the page may be truncated or
+ * invalidated (changing page->mapping to NULL), or
+ * even swizzled back from swapper_space to tmpfs file
+ * mapping. However, page->index will not change
+ * because we have a reference on the page.
+ */
+ if (page->index > end) {
+ /*
+ * can't be range_cyclic (1st pass) because
+ * end == -1 in that case.
+ */
+ done = 1;
+ break;
+ }
+
+ done_index = page->index;
+
+ lock_page(page);
+
+ /*
+ * Page truncated or invalidated. We can freely skip it
+ * then, even for data integrity operations: the page
+ * has disappeared concurrently, so there could be no
+ * real expectation of this data interity operation
+ * even if there is now a new, dirty page at the same
+ * pagecache address.
+ */
+ if (unlikely(page->mapping != mapping)) {
+continue_unlock:
+ unlock_page(page);
+ continue;
+ }
+
+ if (!PageDirty(page)) {
+ /* someone wrote it for us */
+ goto continue_unlock;
+ }
+
+ if (PageWriteback(page)) {
+ if (wbc->sync_mode != WB_SYNC_NONE)
+ wait_on_page_writeback(page);
+ else
+ goto continue_unlock;
+ }
+
+ BUG_ON(PageWriteback(page));
+ if (!clear_page_dirty_for_io(page))
+ goto continue_unlock;
+
+ trace_wbc_writepage(wbc, mapping->backing_dev_info);
+ ret = (*writepage)(page, wbc, data);
+ if (unlikely(ret)) {
+ if (ret == AOP_WRITEPAGE_ACTIVATE) {
+ unlock_page(page);
+ ret = 0;
+ } else {
+ /*
+ * done_index is set past this page,
+ * so media errors will not choke
+ * background writeout for the entire
+ * file. This has consequences for
+ * range_cyclic semantics (ie. it may
+ * not be suitable for data integrity
+ * writeout).
+ */
+ done_index = page->index + 1;
+ done = 1;
+ break;
+ }
+ }
+
+ /*
+ * We stop writing back only if we are not doing
+ * integrity sync. In case of integrity sync we have to
+ * keep going until we have written all the pages
+ * we tagged for writeback prior to entering this loop.
+ */
+ if (--wbc->nr_to_write <= 0 &&
+ wbc->sync_mode == WB_SYNC_NONE) {
+ done = 1;
+ break;
+ }
+ }
+ pagevec_release(&pvec);
+ cond_resched();
+ }
+ if (!cycled && !done) {
+ /*
+ * range_cyclic:
+ * We hit the last page and there is more work to be done: wrap
+ * back to the start of the file
+ */
+ cycled = 1;
+ index = 0;
+ end = writeback_index - 1;
+ goto retry;
+ }
+ if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
+ mapping->writeback_index = done_index;
+
+ return ret;
+}
+EXPORT_SYMBOL(write_cache_pages);
+
+/*
+ * Function used by generic_writepages to call the real writepage
+ * function and set the mapping flags on error
+ */
+static int __writepage(struct page *page, struct writeback_control *wbc,
+ void *data)
+{
+ struct address_space *mapping = data;
+ int ret = mapping->a_ops->writepage(page, wbc);
+ mapping_set_error(mapping, ret);
+ return ret;
+}
+
+/**
+ * generic_writepages - walk the list of dirty pages of the given address space and writepage() all of them.
+ * @mapping: address space structure to write
+ * @wbc: subtract the number of written pages from *@wbc->nr_to_write
+ *
+ * This is a library function, which implements the writepages()
+ * address_space_operation.
+ */
+int generic_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct blk_plug plug;
+ int ret;
+
+ /* deal with chardevs and other special file */
+ if (!mapping->a_ops->writepage)
+ return 0;
+
+ blk_start_plug(&plug);
+ ret = write_cache_pages(mapping, wbc, __writepage, mapping);
+ blk_finish_plug(&plug);
+ return ret;
+}
+
+EXPORT_SYMBOL(generic_writepages);
+
+int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+ int ret;
+
+ if (wbc->nr_to_write <= 0)
+ return 0;
+ if (mapping->a_ops->writepages)
+ ret = mapping->a_ops->writepages(mapping, wbc);
+ else
+ ret = generic_writepages(mapping, wbc);
+ return ret;
+}
+
+/**
+ * write_one_page - write out a single page and optionally wait on I/O
+ * @page: the page to write
+ * @wait: if true, wait on writeout
+ *
+ * The page must be locked by the caller and will be unlocked upon return.
+ *
+ * write_one_page() returns a negative error code if I/O failed.
+ */
+int write_one_page(struct page *page, int wait)
+{
+ struct address_space *mapping = page->mapping;
+ int ret = 0;
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_ALL,
+ .nr_to_write = 1,
+ };
+
+ BUG_ON(!PageLocked(page));
+
+ if (wait)
+ wait_on_page_writeback(page);
+
+ if (clear_page_dirty_for_io(page)) {
+ page_cache_get(page);
+ ret = mapping->a_ops->writepage(page, &wbc);
+ if (ret == 0 && wait) {
+ wait_on_page_writeback(page);
+ if (PageError(page))
+ ret = -EIO;
+ }
+ page_cache_release(page);
+ } else {
+ unlock_page(page);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(write_one_page);
+
+/*
+ * For address_spaces which do not use buffers nor write back.
+ */
+int __set_page_dirty_no_writeback(struct page *page)
+{
+ if (!PageDirty(page))
+ return !TestSetPageDirty(page);
+ return 0;
+}
+
+/*
+ * Helper function for set_page_dirty family.
+ * NOTE: This relies on being atomic wrt interrupts.
+ */
+void account_page_dirtied(struct page *page, struct address_space *mapping)
+{
+ if (mapping_cap_account_dirty(mapping)) {
+ __inc_zone_page_state(page, NR_FILE_DIRTY);
+ __inc_zone_page_state(page, NR_DIRTIED);
+ __inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
+ __inc_bdi_stat(mapping->backing_dev_info, BDI_DIRTIED);
+ task_io_account_write(PAGE_CACHE_SIZE);
+ current->nr_dirtied++;
+ this_cpu_inc(bdp_ratelimits);
+ }
+}
+EXPORT_SYMBOL(account_page_dirtied);
+
+/*
+ * Helper function for set_page_writeback family.
+ * NOTE: Unlike account_page_dirtied this does not rely on being atomic
+ * wrt interrupts.
+ */
+void account_page_writeback(struct page *page)
+{
+ inc_zone_page_state(page, NR_WRITEBACK);
+}
+EXPORT_SYMBOL(account_page_writeback);
+
+/*
+ * For address_spaces which do not use buffers. Just tag the page as dirty in
+ * its radix tree.
+ *
+ * This is also used when a single buffer is being dirtied: we want to set the
+ * page dirty in that case, but not all the buffers. This is a "bottom-up"
+ * dirtying, whereas __set_page_dirty_buffers() is a "top-down" dirtying.
+ *
+ * The caller must ensure this doesn't race with truncation. Most will simply
+ * hold the page lock, but e.g. zap_pte_range() calls with the page mapped and
+ * the pte lock held, which also locks out truncat
+ */
+int __set_page_dirty_nobuffers(struct page *page)
+{
+ if (!TestSetPageDirty(page)) {
+ struct address_space *mapping = page_mapping(page);
+ unsigned long flags;
+
+ if (!mapping)
+ return 1;
+
+ spin_lock_irqsave(&mapping->tree_lock, flags);
+ BUG_ON(page_mapping(page) != mapping);
+ WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page));
+ account_page_dirtied(page, mapping);
+ radix_tree_tag_set(&mapping->page_tree, page_index(page),
+ PAGECACHE_TAG_DIRTY);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ if (mapping->host) {
+ /* !PageAnon && !swapper_space */
+ __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
+ }
+ return 1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(__set_page_dirty_nobuffers);
+
+/*
+ * Call this whenever redirtying a page, to de-account the dirty counters
+ * (NR_DIRTIED, BDI_DIRTIED, tsk->nr_dirtied), so that they match the written
+ * counters (NR_WRITTEN, BDI_WRITTEN) in long term. The mismatches will lead to
+ * systematic errors in balanced_dirty_ratelimit and the dirty pages position
+ * control.
+ */
+void account_page_redirty(struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+ if (mapping && mapping_cap_account_dirty(mapping)) {
+ current->nr_dirtied--;
+ dec_zone_page_state(page, NR_DIRTIED);
+ dec_bdi_stat(mapping->backing_dev_info, BDI_DIRTIED);
+ }
+}
+EXPORT_SYMBOL(account_page_redirty);
+
+/*
+ * When a writepage implementation decides that it doesn't want to write this
+ * page for some reason, it should redirty the locked page via
+ * redirty_page_for_writepage() and it should then unlock the page and return 0
+ */
+int redirty_page_for_writepage(struct writeback_control *wbc, struct page *page)
+{
+ wbc->pages_skipped++;
+ account_page_redirty(page);
+ return __set_page_dirty_nobuffers(page);
+}
+EXPORT_SYMBOL(redirty_page_for_writepage);
+
+/*
+ * Dirty a page.
+ *
+ * For pages with a mapping this should be done under the page lock
+ * for the benefit of asynchronous memory errors who prefer a consistent
+ * dirty state. This rule can be broken in some special cases,
+ * but should be better not to.
+ *
+ * If the mapping doesn't provide a set_page_dirty a_op, then
+ * just fall through and assume that it wants buffer_heads.
+ */
+int set_page_dirty(struct page *page)
+{
+ struct address_space *mapping = page_mapping(page);
+
+ if (likely(mapping)) {
+ int (*spd)(struct page *) = mapping->a_ops->set_page_dirty;
+ /*
+ * readahead/lru_deactivate_page could remain
+ * PG_readahead/PG_reclaim due to race with end_page_writeback
+ * About readahead, if the page is written, the flags would be
+ * reset. So no problem.
+ * About lru_deactivate_page, if the page is redirty, the flag
+ * will be reset. So no problem. but if the page is used by readahead
+ * it will confuse readahead and make it restart the size rampup
+ * process. But it's a trivial problem.
+ */
+ ClearPageReclaim(page);
+#ifdef CONFIG_BLOCK
+ if (!spd)
+ spd = __set_page_dirty_buffers;
+#endif
+ return (*spd)(page);
+ }
+ if (!PageDirty(page)) {
+ if (!TestSetPageDirty(page))
+ return 1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(set_page_dirty);
+
+/*
+ * set_page_dirty() is racy if the caller has no reference against
+ * page->mapping->host, and if the page is unlocked. This is because another
+ * CPU could truncate the page off the mapping and then free the mapping.
+ *
+ * Usually, the page _is_ locked, or the caller is a user-space process which
+ * holds a reference on the inode by having an open file.
+ *
+ * In other cases, the page should be locked before running set_page_dirty().
+ */
+int set_page_dirty_lock(struct page *page)
+{
+ int ret;
+
+ lock_page(page);
+ ret = set_page_dirty(page);
+ unlock_page(page);
+ return ret;
+}
+EXPORT_SYMBOL(set_page_dirty_lock);
+
+/*
+ * Clear a page's dirty flag, while caring for dirty memory accounting.
+ * Returns true if the page was previously dirty.
+ *
+ * This is for preparing to put the page under writeout. We leave the page
+ * tagged as dirty in the radix tree so that a concurrent write-for-sync
+ * can discover it via a PAGECACHE_TAG_DIRTY walk. The ->writepage
+ * implementation will run either set_page_writeback() or set_page_dirty(),
+ * at which stage we bring the page's dirty flag and radix-tree dirty tag
+ * back into sync.
+ *
+ * This incoherency between the page's dirty flag and radix-tree tag is
+ * unfortunate, but it only exists while the page is locked.
+ */
+int clear_page_dirty_for_io(struct page *page)
+{
+ struct address_space *mapping = page_mapping(page);
+
+ BUG_ON(!PageLocked(page));
+
+ if (mapping && mapping_cap_account_dirty(mapping)) {
+ /*
+ * Yes, Virginia, this is indeed insane.
+ *
+ * We use this sequence to make sure that
+ * (a) we account for dirty stats properly
+ * (b) we tell the low-level filesystem to
+ * mark the whole page dirty if it was
+ * dirty in a pagetable. Only to then
+ * (c) clean the page again and return 1 to
+ * cause the writeback.
+ *
+ * This way we avoid all nasty races with the
+ * dirty bit in multiple places and clearing
+ * them concurrently from different threads.
+ *
+ * Note! Normally the "set_page_dirty(page)"
+ * has no effect on the actual dirty bit - since
+ * that will already usually be set. But we
+ * need the side effects, and it can help us
+ * avoid races.
+ *
+ * We basically use the page "master dirty bit"
+ * as a serialization point for all the different
+ * threads doing their things.
+ */
+ if (page_mkclean(page))
+ set_page_dirty(page);
+ /*
+ * We carefully synchronise fault handlers against
+ * installing a dirty pte and marking the page dirty
+ * at this point. We do this by having them hold the
+ * page lock while dirtying the page, and pages are
+ * always locked coming in here, so we get the desired
+ * exclusion.
+ */
+ if (TestClearPageDirty(page)) {
+ dec_zone_page_state(page, NR_FILE_DIRTY);
+ dec_bdi_stat(mapping->backing_dev_info,
+ BDI_RECLAIMABLE);
+ return 1;
+ }
+ return 0;
+ }
+ return TestClearPageDirty(page);
+}
+EXPORT_SYMBOL(clear_page_dirty_for_io);
+
+int test_clear_page_writeback(struct page *page)
+{
+ struct address_space *mapping = page_mapping(page);
+ int ret;
+
+ if (mapping) {
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
+ unsigned long flags;
+
+ spin_lock_irqsave(&mapping->tree_lock, flags);
+ ret = TestClearPageWriteback(page);
+ if (ret) {
+ radix_tree_tag_clear(&mapping->page_tree,
+ page_index(page),
+ PAGECACHE_TAG_WRITEBACK);
+ if (bdi_cap_account_writeback(bdi)) {
+ __dec_bdi_stat(bdi, BDI_WRITEBACK);
+ __bdi_writeout_inc(bdi);
+ }
+ }
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ } else {
+ ret = TestClearPageWriteback(page);
+ }
+ if (ret) {
+ dec_zone_page_state(page, NR_WRITEBACK);
+ inc_zone_page_state(page, NR_WRITTEN);
+ }
+ return ret;
+}
+
+int test_set_page_writeback(struct page *page)
+{
+ struct address_space *mapping = page_mapping(page);
+ int ret;
+
+ if (mapping) {
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
+ unsigned long flags;
+
+ spin_lock_irqsave(&mapping->tree_lock, flags);
+ ret = TestSetPageWriteback(page);
+ if (!ret) {
+ radix_tree_tag_set(&mapping->page_tree,
+ page_index(page),
+ PAGECACHE_TAG_WRITEBACK);
+ if (bdi_cap_account_writeback(bdi))
+ __inc_bdi_stat(bdi, BDI_WRITEBACK);
+ }
+ if (!PageDirty(page))
+ radix_tree_tag_clear(&mapping->page_tree,
+ page_index(page),
+ PAGECACHE_TAG_DIRTY);
+ radix_tree_tag_clear(&mapping->page_tree,
+ page_index(page),
+ PAGECACHE_TAG_TOWRITE);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ } else {
+ ret = TestSetPageWriteback(page);
+ }
+ if (!ret)
+ account_page_writeback(page);
+ return ret;
+
+}
+EXPORT_SYMBOL(test_set_page_writeback);
+
+/*
+ * Return true if any of the pages in the mapping are marked with the
+ * passed tag.
+ */
+int mapping_tagged(struct address_space *mapping, int tag)
+{
+ return radix_tree_tagged(&mapping->page_tree, tag);
+}
+EXPORT_SYMBOL(mapping_tagged);
diff --git a/ap/os/linux/linux-3.4.x/mm/page_alloc.c b/ap/os/linux/linux-3.4.x/mm/page_alloc.c
new file mode 100755
index 0000000..6a391d4
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/page_alloc.c
@@ -0,0 +1,5844 @@
+/*
+ * linux/mm/page_alloc.c
+ *
+ * Manages the free list, the system allocates free pages here.
+ * Note that kmalloc() lives in slab.c
+ *
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ * Swap reorganised 29.12.95, Stephen Tweedie
+ * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
+ * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
+ * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
+ * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
+ * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
+ * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
+ */
+
+#include <linux/stddef.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/interrupt.h>
+#include <linux/pagemap.h>
+#include <linux/jiffies.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/kmemcheck.h>
+#include <linux/module.h>
+#include <linux/suspend.h>
+#include <linux/pagevec.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include <linux/ratelimit.h>
+#include <linux/oom.h>
+#include <linux/notifier.h>
+#include <linux/topology.h>
+#include <linux/sysctl.h>
+#include <linux/cpu.h>
+#include <linux/cpuset.h>
+#include <linux/memory_hotplug.h>
+#include <linux/nodemask.h>
+#include <linux/vmalloc.h>
+#include <linux/vmstat.h>
+#include <linux/mempolicy.h>
+#include <linux/stop_machine.h>
+#include <linux/sort.h>
+#include <linux/pfn.h>
+#include <linux/backing-dev.h>
+#include <linux/fault-inject.h>
+#include <linux/page-isolation.h>
+#include <linux/page_cgroup.h>
+#include <linux/debugobjects.h>
+#include <linux/kmemleak.h>
+#include <linux/memory.h>
+#include <linux/compaction.h>
+#include <trace/events/kmem.h>
+#include <linux/ftrace_event.h>
+#include <linux/memcontrol.h>
+#include <linux/prefetch.h>
+#include <linux/locallock.h>
+#include <linux/page-debug-flags.h>
+
+#include <asm/tlbflush.h>
+#include <asm/div64.h>
+#include "internal.h"
+#ifdef CONFIG_MEM_TRACKER
+#include <linux/mem_tracker_def.h>
+#endif
+
+
+#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
+DEFINE_PER_CPU(int, numa_node);
+EXPORT_PER_CPU_SYMBOL(numa_node);
+#endif
+
+#ifdef CONFIG_HAVE_MEMORYLESS_NODES
+/*
+ * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
+ * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
+ * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
+ * defined in <linux/topology.h>.
+ */
+DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
+EXPORT_PER_CPU_SYMBOL(_numa_mem_);
+#endif
+
+/*
+ * Array of node states.
+ */
+nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
+ [N_POSSIBLE] = NODE_MASK_ALL,
+ [N_ONLINE] = { { [0] = 1UL } },
+#ifndef CONFIG_NUMA
+ [N_NORMAL_MEMORY] = { { [0] = 1UL } },
+#ifdef CONFIG_HIGHMEM
+ [N_HIGH_MEMORY] = { { [0] = 1UL } },
+#endif
+ [N_CPU] = { { [0] = 1UL } },
+#endif /* NUMA */
+};
+EXPORT_SYMBOL(node_states);
+
+unsigned long totalram_pages __read_mostly;
+unsigned long totalreserve_pages __read_mostly;
+/*
+ * When calculating the number of globally allowed dirty pages, there
+ * is a certain number of per-zone reserves that should not be
+ * considered dirtyable memory. This is the sum of those reserves
+ * over all existing zones that contribute dirtyable memory.
+ */
+unsigned long dirty_balance_reserve __read_mostly;
+
+int percpu_pagelist_fraction;
+gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
+
+#ifdef CONFIG_PM_SLEEP
+/*
+ * The following functions are used by the suspend/hibernate code to temporarily
+ * change gfp_allowed_mask in order to avoid using I/O during memory allocations
+ * while devices are suspended. To avoid races with the suspend/hibernate code,
+ * they should always be called with pm_mutex held (gfp_allowed_mask also should
+ * only be modified with pm_mutex held, unless the suspend/hibernate code is
+ * guaranteed not to run in parallel with that modification).
+ */
+
+static gfp_t saved_gfp_mask;
+
+void pm_restore_gfp_mask(void)
+{
+ WARN_ON(!mutex_is_locked(&pm_mutex));
+ if (saved_gfp_mask) {
+ gfp_allowed_mask = saved_gfp_mask;
+ saved_gfp_mask = 0;
+ }
+}
+
+void pm_restrict_gfp_mask(void)
+{
+ WARN_ON(!mutex_is_locked(&pm_mutex));
+ WARN_ON(saved_gfp_mask);
+ saved_gfp_mask = gfp_allowed_mask;
+ gfp_allowed_mask &= ~GFP_IOFS;
+}
+
+bool pm_suspended_storage(void)
+{
+ if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
+ return false;
+ return true;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
+int pageblock_order __read_mostly;
+#endif
+
+static void __free_pages_ok(struct page *page, unsigned int order);
+
+/* ratio of page cache in whole memory */
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+int sysctl_pagecache_ratio = 8;
+unsigned long pagecache_alloc_failed;
+#endif
+/*
+ * results with 256, 32 in the lowmem_reserve sysctl:
+ * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
+ * 1G machine -> (16M dma, 784M normal, 224M high)
+ * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
+ * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
+ * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
+ *
+ * TBD: should special case ZONE_DMA32 machines here - in those we normally
+ * don't need any ZONE_NORMAL reservation
+ */
+int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
+#ifdef CONFIG_ZONE_DMA
+ 256,
+#endif
+#ifdef CONFIG_ZONE_DMA32
+ 256,
+#endif
+#ifdef CONFIG_HIGHMEM
+ 32,
+#endif
+ 32,
+};
+
+EXPORT_SYMBOL(totalram_pages);
+
+static char * const zone_names[MAX_NR_ZONES] = {
+#ifdef CONFIG_ZONE_DMA
+ "DMA",
+#endif
+#ifdef CONFIG_ZONE_DMA32
+ "DMA32",
+#endif
+ "Normal",
+#ifdef CONFIG_HIGHMEM
+ "HighMem",
+#endif
+ "Movable",
+};
+
+int min_free_kbytes = 1024;
+unsigned long wm_min_pages = 0; // 记录watermark min 值
+int min_free_order_shift = 1;
+
+static unsigned long __meminitdata nr_kernel_pages;
+static unsigned long __meminitdata nr_all_pages;
+static unsigned long __meminitdata dma_reserve;
+
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
+static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
+static unsigned long __initdata required_kernelcore;
+static unsigned long __initdata required_movablecore;
+static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
+
+/* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
+int movable_zone;
+EXPORT_SYMBOL(movable_zone);
+#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
+
+#if MAX_NUMNODES > 1
+int nr_node_ids __read_mostly = MAX_NUMNODES;
+int nr_online_nodes __read_mostly = 1;
+EXPORT_SYMBOL(nr_node_ids);
+EXPORT_SYMBOL(nr_online_nodes);
+#endif
+
+static DEFINE_LOCAL_IRQ_LOCK(pa_lock);
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define cpu_lock_irqsave(cpu, flags) \
+ local_lock_irqsave_on(pa_lock, flags, cpu)
+# define cpu_unlock_irqrestore(cpu, flags) \
+ local_unlock_irqrestore_on(pa_lock, flags, cpu)
+#else
+# define cpu_lock_irqsave(cpu, flags) local_irq_save(flags)
+# define cpu_unlock_irqrestore(cpu, flags) local_irq_restore(flags)
+#endif
+
+int page_group_by_mobility_disabled __read_mostly;
+
+static void set_pageblock_migratetype(struct page *page, int migratetype)
+{
+
+ if (unlikely(page_group_by_mobility_disabled))
+ migratetype = MIGRATE_UNMOVABLE;
+
+ set_pageblock_flags_group(page, (unsigned long)migratetype,
+ PB_migrate, PB_migrate_end);
+}
+
+bool oom_killer_disabled __read_mostly;
+
+#ifdef CONFIG_DEBUG_VM
+static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
+{
+ int ret = 0;
+ unsigned seq;
+ unsigned long pfn = page_to_pfn(page);
+
+ do {
+ seq = zone_span_seqbegin(zone);
+ if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
+ ret = 1;
+ else if (pfn < zone->zone_start_pfn)
+ ret = 1;
+ } while (zone_span_seqretry(zone, seq));
+
+ return ret;
+}
+
+static int page_is_consistent(struct zone *zone, struct page *page)
+{
+ if (!pfn_valid_within(page_to_pfn(page)))
+ return 0;
+ if (zone != page_zone(page))
+ return 0;
+
+ return 1;
+}
+/*
+ * Temporary debugging check for pages not lying within a given zone.
+ */
+static int bad_range(struct zone *zone, struct page *page)
+{
+ if (page_outside_zone_boundaries(zone, page))
+ return 1;
+ if (!page_is_consistent(zone, page))
+ return 1;
+
+ return 0;
+}
+#else
+static inline int bad_range(struct zone *zone, struct page *page)
+{
+ return 0;
+}
+#endif
+
+static void bad_page(struct page *page)
+{
+ static unsigned long resume;
+ static unsigned long nr_shown;
+ static unsigned long nr_unshown;
+
+ /* Don't complain about poisoned pages */
+ if (PageHWPoison(page)) {
+ reset_page_mapcount(page); /* remove PageBuddy */
+ return;
+ }
+
+ /*
+ * Allow a burst of 60 reports, then keep quiet for that minute;
+ * or allow a steady drip of one report per second.
+ */
+ if (nr_shown == 60) {
+ if (time_before(jiffies, resume)) {
+ nr_unshown++;
+ goto out;
+ }
+ if (nr_unshown) {
+ printk(KERN_ALERT
+ "BUG: Bad page state: %lu messages suppressed\n",
+ nr_unshown);
+ nr_unshown = 0;
+ }
+ nr_shown = 0;
+ }
+ if (nr_shown++ == 0)
+ resume = jiffies + 60 * HZ;
+
+ printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
+ current->comm, page_to_pfn(page));
+ dump_page(page);
+
+ print_modules();
+ dump_stack();
+out:
+ /* Leave bad fields for debug, except PageBuddy could make trouble */
+ reset_page_mapcount(page); /* remove PageBuddy */
+ add_taint(TAINT_BAD_PAGE);
+}
+
+/*
+ * Higher-order pages are called "compound pages". They are structured thusly:
+ *
+ * The first PAGE_SIZE page is called the "head page".
+ *
+ * The remaining PAGE_SIZE pages are called "tail pages".
+ *
+ * All pages have PG_compound set. All tail pages have their ->first_page
+ * pointing at the head page.
+ *
+ * The first tail page's ->lru.next holds the address of the compound page's
+ * put_page() function. Its ->lru.prev holds the order of allocation.
+ * This usage means that zero-order pages may not be compound.
+ */
+
+static void free_compound_page(struct page *page)
+{
+ __free_pages_ok(page, compound_order(page));
+}
+
+void prep_compound_page(struct page *page, unsigned long order)
+{
+ int i;
+ int nr_pages = 1 << order;
+
+ set_compound_page_dtor(page, free_compound_page);
+ set_compound_order(page, order);
+ __SetPageHead(page);
+ for (i = 1; i < nr_pages; i++) {
+ struct page *p = page + i;
+ __SetPageTail(p);
+ set_page_count(p, 0);
+ p->first_page = page;
+ }
+}
+
+/* update __split_huge_page_refcount if you change this function */
+static int destroy_compound_page(struct page *page, unsigned long order)
+{
+ int i;
+ int nr_pages = 1 << order;
+ int bad = 0;
+
+ if (unlikely(compound_order(page) != order) ||
+ unlikely(!PageHead(page))) {
+ bad_page(page);
+ bad++;
+ }
+
+ __ClearPageHead(page);
+
+ for (i = 1; i < nr_pages; i++) {
+ struct page *p = page + i;
+
+ if (unlikely(!PageTail(p) || (p->first_page != page))) {
+ bad_page(page);
+ bad++;
+ }
+ __ClearPageTail(p);
+ }
+
+ return bad;
+}
+
+static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
+{
+ int i;
+
+ /*
+ * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
+ * and __GFP_HIGHMEM from hard or soft interrupt context.
+ */
+ VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
+ for (i = 0; i < (1 << order); i++)
+ clear_highpage(page + i);
+}
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+unsigned int _debug_guardpage_minorder;
+
+static int __init debug_guardpage_minorder_setup(char *buf)
+{
+ unsigned long res;
+
+ if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
+ printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
+ return 0;
+ }
+ _debug_guardpage_minorder = res;
+ printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
+ return 0;
+}
+__setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
+
+static inline void set_page_guard_flag(struct page *page)
+{
+ __set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
+}
+
+static inline void clear_page_guard_flag(struct page *page)
+{
+ __clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
+}
+#else
+static inline void set_page_guard_flag(struct page *page) { }
+static inline void clear_page_guard_flag(struct page *page) { }
+#endif
+
+static inline void set_page_order(struct page *page, int order)
+{
+ set_page_private(page, order);
+ __SetPageBuddy(page);
+}
+
+static inline void rmv_page_order(struct page *page)
+{
+ __ClearPageBuddy(page);
+ set_page_private(page, 0);
+}
+
+/*
+ * Locate the struct page for both the matching buddy in our
+ * pair (buddy1) and the combined O(n+1) page they form (page).
+ *
+ * 1) Any buddy B1 will have an order O twin B2 which satisfies
+ * the following equation:
+ * B2 = B1 ^ (1 << O)
+ * For example, if the starting buddy (buddy2) is #8 its order
+ * 1 buddy is #10:
+ * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
+ *
+ * 2) Any buddy B will have an order O+1 parent P which
+ * satisfies the following equation:
+ * P = B & ~(1 << O)
+ *
+ * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
+ */
+static inline unsigned long
+__find_buddy_index(unsigned long page_idx, unsigned int order)
+{
+ return page_idx ^ (1 << order);
+}
+
+/*
+ * This function checks whether a page is free && is the buddy
+ * we can do coalesce a page and its buddy if
+ * (a) the buddy is not in a hole &&
+ * (b) the buddy is in the buddy system &&
+ * (c) a page and its buddy have the same order &&
+ * (d) a page and its buddy are in the same zone.
+ *
+ * For recording whether a page is in the buddy system, we set ->_mapcount -2.
+ * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
+ *
+ * For recording page's order, we use page_private(page).
+ */
+static inline int page_is_buddy(struct page *page, struct page *buddy,
+ int order)
+{
+ if (!pfn_valid_within(page_to_pfn(buddy)))
+ return 0;
+
+ if (page_zone_id(page) != page_zone_id(buddy))
+ return 0;
+
+ if (page_is_guard(buddy) && page_order(buddy) == order) {
+ VM_BUG_ON(page_count(buddy) != 0);
+ return 1;
+ }
+
+ if (PageBuddy(buddy) && page_order(buddy) == order) {
+ VM_BUG_ON(page_count(buddy) != 0);
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * Freeing function for a buddy system allocator.
+ *
+ * The concept of a buddy system is to maintain direct-mapped table
+ * (containing bit values) for memory blocks of various "orders".
+ * The bottom level table contains the map for the smallest allocatable
+ * units of memory (here, pages), and each level above it describes
+ * pairs of units from the levels below, hence, "buddies".
+ * At a high level, all that happens here is marking the table entry
+ * at the bottom level available, and propagating the changes upward
+ * as necessary, plus some accounting needed to play nicely with other
+ * parts of the VM system.
+ * At each level, we keep a list of pages, which are heads of continuous
+ * free pages of length of (1 << order) and marked with _mapcount -2. Page's
+ * order is recorded in page_private(page) field.
+ * So when we are allocating or freeing one, we can derive the state of the
+ * other. That is, if we allocate a small block, and both were
+ * free, the remainder of the region must be split into blocks.
+ * If a block is freed, and its buddy is also free, then this
+ * triggers coalescing into a block of larger size.
+ *
+ * -- wli
+ */
+
+static inline void __free_one_page(struct page *page,
+ struct zone *zone, unsigned int order,
+ int migratetype)
+{
+ unsigned long page_idx;
+ unsigned long combined_idx;
+ unsigned long uninitialized_var(buddy_idx);
+ struct page *buddy;
+
+ if (unlikely(PageCompound(page)))
+ if (unlikely(destroy_compound_page(page, order)))
+ return;
+
+ VM_BUG_ON(migratetype == -1);
+
+ page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
+
+ VM_BUG_ON(page_idx & ((1 << order) - 1));
+ VM_BUG_ON(bad_range(zone, page));
+
+ while (order < MAX_ORDER-1) {
+ buddy_idx = __find_buddy_index(page_idx, order);
+ buddy = page + (buddy_idx - page_idx);
+ if (!page_is_buddy(page, buddy, order))
+ break;
+ /*
+ * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
+ * merge with it and move up one order.
+ */
+ if (page_is_guard(buddy)) {
+ clear_page_guard_flag(buddy);
+ set_page_private(page, 0);
+ __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
+ } else {
+ list_del(&buddy->lru);
+ zone->free_area[order].nr_free--;
+ rmv_page_order(buddy);
+ }
+ combined_idx = buddy_idx & page_idx;
+ page = page + (combined_idx - page_idx);
+ page_idx = combined_idx;
+ order++;
+ }
+ set_page_order(page, order);
+
+ /*
+ * If this is not the largest possible page, check if the buddy
+ * of the next-highest order is free. If it is, it's possible
+ * that pages are being freed that will coalesce soon. In case,
+ * that is happening, add the free page to the tail of the list
+ * so it's less likely to be used soon and more likely to be merged
+ * as a higher order page
+ */
+ if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
+ struct page *higher_page, *higher_buddy;
+ combined_idx = buddy_idx & page_idx;
+ higher_page = page + (combined_idx - page_idx);
+ buddy_idx = __find_buddy_index(combined_idx, order + 1);
+ higher_buddy = higher_page + (buddy_idx - combined_idx);
+ if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
+ list_add_tail(&page->lru,
+ &zone->free_area[order].free_list[migratetype]);
+ goto out;
+ }
+ }
+
+ list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
+out:
+ zone->free_area[order].nr_free++;
+}
+
+/*
+ * free_page_mlock() -- clean up attempts to free and mlocked() page.
+ * Page should not be on lru, so no need to fix that up.
+ * free_pages_check() will verify...
+ */
+static inline void free_page_mlock(struct page *page)
+{
+ __dec_zone_page_state(page, NR_MLOCK);
+ __count_vm_event(UNEVICTABLE_MLOCKFREED);
+}
+
+static inline int free_pages_check(struct page *page)
+{
+ if (unlikely(page_mapcount(page) |
+ (page->mapping != NULL) |
+ (atomic_read(&page->_count) != 0) |
+ (page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
+ (mem_cgroup_bad_page_check(page)))) {
+ bad_page(page);
+ return 1;
+ }
+ if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
+ page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
+ return 0;
+}
+
+/*
+ * Frees a number of pages which have been collected from the pcp lists.
+ * Assumes all pages on list are in same zone, and of same order.
+ * count is the number of pages to free.
+ *
+ * If the zone was previously in an "all pages pinned" state then look to
+ * see if this freeing clears that state.
+ *
+ * And clear the zone's pages_scanned counter, to hold off the "all pages are
+ * pinned" detection logic.
+ */
+static void free_pcppages_bulk(struct zone *zone, int count,
+ struct list_head *list)
+{
+ int to_free = count;
+ unsigned long flags;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ zone->all_unreclaimable = 0;
+ zone->pages_scanned = 0;
+
+ while (!list_empty(list)) {
+ struct page *page = list_first_entry(list, struct page, lru);
+
+ /* must delete as __free_one_page list manipulates */
+ list_del(&page->lru);
+ /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
+ __free_one_page(page, zone, 0, page_private(page));
+ trace_mm_page_pcpu_drain(page, 0, page_private(page));
+ to_free--;
+ }
+ WARN_ON(to_free != 0);
+ __mod_zone_page_state(zone, NR_FREE_PAGES, count);
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+
+/*
+ * Moves a number of pages from the PCP lists to free list which
+ * is freed outside of the locked region.
+ *
+ * Assumes all pages on list are in same zone, and of same order.
+ * count is the number of pages to free.
+ */
+static void isolate_pcp_pages(int to_free, struct per_cpu_pages *src,
+ struct list_head *dst)
+{
+ int migratetype = 0, batch_free = 0;
+
+ while (to_free) {
+ struct page *page;
+ struct list_head *list;
+
+ /*
+ * Remove pages from lists in a round-robin fashion. A
+ * batch_free count is maintained that is incremented when an
+ * empty list is encountered. This is so more pages are freed
+ * off fuller lists instead of spinning excessively around empty
+ * lists
+ */
+ do {
+ batch_free++;
+ if (++migratetype == MIGRATE_PCPTYPES)
+ migratetype = 0;
+ list = &src->lists[migratetype];
+ } while (list_empty(list));
+
+ /* This is the only non-empty list. Free them all. */
+ if (batch_free == MIGRATE_PCPTYPES)
+ batch_free = to_free;
+
+ do {
+ page = list_last_entry(list, struct page, lru);
+ list_del(&page->lru);
+ list_add(&page->lru, dst);
+ } while (--to_free && --batch_free && !list_empty(list));
+ }
+}
+
+static void free_one_page(struct zone *zone, struct page *page, int order,
+ int migratetype)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ zone->all_unreclaimable = 0;
+ zone->pages_scanned = 0;
+
+ __free_one_page(page, zone, order, migratetype);
+ __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+
+static bool free_pages_prepare(struct page *page, unsigned int order)
+{
+ int i;
+ int bad = 0;
+
+ trace_mm_page_free(page, order);
+ kmemcheck_free_shadow(page, order);
+
+ if (PageAnon(page))
+ page->mapping = NULL;
+ for (i = 0; i < (1 << order); i++)
+ bad += free_pages_check(page + i);
+ if (bad)
+ return false;
+
+ if (!PageHighMem(page)) {
+ debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
+ debug_check_no_obj_freed(page_address(page),
+ PAGE_SIZE << order);
+ }
+ arch_free_page(page, order);
+ kernel_map_pages(page, 1 << order, 0);
+
+ return true;
+}
+
+static void __free_pages_ok(struct page *page, unsigned int order)
+{
+ unsigned long flags;
+ int wasMlocked = __TestClearPageMlocked(page);
+
+ if (!free_pages_prepare(page, order))
+ return;
+
+#ifdef CONFIG_MEM_TRACKER
+ mem_free_tracker(page->mem_track_entry, MEM_TRACKER_TYPE_BUDDY);
+#endif
+
+ local_lock_irqsave(pa_lock, flags);
+ if (unlikely(wasMlocked))
+ free_page_mlock(page);
+ __count_vm_events(PGFREE, 1 << order);
+ free_one_page(page_zone(page), page, order,
+ get_pageblock_migratetype(page));
+ local_unlock_irqrestore(pa_lock, flags);
+}
+
+void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
+{
+ unsigned int nr_pages = 1 << order;
+ unsigned int loop;
+
+ prefetchw(page);
+ for (loop = 0; loop < nr_pages; loop++) {
+ struct page *p = &page[loop];
+
+ if (loop + 1 < nr_pages)
+ prefetchw(p + 1);
+ __ClearPageReserved(p);
+ set_page_count(p, 0);
+ }
+
+ set_page_refcounted(page);
+ __free_pages(page, order);
+}
+
+
+/*
+ * The order of subdivision here is critical for the IO subsystem.
+ * Please do not alter this order without good reasons and regression
+ * testing. Specifically, as large blocks of memory are subdivided,
+ * the order in which smaller blocks are delivered depends on the order
+ * they're subdivided in this function. This is the primary factor
+ * influencing the order in which pages are delivered to the IO
+ * subsystem according to empirical testing, and this is also justified
+ * by considering the behavior of a buddy system containing a single
+ * large block of memory acted on by a series of small allocations.
+ * This behavior is a critical factor in sglist merging's success.
+ *
+ * -- wli
+ */
+static inline void expand(struct zone *zone, struct page *page,
+ int low, int high, struct free_area *area,
+ int migratetype)
+{
+ unsigned long size = 1 << high;
+
+ while (high > low) {
+ area--;
+ high--;
+ size >>= 1;
+ VM_BUG_ON(bad_range(zone, &page[size]));
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ if (high < debug_guardpage_minorder()) {
+ /*
+ * Mark as guard pages (or page), that will allow to
+ * merge back to allocator when buddy will be freed.
+ * Corresponding page table entries will not be touched,
+ * pages will stay not present in virtual address space
+ */
+ INIT_LIST_HEAD(&page[size].lru);
+ set_page_guard_flag(&page[size]);
+ set_page_private(&page[size], high);
+ /* Guard pages are not available for any usage */
+ __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << high));
+ continue;
+ }
+#endif
+ list_add(&page[size].lru, &area->free_list[migratetype]);
+ area->nr_free++;
+ set_page_order(&page[size], high);
+ }
+}
+
+/*
+ * This page is about to be returned from the page allocator
+ */
+static inline int check_new_page(struct page *page)
+{
+ if (unlikely(page_mapcount(page) |
+ (page->mapping != NULL) |
+ (atomic_read(&page->_count) != 0) |
+ (page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
+ (mem_cgroup_bad_page_check(page)))) {
+ bad_page(page);
+ return 1;
+ }
+ return 0;
+}
+
+static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
+{
+ int i;
+
+ for (i = 0; i < (1 << order); i++) {
+ struct page *p = page + i;
+ if (unlikely(check_new_page(p)))
+ return 1;
+ }
+
+ set_page_private(page, 0);
+ set_page_refcounted(page);
+
+ arch_alloc_page(page, order);
+ kernel_map_pages(page, 1 << order, 1);
+
+ if (gfp_flags & __GFP_ZERO)
+ prep_zero_page(page, order, gfp_flags);
+
+ if (order && (gfp_flags & __GFP_COMP))
+ prep_compound_page(page, order);
+
+ return 0;
+}
+
+/*
+ * Go through the free lists for the given migratetype and remove
+ * the smallest available page from the freelists
+ */
+static inline
+struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
+ int migratetype)
+{
+ unsigned int current_order;
+ struct free_area * area;
+ struct page *page;
+
+ /* Find a page of the appropriate size in the preferred list */
+ for (current_order = order; current_order < MAX_ORDER; ++current_order) {
+ area = &(zone->free_area[current_order]);
+ if (list_empty(&area->free_list[migratetype]))
+ continue;
+
+ page = list_entry(area->free_list[migratetype].next,
+ struct page, lru);
+ list_del(&page->lru);
+ rmv_page_order(page);
+ area->nr_free--;
+ expand(zone, page, order, current_order, area, migratetype);
+ return page;
+ }
+
+ return NULL;
+}
+
+
+/*
+ * This array describes the order lists are fallen back to when
+ * the free lists for the desirable migrate type are depleted
+ */
+static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
+ [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
+ [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
+ [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
+ [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */
+};
+
+/*
+ * Move the free pages in a range to the free lists of the requested type.
+ * Note that start_page and end_pages are not aligned on a pageblock
+ * boundary. If alignment is required, use move_freepages_block()
+ */
+static int move_freepages(struct zone *zone,
+ struct page *start_page, struct page *end_page,
+ int migratetype)
+{
+ struct page *page;
+ unsigned long order;
+ int pages_moved = 0;
+
+#ifndef CONFIG_HOLES_IN_ZONE
+ /*
+ * page_zone is not safe to call in this context when
+ * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
+ * anyway as we check zone boundaries in move_freepages_block().
+ * Remove at a later date when no bug reports exist related to
+ * grouping pages by mobility
+ */
+ BUG_ON(page_zone(start_page) != page_zone(end_page));
+#endif
+
+ for (page = start_page; page <= end_page;) {
+ /* Make sure we are not inadvertently changing nodes */
+ VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));
+
+ if (!pfn_valid_within(page_to_pfn(page))) {
+ page++;
+ continue;
+ }
+
+ if (!PageBuddy(page)) {
+ page++;
+ continue;
+ }
+
+ order = page_order(page);
+ list_move(&page->lru,
+ &zone->free_area[order].free_list[migratetype]);
+ page += 1 << order;
+ pages_moved += 1 << order;
+ }
+
+ return pages_moved;
+}
+
+static int move_freepages_block(struct zone *zone, struct page *page,
+ int migratetype)
+{
+ unsigned long start_pfn, end_pfn;
+ struct page *start_page, *end_page;
+
+ start_pfn = page_to_pfn(page);
+ start_pfn = start_pfn & ~(pageblock_nr_pages-1);
+ start_page = pfn_to_page(start_pfn);
+ end_page = start_page + pageblock_nr_pages - 1;
+ end_pfn = start_pfn + pageblock_nr_pages - 1;
+
+ /* Do not cross zone boundaries */
+ if (start_pfn < zone->zone_start_pfn)
+ start_page = page;
+ if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
+ return 0;
+
+ return move_freepages(zone, start_page, end_page, migratetype);
+}
+
+static void change_pageblock_range(struct page *pageblock_page,
+ int start_order, int migratetype)
+{
+ int nr_pageblocks = 1 << (start_order - pageblock_order);
+
+ while (nr_pageblocks--) {
+ set_pageblock_migratetype(pageblock_page, migratetype);
+ pageblock_page += pageblock_nr_pages;
+ }
+}
+
+/* Remove an element from the buddy allocator from the fallback list */
+static inline struct page *
+__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
+{
+ struct free_area * area;
+ int current_order;
+ struct page *page;
+ int migratetype, i;
+
+ /* Find the largest possible block of pages in the other list */
+ for (current_order = MAX_ORDER-1; current_order >= order;
+ --current_order) {
+ for (i = 0; i < MIGRATE_TYPES - 1; i++) {
+ migratetype = fallbacks[start_migratetype][i];
+
+ /* MIGRATE_RESERVE handled later if necessary */
+ if (migratetype == MIGRATE_RESERVE)
+ continue;
+
+ area = &(zone->free_area[current_order]);
+ if (list_empty(&area->free_list[migratetype]))
+ continue;
+
+ page = list_entry(area->free_list[migratetype].next,
+ struct page, lru);
+ area->nr_free--;
+
+ /*
+ * If breaking a large block of pages, move all free
+ * pages to the preferred allocation list. If falling
+ * back for a reclaimable kernel allocation, be more
+ * aggressive about taking ownership of free pages
+ */
+ if (unlikely(current_order >= (pageblock_order >> 1)) ||
+ start_migratetype == MIGRATE_RECLAIMABLE ||
+ page_group_by_mobility_disabled) {
+ unsigned long pages;
+ pages = move_freepages_block(zone, page,
+ start_migratetype);
+
+ /* Claim the whole block if over half of it is free */
+ if (pages >= (1 << (pageblock_order-1)) ||
+ page_group_by_mobility_disabled)
+ set_pageblock_migratetype(page,
+ start_migratetype);
+
+ migratetype = start_migratetype;
+ }
+
+ /* Remove the page from the freelists */
+ list_del(&page->lru);
+ rmv_page_order(page);
+
+ /* Take ownership for orders >= pageblock_order */
+ if (current_order >= pageblock_order)
+ change_pageblock_range(page, current_order,
+ start_migratetype);
+
+ expand(zone, page, order, current_order, area, migratetype);
+
+ trace_mm_page_alloc_extfrag(page, order, current_order,
+ start_migratetype, migratetype);
+
+ return page;
+ }
+ }
+
+ return NULL;
+}
+
+/*
+ * Do the hard work of removing an element from the buddy allocator.
+ * Call me with the zone->lock already held.
+ */
+static struct page *__rmqueue(struct zone *zone, unsigned int order,
+ int migratetype)
+{
+ struct page *page;
+
+retry_reserve:
+ page = __rmqueue_smallest(zone, order, migratetype);
+
+ if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
+ page = __rmqueue_fallback(zone, order, migratetype);
+
+ /*
+ * Use MIGRATE_RESERVE rather than fail an allocation. goto
+ * is used because __rmqueue_smallest is an inline function
+ * and we want just one call site
+ */
+ if (!page) {
+ migratetype = MIGRATE_RESERVE;
+ goto retry_reserve;
+ }
+ }
+
+ trace_mm_page_alloc_zone_locked(page, order, migratetype);
+ return page;
+}
+
+/*
+ * Obtain a specified number of elements from the buddy allocator, all under
+ * a single hold of the lock, for efficiency. Add them to the supplied list.
+ * Returns the number of new pages which were placed at *list.
+ */
+static int rmqueue_bulk(struct zone *zone, unsigned int order,
+ unsigned long count, struct list_head *list,
+ int migratetype, int cold)
+{
+ int i;
+
+ spin_lock(&zone->lock);
+ for (i = 0; i < count; ++i) {
+ struct page *page = __rmqueue(zone, order, migratetype);
+ if (unlikely(page == NULL))
+ break;
+
+ /*
+ * Split buddy pages returned by expand() are received here
+ * in physical page order. The page is added to the callers and
+ * list and the list head then moves forward. From the callers
+ * perspective, the linked list is ordered by page number in
+ * some conditions. This is useful for IO devices that can
+ * merge IO requests if the physical pages are ordered
+ * properly.
+ */
+ if (likely(cold == 0))
+ list_add(&page->lru, list);
+ else
+ list_add_tail(&page->lru, list);
+ set_page_private(page, migratetype);
+ list = &page->lru;
+ }
+ __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
+ spin_unlock(&zone->lock);
+ return i;
+}
+
+#ifdef CONFIG_NUMA
+/*
+ * Called from the vmstat counter updater to drain pagesets of this
+ * currently executing processor on remote nodes after they have
+ * expired.
+ *
+ * Note that this function must be called with the thread pinned to
+ * a single processor.
+ */
+void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
+{
+ unsigned long flags;
+ LIST_HEAD(dst);
+ int to_drain;
+
+ local_lock_irqsave(pa_lock, flags);
+ if (pcp->count >= pcp->batch)
+ to_drain = pcp->batch;
+ else
+ to_drain = pcp->count;
+ isolate_pcp_pages(to_drain, pcp, &dst);
+ pcp->count -= to_drain;
+ local_unlock_irqrestore(pa_lock, flags);
+ free_pcppages_bulk(zone, to_drain, &dst);
+}
+#endif
+
+/*
+ * Drain pages of the indicated processor.
+ *
+ * The processor must either be the current processor and the
+ * thread pinned to the current processor or a processor that
+ * is not online.
+ */
+static void drain_pages(unsigned int cpu)
+{
+ unsigned long flags;
+ struct zone *zone;
+
+ for_each_populated_zone(zone) {
+ struct per_cpu_pageset *pset;
+ struct per_cpu_pages *pcp;
+ LIST_HEAD(dst);
+ int count;
+
+ cpu_lock_irqsave(cpu, flags);
+ pset = per_cpu_ptr(zone->pageset, cpu);
+
+ pcp = &pset->pcp;
+ count = pcp->count;
+ if (count) {
+ isolate_pcp_pages(count, pcp, &dst);
+ pcp->count = 0;
+ }
+ cpu_unlock_irqrestore(cpu, flags);
+ if (count)
+ free_pcppages_bulk(zone, count, &dst);
+ }
+}
+
+/*
+ * Spill all of this CPU's per-cpu pages back into the buddy allocator.
+ */
+void drain_local_pages(void *arg)
+{
+ drain_pages(smp_processor_id());
+}
+
+/*
+ * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
+ *
+ * Note that this code is protected against sending an IPI to an offline
+ * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
+ * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
+ * nothing keeps CPUs from showing up after we populated the cpumask and
+ * before the call to on_each_cpu_mask().
+ */
+void drain_all_pages(void)
+{
+ int cpu;
+ struct per_cpu_pageset *pcp;
+ struct zone *zone;
+
+ /*
+ * Allocate in the BSS so we wont require allocation in
+ * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
+ */
+ static cpumask_t cpus_with_pcps;
+
+ /*
+ * We don't care about racing with CPU hotplug event
+ * as offline notification will cause the notified
+ * cpu to drain that CPU pcps and on_each_cpu_mask
+ * disables preemption as part of its processing
+ */
+ for_each_online_cpu(cpu) {
+ bool has_pcps = false;
+ for_each_populated_zone(zone) {
+ pcp = per_cpu_ptr(zone->pageset, cpu);
+ if (pcp->pcp.count) {
+ has_pcps = true;
+ break;
+ }
+ }
+ if (has_pcps)
+ cpumask_set_cpu(cpu, &cpus_with_pcps);
+ else
+ cpumask_clear_cpu(cpu, &cpus_with_pcps);
+ }
+#ifndef CONFIG_PREEMPT_RT_BASE
+ on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, NULL, 1);
+#else
+ for_each_cpu(cpu, &cpus_with_pcps)
+ drain_pages(cpu);
+#endif
+}
+
+#ifdef CONFIG_HIBERNATION
+
+void mark_free_pages(struct zone *zone)
+{
+ unsigned long pfn, max_zone_pfn;
+ unsigned long flags;
+ int order, t;
+ struct list_head *curr;
+
+ if (!zone->spanned_pages)
+ return;
+
+ spin_lock_irqsave(&zone->lock, flags);
+
+ max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
+ for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+ if (pfn_valid(pfn)) {
+ struct page *page = pfn_to_page(pfn);
+
+ if (!swsusp_page_is_forbidden(page))
+ swsusp_unset_page_free(page);
+ }
+
+ for_each_migratetype_order(order, t) {
+ list_for_each(curr, &zone->free_area[order].free_list[t]) {
+ unsigned long i;
+
+ pfn = page_to_pfn(list_entry(curr, struct page, lru));
+ for (i = 0; i < (1UL << order); i++)
+ swsusp_set_page_free(pfn_to_page(pfn + i));
+ }
+ }
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+#endif /* CONFIG_PM */
+
+/*
+ * Free a 0-order page
+ * cold == 1 ? free a cold page : free a hot page
+ */
+void free_hot_cold_page(struct page *page, int cold)
+{
+ struct zone *zone = page_zone(page);
+ struct per_cpu_pages *pcp;
+ unsigned long flags;
+ int migratetype;
+ int wasMlocked = __TestClearPageMlocked(page);
+
+ if (!free_pages_prepare(page, 0))
+ return;
+
+#ifdef CONFIG_MEM_TRACKER
+ mem_free_tracker(page->mem_track_entry, MEM_TRACKER_TYPE_BUDDY);
+#endif
+ migratetype = get_pageblock_migratetype(page);
+ set_page_private(page, migratetype);
+ local_lock_irqsave(pa_lock, flags);
+ if (unlikely(wasMlocked))
+ free_page_mlock(page);
+ __count_vm_event(PGFREE);
+
+ /*
+ * We only track unmovable, reclaimable and movable on pcp lists.
+ * Free ISOLATE pages back to the allocator because they are being
+ * offlined but treat RESERVE as movable pages so we can get those
+ * areas back if necessary. Otherwise, we may have to free
+ * excessively into the page allocator
+ */
+ if (migratetype >= MIGRATE_PCPTYPES) {
+ if (unlikely(migratetype == MIGRATE_ISOLATE)) {
+ free_one_page(zone, page, 0, migratetype);
+ goto out;
+ }
+ migratetype = MIGRATE_MOVABLE;
+ }
+
+ pcp = &this_cpu_ptr(zone->pageset)->pcp;
+ if (cold)
+ list_add_tail(&page->lru, &pcp->lists[migratetype]);
+ else
+ list_add(&page->lru, &pcp->lists[migratetype]);
+ pcp->count++;
+ if (pcp->count >= pcp->high) {
+ LIST_HEAD(dst);
+ int count;
+
+ isolate_pcp_pages(pcp->batch, pcp, &dst);
+ pcp->count -= pcp->batch;
+ count = pcp->batch;
+ local_unlock_irqrestore(pa_lock, flags);
+ free_pcppages_bulk(zone, count, &dst);
+ return;
+ }
+
+out:
+ local_unlock_irqrestore(pa_lock, flags);
+}
+
+/*
+ * Free a list of 0-order pages
+ */
+void free_hot_cold_page_list(struct list_head *list, int cold)
+{
+ struct page *page, *next;
+
+ list_for_each_entry_safe(page, next, list, lru) {
+ trace_mm_page_free_batched(page, cold);
+ free_hot_cold_page(page, cold);
+ }
+}
+
+/*
+ * split_page takes a non-compound higher-order page, and splits it into
+ * n (1<<order) sub-pages: page[0..n]
+ * Each sub-page must be freed individually.
+ *
+ * Note: this is probably too low level an operation for use in drivers.
+ * Please consult with lkml before using this in your driver.
+ */
+void split_page(struct page *page, unsigned int order)
+{
+ int i;
+
+ VM_BUG_ON(PageCompound(page));
+ VM_BUG_ON(!page_count(page));
+
+#ifdef CONFIG_KMEMCHECK
+ /*
+ * Split shadow pages too, because free(page[0]) would
+ * otherwise free the whole shadow.
+ */
+ if (kmemcheck_page_is_tracked(page))
+ split_page(virt_to_page(page[0].shadow), order);
+#endif
+
+ for (i = 1; i < (1 << order); i++)
+ set_page_refcounted(page + i);
+}
+
+/*
+ * Similar to split_page except the page is already free. As this is only
+ * being used for migration, the migratetype of the block also changes.
+ * As this is called with interrupts disabled, the caller is responsible
+ * for calling arch_alloc_page() and kernel_map_page() after interrupts
+ * are enabled.
+ *
+ * Note: this is probably too low level an operation for use in drivers.
+ * Please consult with lkml before using this in your driver.
+ */
+int split_free_page(struct page *page)
+{
+ unsigned int order;
+ unsigned long watermark;
+ struct zone *zone;
+
+ BUG_ON(!PageBuddy(page));
+
+ zone = page_zone(page);
+ order = page_order(page);
+
+ /* Obey watermarks as if the page was being allocated */
+ watermark = low_wmark_pages(zone) + (1 << order);
+ if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
+ return 0;
+
+ /* Remove page from free list */
+ list_del(&page->lru);
+ zone->free_area[order].nr_free--;
+ rmv_page_order(page);
+ __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
+
+ /* Split into individual pages */
+ set_page_refcounted(page);
+ split_page(page, order);
+
+ if (order >= pageblock_order - 1) {
+ struct page *endpage = page + (1 << order) - 1;
+ for (; page < endpage; page += pageblock_nr_pages)
+ set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+ }
+
+ return 1 << order;
+}
+
+/*
+ * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
+ * we cheat by calling it from here, in the order > 0 path. Saves a branch
+ * or two.
+ */
+static inline
+struct page *buffered_rmqueue(struct zone *preferred_zone,
+ struct zone *zone, int order, gfp_t gfp_flags,
+ int migratetype)
+{
+ unsigned long flags;
+ struct page *page;
+ int cold = !!(gfp_flags & __GFP_COLD);
+
+again:
+ if (likely(order == 0)) {
+ struct per_cpu_pages *pcp;
+ struct list_head *list;
+
+ local_lock_irqsave(pa_lock, flags);
+ pcp = &this_cpu_ptr(zone->pageset)->pcp;
+ list = &pcp->lists[migratetype];
+ if (list_empty(list)) {
+ pcp->count += rmqueue_bulk(zone, 0,
+ pcp->batch, list,
+ migratetype, cold);
+ if (unlikely(list_empty(list)))
+ goto failed;
+ }
+
+ if (cold)
+ page = list_entry(list->prev, struct page, lru);
+ else
+ page = list_entry(list->next, struct page, lru);
+
+ list_del(&page->lru);
+ pcp->count--;
+ } else {
+ if (unlikely(gfp_flags & __GFP_NOFAIL)) {
+ /*
+ * __GFP_NOFAIL is not to be used in new code.
+ *
+ * All __GFP_NOFAIL callers should be fixed so that they
+ * properly detect and handle allocation failures.
+ *
+ * We most definitely don't want callers attempting to
+ * allocate greater than order-1 page units with
+ * __GFP_NOFAIL.
+ */
+ WARN_ON_ONCE(order > 1);
+ }
+ local_spin_lock_irqsave(pa_lock, &zone->lock, flags);
+ page = __rmqueue(zone, order, migratetype);
+ if (!page) {
+ spin_unlock(&zone->lock);
+ goto failed;
+ }
+ __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
+ spin_unlock(&zone->lock);
+ }
+
+ __count_zone_vm_events(PGALLOC, zone, 1 << order);
+ zone_statistics(preferred_zone, zone, gfp_flags);
+ local_unlock_irqrestore(pa_lock, flags);
+
+ VM_BUG_ON(bad_range(zone, page));
+ if (prep_new_page(page, order, gfp_flags))
+ goto again;
+ return page;
+
+failed:
+ local_unlock_irqrestore(pa_lock, flags);
+ return NULL;
+}
+
+/* The ALLOC_WMARK bits are used as an index to zone->watermark */
+#define ALLOC_WMARK_MIN WMARK_MIN
+#define ALLOC_WMARK_LOW WMARK_LOW
+#define ALLOC_WMARK_HIGH WMARK_HIGH
+#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
+
+/* Mask to get the watermark bits */
+#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
+
+#define ALLOC_HARDER 0x10 /* try to alloc harder */
+#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
+#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
+
+#ifdef CONFIG_FAIL_PAGE_ALLOC
+
+static struct {
+ struct fault_attr attr;
+
+ u32 ignore_gfp_highmem;
+ u32 ignore_gfp_wait;
+ u32 min_order;
+} fail_page_alloc = {
+ .attr = FAULT_ATTR_INITIALIZER,
+ .ignore_gfp_wait = 1,
+ .ignore_gfp_highmem = 1,
+ .min_order = 1,
+};
+
+static int __init setup_fail_page_alloc(char *str)
+{
+ return setup_fault_attr(&fail_page_alloc.attr, str);
+}
+__setup("fail_page_alloc=", setup_fail_page_alloc);
+
+static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
+{
+ if (order < fail_page_alloc.min_order)
+ return 0;
+ if (gfp_mask & __GFP_NOFAIL)
+ return 0;
+ if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
+ return 0;
+ if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
+ return 0;
+
+ return should_fail(&fail_page_alloc.attr, 1 << order);
+}
+
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+
+static int __init fail_page_alloc_debugfs(void)
+{
+ umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
+ struct dentry *dir;
+
+ dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
+ &fail_page_alloc.attr);
+ if (IS_ERR(dir))
+ return PTR_ERR(dir);
+
+ if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
+ &fail_page_alloc.ignore_gfp_wait))
+ goto fail;
+ if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
+ &fail_page_alloc.ignore_gfp_highmem))
+ goto fail;
+ if (!debugfs_create_u32("min-order", mode, dir,
+ &fail_page_alloc.min_order))
+ goto fail;
+
+ return 0;
+fail:
+ debugfs_remove_recursive(dir);
+
+ return -ENOMEM;
+}
+
+late_initcall(fail_page_alloc_debugfs);
+
+#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
+
+#else /* CONFIG_FAIL_PAGE_ALLOC */
+
+static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
+{
+ return 0;
+}
+
+#endif /* CONFIG_FAIL_PAGE_ALLOC */
+
+/*
+ * Return true if free pages are above 'mark'. This takes into account the order
+ * of the allocation.
+ */
+static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
+ int classzone_idx, int alloc_flags, long free_pages)
+{
+ /* free_pages my go negative - that's OK */
+ long min = mark;
+ int o;
+
+ free_pages -= (1 << order) - 1;
+ if (alloc_flags & ALLOC_HIGH)
+ min -= min / 2;
+ if (alloc_flags & ALLOC_HARDER)
+ min -= min / 4;
+
+ if (free_pages <= min + z->lowmem_reserve[classzone_idx])
+ return false;
+ for (o = 0; o < order; o++) {
+ /* At the next order, this order's pages become unavailable */
+ free_pages -= z->free_area[o].nr_free << o;
+
+ /* Require fewer higher order pages to be free */
+ min >>= min_free_order_shift;
+
+ if (free_pages <= min)
+ return false;
+ }
+ return true;
+}
+
+bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
+ int classzone_idx, int alloc_flags)
+{
+ return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
+ zone_page_state(z, NR_FREE_PAGES));
+}
+
+bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
+ int classzone_idx, int alloc_flags)
+{
+ long free_pages = zone_page_state(z, NR_FREE_PAGES);
+
+ if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
+ free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
+
+ return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
+ free_pages);
+}
+
+#ifdef CONFIG_NUMA
+/*
+ * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
+ * skip over zones that are not allowed by the cpuset, or that have
+ * been recently (in last second) found to be nearly full. See further
+ * comments in mmzone.h. Reduces cache footprint of zonelist scans
+ * that have to skip over a lot of full or unallowed zones.
+ *
+ * If the zonelist cache is present in the passed in zonelist, then
+ * returns a pointer to the allowed node mask (either the current
+ * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
+ *
+ * If the zonelist cache is not available for this zonelist, does
+ * nothing and returns NULL.
+ *
+ * If the fullzones BITMAP in the zonelist cache is stale (more than
+ * a second since last zap'd) then we zap it out (clear its bits.)
+ *
+ * We hold off even calling zlc_setup, until after we've checked the
+ * first zone in the zonelist, on the theory that most allocations will
+ * be satisfied from that first zone, so best to examine that zone as
+ * quickly as we can.
+ */
+static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
+{
+ struct zonelist_cache *zlc; /* cached zonelist speedup info */
+ nodemask_t *allowednodes; /* zonelist_cache approximation */
+
+ zlc = zonelist->zlcache_ptr;
+ if (!zlc)
+ return NULL;
+
+ if (time_after(jiffies, zlc->last_full_zap + HZ)) {
+ bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
+ zlc->last_full_zap = jiffies;
+ }
+
+ allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
+ &cpuset_current_mems_allowed :
+ &node_states[N_HIGH_MEMORY];
+ return allowednodes;
+}
+
+/*
+ * Given 'z' scanning a zonelist, run a couple of quick checks to see
+ * if it is worth looking at further for free memory:
+ * 1) Check that the zone isn't thought to be full (doesn't have its
+ * bit set in the zonelist_cache fullzones BITMAP).
+ * 2) Check that the zones node (obtained from the zonelist_cache
+ * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
+ * Return true (non-zero) if zone is worth looking at further, or
+ * else return false (zero) if it is not.
+ *
+ * This check -ignores- the distinction between various watermarks,
+ * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
+ * found to be full for any variation of these watermarks, it will
+ * be considered full for up to one second by all requests, unless
+ * we are so low on memory on all allowed nodes that we are forced
+ * into the second scan of the zonelist.
+ *
+ * In the second scan we ignore this zonelist cache and exactly
+ * apply the watermarks to all zones, even it is slower to do so.
+ * We are low on memory in the second scan, and should leave no stone
+ * unturned looking for a free page.
+ */
+static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
+ nodemask_t *allowednodes)
+{
+ struct zonelist_cache *zlc; /* cached zonelist speedup info */
+ int i; /* index of *z in zonelist zones */
+ int n; /* node that zone *z is on */
+
+ zlc = zonelist->zlcache_ptr;
+ if (!zlc)
+ return 1;
+
+ i = z - zonelist->_zonerefs;
+ n = zlc->z_to_n[i];
+
+ /* This zone is worth trying if it is allowed but not full */
+ return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
+}
+
+/*
+ * Given 'z' scanning a zonelist, set the corresponding bit in
+ * zlc->fullzones, so that subsequent attempts to allocate a page
+ * from that zone don't waste time re-examining it.
+ */
+static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
+{
+ struct zonelist_cache *zlc; /* cached zonelist speedup info */
+ int i; /* index of *z in zonelist zones */
+
+ zlc = zonelist->zlcache_ptr;
+ if (!zlc)
+ return;
+
+ i = z - zonelist->_zonerefs;
+
+ set_bit(i, zlc->fullzones);
+}
+
+/*
+ * clear all zones full, called after direct reclaim makes progress so that
+ * a zone that was recently full is not skipped over for up to a second
+ */
+static void zlc_clear_zones_full(struct zonelist *zonelist)
+{
+ struct zonelist_cache *zlc; /* cached zonelist speedup info */
+
+ zlc = zonelist->zlcache_ptr;
+ if (!zlc)
+ return;
+
+ bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
+}
+
+#else /* CONFIG_NUMA */
+
+static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
+{
+ return NULL;
+}
+
+static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
+ nodemask_t *allowednodes)
+{
+ return 1;
+}
+
+static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
+{
+}
+
+static void zlc_clear_zones_full(struct zonelist *zonelist)
+{
+}
+#endif /* CONFIG_NUMA */
+
+/*
+ * get_page_from_freelist goes through the zonelist trying to allocate
+ * a page.
+ */
+static struct page *
+get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
+ struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
+ struct zone *preferred_zone, int migratetype)
+{
+ struct zoneref *z;
+ struct page *page = NULL;
+ int classzone_idx;
+ struct zone *zone;
+ nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
+ int zlc_active = 0; /* set if using zonelist_cache */
+ int did_zlc_setup = 0; /* just call zlc_setup() one time */
+
+ classzone_idx = zone_idx(preferred_zone);
+zonelist_scan:
+ /*
+ * Scan zonelist, looking for a zone with enough free.
+ * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
+ */
+ for_each_zone_zonelist_nodemask(zone, z, zonelist,
+ high_zoneidx, nodemask) {
+ if (NUMA_BUILD && zlc_active &&
+ !zlc_zone_worth_trying(zonelist, z, allowednodes))
+ continue;
+ if ((alloc_flags & ALLOC_CPUSET) &&
+ !cpuset_zone_allowed_softwall(zone, gfp_mask))
+ continue;
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+ if ((gfp_mask & __GFP_PAGECACHE) &&
+ (zone_page_state(zone, NR_FILE_PAGES) -
+ zone_page_state(zone, NR_RAMFS_PAGES) -
+ zone_page_state(zone, NR_TMPFS_PAGES)) >
+ zone->max_pagecache_pages) {
+ pagecache_alloc_failed++;
+ continue;
+ }
+#endif
+ /*
+ * When allocating a page cache page for writing, we
+ * want to get it from a zone that is within its dirty
+ * limit, such that no single zone holds more than its
+ * proportional share of globally allowed dirty pages.
+ * The dirty limits take into account the zone's
+ * lowmem reserves and high watermark so that kswapd
+ * should be able to balance it without having to
+ * write pages from its LRU list.
+ *
+ * This may look like it could increase pressure on
+ * lower zones by failing allocations in higher zones
+ * before they are full. But the pages that do spill
+ * over are limited as the lower zones are protected
+ * by this very same mechanism. It should not become
+ * a practical burden to them.
+ *
+ * XXX: For now, allow allocations to potentially
+ * exceed the per-zone dirty limit in the slowpath
+ * (ALLOC_WMARK_LOW unset) before going into reclaim,
+ * which is important when on a NUMA setup the allowed
+ * zones are together not big enough to reach the
+ * global limit. The proper fix for these situations
+ * will require awareness of zones in the
+ * dirty-throttling and the flusher threads.
+ */
+ if ((alloc_flags & ALLOC_WMARK_LOW) &&
+ (gfp_mask & __GFP_WRITE) && !zone_dirty_ok(zone))
+ goto this_zone_full;
+
+ BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
+ if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
+ unsigned long mark;
+ int ret;
+
+ mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
+ if (zone_watermark_ok(zone, order, mark,
+ classzone_idx, alloc_flags))
+ goto try_this_zone;
+
+ if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
+ /*
+ * we do zlc_setup if there are multiple nodes
+ * and before considering the first zone allowed
+ * by the cpuset.
+ */
+ allowednodes = zlc_setup(zonelist, alloc_flags);
+ zlc_active = 1;
+ did_zlc_setup = 1;
+ }
+
+ if (zone_reclaim_mode == 0)
+ goto this_zone_full;
+
+ /*
+ * As we may have just activated ZLC, check if the first
+ * eligible zone has failed zone_reclaim recently.
+ */
+ if (NUMA_BUILD && zlc_active &&
+ !zlc_zone_worth_trying(zonelist, z, allowednodes))
+ continue;
+
+ ret = zone_reclaim(zone, gfp_mask, order);
+ switch (ret) {
+ case ZONE_RECLAIM_NOSCAN:
+ /* did not scan */
+ continue;
+ case ZONE_RECLAIM_FULL:
+ /* scanned but unreclaimable */
+ continue;
+ default:
+ /* did we reclaim enough */
+ if (!zone_watermark_ok(zone, order, mark,
+ classzone_idx, alloc_flags))
+ goto this_zone_full;
+ }
+ }
+
+try_this_zone:
+ page = buffered_rmqueue(preferred_zone, zone, order,
+ gfp_mask, migratetype);
+ if (page)
+ break;
+this_zone_full:
+ if (NUMA_BUILD)
+ zlc_mark_zone_full(zonelist, z);
+ }
+
+ if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
+ /* Disable zlc cache for second zonelist scan */
+ zlc_active = 0;
+ goto zonelist_scan;
+ }
+ return page;
+}
+
+/*
+ * Large machines with many possible nodes should not always dump per-node
+ * meminfo in irq context.
+ */
+static inline bool should_suppress_show_mem(void)
+{
+ bool ret = false;
+
+#if NODES_SHIFT > 8
+ ret = in_interrupt();
+#endif
+ return ret;
+}
+
+static DEFINE_RATELIMIT_STATE(nopage_rs,
+ DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
+{
+ unsigned int filter = SHOW_MEM_FILTER_NODES;
+
+ if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
+ debug_guardpage_minorder() > 0)
+ return;
+
+ /*
+ * Walking all memory to count page types is very expensive and should
+ * be inhibited in non-blockable contexts.
+ */
+ if (!(gfp_mask & __GFP_WAIT))
+ filter |= SHOW_MEM_FILTER_PAGE_COUNT;
+
+ /*
+ * This documents exceptions given to allocations in certain
+ * contexts that are allowed to allocate outside current's set
+ * of allowed nodes.
+ */
+ if (!(gfp_mask & __GFP_NOMEMALLOC))
+ if (test_thread_flag(TIF_MEMDIE) ||
+ (current->flags & (PF_MEMALLOC | PF_EXITING)))
+ filter &= ~SHOW_MEM_FILTER_NODES;
+ if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
+ filter &= ~SHOW_MEM_FILTER_NODES;
+
+ if (fmt) {
+ struct va_format vaf;
+ va_list args;
+
+ va_start(args, fmt);
+
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ pr_warn("%pV", &vaf);
+
+ va_end(args);
+ }
+
+ pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
+ current->comm, order, gfp_mask);
+
+ //dump_stack();
+ //if (!should_suppress_show_mem())
+ //show_mem(filter);
+}
+
+static inline int
+should_alloc_retry(gfp_t gfp_mask, unsigned int order,
+ unsigned long did_some_progress,
+ unsigned long pages_reclaimed)
+{
+ /* Do not loop if specifically requested */
+ if (gfp_mask & __GFP_NORETRY)
+ return 0;
+
+ /* Always retry if specifically requested */
+ if (gfp_mask & __GFP_NOFAIL)
+ return 1;
+
+ /*
+ * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
+ * making forward progress without invoking OOM. Suspend also disables
+ * storage devices so kswapd will not help. Bail if we are suspending.
+ */
+ if (!did_some_progress && pm_suspended_storage())
+ return 0;
+
+ /*
+ * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
+ * means __GFP_NOFAIL, but that may not be true in other
+ * implementations.
+ */
+ if (order <= PAGE_ALLOC_COSTLY_ORDER)
+ return 1;
+
+ /*
+ * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
+ * specified, then we retry until we no longer reclaim any pages
+ * (above), or we've reclaimed an order of pages at least as
+ * large as the allocation's order. In both cases, if the
+ * allocation still fails, we stop retrying.
+ */
+ if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
+ return 1;
+
+ return 0;
+}
+
+static inline struct page *
+__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
+ struct zonelist *zonelist, enum zone_type high_zoneidx,
+ nodemask_t *nodemask, struct zone *preferred_zone,
+ int migratetype)
+{
+ struct page *page;
+
+ /* Acquire the OOM killer lock for the zones in zonelist */
+ if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
+ schedule_timeout_uninterruptible(1);
+ return NULL;
+ }
+
+ /*
+ * PM-freezer should be notified that there might be an OOM killer on
+ * its way to kill and wake somebody up. This is too early and we might
+ * end up not killing anything but false positives are acceptable.
+ * See freeze_processes.
+ */
+ note_oom_kill();
+
+ /*
+ * Go through the zonelist yet one more time, keep very high watermark
+ * here, this is only to catch a parallel oom killing, we must fail if
+ * we're still under heavy pressure.
+ */
+ page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
+ order, zonelist, high_zoneidx,
+ ALLOC_WMARK_HIGH|ALLOC_CPUSET,
+ preferred_zone, migratetype);
+ if (page)
+ goto out;
+
+ if (!(gfp_mask & __GFP_NOFAIL)) {
+ /* The OOM killer will not help higher order allocs */
+ if (order > PAGE_ALLOC_COSTLY_ORDER)
+ goto out;
+ /* The OOM killer does not needlessly kill tasks for lowmem */
+ if (high_zoneidx < ZONE_NORMAL)
+ goto out;
+ /*
+ * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
+ * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
+ * The caller should handle page allocation failure by itself if
+ * it specifies __GFP_THISNODE.
+ * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
+ */
+ if (gfp_mask & __GFP_THISNODE)
+ goto out;
+ }
+ /* Exhausted what can be done so it's blamo time */
+ out_of_memory(zonelist, gfp_mask, order, nodemask, false);
+
+out:
+ clear_zonelist_oom(zonelist, gfp_mask);
+ return page;
+}
+
+#ifdef CONFIG_COMPACTION
+/* Try memory compaction for high-order allocations before reclaim */
+static struct page *
+__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
+ struct zonelist *zonelist, enum zone_type high_zoneidx,
+ nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
+ int migratetype, bool sync_migration,
+ bool *deferred_compaction,
+ unsigned long *did_some_progress)
+{
+ struct page *page;
+
+ if (!order)
+ return NULL;
+
+ if (compaction_deferred(preferred_zone, order)) {
+ *deferred_compaction = true;
+ return NULL;
+ }
+
+ current->flags |= PF_MEMALLOC;
+ *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
+ nodemask, sync_migration);
+ current->flags &= ~PF_MEMALLOC;
+ if (*did_some_progress != COMPACT_SKIPPED) {
+
+ /* Page migration frees to the PCP lists but we want merging */
+ drain_pages(get_cpu_light());
+ put_cpu_light();
+
+ page = get_page_from_freelist(gfp_mask, nodemask,
+ order, zonelist, high_zoneidx,
+ alloc_flags, preferred_zone,
+ migratetype);
+ if (page) {
+ preferred_zone->compact_considered = 0;
+ preferred_zone->compact_defer_shift = 0;
+ if (order >= preferred_zone->compact_order_failed)
+ preferred_zone->compact_order_failed = order + 1;
+ count_vm_event(COMPACTSUCCESS);
+ return page;
+ }
+
+ /*
+ * It's bad if compaction run occurs and fails.
+ * The most likely reason is that pages exist,
+ * but not enough to satisfy watermarks.
+ */
+ count_vm_event(COMPACTFAIL);
+
+ /*
+ * As async compaction considers a subset of pageblocks, only
+ * defer if the failure was a sync compaction failure.
+ */
+ if (sync_migration)
+ defer_compaction(preferred_zone, order);
+
+ cond_resched();
+ }
+
+ return NULL;
+}
+#else
+static inline struct page *
+__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
+ struct zonelist *zonelist, enum zone_type high_zoneidx,
+ nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
+ int migratetype, bool sync_migration,
+ bool *deferred_compaction,
+ unsigned long *did_some_progress)
+{
+ return NULL;
+}
+#endif /* CONFIG_COMPACTION */
+
+/* The really slow allocator path where we enter direct reclaim */
+static inline struct page *
+__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
+ struct zonelist *zonelist, enum zone_type high_zoneidx,
+ nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
+ int migratetype, unsigned long *did_some_progress)
+{
+ struct page *page = NULL;
+ struct reclaim_state reclaim_state;
+ bool drained = false;
+
+ cond_resched();
+
+ /* We now go into synchronous reclaim */
+ cpuset_memory_pressure_bump();
+ current->flags |= PF_MEMALLOC;
+ lockdep_set_current_reclaim_state(gfp_mask);
+ reclaim_state.reclaimed_slab = 0;
+ current->reclaim_state = &reclaim_state;
+
+ *did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
+
+ current->reclaim_state = NULL;
+ lockdep_clear_current_reclaim_state();
+ current->flags &= ~PF_MEMALLOC;
+
+ cond_resched();
+#ifndef CONFIG_SPEED_OPT_DYNAMIC_POOL
+ if (unlikely(!(*did_some_progress)))
+ return NULL;
+#endif
+ /* After successful reclaim, reconsider all zones for allocation */
+ if (NUMA_BUILD)
+ zlc_clear_zones_full(zonelist);
+
+retry:
+ page = get_page_from_freelist(gfp_mask & (~__GFP_PAGECACHE), nodemask, order,
+ zonelist, high_zoneidx,
+ alloc_flags, preferred_zone,
+ migratetype);
+
+ /*
+ * If an allocation failed after direct reclaim, it could be because
+ * pages are pinned on the per-cpu lists. Drain them and try again
+ */
+ if (!page && !drained) {
+ drain_all_pages();
+ drained = true;
+ goto retry;
+ }
+
+ return page;
+}
+
+/*
+ * This is called in the allocator slow-path if the allocation request is of
+ * sufficient urgency to ignore watermarks and take other desperate measures
+ */
+static inline struct page *
+__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
+ struct zonelist *zonelist, enum zone_type high_zoneidx,
+ nodemask_t *nodemask, struct zone *preferred_zone,
+ int migratetype)
+{
+ struct page *page;
+
+ do {
+ page = get_page_from_freelist(gfp_mask, nodemask, order,
+ zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
+ preferred_zone, migratetype);
+
+ if (!page && gfp_mask & __GFP_NOFAIL)
+ wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
+ } while (!page && (gfp_mask & __GFP_NOFAIL));
+
+ return page;
+}
+
+static inline
+void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
+ enum zone_type high_zoneidx,
+ enum zone_type classzone_idx)
+{
+ struct zoneref *z;
+ struct zone *zone;
+
+ for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
+ wakeup_kswapd(zone, order, classzone_idx);
+}
+
+static inline int
+gfp_to_alloc_flags(gfp_t gfp_mask)
+{
+ int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
+ const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD));
+
+ /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
+ BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
+
+ /*
+ * The caller may dip into page reserves a bit more if the caller
+ * cannot run direct reclaim, or if the caller has realtime scheduling
+ * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
+ * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
+ */
+ alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
+
+ if (atomic) {
+ /*
+ * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
+ * if it can't schedule.
+ */
+ if (!(gfp_mask & __GFP_NOMEMALLOC))
+ alloc_flags |= ALLOC_HARDER;
+ /*
+ * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
+ * comment for __cpuset_node_allowed_softwall().
+ */
+ alloc_flags &= ~ALLOC_CPUSET;
+ } else if (unlikely(rt_task(current)) && !in_interrupt())
+ alloc_flags |= ALLOC_HARDER;
+
+ if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
+ if (!in_interrupt() &&
+ ((current->flags & PF_MEMALLOC) ||
+ unlikely(test_thread_flag(TIF_MEMDIE))))
+ alloc_flags |= ALLOC_NO_WATERMARKS;
+ }
+
+ return alloc_flags;
+}
+
+static inline struct page *
+__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
+ struct zonelist *zonelist, enum zone_type high_zoneidx,
+ nodemask_t *nodemask, struct zone *preferred_zone,
+ int migratetype)
+{
+ const gfp_t wait = gfp_mask & __GFP_WAIT;
+ struct page *page = NULL;
+ int alloc_flags;
+ unsigned long pages_reclaimed = 0;
+ unsigned long did_some_progress;
+ bool sync_migration = false;
+ bool deferred_compaction = false;
+
+ /*
+ * In the slowpath, we sanity check order to avoid ever trying to
+ * reclaim >= MAX_ORDER areas which will never succeed. Callers may
+ * be using allocators in order of preference for an area that is
+ * too large.
+ */
+ if (order >= MAX_ORDER) {
+ WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
+ return NULL;
+ }
+
+ /*
+ * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
+ * __GFP_NOWARN set) should not cause reclaim since the subsystem
+ * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
+ * using a larger set of nodes after it has established that the
+ * allowed per node queues are empty and that nodes are
+ * over allocated.
+ */
+ if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
+ goto nopage;
+
+restart:
+ if (!(gfp_mask & __GFP_NO_KSWAPD))
+ wake_all_kswapd(order, zonelist, high_zoneidx,
+ zone_idx(preferred_zone));
+
+ /*
+ * OK, we're below the kswapd watermark and have kicked background
+ * reclaim. Now things get more complex, so set up alloc_flags according
+ * to how we want to proceed.
+ */
+ alloc_flags = gfp_to_alloc_flags(gfp_mask);
+
+ /*
+ * Find the true preferred zone if the allocation is unconstrained by
+ * cpusets.
+ */
+ if (!(alloc_flags & ALLOC_CPUSET) && !nodemask)
+ first_zones_zonelist(zonelist, high_zoneidx, NULL,
+ &preferred_zone);
+
+rebalance:
+ /* This is the last chance, in general, before the goto nopage. */
+ page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
+ high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
+ preferred_zone, migratetype);
+ if (page)
+ goto got_pg;
+
+ if (!page && (gfp_mask & __GFP_PAGEMODEM))
+ goto nopage;
+
+ /* Allocate without watermarks if the context allows */
+ if (alloc_flags & ALLOC_NO_WATERMARKS) {
+ page = __alloc_pages_high_priority(gfp_mask, order,
+ zonelist, high_zoneidx, nodemask,
+ preferred_zone, migratetype);
+ if (page)
+ goto got_pg;
+ }
+
+ /* Atomic allocations - we can't balance anything */
+ if (!wait)
+ goto nopage;
+
+ /* Avoid recursion of direct reclaim */
+ if (current->flags & PF_MEMALLOC)
+ goto nopage;
+
+ /* Avoid allocations with no watermarks from looping endlessly */
+ if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
+ goto nopage;
+
+ /*
+ * Try direct compaction. The first pass is asynchronous. Subsequent
+ * attempts after direct reclaim are synchronous
+ */
+ page = __alloc_pages_direct_compact(gfp_mask, order,
+ zonelist, high_zoneidx,
+ nodemask,
+ alloc_flags, preferred_zone,
+ migratetype, sync_migration,
+ &deferred_compaction,
+ &did_some_progress);
+ if (page)
+ goto got_pg;
+ sync_migration = true;
+
+ /*
+ * If compaction is deferred for high-order allocations, it is because
+ * sync compaction recently failed. In this is the case and the caller
+ * has requested the system not be heavily disrupted, fail the
+ * allocation now instead of entering direct reclaim
+ */
+ if (deferred_compaction && (gfp_mask & __GFP_NO_KSWAPD))
+ goto nopage;
+
+ /* Try direct reclaim and then allocating */
+ page = __alloc_pages_direct_reclaim(gfp_mask, order,
+ zonelist, high_zoneidx,
+ nodemask,
+ alloc_flags, preferred_zone,
+ migratetype, &did_some_progress);
+ if (page)
+ goto got_pg;
+
+ /*
+ * If we failed to make any progress reclaiming, then we are
+ * running out of options and have to consider going OOM
+ */
+ if (!did_some_progress) {
+ if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
+ if (oom_killer_disabled)
+ goto nopage;
+ /* Coredumps can quickly deplete all memory reserves */
+ if ((current->flags & PF_DUMPCORE) &&
+ !(gfp_mask & __GFP_NOFAIL))
+ goto nopage;
+ page = __alloc_pages_may_oom(gfp_mask, order,
+ zonelist, high_zoneidx,
+ nodemask, preferred_zone,
+ migratetype);
+ if (page)
+ goto got_pg;
+
+ if (!(gfp_mask & __GFP_NOFAIL)) {
+ /*
+ * The oom killer is not called for high-order
+ * allocations that may fail, so if no progress
+ * is being made, there are no other options and
+ * retrying is unlikely to help.
+ */
+ if (order > PAGE_ALLOC_COSTLY_ORDER)
+ goto nopage;
+ /*
+ * The oom killer is not called for lowmem
+ * allocations to prevent needlessly killing
+ * innocent tasks.
+ */
+ if (high_zoneidx < ZONE_NORMAL)
+ goto nopage;
+ }
+
+ goto restart;
+ }
+ }
+
+ /* Check if we should retry the allocation */
+ pages_reclaimed += did_some_progress;
+ if (should_alloc_retry(gfp_mask, order, did_some_progress,
+ pages_reclaimed)) {
+ /* Wait for some write requests to complete then retry */
+ wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
+ goto rebalance;
+ } else {
+ /*
+ * High-order allocations do not necessarily loop after
+ * direct reclaim and reclaim/compaction depends on compaction
+ * being called after reclaim so call directly if necessary
+ */
+ page = __alloc_pages_direct_compact(gfp_mask, order,
+ zonelist, high_zoneidx,
+ nodemask,
+ alloc_flags, preferred_zone,
+ migratetype, sync_migration,
+ &deferred_compaction,
+ &did_some_progress);
+ if (page)
+ goto got_pg;
+ }
+
+nopage:
+ warn_alloc_failed(gfp_mask, order, NULL);
+ return page;
+got_pg:
+ if (kmemcheck_enabled)
+ kmemcheck_pagealloc_alloc(page, order, gfp_mask);
+ return page;
+
+}
+
+/*
+ * This is the 'heart' of the zoned buddy allocator.
+ */
+struct page *
+__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
+ struct zonelist *zonelist, nodemask_t *nodemask)
+{
+ enum zone_type high_zoneidx = gfp_zone(gfp_mask);
+ struct zone *preferred_zone;
+ struct page *page = NULL;
+ int migratetype = allocflags_to_migratetype(gfp_mask);
+ unsigned int cpuset_mems_cookie;
+
+ gfp_mask &= gfp_allowed_mask;
+
+ lockdep_trace_alloc(gfp_mask);
+
+ might_sleep_if(gfp_mask & __GFP_WAIT);
+
+ if (should_fail_alloc_page(gfp_mask, order))
+ return NULL;
+
+ /*
+ * Check the zones suitable for the gfp_mask contain at least one
+ * valid zone. It's possible to have an empty zonelist as a result
+ * of GFP_THISNODE and a memoryless node
+ */
+ if (unlikely(!zonelist->_zonerefs->zone))
+ return NULL;
+
+retry_cpuset:
+ cpuset_mems_cookie = get_mems_allowed();
+
+ /* The preferred zone is used for statistics later */
+ first_zones_zonelist(zonelist, high_zoneidx,
+ nodemask ? : &cpuset_current_mems_allowed,
+ &preferred_zone);
+ if (!preferred_zone)
+ goto out;
+
+ /* First allocation attempt */
+ page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
+ zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
+ preferred_zone, migratetype);
+ if (unlikely(!page))
+ page = __alloc_pages_slowpath(gfp_mask, order,
+ zonelist, high_zoneidx, nodemask,
+ preferred_zone, migratetype);
+
+ trace_mm_page_alloc(page, order, gfp_mask, migratetype);
+
+out:
+ /*
+ * When updating a task's mems_allowed, it is possible to race with
+ * parallel threads in such a way that an allocation can fail while
+ * the mask is being updated. If a page allocation is about to fail,
+ * check if the cpuset changed during allocation and if so, retry.
+ */
+ if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
+ goto retry_cpuset;
+
+#ifdef CONFIG_MEM_TRACKER
+ if (page) {
+ page->mem_track_entry = NULL;
+ mem_alloc_tracker(page, order);
+ }
+#endif
+ return page;
+}
+EXPORT_SYMBOL(__alloc_pages_nodemask);
+
+/*
+ * Common helper functions.
+ */
+unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
+{
+ struct page *page;
+
+ /*
+ * __get_free_pages() returns a 32-bit address, which cannot represent
+ * a highmem page
+ */
+ VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
+
+ page = alloc_pages(gfp_mask, order);
+ if (!page)
+ return 0;
+ return (unsigned long) page_address(page);
+}
+EXPORT_SYMBOL(__get_free_pages);
+
+unsigned long get_zeroed_page(gfp_t gfp_mask)
+{
+ return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
+}
+EXPORT_SYMBOL(get_zeroed_page);
+
+void __free_pages(struct page *page, unsigned int order)
+{
+ if (put_page_testzero(page)) {
+ if (order == 0)
+ free_hot_cold_page(page, 0);
+ else
+ __free_pages_ok(page, order);
+ }
+}
+
+EXPORT_SYMBOL(__free_pages);
+
+void free_pages(unsigned long addr, unsigned int order)
+{
+ if (addr != 0) {
+ VM_BUG_ON(!virt_addr_valid((void *)addr));
+ __free_pages(virt_to_page((void *)addr), order);
+ }
+}
+
+EXPORT_SYMBOL(free_pages);
+
+static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
+{
+ if (addr) {
+ unsigned long alloc_end = addr + (PAGE_SIZE << order);
+ unsigned long used = addr + PAGE_ALIGN(size);
+
+ split_page(virt_to_page((void *)addr), order);
+ while (used < alloc_end) {
+ free_page(used);
+ used += PAGE_SIZE;
+ }
+ }
+ return (void *)addr;
+}
+
+/**
+ * alloc_pages_exact - allocate an exact number physically-contiguous pages.
+ * @size: the number of bytes to allocate
+ * @gfp_mask: GFP flags for the allocation
+ *
+ * This function is similar to alloc_pages(), except that it allocates the
+ * minimum number of pages to satisfy the request. alloc_pages() can only
+ * allocate memory in power-of-two pages.
+ *
+ * This function is also limited by MAX_ORDER.
+ *
+ * Memory allocated by this function must be released by free_pages_exact().
+ */
+void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
+{
+ unsigned int order = get_order(size);
+ unsigned long addr;
+
+ addr = __get_free_pages(gfp_mask, order);
+ return make_alloc_exact(addr, order, size);
+}
+EXPORT_SYMBOL(alloc_pages_exact);
+
+/**
+ * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
+ * pages on a node.
+ * @nid: the preferred node ID where memory should be allocated
+ * @size: the number of bytes to allocate
+ * @gfp_mask: GFP flags for the allocation
+ *
+ * Like alloc_pages_exact(), but try to allocate on node nid first before falling
+ * back.
+ * Note this is not alloc_pages_exact_node() which allocates on a specific node,
+ * but is not exact.
+ */
+void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
+{
+ unsigned order = get_order(size);
+ struct page *p = alloc_pages_node(nid, gfp_mask, order);
+ if (!p)
+ return NULL;
+ return make_alloc_exact((unsigned long)page_address(p), order, size);
+}
+EXPORT_SYMBOL(alloc_pages_exact_nid);
+
+/**
+ * free_pages_exact - release memory allocated via alloc_pages_exact()
+ * @virt: the value returned by alloc_pages_exact.
+ * @size: size of allocation, same value as passed to alloc_pages_exact().
+ *
+ * Release the memory allocated by a previous call to alloc_pages_exact.
+ */
+void free_pages_exact(void *virt, size_t size)
+{
+ unsigned long addr = (unsigned long)virt;
+ unsigned long end = addr + PAGE_ALIGN(size);
+
+ while (addr < end) {
+ free_page(addr);
+ addr += PAGE_SIZE;
+ }
+}
+EXPORT_SYMBOL(free_pages_exact);
+
+static unsigned int nr_free_zone_pages(int offset)
+{
+ struct zoneref *z;
+ struct zone *zone;
+
+ /* Just pick one node, since fallback list is circular */
+ unsigned int sum = 0;
+
+ struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
+
+ for_each_zone_zonelist(zone, z, zonelist, offset) {
+ unsigned long size = zone->present_pages;
+ unsigned long high = high_wmark_pages(zone);
+ if (size > high)
+ sum += size - high;
+ }
+
+ return sum;
+}
+
+/*
+ * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
+ */
+unsigned int nr_free_buffer_pages(void)
+{
+ return nr_free_zone_pages(gfp_zone(GFP_USER));
+}
+EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
+
+/*
+ * Amount of free RAM allocatable within all zones
+ */
+unsigned int nr_free_pagecache_pages(void)
+{
+ return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
+}
+
+static inline void show_node(struct zone *zone)
+{
+ if (NUMA_BUILD)
+ printk("Node %d ", zone_to_nid(zone));
+}
+
+void si_meminfo(struct sysinfo *val)
+{
+ val->totalram = totalram_pages;
+ val->sharedram = 0;
+ val->freeram = global_page_state(NR_FREE_PAGES);
+ val->bufferram = nr_blockdev_pages();
+ val->totalhigh = totalhigh_pages;
+ val->freehigh = nr_free_highpages();
+ val->mem_unit = PAGE_SIZE;
+}
+
+EXPORT_SYMBOL(si_meminfo);
+
+#ifdef CONFIG_NUMA
+void si_meminfo_node(struct sysinfo *val, int nid)
+{
+ pg_data_t *pgdat = NODE_DATA(nid);
+
+ val->totalram = pgdat->node_present_pages;
+ val->freeram = node_page_state(nid, NR_FREE_PAGES);
+#ifdef CONFIG_HIGHMEM
+ val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
+ val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
+ NR_FREE_PAGES);
+#else
+ val->totalhigh = 0;
+ val->freehigh = 0;
+#endif
+ val->mem_unit = PAGE_SIZE;
+}
+#endif
+
+/*
+ * Determine whether the node should be displayed or not, depending on whether
+ * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
+ */
+bool skip_free_areas_node(unsigned int flags, int nid)
+{
+ bool ret = false;
+ unsigned int cpuset_mems_cookie;
+
+ if (!(flags & SHOW_MEM_FILTER_NODES))
+ goto out;
+
+ do {
+ cpuset_mems_cookie = get_mems_allowed();
+ ret = !node_isset(nid, cpuset_current_mems_allowed);
+ } while (!put_mems_allowed(cpuset_mems_cookie));
+out:
+ return ret;
+}
+
+#define K(x) ((x) << (PAGE_SHIFT-10))
+
+/*
+ * Show free area list (used inside shift_scroll-lock stuff)
+ * We also calculate the percentage fragmentation. We do this by counting the
+ * memory on each free list with the exception of the first item on the list.
+ * Suppresses nodes that are not allowed by current's cpuset if
+ * SHOW_MEM_FILTER_NODES is passed.
+ */
+void show_free_areas(unsigned int filter)
+{
+ int cpu;
+ struct zone *zone;
+
+ for_each_populated_zone(zone) {
+ if (skip_free_areas_node(filter, zone_to_nid(zone)))
+ continue;
+ show_node(zone);
+ printk("%s per-cpu:\n", zone->name);
+
+ for_each_online_cpu(cpu) {
+ struct per_cpu_pageset *pageset;
+
+ pageset = per_cpu_ptr(zone->pageset, cpu);
+
+ printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
+ cpu, pageset->pcp.high,
+ pageset->pcp.batch, pageset->pcp.count);
+ }
+ }
+
+ printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
+ " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
+ " unevictable:%lu"
+ " dirty:%lu writeback:%lu unstable:%lu\n"
+ " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
+ " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
+ global_page_state(NR_ACTIVE_ANON),
+ global_page_state(NR_INACTIVE_ANON),
+ global_page_state(NR_ISOLATED_ANON),
+ global_page_state(NR_ACTIVE_FILE),
+ global_page_state(NR_INACTIVE_FILE),
+ global_page_state(NR_ISOLATED_FILE),
+ global_page_state(NR_UNEVICTABLE),
+ global_page_state(NR_FILE_DIRTY),
+ global_page_state(NR_WRITEBACK),
+ global_page_state(NR_UNSTABLE_NFS),
+ global_page_state(NR_FREE_PAGES),
+ global_page_state(NR_SLAB_RECLAIMABLE),
+ global_page_state(NR_SLAB_UNRECLAIMABLE),
+ global_page_state(NR_FILE_MAPPED),
+ global_page_state(NR_SHMEM),
+ global_page_state(NR_PAGETABLE),
+ global_page_state(NR_BOUNCE));
+
+ for_each_populated_zone(zone) {
+ int i;
+
+ if (skip_free_areas_node(filter, zone_to_nid(zone)))
+ continue;
+ show_node(zone);
+ printk("%s"
+ " free:%lukB"
+ " min:%lukB"
+ " low:%lukB"
+ " high:%lukB"
+ " active_anon:%lukB"
+ " inactive_anon:%lukB"
+ " active_file:%lukB"
+ " inactive_file:%lukB"
+ " unevictable:%lukB"
+ " isolated(anon):%lukB"
+ " isolated(file):%lukB"
+ " present:%lukB"
+ " mlocked:%lukB"
+ " dirty:%lukB"
+ " writeback:%lukB"
+ " mapped:%lukB"
+ " shmem:%lukB"
+ " slab_reclaimable:%lukB"
+ " slab_unreclaimable:%lukB"
+ " kernel_stack:%lukB"
+ " pagetables:%lukB"
+ " unstable:%lukB"
+ " bounce:%lukB"
+ " writeback_tmp:%lukB"
+ " pages_scanned:%lu"
+ " all_unreclaimable? %s"
+ "\n",
+ zone->name,
+ K(zone_page_state(zone, NR_FREE_PAGES)),
+ K(min_wmark_pages(zone)),
+ K(low_wmark_pages(zone)),
+ K(high_wmark_pages(zone)),
+ K(zone_page_state(zone, NR_ACTIVE_ANON)),
+ K(zone_page_state(zone, NR_INACTIVE_ANON)),
+ K(zone_page_state(zone, NR_ACTIVE_FILE)),
+ K(zone_page_state(zone, NR_INACTIVE_FILE)),
+ K(zone_page_state(zone, NR_UNEVICTABLE)),
+ K(zone_page_state(zone, NR_ISOLATED_ANON)),
+ K(zone_page_state(zone, NR_ISOLATED_FILE)),
+ K(zone->present_pages),
+ K(zone_page_state(zone, NR_MLOCK)),
+ K(zone_page_state(zone, NR_FILE_DIRTY)),
+ K(zone_page_state(zone, NR_WRITEBACK)),
+ K(zone_page_state(zone, NR_FILE_MAPPED)),
+ K(zone_page_state(zone, NR_SHMEM)),
+ K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
+ K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
+ zone_page_state(zone, NR_KERNEL_STACK) *
+ THREAD_SIZE / 1024,
+ K(zone_page_state(zone, NR_PAGETABLE)),
+ K(zone_page_state(zone, NR_UNSTABLE_NFS)),
+ K(zone_page_state(zone, NR_BOUNCE)),
+ K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
+ zone->pages_scanned,
+ (zone->all_unreclaimable ? "yes" : "no")
+ );
+ printk("lowmem_reserve[]:");
+ for (i = 0; i < MAX_NR_ZONES; i++)
+ printk(" %lu", zone->lowmem_reserve[i]);
+ printk("\n");
+ }
+
+ for_each_populated_zone(zone) {
+ unsigned long nr[MAX_ORDER], flags, order, total = 0;
+
+ if (skip_free_areas_node(filter, zone_to_nid(zone)))
+ continue;
+ show_node(zone);
+ printk("%s: ", zone->name);
+
+ spin_lock_irqsave(&zone->lock, flags);
+ for (order = 0; order < MAX_ORDER; order++) {
+ nr[order] = zone->free_area[order].nr_free;
+ total += nr[order] << order;
+ }
+ spin_unlock_irqrestore(&zone->lock, flags);
+ for (order = 0; order < MAX_ORDER; order++)
+ printk("%lu*%lukB ", nr[order], K(1UL) << order);
+ printk("= %lukB\n", K(total));
+ }
+
+ printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
+
+ show_swap_cache_info();
+}
+
+static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
+{
+ zoneref->zone = zone;
+ zoneref->zone_idx = zone_idx(zone);
+}
+
+/*
+ * Builds allocation fallback zone lists.
+ *
+ * Add all populated zones of a node to the zonelist.
+ */
+static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
+ int nr_zones, enum zone_type zone_type)
+{
+ struct zone *zone;
+
+ BUG_ON(zone_type >= MAX_NR_ZONES);
+ zone_type++;
+
+ do {
+ zone_type--;
+ zone = pgdat->node_zones + zone_type;
+ if (populated_zone(zone)) {
+ zoneref_set_zone(zone,
+ &zonelist->_zonerefs[nr_zones++]);
+ check_highest_zone(zone_type);
+ }
+
+ } while (zone_type);
+ return nr_zones;
+}
+
+
+/*
+ * zonelist_order:
+ * 0 = automatic detection of better ordering.
+ * 1 = order by ([node] distance, -zonetype)
+ * 2 = order by (-zonetype, [node] distance)
+ *
+ * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
+ * the same zonelist. So only NUMA can configure this param.
+ */
+#define ZONELIST_ORDER_DEFAULT 0
+#define ZONELIST_ORDER_NODE 1
+#define ZONELIST_ORDER_ZONE 2
+
+/* zonelist order in the kernel.
+ * set_zonelist_order() will set this to NODE or ZONE.
+ */
+static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
+static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
+
+
+#ifdef CONFIG_NUMA
+/* The value user specified ....changed by config */
+static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
+/* string for sysctl */
+#define NUMA_ZONELIST_ORDER_LEN 16
+char numa_zonelist_order[16] = "default";
+
+/*
+ * interface for configure zonelist ordering.
+ * command line option "numa_zonelist_order"
+ * = "[dD]efault - default, automatic configuration.
+ * = "[nN]ode - order by node locality, then by zone within node
+ * = "[zZ]one - order by zone, then by locality within zone
+ */
+
+static int __parse_numa_zonelist_order(char *s)
+{
+ if (*s == 'd' || *s == 'D') {
+ user_zonelist_order = ZONELIST_ORDER_DEFAULT;
+ } else if (*s == 'n' || *s == 'N') {
+ user_zonelist_order = ZONELIST_ORDER_NODE;
+ } else if (*s == 'z' || *s == 'Z') {
+ user_zonelist_order = ZONELIST_ORDER_ZONE;
+ } else {
+ printk(KERN_WARNING
+ "Ignoring invalid numa_zonelist_order value: "
+ "%s\n", s);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static __init int setup_numa_zonelist_order(char *s)
+{
+ int ret;
+
+ if (!s)
+ return 0;
+
+ ret = __parse_numa_zonelist_order(s);
+ if (ret == 0)
+ strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
+
+ return ret;
+}
+early_param("numa_zonelist_order", setup_numa_zonelist_order);
+
+/*
+ * sysctl handler for numa_zonelist_order
+ */
+int numa_zonelist_order_handler(ctl_table *table, int write,
+ void __user *buffer, size_t *length,
+ loff_t *ppos)
+{
+ char saved_string[NUMA_ZONELIST_ORDER_LEN];
+ int ret;
+ static DEFINE_MUTEX(zl_order_mutex);
+
+ mutex_lock(&zl_order_mutex);
+ if (write)
+ strcpy(saved_string, (char*)table->data);
+ ret = proc_dostring(table, write, buffer, length, ppos);
+ if (ret)
+ goto out;
+ if (write) {
+ int oldval = user_zonelist_order;
+ if (__parse_numa_zonelist_order((char*)table->data)) {
+ /*
+ * bogus value. restore saved string
+ */
+ strncpy((char*)table->data, saved_string,
+ NUMA_ZONELIST_ORDER_LEN);
+ user_zonelist_order = oldval;
+ } else if (oldval != user_zonelist_order) {
+ mutex_lock(&zonelists_mutex);
+ build_all_zonelists(NULL);
+ mutex_unlock(&zonelists_mutex);
+ }
+ }
+out:
+ mutex_unlock(&zl_order_mutex);
+ return ret;
+}
+
+
+#define MAX_NODE_LOAD (nr_online_nodes)
+static int node_load[MAX_NUMNODES];
+
+/**
+ * find_next_best_node - find the next node that should appear in a given node's fallback list
+ * @node: node whose fallback list we're appending
+ * @used_node_mask: nodemask_t of already used nodes
+ *
+ * We use a number of factors to determine which is the next node that should
+ * appear on a given node's fallback list. The node should not have appeared
+ * already in @node's fallback list, and it should be the next closest node
+ * according to the distance array (which contains arbitrary distance values
+ * from each node to each node in the system), and should also prefer nodes
+ * with no CPUs, since presumably they'll have very little allocation pressure
+ * on them otherwise.
+ * It returns -1 if no node is found.
+ */
+static int find_next_best_node(int node, nodemask_t *used_node_mask)
+{
+ int n, val;
+ int min_val = INT_MAX;
+ int best_node = -1;
+ const struct cpumask *tmp = cpumask_of_node(0);
+
+ /* Use the local node if we haven't already */
+ if (!node_isset(node, *used_node_mask)) {
+ node_set(node, *used_node_mask);
+ return node;
+ }
+
+ for_each_node_state(n, N_HIGH_MEMORY) {
+
+ /* Don't want a node to appear more than once */
+ if (node_isset(n, *used_node_mask))
+ continue;
+
+ /* Use the distance array to find the distance */
+ val = node_distance(node, n);
+
+ /* Penalize nodes under us ("prefer the next node") */
+ val += (n < node);
+
+ /* Give preference to headless and unused nodes */
+ tmp = cpumask_of_node(n);
+ if (!cpumask_empty(tmp))
+ val += PENALTY_FOR_NODE_WITH_CPUS;
+
+ /* Slight preference for less loaded node */
+ val *= (MAX_NODE_LOAD*MAX_NUMNODES);
+ val += node_load[n];
+
+ if (val < min_val) {
+ min_val = val;
+ best_node = n;
+ }
+ }
+
+ if (best_node >= 0)
+ node_set(best_node, *used_node_mask);
+
+ return best_node;
+}
+
+
+/*
+ * Build zonelists ordered by node and zones within node.
+ * This results in maximum locality--normal zone overflows into local
+ * DMA zone, if any--but risks exhausting DMA zone.
+ */
+static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
+{
+ int j;
+ struct zonelist *zonelist;
+
+ zonelist = &pgdat->node_zonelists[0];
+ for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
+ ;
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j,
+ MAX_NR_ZONES - 1);
+ zonelist->_zonerefs[j].zone = NULL;
+ zonelist->_zonerefs[j].zone_idx = 0;
+}
+
+/*
+ * Build gfp_thisnode zonelists
+ */
+static void build_thisnode_zonelists(pg_data_t *pgdat)
+{
+ int j;
+ struct zonelist *zonelist;
+
+ zonelist = &pgdat->node_zonelists[1];
+ j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
+ zonelist->_zonerefs[j].zone = NULL;
+ zonelist->_zonerefs[j].zone_idx = 0;
+}
+
+/*
+ * Build zonelists ordered by zone and nodes within zones.
+ * This results in conserving DMA zone[s] until all Normal memory is
+ * exhausted, but results in overflowing to remote node while memory
+ * may still exist in local DMA zone.
+ */
+static int node_order[MAX_NUMNODES];
+
+static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
+{
+ int pos, j, node;
+ int zone_type; /* needs to be signed */
+ struct zone *z;
+ struct zonelist *zonelist;
+
+ zonelist = &pgdat->node_zonelists[0];
+ pos = 0;
+ for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
+ for (j = 0; j < nr_nodes; j++) {
+ node = node_order[j];
+ z = &NODE_DATA(node)->node_zones[zone_type];
+ if (populated_zone(z)) {
+ zoneref_set_zone(z,
+ &zonelist->_zonerefs[pos++]);
+ check_highest_zone(zone_type);
+ }
+ }
+ }
+ zonelist->_zonerefs[pos].zone = NULL;
+ zonelist->_zonerefs[pos].zone_idx = 0;
+}
+
+static int default_zonelist_order(void)
+{
+ int nid, zone_type;
+ unsigned long low_kmem_size,total_size;
+ struct zone *z;
+ int average_size;
+ /*
+ * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
+ * If they are really small and used heavily, the system can fall
+ * into OOM very easily.
+ * This function detect ZONE_DMA/DMA32 size and configures zone order.
+ */
+ /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
+ low_kmem_size = 0;
+ total_size = 0;
+ for_each_online_node(nid) {
+ for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
+ z = &NODE_DATA(nid)->node_zones[zone_type];
+ if (populated_zone(z)) {
+ if (zone_type < ZONE_NORMAL)
+ low_kmem_size += z->present_pages;
+ total_size += z->present_pages;
+ } else if (zone_type == ZONE_NORMAL) {
+ /*
+ * If any node has only lowmem, then node order
+ * is preferred to allow kernel allocations
+ * locally; otherwise, they can easily infringe
+ * on other nodes when there is an abundance of
+ * lowmem available to allocate from.
+ */
+ return ZONELIST_ORDER_NODE;
+ }
+ }
+ }
+ if (!low_kmem_size || /* there are no DMA area. */
+ low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
+ return ZONELIST_ORDER_NODE;
+ /*
+ * look into each node's config.
+ * If there is a node whose DMA/DMA32 memory is very big area on
+ * local memory, NODE_ORDER may be suitable.
+ */
+ average_size = total_size /
+ (nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
+ for_each_online_node(nid) {
+ low_kmem_size = 0;
+ total_size = 0;
+ for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
+ z = &NODE_DATA(nid)->node_zones[zone_type];
+ if (populated_zone(z)) {
+ if (zone_type < ZONE_NORMAL)
+ low_kmem_size += z->present_pages;
+ total_size += z->present_pages;
+ }
+ }
+ if (low_kmem_size &&
+ total_size > average_size && /* ignore small node */
+ low_kmem_size > total_size * 70/100)
+ return ZONELIST_ORDER_NODE;
+ }
+ return ZONELIST_ORDER_ZONE;
+}
+
+static void set_zonelist_order(void)
+{
+ if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
+ current_zonelist_order = default_zonelist_order();
+ else
+ current_zonelist_order = user_zonelist_order;
+}
+
+static void build_zonelists(pg_data_t *pgdat)
+{
+ int j, node, load;
+ enum zone_type i;
+ nodemask_t used_mask;
+ int local_node, prev_node;
+ struct zonelist *zonelist;
+ int order = current_zonelist_order;
+
+ /* initialize zonelists */
+ for (i = 0; i < MAX_ZONELISTS; i++) {
+ zonelist = pgdat->node_zonelists + i;
+ zonelist->_zonerefs[0].zone = NULL;
+ zonelist->_zonerefs[0].zone_idx = 0;
+ }
+
+ /* NUMA-aware ordering of nodes */
+ local_node = pgdat->node_id;
+ load = nr_online_nodes;
+ prev_node = local_node;
+ nodes_clear(used_mask);
+
+ memset(node_order, 0, sizeof(node_order));
+ j = 0;
+
+ while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
+ int distance = node_distance(local_node, node);
+
+ /*
+ * If another node is sufficiently far away then it is better
+ * to reclaim pages in a zone before going off node.
+ */
+ if (distance > RECLAIM_DISTANCE)
+ zone_reclaim_mode = 1;
+
+ /*
+ * We don't want to pressure a particular node.
+ * So adding penalty to the first node in same
+ * distance group to make it round-robin.
+ */
+ if (distance != node_distance(local_node, prev_node))
+ node_load[node] = load;
+
+ prev_node = node;
+ load--;
+ if (order == ZONELIST_ORDER_NODE)
+ build_zonelists_in_node_order(pgdat, node);
+ else
+ node_order[j++] = node; /* remember order */
+ }
+
+ if (order == ZONELIST_ORDER_ZONE) {
+ /* calculate node order -- i.e., DMA last! */
+ build_zonelists_in_zone_order(pgdat, j);
+ }
+
+ build_thisnode_zonelists(pgdat);
+}
+
+/* Construct the zonelist performance cache - see further mmzone.h */
+static void build_zonelist_cache(pg_data_t *pgdat)
+{
+ struct zonelist *zonelist;
+ struct zonelist_cache *zlc;
+ struct zoneref *z;
+
+ zonelist = &pgdat->node_zonelists[0];
+ zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
+ bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
+ for (z = zonelist->_zonerefs; z->zone; z++)
+ zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
+}
+
+#ifdef CONFIG_HAVE_MEMORYLESS_NODES
+/*
+ * Return node id of node used for "local" allocations.
+ * I.e., first node id of first zone in arg node's generic zonelist.
+ * Used for initializing percpu 'numa_mem', which is used primarily
+ * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
+ */
+int local_memory_node(int node)
+{
+ struct zone *zone;
+
+ (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
+ gfp_zone(GFP_KERNEL),
+ NULL,
+ &zone);
+ return zone->node;
+}
+#endif
+
+#else /* CONFIG_NUMA */
+
+static void set_zonelist_order(void)
+{
+ current_zonelist_order = ZONELIST_ORDER_ZONE;
+}
+
+static void build_zonelists(pg_data_t *pgdat)
+{
+ int node, local_node;
+ enum zone_type j;
+ struct zonelist *zonelist;
+
+ local_node = pgdat->node_id;
+
+ zonelist = &pgdat->node_zonelists[0];
+ j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
+
+ /*
+ * Now we build the zonelist so that it contains the zones
+ * of all the other nodes.
+ * We don't want to pressure a particular node, so when
+ * building the zones for node N, we make sure that the
+ * zones coming right after the local ones are those from
+ * node N+1 (modulo N)
+ */
+ for (node = local_node + 1; node < MAX_NUMNODES; node++) {
+ if (!node_online(node))
+ continue;
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j,
+ MAX_NR_ZONES - 1);
+ }
+ for (node = 0; node < local_node; node++) {
+ if (!node_online(node))
+ continue;
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j,
+ MAX_NR_ZONES - 1);
+ }
+
+ zonelist->_zonerefs[j].zone = NULL;
+ zonelist->_zonerefs[j].zone_idx = 0;
+}
+
+/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
+static void build_zonelist_cache(pg_data_t *pgdat)
+{
+ pgdat->node_zonelists[0].zlcache_ptr = NULL;
+}
+
+#endif /* CONFIG_NUMA */
+
+/*
+ * Boot pageset table. One per cpu which is going to be used for all
+ * zones and all nodes. The parameters will be set in such a way
+ * that an item put on a list will immediately be handed over to
+ * the buddy list. This is safe since pageset manipulation is done
+ * with interrupts disabled.
+ *
+ * The boot_pagesets must be kept even after bootup is complete for
+ * unused processors and/or zones. They do play a role for bootstrapping
+ * hotplugged processors.
+ *
+ * zoneinfo_show() and maybe other functions do
+ * not check if the processor is online before following the pageset pointer.
+ * Other parts of the kernel may not check if the zone is available.
+ */
+static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
+static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
+static void setup_zone_pageset(struct zone *zone);
+
+/*
+ * Global mutex to protect against size modification of zonelists
+ * as well as to serialize pageset setup for the new populated zone.
+ */
+DEFINE_MUTEX(zonelists_mutex);
+
+/* return values int ....just for stop_machine() */
+static __init_refok int __build_all_zonelists(void *data)
+{
+ int nid;
+ int cpu;
+
+#ifdef CONFIG_NUMA
+ memset(node_load, 0, sizeof(node_load));
+#endif
+ for_each_online_node(nid) {
+ pg_data_t *pgdat = NODE_DATA(nid);
+
+ build_zonelists(pgdat);
+ build_zonelist_cache(pgdat);
+ }
+
+ /*
+ * Initialize the boot_pagesets that are going to be used
+ * for bootstrapping processors. The real pagesets for
+ * each zone will be allocated later when the per cpu
+ * allocator is available.
+ *
+ * boot_pagesets are used also for bootstrapping offline
+ * cpus if the system is already booted because the pagesets
+ * are needed to initialize allocators on a specific cpu too.
+ * F.e. the percpu allocator needs the page allocator which
+ * needs the percpu allocator in order to allocate its pagesets
+ * (a chicken-egg dilemma).
+ */
+ for_each_possible_cpu(cpu) {
+ setup_pageset(&per_cpu(boot_pageset, cpu), 0);
+
+#ifdef CONFIG_HAVE_MEMORYLESS_NODES
+ /*
+ * We now know the "local memory node" for each node--
+ * i.e., the node of the first zone in the generic zonelist.
+ * Set up numa_mem percpu variable for on-line cpus. During
+ * boot, only the boot cpu should be on-line; we'll init the
+ * secondary cpus' numa_mem as they come on-line. During
+ * node/memory hotplug, we'll fixup all on-line cpus.
+ */
+ if (cpu_online(cpu))
+ set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
+#endif
+ }
+
+ return 0;
+}
+
+/*
+ * Called with zonelists_mutex held always
+ * unless system_state == SYSTEM_BOOTING.
+ */
+void __ref build_all_zonelists(void *data)
+{
+ set_zonelist_order();
+
+ if (system_state == SYSTEM_BOOTING) {
+ __build_all_zonelists(NULL);
+ mminit_verify_zonelist();
+ cpuset_init_current_mems_allowed();
+ } else {
+ /* we have to stop all cpus to guarantee there is no user
+ of zonelist */
+#ifdef CONFIG_MEMORY_HOTPLUG
+ if (data)
+ setup_zone_pageset((struct zone *)data);
+#endif
+ stop_machine(__build_all_zonelists, NULL, NULL);
+ /* cpuset refresh routine should be here */
+ }
+ vm_total_pages = nr_free_pagecache_pages();
+ /*
+ * Disable grouping by mobility if the number of pages in the
+ * system is too low to allow the mechanism to work. It would be
+ * more accurate, but expensive to check per-zone. This check is
+ * made on memory-hotadd so a system can start with mobility
+ * disabled and enable it later
+ */
+ if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
+ page_group_by_mobility_disabled = 1;
+ else
+ page_group_by_mobility_disabled = 0;
+
+ printk("Built %i zonelists in %s order, mobility grouping %s. "
+ "Total pages: %ld\n",
+ nr_online_nodes,
+ zonelist_order_name[current_zonelist_order],
+ page_group_by_mobility_disabled ? "off" : "on",
+ vm_total_pages);
+#ifdef CONFIG_NUMA
+ printk("Policy zone: %s\n", zone_names[policy_zone]);
+#endif
+}
+
+/*
+ * Helper functions to size the waitqueue hash table.
+ * Essentially these want to choose hash table sizes sufficiently
+ * large so that collisions trying to wait on pages are rare.
+ * But in fact, the number of active page waitqueues on typical
+ * systems is ridiculously low, less than 200. So this is even
+ * conservative, even though it seems large.
+ *
+ * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
+ * waitqueues, i.e. the size of the waitq table given the number of pages.
+ */
+#define PAGES_PER_WAITQUEUE 256
+
+#ifndef CONFIG_MEMORY_HOTPLUG
+static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
+{
+ unsigned long size = 1;
+
+ pages /= PAGES_PER_WAITQUEUE;
+
+ while (size < pages)
+ size <<= 1;
+
+ /*
+ * Once we have dozens or even hundreds of threads sleeping
+ * on IO we've got bigger problems than wait queue collision.
+ * Limit the size of the wait table to a reasonable size.
+ */
+ size = min(size, 4096UL);
+
+ return max(size, 4UL);
+}
+#else
+/*
+ * A zone's size might be changed by hot-add, so it is not possible to determine
+ * a suitable size for its wait_table. So we use the maximum size now.
+ *
+ * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
+ *
+ * i386 (preemption config) : 4096 x 16 = 64Kbyte.
+ * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
+ * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
+ *
+ * The maximum entries are prepared when a zone's memory is (512K + 256) pages
+ * or more by the traditional way. (See above). It equals:
+ *
+ * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
+ * ia64(16K page size) : = ( 8G + 4M)byte.
+ * powerpc (64K page size) : = (32G +16M)byte.
+ */
+static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
+{
+ return 4096UL;
+}
+#endif
+
+/*
+ * This is an integer logarithm so that shifts can be used later
+ * to extract the more random high bits from the multiplicative
+ * hash function before the remainder is taken.
+ */
+static inline unsigned long wait_table_bits(unsigned long size)
+{
+ return ffz(~size);
+}
+
+#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
+
+/*
+ * Check if a pageblock contains reserved pages
+ */
+static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
+{
+ unsigned long pfn;
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn++) {
+ if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * Mark a number of pageblocks as MIGRATE_RESERVE. The number
+ * of blocks reserved is based on min_wmark_pages(zone). The memory within
+ * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
+ * higher will lead to a bigger reserve which will get freed as contiguous
+ * blocks as reclaim kicks in
+ */
+static void setup_zone_migrate_reserve(struct zone *zone)
+{
+ unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
+ struct page *page;
+ unsigned long block_migratetype;
+ int reserve;
+
+ /*
+ * Get the start pfn, end pfn and the number of blocks to reserve
+ * We have to be careful to be aligned to pageblock_nr_pages to
+ * make sure that we always check pfn_valid for the first page in
+ * the block.
+ */
+ start_pfn = zone->zone_start_pfn;
+ end_pfn = start_pfn + zone->spanned_pages;
+ start_pfn = roundup(start_pfn, pageblock_nr_pages);
+ reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
+ pageblock_order;
+
+ /*
+ * Reserve blocks are generally in place to help high-order atomic
+ * allocations that are short-lived. A min_free_kbytes value that
+ * would result in more than 2 reserve blocks for atomic allocations
+ * is assumed to be in place to help anti-fragmentation for the
+ * future allocation of hugepages at runtime.
+ */
+ reserve = min(2, reserve);
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
+ if (!pfn_valid(pfn))
+ continue;
+ page = pfn_to_page(pfn);
+
+ /* Watch out for overlapping nodes */
+ if (page_to_nid(page) != zone_to_nid(zone))
+ continue;
+
+ block_migratetype = get_pageblock_migratetype(page);
+
+ /* Only test what is necessary when the reserves are not met */
+ if (reserve > 0) {
+ /*
+ * Blocks with reserved pages will never free, skip
+ * them.
+ */
+ block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
+ if (pageblock_is_reserved(pfn, block_end_pfn))
+ continue;
+
+ /* If this block is reserved, account for it */
+ if (block_migratetype == MIGRATE_RESERVE) {
+ reserve--;
+ continue;
+ }
+
+ /* Suitable for reserving if this block is movable */
+ if (block_migratetype == MIGRATE_MOVABLE) {
+ set_pageblock_migratetype(page,
+ MIGRATE_RESERVE);
+ move_freepages_block(zone, page,
+ MIGRATE_RESERVE);
+ reserve--;
+ continue;
+ }
+ }
+
+ /*
+ * If the reserve is met and this is a previous reserved block,
+ * take it back
+ */
+ if (block_migratetype == MIGRATE_RESERVE) {
+ set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+ move_freepages_block(zone, page, MIGRATE_MOVABLE);
+ }
+ }
+}
+
+/*
+ * Initially all pages are reserved - free ones are freed
+ * up by free_all_bootmem() once the early boot process is
+ * done. Non-atomic initialization, single-pass.
+ */
+void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
+ unsigned long start_pfn, enum memmap_context context)
+{
+ struct page *page;
+ unsigned long end_pfn = start_pfn + size;
+ unsigned long pfn;
+ struct zone *z;
+
+ if (highest_memmap_pfn < end_pfn - 1)
+ highest_memmap_pfn = end_pfn - 1;
+
+ z = &NODE_DATA(nid)->node_zones[zone];
+ for (pfn = start_pfn; pfn < end_pfn; pfn++) {
+ /*
+ * There can be holes in boot-time mem_map[]s
+ * handed to this function. They do not
+ * exist on hotplugged memory.
+ */
+ if (context == MEMMAP_EARLY) {
+ if (!early_pfn_valid(pfn))
+ continue;
+ if (!early_pfn_in_nid(pfn, nid))
+ continue;
+ }
+ page = pfn_to_page(pfn);
+ set_page_links(page, zone, nid, pfn);
+ mminit_verify_page_links(page, zone, nid, pfn);
+ init_page_count(page);
+ reset_page_mapcount(page);
+ SetPageReserved(page);
+ /*
+ * Mark the block movable so that blocks are reserved for
+ * movable at startup. This will force kernel allocations
+ * to reserve their blocks rather than leaking throughout
+ * the address space during boot when many long-lived
+ * kernel allocations are made. Later some blocks near
+ * the start are marked MIGRATE_RESERVE by
+ * setup_zone_migrate_reserve()
+ *
+ * bitmap is created for zone's valid pfn range. but memmap
+ * can be created for invalid pages (for alignment)
+ * check here not to call set_pageblock_migratetype() against
+ * pfn out of zone.
+ */
+ if ((z->zone_start_pfn <= pfn)
+ && (pfn < z->zone_start_pfn + z->spanned_pages)
+ && !(pfn & (pageblock_nr_pages - 1)))
+ set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+
+ INIT_LIST_HEAD(&page->lru);
+#ifdef WANT_PAGE_VIRTUAL
+ /* The shift won't overflow because ZONE_NORMAL is below 4G. */
+ if (!is_highmem_idx(zone))
+ set_page_address(page, __va(pfn << PAGE_SHIFT));
+#endif
+ }
+}
+
+static void __meminit zone_init_free_lists(struct zone *zone)
+{
+ int order, t;
+ for_each_migratetype_order(order, t) {
+ INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
+ zone->free_area[order].nr_free = 0;
+ }
+}
+
+#ifndef __HAVE_ARCH_MEMMAP_INIT
+#define memmap_init(size, nid, zone, start_pfn) \
+ memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
+#endif
+
+static int zone_batchsize(struct zone *zone)
+{
+#ifdef CONFIG_MMU
+ int batch;
+
+ /*
+ * The per-cpu-pages pools are set to around 1000th of the
+ * size of the zone. But no more than 1/2 of a meg.
+ *
+ * OK, so we don't know how big the cache is. So guess.
+ */
+ batch = zone->present_pages / 1024;
+ if (batch * PAGE_SIZE > 512 * 1024)
+ batch = (512 * 1024) / PAGE_SIZE;
+ batch /= 4; /* We effectively *= 4 below */
+ if (batch < 1)
+ batch = 1;
+
+ /*
+ * Clamp the batch to a 2^n - 1 value. Having a power
+ * of 2 value was found to be more likely to have
+ * suboptimal cache aliasing properties in some cases.
+ *
+ * For example if 2 tasks are alternately allocating
+ * batches of pages, one task can end up with a lot
+ * of pages of one half of the possible page colors
+ * and the other with pages of the other colors.
+ */
+ batch = rounddown_pow_of_two(batch + batch/2) - 1;
+
+ return batch;
+
+#else
+ /* The deferral and batching of frees should be suppressed under NOMMU
+ * conditions.
+ *
+ * The problem is that NOMMU needs to be able to allocate large chunks
+ * of contiguous memory as there's no hardware page translation to
+ * assemble apparent contiguous memory from discontiguous pages.
+ *
+ * Queueing large contiguous runs of pages for batching, however,
+ * causes the pages to actually be freed in smaller chunks. As there
+ * can be a significant delay between the individual batches being
+ * recycled, this leads to the once large chunks of space being
+ * fragmented and becoming unavailable for high-order allocations.
+ */
+ return 0;
+#endif
+}
+
+static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
+{
+ struct per_cpu_pages *pcp;
+ int migratetype;
+
+ memset(p, 0, sizeof(*p));
+
+ pcp = &p->pcp;
+ pcp->count = 0;
+ pcp->high = 6 * batch;
+ pcp->batch = max(1UL, 1 * batch);
+ for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
+ INIT_LIST_HEAD(&pcp->lists[migratetype]);
+}
+
+/*
+ * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
+ * to the value high for the pageset p.
+ */
+
+static void setup_pagelist_highmark(struct per_cpu_pageset *p,
+ unsigned long high)
+{
+ struct per_cpu_pages *pcp;
+
+ pcp = &p->pcp;
+ pcp->high = high;
+ pcp->batch = max(1UL, high/4);
+ if ((high/4) > (PAGE_SHIFT * 8))
+ pcp->batch = PAGE_SHIFT * 8;
+}
+
+static void setup_zone_pageset(struct zone *zone)
+{
+ int cpu;
+
+ zone->pageset = alloc_percpu(struct per_cpu_pageset);
+
+ for_each_possible_cpu(cpu) {
+ struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
+
+ setup_pageset(pcp, zone_batchsize(zone));
+
+ if (percpu_pagelist_fraction)
+ setup_pagelist_highmark(pcp,
+ (zone->present_pages /
+ percpu_pagelist_fraction));
+ }
+}
+
+/*
+ * Allocate per cpu pagesets and initialize them.
+ * Before this call only boot pagesets were available.
+ */
+void __init setup_per_cpu_pageset(void)
+{
+ struct zone *zone;
+
+ for_each_populated_zone(zone)
+ setup_zone_pageset(zone);
+}
+
+static noinline __init_refok
+int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
+{
+ int i;
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ size_t alloc_size;
+
+ /*
+ * The per-page waitqueue mechanism uses hashed waitqueues
+ * per zone.
+ */
+ zone->wait_table_hash_nr_entries =
+ wait_table_hash_nr_entries(zone_size_pages);
+ zone->wait_table_bits =
+ wait_table_bits(zone->wait_table_hash_nr_entries);
+ alloc_size = zone->wait_table_hash_nr_entries
+ * sizeof(wait_queue_head_t);
+
+ if (!slab_is_available()) {
+ zone->wait_table = (wait_queue_head_t *)
+ alloc_bootmem_node_nopanic(pgdat, alloc_size);
+ } else {
+ /*
+ * This case means that a zone whose size was 0 gets new memory
+ * via memory hot-add.
+ * But it may be the case that a new node was hot-added. In
+ * this case vmalloc() will not be able to use this new node's
+ * memory - this wait_table must be initialized to use this new
+ * node itself as well.
+ * To use this new node's memory, further consideration will be
+ * necessary.
+ */
+ zone->wait_table = vmalloc(alloc_size);
+ }
+ if (!zone->wait_table)
+ return -ENOMEM;
+
+ for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
+ init_waitqueue_head(zone->wait_table + i);
+
+ return 0;
+}
+
+static int __zone_pcp_update(void *data)
+{
+ struct zone *zone = data;
+ int cpu;
+ unsigned long batch = zone_batchsize(zone), flags;
+
+ for_each_possible_cpu(cpu) {
+ struct per_cpu_pageset *pset;
+ struct per_cpu_pages *pcp;
+ LIST_HEAD(dst);
+
+ pset = per_cpu_ptr(zone->pageset, cpu);
+ pcp = &pset->pcp;
+
+ cpu_lock_irqsave(cpu, flags);
+ isolate_pcp_pages(pcp->count, pcp, &dst);
+ free_pcppages_bulk(zone, pcp->count, &dst);
+ setup_pageset(pset, batch);
+ cpu_unlock_irqrestore(cpu, flags);
+ }
+ return 0;
+}
+
+void zone_pcp_update(struct zone *zone)
+{
+ stop_machine(__zone_pcp_update, zone, NULL);
+}
+
+static __meminit void zone_pcp_init(struct zone *zone)
+{
+ /*
+ * per cpu subsystem is not up at this point. The following code
+ * relies on the ability of the linker to provide the
+ * offset of a (static) per cpu variable into the per cpu area.
+ */
+ zone->pageset = &boot_pageset;
+
+ if (zone->present_pages)
+ printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
+ zone->name, zone->present_pages,
+ zone_batchsize(zone));
+}
+
+__meminit int init_currently_empty_zone(struct zone *zone,
+ unsigned long zone_start_pfn,
+ unsigned long size,
+ enum memmap_context context)
+{
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ int ret;
+ ret = zone_wait_table_init(zone, size);
+ if (ret)
+ return ret;
+ pgdat->nr_zones = zone_idx(zone) + 1;
+
+ zone->zone_start_pfn = zone_start_pfn;
+
+ mminit_dprintk(MMINIT_TRACE, "memmap_init",
+ "Initialising map node %d zone %lu pfns %lu -> %lu\n",
+ pgdat->node_id,
+ (unsigned long)zone_idx(zone),
+ zone_start_pfn, (zone_start_pfn + size));
+
+ zone_init_free_lists(zone);
+
+ return 0;
+}
+
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
+/*
+ * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
+ * Architectures may implement their own version but if add_active_range()
+ * was used and there are no special requirements, this is a convenient
+ * alternative
+ */
+int __meminit __early_pfn_to_nid(unsigned long pfn)
+{
+ unsigned long start_pfn, end_pfn;
+ int i, nid;
+
+ for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
+ if (start_pfn <= pfn && pfn < end_pfn)
+ return nid;
+ /* This is a memory hole */
+ return -1;
+}
+#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
+
+int __meminit early_pfn_to_nid(unsigned long pfn)
+{
+ int nid;
+
+ nid = __early_pfn_to_nid(pfn);
+ if (nid >= 0)
+ return nid;
+ /* just returns 0 */
+ return 0;
+}
+
+#ifdef CONFIG_NODES_SPAN_OTHER_NODES
+bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
+{
+ int nid;
+
+ nid = __early_pfn_to_nid(pfn);
+ if (nid >= 0 && nid != node)
+ return false;
+ return true;
+}
+#endif
+
+/**
+ * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
+ * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
+ * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
+ *
+ * If an architecture guarantees that all ranges registered with
+ * add_active_ranges() contain no holes and may be freed, this
+ * this function may be used instead of calling free_bootmem() manually.
+ */
+void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
+{
+ unsigned long start_pfn, end_pfn;
+ int i, this_nid;
+
+ for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
+ start_pfn = min(start_pfn, max_low_pfn);
+ end_pfn = min(end_pfn, max_low_pfn);
+
+ if (start_pfn < end_pfn)
+ free_bootmem_node(NODE_DATA(this_nid),
+ PFN_PHYS(start_pfn),
+ (end_pfn - start_pfn) << PAGE_SHIFT);
+ }
+}
+
+/**
+ * sparse_memory_present_with_active_regions - Call memory_present for each active range
+ * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
+ *
+ * If an architecture guarantees that all ranges registered with
+ * add_active_ranges() contain no holes and may be freed, this
+ * function may be used instead of calling memory_present() manually.
+ */
+void __init sparse_memory_present_with_active_regions(int nid)
+{
+ unsigned long start_pfn, end_pfn;
+ int i, this_nid;
+
+ for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
+ memory_present(this_nid, start_pfn, end_pfn);
+}
+
+/**
+ * get_pfn_range_for_nid - Return the start and end page frames for a node
+ * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
+ * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
+ * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
+ *
+ * It returns the start and end page frame of a node based on information
+ * provided by an arch calling add_active_range(). If called for a node
+ * with no available memory, a warning is printed and the start and end
+ * PFNs will be 0.
+ */
+void __meminit get_pfn_range_for_nid(unsigned int nid,
+ unsigned long *start_pfn, unsigned long *end_pfn)
+{
+ unsigned long this_start_pfn, this_end_pfn;
+ int i;
+
+ *start_pfn = -1UL;
+ *end_pfn = 0;
+
+ for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
+ *start_pfn = min(*start_pfn, this_start_pfn);
+ *end_pfn = max(*end_pfn, this_end_pfn);
+ }
+
+ if (*start_pfn == -1UL)
+ *start_pfn = 0;
+}
+
+/*
+ * This finds a zone that can be used for ZONE_MOVABLE pages. The
+ * assumption is made that zones within a node are ordered in monotonic
+ * increasing memory addresses so that the "highest" populated zone is used
+ */
+static void __init find_usable_zone_for_movable(void)
+{
+ int zone_index;
+ for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
+ if (zone_index == ZONE_MOVABLE)
+ continue;
+
+ if (arch_zone_highest_possible_pfn[zone_index] >
+ arch_zone_lowest_possible_pfn[zone_index])
+ break;
+ }
+
+ VM_BUG_ON(zone_index == -1);
+ movable_zone = zone_index;
+}
+
+/*
+ * The zone ranges provided by the architecture do not include ZONE_MOVABLE
+ * because it is sized independent of architecture. Unlike the other zones,
+ * the starting point for ZONE_MOVABLE is not fixed. It may be different
+ * in each node depending on the size of each node and how evenly kernelcore
+ * is distributed. This helper function adjusts the zone ranges
+ * provided by the architecture for a given node by using the end of the
+ * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
+ * zones within a node are in order of monotonic increases memory addresses
+ */
+static void __meminit adjust_zone_range_for_zone_movable(int nid,
+ unsigned long zone_type,
+ unsigned long node_start_pfn,
+ unsigned long node_end_pfn,
+ unsigned long *zone_start_pfn,
+ unsigned long *zone_end_pfn)
+{
+ /* Only adjust if ZONE_MOVABLE is on this node */
+ if (zone_movable_pfn[nid]) {
+ /* Size ZONE_MOVABLE */
+ if (zone_type == ZONE_MOVABLE) {
+ *zone_start_pfn = zone_movable_pfn[nid];
+ *zone_end_pfn = min(node_end_pfn,
+ arch_zone_highest_possible_pfn[movable_zone]);
+
+ /* Adjust for ZONE_MOVABLE starting within this range */
+ } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
+ *zone_end_pfn > zone_movable_pfn[nid]) {
+ *zone_end_pfn = zone_movable_pfn[nid];
+
+ /* Check if this whole range is within ZONE_MOVABLE */
+ } else if (*zone_start_pfn >= zone_movable_pfn[nid])
+ *zone_start_pfn = *zone_end_pfn;
+ }
+}
+
+/*
+ * Return the number of pages a zone spans in a node, including holes
+ * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
+ */
+static unsigned long __meminit zone_spanned_pages_in_node(int nid,
+ unsigned long zone_type,
+ unsigned long *ignored)
+{
+ unsigned long node_start_pfn, node_end_pfn;
+ unsigned long zone_start_pfn, zone_end_pfn;
+
+ /* Get the start and end of the node and zone */
+ get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
+ zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
+ zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
+ adjust_zone_range_for_zone_movable(nid, zone_type,
+ node_start_pfn, node_end_pfn,
+ &zone_start_pfn, &zone_end_pfn);
+
+ /* Check that this node has pages within the zone's required range */
+ if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
+ return 0;
+
+ /* Move the zone boundaries inside the node if necessary */
+ zone_end_pfn = min(zone_end_pfn, node_end_pfn);
+ zone_start_pfn = max(zone_start_pfn, node_start_pfn);
+
+ /* Return the spanned pages */
+ return zone_end_pfn - zone_start_pfn;
+}
+
+/*
+ * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
+ * then all holes in the requested range will be accounted for.
+ */
+unsigned long __meminit __absent_pages_in_range(int nid,
+ unsigned long range_start_pfn,
+ unsigned long range_end_pfn)
+{
+ unsigned long nr_absent = range_end_pfn - range_start_pfn;
+ unsigned long start_pfn, end_pfn;
+ int i;
+
+ for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
+ start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
+ end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
+ nr_absent -= end_pfn - start_pfn;
+ }
+ return nr_absent;
+}
+
+/**
+ * absent_pages_in_range - Return number of page frames in holes within a range
+ * @start_pfn: The start PFN to start searching for holes
+ * @end_pfn: The end PFN to stop searching for holes
+ *
+ * It returns the number of pages frames in memory holes within a range.
+ */
+unsigned long __init absent_pages_in_range(unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
+}
+
+/* Return the number of page frames in holes in a zone on a node */
+static unsigned long __meminit zone_absent_pages_in_node(int nid,
+ unsigned long zone_type,
+ unsigned long *ignored)
+{
+ unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
+ unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
+ unsigned long node_start_pfn, node_end_pfn;
+ unsigned long zone_start_pfn, zone_end_pfn;
+
+ get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
+ zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
+ zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
+
+ adjust_zone_range_for_zone_movable(nid, zone_type,
+ node_start_pfn, node_end_pfn,
+ &zone_start_pfn, &zone_end_pfn);
+ return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
+}
+
+#else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
+static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
+ unsigned long zone_type,
+ unsigned long *zones_size)
+{
+ return zones_size[zone_type];
+}
+
+static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
+ unsigned long zone_type,
+ unsigned long *zholes_size)
+{
+ if (!zholes_size)
+ return 0;
+
+ return zholes_size[zone_type];
+}
+
+#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
+
+static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
+ unsigned long *zones_size, unsigned long *zholes_size)
+{
+ unsigned long realtotalpages, totalpages = 0;
+ enum zone_type i;
+
+ for (i = 0; i < MAX_NR_ZONES; i++)
+ totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
+ zones_size);
+ pgdat->node_spanned_pages = totalpages;
+
+ realtotalpages = totalpages;
+ for (i = 0; i < MAX_NR_ZONES; i++)
+ realtotalpages -=
+ zone_absent_pages_in_node(pgdat->node_id, i,
+ zholes_size);
+ pgdat->node_present_pages = realtotalpages;
+ printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
+ realtotalpages);
+}
+
+#ifndef CONFIG_SPARSEMEM
+/*
+ * Calculate the size of the zone->blockflags rounded to an unsigned long
+ * Start by making sure zonesize is a multiple of pageblock_order by rounding
+ * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
+ * round what is now in bits to nearest long in bits, then return it in
+ * bytes.
+ */
+static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
+{
+ unsigned long usemapsize;
+
+ zonesize += zone_start_pfn & (pageblock_nr_pages-1);
+ usemapsize = roundup(zonesize, pageblock_nr_pages);
+ usemapsize = usemapsize >> pageblock_order;
+ usemapsize *= NR_PAGEBLOCK_BITS;
+ usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
+
+ return usemapsize / 8;
+}
+
+static void __init setup_usemap(struct pglist_data *pgdat,
+ struct zone *zone,
+ unsigned long zone_start_pfn,
+ unsigned long zonesize)
+{
+ unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
+ zone->pageblock_flags = NULL;
+ if (usemapsize)
+ zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat,
+ usemapsize);
+}
+#else
+static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
+ unsigned long zone_start_pfn, unsigned long zonesize) {}
+#endif /* CONFIG_SPARSEMEM */
+
+#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
+
+/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
+void __init set_pageblock_order(void)
+{
+ unsigned int order;
+
+ /* Check that pageblock_nr_pages has not already been setup */
+ if (pageblock_order)
+ return;
+
+ if (HPAGE_SHIFT > PAGE_SHIFT)
+ order = HUGETLB_PAGE_ORDER;
+ else
+ order = MAX_ORDER - 1;
+
+ /*
+ * Assume the largest contiguous order of interest is a huge page.
+ * This value may be variable depending on boot parameters on IA64 and
+ * powerpc.
+ */
+ pageblock_order = order;
+}
+#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
+
+/*
+ * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
+ * is unused as pageblock_order is set at compile-time. See
+ * include/linux/pageblock-flags.h for the values of pageblock_order based on
+ * the kernel config
+ */
+void __init set_pageblock_order(void)
+{
+}
+
+#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
+
+/*
+ * Set up the zone data structures:
+ * - mark all pages reserved
+ * - mark all memory queues empty
+ * - clear the memory bitmaps
+ */
+static void __paginginit free_area_init_core(struct pglist_data *pgdat,
+ unsigned long *zones_size, unsigned long *zholes_size)
+{
+ enum zone_type j;
+ int nid = pgdat->node_id;
+ unsigned long zone_start_pfn = pgdat->node_start_pfn;
+ int ret;
+
+ pgdat_resize_init(pgdat);
+ pgdat->nr_zones = 0;
+ init_waitqueue_head(&pgdat->kswapd_wait);
+ pgdat->kswapd_max_order = 0;
+ pgdat_page_cgroup_init(pgdat);
+
+ for (j = 0; j < MAX_NR_ZONES; j++) {
+ struct zone *zone = pgdat->node_zones + j;
+ unsigned long size, realsize, memmap_pages;
+ enum lru_list lru;
+
+ size = zone_spanned_pages_in_node(nid, j, zones_size);
+ realsize = size - zone_absent_pages_in_node(nid, j,
+ zholes_size);
+
+ /*
+ * Adjust realsize so that it accounts for how much memory
+ * is used by this zone for memmap. This affects the watermark
+ * and per-cpu initialisations
+ */
+ memmap_pages =
+ PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
+ if (realsize >= memmap_pages) {
+ realsize -= memmap_pages;
+ if (memmap_pages)
+ printk(KERN_DEBUG
+ " %s zone: %lu pages used for memmap\n",
+ zone_names[j], memmap_pages);
+ } else
+ printk(KERN_WARNING
+ " %s zone: %lu pages exceeds realsize %lu\n",
+ zone_names[j], memmap_pages, realsize);
+
+ /* Account for reserved pages */
+ if (j == 0 && realsize > dma_reserve) {
+ realsize -= dma_reserve;
+ printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
+ zone_names[0], dma_reserve);
+ }
+
+ if (!is_highmem_idx(j))
+ nr_kernel_pages += realsize;
+ nr_all_pages += realsize;
+
+ zone->spanned_pages = size;
+ zone->present_pages = realsize;
+#ifdef CONFIG_NUMA
+ zone->node = nid;
+ zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
+ / 100;
+ zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
+#endif
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+ zone->max_pagecache_pages =
+ (realsize * sysctl_pagecache_ratio) / 100;
+#endif
+ zone->name = zone_names[j];
+ spin_lock_init(&zone->lock);
+ spin_lock_init(&zone->lru_lock);
+ zone_seqlock_init(zone);
+ zone->zone_pgdat = pgdat;
+
+ zone_pcp_init(zone);
+ for_each_lru(lru)
+ INIT_LIST_HEAD(&zone->lruvec.lists[lru]);
+ zone->reclaim_stat.recent_rotated[0] = 0;
+ zone->reclaim_stat.recent_rotated[1] = 0;
+ zone->reclaim_stat.recent_scanned[0] = 0;
+ zone->reclaim_stat.recent_scanned[1] = 0;
+ zap_zone_vm_stats(zone);
+ zone->flags = 0;
+ if (!size)
+ continue;
+
+ set_pageblock_order();
+ setup_usemap(pgdat, zone, zone_start_pfn, size);
+ ret = init_currently_empty_zone(zone, zone_start_pfn,
+ size, MEMMAP_EARLY);
+ BUG_ON(ret);
+ memmap_init(size, nid, j, zone_start_pfn);
+ zone_start_pfn += size;
+ }
+}
+
+static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
+{
+ /* Skip empty nodes */
+ if (!pgdat->node_spanned_pages)
+ return;
+
+#ifdef CONFIG_FLAT_NODE_MEM_MAP
+ /* ia64 gets its own node_mem_map, before this, without bootmem */
+ if (!pgdat->node_mem_map) {
+ unsigned long size, start, end;
+ struct page *map;
+
+ /*
+ * The zone's endpoints aren't required to be MAX_ORDER
+ * aligned but the node_mem_map endpoints must be in order
+ * for the buddy allocator to function correctly.
+ */
+ start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
+ end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
+ end = ALIGN(end, MAX_ORDER_NR_PAGES);
+ size = (end - start) * sizeof(struct page);
+ map = alloc_remap(pgdat->node_id, size);
+ if (!map)
+ map = alloc_bootmem_node_nopanic(pgdat, size);
+ pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
+ }
+#ifndef CONFIG_NEED_MULTIPLE_NODES
+ /*
+ * With no DISCONTIG, the global mem_map is just set as node 0's
+ */
+ if (pgdat == NODE_DATA(0)) {
+ mem_map = NODE_DATA(0)->node_mem_map;
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+ if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
+ mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
+#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
+ }
+#endif
+#endif /* CONFIG_FLAT_NODE_MEM_MAP */
+}
+
+void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
+ unsigned long node_start_pfn, unsigned long *zholes_size)
+{
+ pg_data_t *pgdat = NODE_DATA(nid);
+
+ pgdat->node_id = nid;
+ pgdat->node_start_pfn = node_start_pfn;
+ calculate_node_totalpages(pgdat, zones_size, zholes_size);
+
+ alloc_node_mem_map(pgdat);
+#ifdef CONFIG_FLAT_NODE_MEM_MAP
+ printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
+ nid, (unsigned long)pgdat,
+ (unsigned long)pgdat->node_mem_map);
+#endif
+
+ free_area_init_core(pgdat, zones_size, zholes_size);
+}
+
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+
+#if MAX_NUMNODES > 1
+/*
+ * Figure out the number of possible node ids.
+ */
+static void __init setup_nr_node_ids(void)
+{
+ unsigned int node;
+ unsigned int highest = 0;
+
+ for_each_node_mask(node, node_possible_map)
+ highest = node;
+ nr_node_ids = highest + 1;
+}
+#else
+static inline void setup_nr_node_ids(void)
+{
+}
+#endif
+
+/**
+ * node_map_pfn_alignment - determine the maximum internode alignment
+ *
+ * This function should be called after node map is populated and sorted.
+ * It calculates the maximum power of two alignment which can distinguish
+ * all the nodes.
+ *
+ * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
+ * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
+ * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
+ * shifted, 1GiB is enough and this function will indicate so.
+ *
+ * This is used to test whether pfn -> nid mapping of the chosen memory
+ * model has fine enough granularity to avoid incorrect mapping for the
+ * populated node map.
+ *
+ * Returns the determined alignment in pfn's. 0 if there is no alignment
+ * requirement (single node).
+ */
+unsigned long __init node_map_pfn_alignment(void)
+{
+ unsigned long accl_mask = 0, last_end = 0;
+ unsigned long start, end, mask;
+ int last_nid = -1;
+ int i, nid;
+
+ for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
+ if (!start || last_nid < 0 || last_nid == nid) {
+ last_nid = nid;
+ last_end = end;
+ continue;
+ }
+
+ /*
+ * Start with a mask granular enough to pin-point to the
+ * start pfn and tick off bits one-by-one until it becomes
+ * too coarse to separate the current node from the last.
+ */
+ mask = ~((1 << __ffs(start)) - 1);
+ while (mask && last_end <= (start & (mask << 1)))
+ mask <<= 1;
+
+ /* accumulate all internode masks */
+ accl_mask |= mask;
+ }
+
+ /* convert mask to number of pages */
+ return ~accl_mask + 1;
+}
+
+/* Find the lowest pfn for a node */
+static unsigned long __init find_min_pfn_for_node(int nid)
+{
+ unsigned long min_pfn = ULONG_MAX;
+ unsigned long start_pfn;
+ int i;
+
+ for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
+ min_pfn = min(min_pfn, start_pfn);
+
+ if (min_pfn == ULONG_MAX) {
+ printk(KERN_WARNING
+ "Could not find start_pfn for node %d\n", nid);
+ return 0;
+ }
+
+ return min_pfn;
+}
+
+/**
+ * find_min_pfn_with_active_regions - Find the minimum PFN registered
+ *
+ * It returns the minimum PFN based on information provided via
+ * add_active_range().
+ */
+unsigned long __init find_min_pfn_with_active_regions(void)
+{
+ return find_min_pfn_for_node(MAX_NUMNODES);
+}
+
+/*
+ * early_calculate_totalpages()
+ * Sum pages in active regions for movable zone.
+ * Populate N_HIGH_MEMORY for calculating usable_nodes.
+ */
+static unsigned long __init early_calculate_totalpages(void)
+{
+ unsigned long totalpages = 0;
+ unsigned long start_pfn, end_pfn;
+ int i, nid;
+
+ for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
+ unsigned long pages = end_pfn - start_pfn;
+
+ totalpages += pages;
+ if (pages)
+ node_set_state(nid, N_HIGH_MEMORY);
+ }
+ return totalpages;
+}
+
+/*
+ * Find the PFN the Movable zone begins in each node. Kernel memory
+ * is spread evenly between nodes as long as the nodes have enough
+ * memory. When they don't, some nodes will have more kernelcore than
+ * others
+ */
+static void __init find_zone_movable_pfns_for_nodes(void)
+{
+ int i, nid;
+ unsigned long usable_startpfn;
+ unsigned long kernelcore_node, kernelcore_remaining;
+ /* save the state before borrow the nodemask */
+ nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
+ unsigned long totalpages = early_calculate_totalpages();
+ int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
+
+ /*
+ * If movablecore was specified, calculate what size of
+ * kernelcore that corresponds so that memory usable for
+ * any allocation type is evenly spread. If both kernelcore
+ * and movablecore are specified, then the value of kernelcore
+ * will be used for required_kernelcore if it's greater than
+ * what movablecore would have allowed.
+ */
+ if (required_movablecore) {
+ unsigned long corepages;
+
+ /*
+ * Round-up so that ZONE_MOVABLE is at least as large as what
+ * was requested by the user
+ */
+ required_movablecore =
+ roundup(required_movablecore, MAX_ORDER_NR_PAGES);
+ corepages = totalpages - required_movablecore;
+
+ required_kernelcore = max(required_kernelcore, corepages);
+ }
+
+ /* If kernelcore was not specified, there is no ZONE_MOVABLE */
+ if (!required_kernelcore)
+ goto out;
+
+ /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
+ find_usable_zone_for_movable();
+ usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
+
+restart:
+ /* Spread kernelcore memory as evenly as possible throughout nodes */
+ kernelcore_node = required_kernelcore / usable_nodes;
+ for_each_node_state(nid, N_HIGH_MEMORY) {
+ unsigned long start_pfn, end_pfn;
+
+ /*
+ * Recalculate kernelcore_node if the division per node
+ * now exceeds what is necessary to satisfy the requested
+ * amount of memory for the kernel
+ */
+ if (required_kernelcore < kernelcore_node)
+ kernelcore_node = required_kernelcore / usable_nodes;
+
+ /*
+ * As the map is walked, we track how much memory is usable
+ * by the kernel using kernelcore_remaining. When it is
+ * 0, the rest of the node is usable by ZONE_MOVABLE
+ */
+ kernelcore_remaining = kernelcore_node;
+
+ /* Go through each range of PFNs within this node */
+ for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
+ unsigned long size_pages;
+
+ start_pfn = max(start_pfn, zone_movable_pfn[nid]);
+ if (start_pfn >= end_pfn)
+ continue;
+
+ /* Account for what is only usable for kernelcore */
+ if (start_pfn < usable_startpfn) {
+ unsigned long kernel_pages;
+ kernel_pages = min(end_pfn, usable_startpfn)
+ - start_pfn;
+
+ kernelcore_remaining -= min(kernel_pages,
+ kernelcore_remaining);
+ required_kernelcore -= min(kernel_pages,
+ required_kernelcore);
+
+ /* Continue if range is now fully accounted */
+ if (end_pfn <= usable_startpfn) {
+
+ /*
+ * Push zone_movable_pfn to the end so
+ * that if we have to rebalance
+ * kernelcore across nodes, we will
+ * not double account here
+ */
+ zone_movable_pfn[nid] = end_pfn;
+ continue;
+ }
+ start_pfn = usable_startpfn;
+ }
+
+ /*
+ * The usable PFN range for ZONE_MOVABLE is from
+ * start_pfn->end_pfn. Calculate size_pages as the
+ * number of pages used as kernelcore
+ */
+ size_pages = end_pfn - start_pfn;
+ if (size_pages > kernelcore_remaining)
+ size_pages = kernelcore_remaining;
+ zone_movable_pfn[nid] = start_pfn + size_pages;
+
+ /*
+ * Some kernelcore has been met, update counts and
+ * break if the kernelcore for this node has been
+ * satisified
+ */
+ required_kernelcore -= min(required_kernelcore,
+ size_pages);
+ kernelcore_remaining -= size_pages;
+ if (!kernelcore_remaining)
+ break;
+ }
+ }
+
+ /*
+ * If there is still required_kernelcore, we do another pass with one
+ * less node in the count. This will push zone_movable_pfn[nid] further
+ * along on the nodes that still have memory until kernelcore is
+ * satisified
+ */
+ usable_nodes--;
+ if (usable_nodes && required_kernelcore > usable_nodes)
+ goto restart;
+
+ /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
+ for (nid = 0; nid < MAX_NUMNODES; nid++)
+ zone_movable_pfn[nid] =
+ roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
+
+out:
+ /* restore the node_state */
+ node_states[N_HIGH_MEMORY] = saved_node_state;
+}
+
+/* Any regular memory on that node ? */
+static void check_for_regular_memory(pg_data_t *pgdat)
+{
+#ifdef CONFIG_HIGHMEM
+ enum zone_type zone_type;
+
+ for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
+ struct zone *zone = &pgdat->node_zones[zone_type];
+ if (zone->present_pages) {
+ node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
+ break;
+ }
+ }
+#endif
+}
+
+/**
+ * free_area_init_nodes - Initialise all pg_data_t and zone data
+ * @max_zone_pfn: an array of max PFNs for each zone
+ *
+ * This will call free_area_init_node() for each active node in the system.
+ * Using the page ranges provided by add_active_range(), the size of each
+ * zone in each node and their holes is calculated. If the maximum PFN
+ * between two adjacent zones match, it is assumed that the zone is empty.
+ * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
+ * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
+ * starts where the previous one ended. For example, ZONE_DMA32 starts
+ * at arch_max_dma_pfn.
+ */
+void __init free_area_init_nodes(unsigned long *max_zone_pfn)
+{
+ unsigned long start_pfn, end_pfn;
+ int i, nid;
+
+ /* Record where the zone boundaries are */
+ memset(arch_zone_lowest_possible_pfn, 0,
+ sizeof(arch_zone_lowest_possible_pfn));
+ memset(arch_zone_highest_possible_pfn, 0,
+ sizeof(arch_zone_highest_possible_pfn));
+ arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
+ arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
+ for (i = 1; i < MAX_NR_ZONES; i++) {
+ if (i == ZONE_MOVABLE)
+ continue;
+ arch_zone_lowest_possible_pfn[i] =
+ arch_zone_highest_possible_pfn[i-1];
+ arch_zone_highest_possible_pfn[i] =
+ max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
+ }
+ arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
+ arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
+
+ /* Find the PFNs that ZONE_MOVABLE begins at in each node */
+ memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
+ find_zone_movable_pfns_for_nodes();
+
+ /* Print out the zone ranges */
+ printk("Zone PFN ranges:\n");
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ if (i == ZONE_MOVABLE)
+ continue;
+ printk(" %-8s ", zone_names[i]);
+ if (arch_zone_lowest_possible_pfn[i] ==
+ arch_zone_highest_possible_pfn[i])
+ printk("empty\n");
+ else
+ printk("%0#10lx -> %0#10lx\n",
+ arch_zone_lowest_possible_pfn[i],
+ arch_zone_highest_possible_pfn[i]);
+ }
+
+ /* Print out the PFNs ZONE_MOVABLE begins at in each node */
+ printk("Movable zone start PFN for each node\n");
+ for (i = 0; i < MAX_NUMNODES; i++) {
+ if (zone_movable_pfn[i])
+ printk(" Node %d: %lu\n", i, zone_movable_pfn[i]);
+ }
+
+ /* Print out the early_node_map[] */
+ printk("Early memory PFN ranges\n");
+ for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
+ printk(" %3d: %0#10lx -> %0#10lx\n", nid, start_pfn, end_pfn);
+
+ /* Initialise every node */
+ mminit_verify_pageflags_layout();
+ setup_nr_node_ids();
+ for_each_online_node(nid) {
+ pg_data_t *pgdat = NODE_DATA(nid);
+ free_area_init_node(nid, NULL,
+ find_min_pfn_for_node(nid), NULL);
+
+ /* Any memory on that node */
+ if (pgdat->node_present_pages)
+ node_set_state(nid, N_HIGH_MEMORY);
+ check_for_regular_memory(pgdat);
+ }
+}
+
+static int __init cmdline_parse_core(char *p, unsigned long *core)
+{
+ unsigned long long coremem;
+ if (!p)
+ return -EINVAL;
+
+ coremem = memparse(p, &p);
+ *core = coremem >> PAGE_SHIFT;
+
+ /* Paranoid check that UL is enough for the coremem value */
+ WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
+
+ return 0;
+}
+
+/*
+ * kernelcore=size sets the amount of memory for use for allocations that
+ * cannot be reclaimed or migrated.
+ */
+static int __init cmdline_parse_kernelcore(char *p)
+{
+ return cmdline_parse_core(p, &required_kernelcore);
+}
+
+/*
+ * movablecore=size sets the amount of memory for use for allocations that
+ * can be reclaimed or migrated.
+ */
+static int __init cmdline_parse_movablecore(char *p)
+{
+ return cmdline_parse_core(p, &required_movablecore);
+}
+
+early_param("kernelcore", cmdline_parse_kernelcore);
+early_param("movablecore", cmdline_parse_movablecore);
+
+#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
+
+/**
+ * set_dma_reserve - set the specified number of pages reserved in the first zone
+ * @new_dma_reserve: The number of pages to mark reserved
+ *
+ * The per-cpu batchsize and zone watermarks are determined by present_pages.
+ * In the DMA zone, a significant percentage may be consumed by kernel image
+ * and other unfreeable allocations which can skew the watermarks badly. This
+ * function may optionally be used to account for unfreeable pages in the
+ * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
+ * smaller per-cpu batchsize.
+ */
+void __init set_dma_reserve(unsigned long new_dma_reserve)
+{
+ dma_reserve = new_dma_reserve;
+}
+
+void __init free_area_init(unsigned long *zones_size)
+{
+ free_area_init_node(0, zones_size,
+ __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
+}
+
+static int page_alloc_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ int cpu = (unsigned long)hcpu;
+
+ if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
+ lru_add_drain_cpu(cpu);
+ drain_pages(cpu);
+
+ /*
+ * Spill the event counters of the dead processor
+ * into the current processors event counters.
+ * This artificially elevates the count of the current
+ * processor.
+ */
+ vm_events_fold_cpu(cpu);
+
+ /*
+ * Zero the differential counters of the dead processor
+ * so that the vm statistics are consistent.
+ *
+ * This is only okay since the processor is dead and cannot
+ * race with what we are doing.
+ */
+ refresh_cpu_vm_stats(cpu);
+ }
+ return NOTIFY_OK;
+}
+
+void __init page_alloc_init(void)
+{
+ hotcpu_notifier(page_alloc_cpu_notify, 0);
+ local_irq_lock_init(pa_lock);
+}
+
+/*
+ * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
+ * or min_free_kbytes changes.
+ */
+static void calculate_totalreserve_pages(void)
+{
+ struct pglist_data *pgdat;
+ unsigned long reserve_pages = 0;
+ enum zone_type i, j;
+
+ for_each_online_pgdat(pgdat) {
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ struct zone *zone = pgdat->node_zones + i;
+ unsigned long max = 0;
+
+ /* Find valid and maximum lowmem_reserve in the zone */
+ for (j = i; j < MAX_NR_ZONES; j++) {
+ if (zone->lowmem_reserve[j] > max)
+ max = zone->lowmem_reserve[j];
+ }
+
+ /* we treat the high watermark as reserved pages. */
+ max += high_wmark_pages(zone);
+
+ if (max > zone->present_pages)
+ max = zone->present_pages;
+ reserve_pages += max;
+ /*
+ * Lowmem reserves are not available to
+ * GFP_HIGHUSER page cache allocations and
+ * kswapd tries to balance zones to their high
+ * watermark. As a result, neither should be
+ * regarded as dirtyable memory, to prevent a
+ * situation where reclaim has to clean pages
+ * in order to balance the zones.
+ */
+ zone->dirty_balance_reserve = max;
+ }
+ }
+ dirty_balance_reserve = reserve_pages;
+ totalreserve_pages = reserve_pages;
+}
+
+/*
+ * setup_per_zone_lowmem_reserve - called whenever
+ * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
+ * has a correct pages reserved value, so an adequate number of
+ * pages are left in the zone after a successful __alloc_pages().
+ */
+static void setup_per_zone_lowmem_reserve(void)
+{
+ struct pglist_data *pgdat;
+ enum zone_type j, idx;
+
+ for_each_online_pgdat(pgdat) {
+ for (j = 0; j < MAX_NR_ZONES; j++) {
+ struct zone *zone = pgdat->node_zones + j;
+ unsigned long present_pages = zone->present_pages;
+
+ zone->lowmem_reserve[j] = 0;
+
+ idx = j;
+ while (idx) {
+ struct zone *lower_zone;
+
+ idx--;
+
+ if (sysctl_lowmem_reserve_ratio[idx] < 1)
+ sysctl_lowmem_reserve_ratio[idx] = 1;
+
+ lower_zone = pgdat->node_zones + idx;
+ lower_zone->lowmem_reserve[j] = present_pages /
+ sysctl_lowmem_reserve_ratio[idx];
+ present_pages += lower_zone->present_pages;
+ }
+ }
+ }
+
+ /* update totalreserve_pages */
+ calculate_totalreserve_pages();
+}
+
+/**
+ * setup_per_zone_wmarks - called when min_free_kbytes changes
+ * or when memory is hot-{added|removed}
+ *
+ * Ensures that the watermark[min,low,high] values for each zone are set
+ * correctly with respect to min_free_kbytes.
+ */
+void setup_per_zone_wmarks(void)
+{
+ //unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
+ //朱迪 20160818 watermark 调整
+ unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10+2);
+ unsigned long lowmem_pages = 0;
+ struct zone *zone;
+ unsigned long flags;
+
+ /* Calculate total number of !ZONE_HIGHMEM pages */
+ for_each_zone(zone) {
+ if (!is_highmem(zone))
+ lowmem_pages += zone->present_pages;
+ }
+
+ for_each_zone(zone) {
+ u64 tmp;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ tmp = (u64)pages_min * zone->present_pages;
+ do_div(tmp, lowmem_pages);
+ if (is_highmem(zone)) {
+ /*
+ * __GFP_HIGH and PF_MEMALLOC allocations usually don't
+ * need highmem pages, so cap pages_min to a small
+ * value here.
+ *
+ * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
+ * deltas controls asynch page reclaim, and so should
+ * not be capped for highmem.
+ */
+ int min_pages;
+
+ min_pages = zone->present_pages / 1024;
+ if (min_pages < SWAP_CLUSTER_MAX)
+ min_pages = SWAP_CLUSTER_MAX;
+ if (min_pages > 128)
+ min_pages = 128;
+ zone->watermark[WMARK_MIN] = min_pages;
+ } else {
+ /*
+ * If it's a lowmem zone, reserve a number of pages
+ * proportionate to the zone's size.
+ */
+ zone->watermark[WMARK_MIN] = tmp;
+ }
+
+ /*zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
+ zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
+ */
+
+ zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 0) + (tmp >> 1);
+ zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + 2 * (tmp >> 0);
+ if(is_normal(zone))
+ wm_min_pages = (zone->watermark[WMARK_MIN] + zone->watermark[WMARK_LOW]) >> 1;
+
+ setup_zone_migrate_reserve(zone);
+ spin_unlock_irqrestore(&zone->lock, flags);
+ }
+
+ /* update totalreserve_pages */
+ calculate_totalreserve_pages();
+}
+
+/*
+ * The inactive anon list should be small enough that the VM never has to
+ * do too much work, but large enough that each inactive page has a chance
+ * to be referenced again before it is swapped out.
+ *
+ * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
+ * INACTIVE_ANON pages on this zone's LRU, maintained by the
+ * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
+ * the anonymous pages are kept on the inactive list.
+ *
+ * total target max
+ * memory ratio inactive anon
+ * -------------------------------------
+ * 10MB 1 5MB
+ * 100MB 1 50MB
+ * 1GB 3 250MB
+ * 10GB 10 0.9GB
+ * 100GB 31 3GB
+ * 1TB 101 10GB
+ * 10TB 320 32GB
+ */
+static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
+{
+ unsigned int gb, ratio;
+
+ /* Zone size in gigabytes */
+ gb = zone->present_pages >> (30 - PAGE_SHIFT);
+ if (gb)
+ ratio = int_sqrt(10 * gb);
+ else
+ ratio = 1;
+
+ zone->inactive_ratio = ratio;
+}
+
+static void __meminit setup_per_zone_inactive_ratio(void)
+{
+ struct zone *zone;
+
+ for_each_zone(zone)
+ calculate_zone_inactive_ratio(zone);
+}
+
+/*
+ * Initialise min_free_kbytes.
+ *
+ * For small machines we want it small (128k min). For large machines
+ * we want it large (64MB max). But it is not linear, because network
+ * bandwidth does not increase linearly with machine size. We use
+ *
+ * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
+ * min_free_kbytes = sqrt(lowmem_kbytes * 16)
+ *
+ * which yields
+ *
+ * 16MB: 512k
+ * 32MB: 724k
+ * 64MB: 1024k
+ * 128MB: 1448k
+ * 256MB: 2048k
+ * 512MB: 2896k
+ * 1024MB: 4096k
+ * 2048MB: 5792k
+ * 4096MB: 8192k
+ * 8192MB: 11584k
+ * 16384MB: 16384k
+ */
+int __meminit init_per_zone_wmark_min(void)
+{
+ unsigned long lowmem_kbytes;
+
+ lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
+
+ min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
+ if (min_free_kbytes < 128)
+ min_free_kbytes = 128;
+ if (min_free_kbytes > 65536)
+ min_free_kbytes = 65536;
+ setup_per_zone_wmarks();
+ refresh_zone_stat_thresholds();
+ setup_per_zone_lowmem_reserve();
+ setup_per_zone_inactive_ratio();
+ return 0;
+}
+module_init(init_per_zone_wmark_min)
+
+/*
+ * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
+ * that we can call two helper functions whenever min_free_kbytes
+ * changes.
+ */
+int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ proc_dointvec(table, write, buffer, length, ppos);
+ if (write)
+ setup_per_zone_wmarks();
+ return 0;
+}
+
+#ifdef CONFIG_NUMA
+int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ struct zone *zone;
+ int rc;
+
+ rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (rc)
+ return rc;
+
+ for_each_zone(zone)
+ zone->min_unmapped_pages = (zone->present_pages *
+ sysctl_min_unmapped_ratio) / 100;
+ return 0;
+}
+
+int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ struct zone *zone;
+ int rc;
+
+ rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (rc)
+ return rc;
+
+ for_each_zone(zone)
+ zone->min_slab_pages = (zone->present_pages *
+ sysctl_min_slab_ratio) / 100;
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+int sysctl_pagecache_ratio_sysctl_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ struct zone *zone;
+ int rc;
+
+ rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (rc)
+ return rc;
+
+ for_each_zone(zone)
+ zone->max_pagecache_pages = (zone->present_pages *
+ sysctl_pagecache_ratio) / 100;
+ return 0;
+}
+
+#endif
+
+/*
+ * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
+ * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
+ * whenever sysctl_lowmem_reserve_ratio changes.
+ *
+ * The reserve ratio obviously has absolutely no relation with the
+ * minimum watermarks. The lowmem reserve ratio can only make sense
+ * if in function of the boot time zone sizes.
+ */
+int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ proc_dointvec_minmax(table, write, buffer, length, ppos);
+ setup_per_zone_lowmem_reserve();
+ return 0;
+}
+
+/*
+ * percpu_pagelist_fraction - changes the pcp->high for each zone on each
+ * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
+ * can have before it gets flushed back to buddy allocator.
+ */
+
+int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ struct zone *zone;
+ unsigned int cpu;
+ int ret;
+
+ ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (!write || (ret < 0))
+ return ret;
+ for_each_populated_zone(zone) {
+ for_each_possible_cpu(cpu) {
+ unsigned long high;
+ high = zone->present_pages / percpu_pagelist_fraction;
+ setup_pagelist_highmark(
+ per_cpu_ptr(zone->pageset, cpu), high);
+ }
+ }
+ return 0;
+}
+
+int hashdist = HASHDIST_DEFAULT;
+
+#ifdef CONFIG_NUMA
+static int __init set_hashdist(char *str)
+{
+ if (!str)
+ return 0;
+ hashdist = simple_strtoul(str, &str, 0);
+ return 1;
+}
+__setup("hashdist=", set_hashdist);
+#endif
+
+/*
+ * allocate a large system hash table from bootmem
+ * - it is assumed that the hash table must contain an exact power-of-2
+ * quantity of entries
+ * - limit is the number of hash buckets, not the total allocation size
+ */
+void *__init alloc_large_system_hash(const char *tablename,
+ unsigned long bucketsize,
+ unsigned long numentries,
+ int scale,
+ int flags,
+ unsigned int *_hash_shift,
+ unsigned int *_hash_mask,
+ unsigned long limit)
+{
+ unsigned long long max = limit;
+ unsigned long log2qty, size;
+ void *table = NULL;
+
+ /* allow the kernel cmdline to have a say */
+ if (!numentries) {
+ /* round applicable memory size up to nearest megabyte */
+ numentries = nr_kernel_pages;
+ numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
+ numentries >>= 20 - PAGE_SHIFT;
+ numentries <<= 20 - PAGE_SHIFT;
+
+ /* limit to 1 bucket per 2^scale bytes of low memory */
+ if (scale > PAGE_SHIFT)
+ numentries >>= (scale - PAGE_SHIFT);
+ else
+ numentries <<= (PAGE_SHIFT - scale);
+
+ /* Make sure we've got at least a 0-order allocation.. */
+ if (unlikely(flags & HASH_SMALL)) {
+ /* Makes no sense without HASH_EARLY */
+ WARN_ON(!(flags & HASH_EARLY));
+ if (!(numentries >> *_hash_shift)) {
+ numentries = 1UL << *_hash_shift;
+ BUG_ON(!numentries);
+ }
+ } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
+ numentries = PAGE_SIZE / bucketsize;
+ }
+ numentries = roundup_pow_of_two(numentries);
+
+ /* limit allocation size to 1/16 total memory by default */
+ if (max == 0) {
+ max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
+ do_div(max, bucketsize);
+ }
+ max = min(max, 0x80000000ULL);
+
+ if (numentries > max)
+ numentries = max;
+
+ log2qty = ilog2(numentries);
+
+ do {
+ size = bucketsize << log2qty;
+ if (flags & HASH_EARLY)
+ table = alloc_bootmem_nopanic(size);
+ else if (hashdist)
+ table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
+ else {
+ /*
+ * If bucketsize is not a power-of-two, we may free
+ * some pages at the end of hash table which
+ * alloc_pages_exact() automatically does
+ */
+ if (get_order(size) < MAX_ORDER) {
+ table = alloc_pages_exact(size, GFP_ATOMIC);
+ kmemleak_alloc(table, size, 1, GFP_ATOMIC);
+ }
+ }
+ } while (!table && size > PAGE_SIZE && --log2qty);
+
+ if (!table)
+ panic("Failed to allocate %s hash table\n", tablename);
+
+ printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
+ tablename,
+ (1UL << log2qty),
+ ilog2(size) - PAGE_SHIFT,
+ size);
+
+ if (_hash_shift)
+ *_hash_shift = log2qty;
+ if (_hash_mask)
+ *_hash_mask = (1 << log2qty) - 1;
+
+ return table;
+}
+
+/* Return a pointer to the bitmap storing bits affecting a block of pages */
+static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
+ unsigned long pfn)
+{
+#ifdef CONFIG_SPARSEMEM
+ return __pfn_to_section(pfn)->pageblock_flags;
+#else
+ return zone->pageblock_flags;
+#endif /* CONFIG_SPARSEMEM */
+}
+
+static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
+{
+#ifdef CONFIG_SPARSEMEM
+ pfn &= (PAGES_PER_SECTION-1);
+ return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
+#else
+ pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
+ return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
+#endif /* CONFIG_SPARSEMEM */
+}
+
+/**
+ * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
+ * @page: The page within the block of interest
+ * @start_bitidx: The first bit of interest to retrieve
+ * @end_bitidx: The last bit of interest
+ * returns pageblock_bits flags
+ */
+unsigned long get_pageblock_flags_group(struct page *page,
+ int start_bitidx, int end_bitidx)
+{
+ struct zone *zone;
+ unsigned long *bitmap;
+ unsigned long pfn, bitidx;
+ unsigned long flags = 0;
+ unsigned long value = 1;
+
+ zone = page_zone(page);
+ pfn = page_to_pfn(page);
+ bitmap = get_pageblock_bitmap(zone, pfn);
+ bitidx = pfn_to_bitidx(zone, pfn);
+
+ for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
+ if (test_bit(bitidx + start_bitidx, bitmap))
+ flags |= value;
+
+ return flags;
+}
+
+/**
+ * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
+ * @page: The page within the block of interest
+ * @start_bitidx: The first bit of interest
+ * @end_bitidx: The last bit of interest
+ * @flags: The flags to set
+ */
+void set_pageblock_flags_group(struct page *page, unsigned long flags,
+ int start_bitidx, int end_bitidx)
+{
+ struct zone *zone;
+ unsigned long *bitmap;
+ unsigned long pfn, bitidx;
+ unsigned long value = 1;
+
+ zone = page_zone(page);
+ pfn = page_to_pfn(page);
+ bitmap = get_pageblock_bitmap(zone, pfn);
+ bitidx = pfn_to_bitidx(zone, pfn);
+ VM_BUG_ON(pfn < zone->zone_start_pfn);
+ VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
+
+ for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
+ if (flags & value)
+ __set_bit(bitidx + start_bitidx, bitmap);
+ else
+ __clear_bit(bitidx + start_bitidx, bitmap);
+}
+
+/*
+ * This is designed as sub function...plz see page_isolation.c also.
+ * set/clear page block's type to be ISOLATE.
+ * page allocater never alloc memory from ISOLATE block.
+ */
+
+static int
+__count_immobile_pages(struct zone *zone, struct page *page, int count)
+{
+ unsigned long pfn, iter, found;
+ /*
+ * For avoiding noise data, lru_add_drain_all() should be called
+ * If ZONE_MOVABLE, the zone never contains immobile pages
+ */
+ if (zone_idx(zone) == ZONE_MOVABLE)
+ return true;
+
+ if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE)
+ return true;
+
+ pfn = page_to_pfn(page);
+ for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
+ unsigned long check = pfn + iter;
+
+ if (!pfn_valid_within(check))
+ continue;
+
+ page = pfn_to_page(check);
+ if (!page_count(page)) {
+ if (PageBuddy(page))
+ iter += (1 << page_order(page)) - 1;
+ continue;
+ }
+ if (!PageLRU(page))
+ found++;
+ /*
+ * If there are RECLAIMABLE pages, we need to check it.
+ * But now, memory offline itself doesn't call shrink_slab()
+ * and it still to be fixed.
+ */
+ /*
+ * If the page is not RAM, page_count()should be 0.
+ * we don't need more check. This is an _used_ not-movable page.
+ *
+ * The problematic thing here is PG_reserved pages. PG_reserved
+ * is set to both of a memory hole page and a _used_ kernel
+ * page at boot.
+ */
+ if (found > count)
+ return false;
+ }
+ return true;
+}
+
+bool is_pageblock_removable_nolock(struct page *page)
+{
+ struct zone *zone;
+ unsigned long pfn;
+
+ /*
+ * We have to be careful here because we are iterating over memory
+ * sections which are not zone aware so we might end up outside of
+ * the zone but still within the section.
+ * We have to take care about the node as well. If the node is offline
+ * its NODE_DATA will be NULL - see page_zone.
+ */
+ if (!node_online(page_to_nid(page)))
+ return false;
+
+ zone = page_zone(page);
+ pfn = page_to_pfn(page);
+ if (zone->zone_start_pfn > pfn ||
+ zone->zone_start_pfn + zone->spanned_pages <= pfn)
+ return false;
+
+ return __count_immobile_pages(zone, page, 0);
+}
+
+int set_migratetype_isolate(struct page *page)
+{
+ struct zone *zone;
+ unsigned long flags, pfn;
+ struct memory_isolate_notify arg;
+ int notifier_ret;
+ int ret = -EBUSY;
+
+ zone = page_zone(page);
+
+ spin_lock_irqsave(&zone->lock, flags);
+
+ pfn = page_to_pfn(page);
+ arg.start_pfn = pfn;
+ arg.nr_pages = pageblock_nr_pages;
+ arg.pages_found = 0;
+
+ /*
+ * It may be possible to isolate a pageblock even if the
+ * migratetype is not MIGRATE_MOVABLE. The memory isolation
+ * notifier chain is used by balloon drivers to return the
+ * number of pages in a range that are held by the balloon
+ * driver to shrink memory. If all the pages are accounted for
+ * by balloons, are free, or on the LRU, isolation can continue.
+ * Later, for example, when memory hotplug notifier runs, these
+ * pages reported as "can be isolated" should be isolated(freed)
+ * by the balloon driver through the memory notifier chain.
+ */
+ notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
+ notifier_ret = notifier_to_errno(notifier_ret);
+ if (notifier_ret)
+ goto out;
+ /*
+ * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
+ * We just check MOVABLE pages.
+ */
+ if (__count_immobile_pages(zone, page, arg.pages_found))
+ ret = 0;
+
+ /*
+ * immobile means "not-on-lru" paes. If immobile is larger than
+ * removable-by-driver pages reported by notifier, we'll fail.
+ */
+
+out:
+ if (!ret) {
+ set_pageblock_migratetype(page, MIGRATE_ISOLATE);
+ move_freepages_block(zone, page, MIGRATE_ISOLATE);
+ }
+
+ spin_unlock_irqrestore(&zone->lock, flags);
+ if (!ret)
+ drain_all_pages();
+ return ret;
+}
+
+void unset_migratetype_isolate(struct page *page)
+{
+ struct zone *zone;
+ unsigned long flags;
+ zone = page_zone(page);
+ spin_lock_irqsave(&zone->lock, flags);
+ if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
+ goto out;
+ set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+ move_freepages_block(zone, page, MIGRATE_MOVABLE);
+out:
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+/*
+ * All pages in the range must be isolated before calling this.
+ */
+void
+__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
+{
+ struct page *page;
+ struct zone *zone;
+ int order, i;
+ unsigned long pfn;
+ unsigned long flags;
+ /* find the first valid pfn */
+ for (pfn = start_pfn; pfn < end_pfn; pfn++)
+ if (pfn_valid(pfn))
+ break;
+ if (pfn == end_pfn)
+ return;
+ zone = page_zone(pfn_to_page(pfn));
+ spin_lock_irqsave(&zone->lock, flags);
+ pfn = start_pfn;
+ while (pfn < end_pfn) {
+ if (!pfn_valid(pfn)) {
+ pfn++;
+ continue;
+ }
+ page = pfn_to_page(pfn);
+ BUG_ON(page_count(page));
+ BUG_ON(!PageBuddy(page));
+ order = page_order(page);
+#ifdef CONFIG_DEBUG_VM
+ printk(KERN_INFO "remove from free list %lx %d %lx\n",
+ pfn, 1 << order, end_pfn);
+#endif
+ list_del(&page->lru);
+ rmv_page_order(page);
+ zone->free_area[order].nr_free--;
+ __mod_zone_page_state(zone, NR_FREE_PAGES,
+ - (1UL << order));
+#ifdef CONFIG_HIGHMEM
+ if (PageHighMem(page))
+ totalhigh_pages -= 1 << order;
+#endif
+ for (i = 0; i < (1 << order); i++)
+ SetPageReserved((page+i));
+ pfn += (1 << order);
+ }
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+#endif
+
+#ifdef CONFIG_MEMORY_FAILURE
+bool is_free_buddy_page(struct page *page)
+{
+ struct zone *zone = page_zone(page);
+ unsigned long pfn = page_to_pfn(page);
+ unsigned long flags;
+ int order;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ for (order = 0; order < MAX_ORDER; order++) {
+ struct page *page_head = page - (pfn & ((1 << order) - 1));
+
+ if (PageBuddy(page_head) && page_order(page_head) >= order)
+ break;
+ }
+ spin_unlock_irqrestore(&zone->lock, flags);
+
+ return order < MAX_ORDER;
+}
+#endif
+
+static struct trace_print_flags pageflag_names[] = {
+ {1UL << PG_locked, "locked" },
+ {1UL << PG_error, "error" },
+ {1UL << PG_referenced, "referenced" },
+ {1UL << PG_uptodate, "uptodate" },
+ {1UL << PG_dirty, "dirty" },
+ {1UL << PG_lru, "lru" },
+ {1UL << PG_active, "active" },
+ {1UL << PG_slab, "slab" },
+ {1UL << PG_owner_priv_1, "owner_priv_1" },
+ {1UL << PG_arch_1, "arch_1" },
+ {1UL << PG_reserved, "reserved" },
+ {1UL << PG_private, "private" },
+ {1UL << PG_private_2, "private_2" },
+ {1UL << PG_writeback, "writeback" },
+#ifdef CONFIG_PAGEFLAGS_EXTENDED
+ {1UL << PG_head, "head" },
+ {1UL << PG_tail, "tail" },
+#else
+ {1UL << PG_compound, "compound" },
+#endif
+ {1UL << PG_swapcache, "swapcache" },
+ {1UL << PG_mappedtodisk, "mappedtodisk" },
+ {1UL << PG_reclaim, "reclaim" },
+ {1UL << PG_swapbacked, "swapbacked" },
+ {1UL << PG_unevictable, "unevictable" },
+#ifdef CONFIG_MMU
+ {1UL << PG_mlocked, "mlocked" },
+#endif
+#ifdef CONFIG_ARCH_USES_PG_UNCACHED
+ {1UL << PG_uncached, "uncached" },
+#endif
+#ifdef CONFIG_MEMORY_FAILURE
+ {1UL << PG_hwpoison, "hwpoison" },
+#endif
+ {-1UL, NULL },
+};
+
+static void dump_page_flags(unsigned long flags)
+{
+ const char *delim = "";
+ unsigned long mask;
+ int i;
+
+ printk(KERN_ALERT "page flags: %#lx(", flags);
+
+ /* remove zone id */
+ flags &= (1UL << NR_PAGEFLAGS) - 1;
+
+ for (i = 0; pageflag_names[i].name && flags; i++) {
+
+ mask = pageflag_names[i].mask;
+ if ((flags & mask) != mask)
+ continue;
+
+ flags &= ~mask;
+ printk("%s%s", delim, pageflag_names[i].name);
+ delim = "|";
+ }
+
+ /* check for left over flags */
+ if (flags)
+ printk("%s%#lx", delim, flags);
+
+ printk(")\n");
+}
+
+void dump_page(struct page *page)
+{
+ printk(KERN_ALERT
+ "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
+ page, atomic_read(&page->_count), page_mapcount(page),
+ page->mapping, page->index);
+ dump_page_flags(page->flags);
+ mem_cgroup_print_bad_page(page);
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/page_cgroup.c b/ap/os/linux/linux-3.4.x/mm/page_cgroup.c
new file mode 100644
index 0000000..9012038
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/page_cgroup.c
@@ -0,0 +1,537 @@
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/bootmem.h>
+#include <linux/bit_spinlock.h>
+#include <linux/page_cgroup.h>
+#include <linux/hash.h>
+#include <linux/slab.h>
+#include <linux/memory.h>
+#include <linux/vmalloc.h>
+#include <linux/cgroup.h>
+#include <linux/swapops.h>
+#include <linux/kmemleak.h>
+
+static unsigned long total_usage;
+
+static void page_cgroup_lock_init(struct page_cgroup *pc, int nr_pages)
+{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ for (; nr_pages; nr_pages--, pc++)
+ spin_lock_init(&pc->pcg_lock);
+#endif
+}
+
+#if !defined(CONFIG_SPARSEMEM)
+
+
+void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
+{
+ pgdat->node_page_cgroup = NULL;
+}
+
+struct page_cgroup *lookup_page_cgroup(struct page *page)
+{
+ unsigned long pfn = page_to_pfn(page);
+ unsigned long offset;
+ struct page_cgroup *base;
+
+ base = NODE_DATA(page_to_nid(page))->node_page_cgroup;
+#ifdef CONFIG_DEBUG_VM
+ /*
+ * The sanity checks the page allocator does upon freeing a
+ * page can reach here before the page_cgroup arrays are
+ * allocated when feeding a range of pages to the allocator
+ * for the first time during bootup or memory hotplug.
+ */
+ if (unlikely(!base))
+ return NULL;
+#endif
+ offset = pfn - NODE_DATA(page_to_nid(page))->node_start_pfn;
+ return base + offset;
+}
+
+static int __init alloc_node_page_cgroup(int nid)
+{
+ struct page_cgroup *base;
+ unsigned long table_size;
+ unsigned long nr_pages;
+
+ nr_pages = NODE_DATA(nid)->node_spanned_pages;
+ if (!nr_pages)
+ return 0;
+
+ table_size = sizeof(struct page_cgroup) * nr_pages;
+
+ base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
+ table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
+ if (!base)
+ return -ENOMEM;
+ NODE_DATA(nid)->node_page_cgroup = base;
+ total_usage += table_size;
+ page_cgroup_lock_init(base, nr_pages);
+ return 0;
+}
+
+void __init page_cgroup_init_flatmem(void)
+{
+
+ int nid, fail;
+
+ if (mem_cgroup_disabled())
+ return;
+
+ for_each_online_node(nid) {
+ fail = alloc_node_page_cgroup(nid);
+ if (fail)
+ goto fail;
+ }
+ printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
+ printk(KERN_INFO "please try 'cgroup_disable=memory' option if you"
+ " don't want memory cgroups\n");
+ return;
+fail:
+ printk(KERN_CRIT "allocation of page_cgroup failed.\n");
+ printk(KERN_CRIT "please try 'cgroup_disable=memory' boot option\n");
+ panic("Out of memory");
+}
+
+#else /* CONFIG_FLAT_NODE_MEM_MAP */
+
+struct page_cgroup *lookup_page_cgroup(struct page *page)
+{
+ unsigned long pfn = page_to_pfn(page);
+ struct mem_section *section = __pfn_to_section(pfn);
+#ifdef CONFIG_DEBUG_VM
+ /*
+ * The sanity checks the page allocator does upon freeing a
+ * page can reach here before the page_cgroup arrays are
+ * allocated when feeding a range of pages to the allocator
+ * for the first time during bootup or memory hotplug.
+ */
+ if (!section->page_cgroup)
+ return NULL;
+#endif
+ return section->page_cgroup + pfn;
+}
+
+static void *__meminit alloc_page_cgroup(size_t size, int nid)
+{
+ gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN;
+ void *addr = NULL;
+
+ addr = alloc_pages_exact_nid(nid, size, flags);
+ if (addr) {
+ kmemleak_alloc(addr, size, 1, flags);
+ return addr;
+ }
+
+ if (node_state(nid, N_HIGH_MEMORY))
+ addr = vzalloc_node(size, nid);
+ else
+ addr = vzalloc(size);
+
+ return addr;
+}
+
+static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
+{
+ struct mem_section *section;
+ struct page_cgroup *base;
+ unsigned long table_size;
+
+ section = __pfn_to_section(pfn);
+
+ if (section->page_cgroup)
+ return 0;
+
+ table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
+ base = alloc_page_cgroup(table_size, nid);
+
+ /*
+ * The value stored in section->page_cgroup is (base - pfn)
+ * and it does not point to the memory block allocated above,
+ * causing kmemleak false positives.
+ */
+ kmemleak_not_leak(base);
+
+ if (!base) {
+ printk(KERN_ERR "page cgroup allocation failure\n");
+ return -ENOMEM;
+ }
+
+ page_cgroup_lock_init(base, PAGES_PER_SECTION);
+
+ /*
+ * The passed "pfn" may not be aligned to SECTION. For the calculation
+ * we need to apply a mask.
+ */
+ pfn &= PAGE_SECTION_MASK;
+ section->page_cgroup = base - pfn;
+ total_usage += table_size;
+ return 0;
+}
+#ifdef CONFIG_MEMORY_HOTPLUG
+static void free_page_cgroup(void *addr)
+{
+ if (is_vmalloc_addr(addr)) {
+ vfree(addr);
+ } else {
+ struct page *page = virt_to_page(addr);
+ size_t table_size =
+ sizeof(struct page_cgroup) * PAGES_PER_SECTION;
+
+ BUG_ON(PageReserved(page));
+ kmemleak_free(addr);
+ free_pages_exact(addr, table_size);
+ }
+}
+
+void __free_page_cgroup(unsigned long pfn)
+{
+ struct mem_section *ms;
+ struct page_cgroup *base;
+
+ ms = __pfn_to_section(pfn);
+ if (!ms || !ms->page_cgroup)
+ return;
+ base = ms->page_cgroup + pfn;
+ free_page_cgroup(base);
+ ms->page_cgroup = NULL;
+}
+
+int __meminit online_page_cgroup(unsigned long start_pfn,
+ unsigned long nr_pages,
+ int nid)
+{
+ unsigned long start, end, pfn;
+ int fail = 0;
+
+ start = SECTION_ALIGN_DOWN(start_pfn);
+ end = SECTION_ALIGN_UP(start_pfn + nr_pages);
+
+ if (nid == -1) {
+ /*
+ * In this case, "nid" already exists and contains valid memory.
+ * "start_pfn" passed to us is a pfn which is an arg for
+ * online__pages(), and start_pfn should exist.
+ */
+ nid = pfn_to_nid(start_pfn);
+ VM_BUG_ON(!node_state(nid, N_ONLINE));
+ }
+
+ for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
+ if (!pfn_present(pfn))
+ continue;
+ fail = init_section_page_cgroup(pfn, nid);
+ }
+ if (!fail)
+ return 0;
+
+ /* rollback */
+ for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
+ __free_page_cgroup(pfn);
+
+ return -ENOMEM;
+}
+
+int __meminit offline_page_cgroup(unsigned long start_pfn,
+ unsigned long nr_pages, int nid)
+{
+ unsigned long start, end, pfn;
+
+ start = SECTION_ALIGN_DOWN(start_pfn);
+ end = SECTION_ALIGN_UP(start_pfn + nr_pages);
+
+ for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
+ __free_page_cgroup(pfn);
+ return 0;
+
+}
+
+static int __meminit page_cgroup_callback(struct notifier_block *self,
+ unsigned long action, void *arg)
+{
+ struct memory_notify *mn = arg;
+ int ret = 0;
+ switch (action) {
+ case MEM_GOING_ONLINE:
+ ret = online_page_cgroup(mn->start_pfn,
+ mn->nr_pages, mn->status_change_nid);
+ break;
+ case MEM_OFFLINE:
+ offline_page_cgroup(mn->start_pfn,
+ mn->nr_pages, mn->status_change_nid);
+ break;
+ case MEM_CANCEL_ONLINE:
+ case MEM_GOING_OFFLINE:
+ break;
+ case MEM_ONLINE:
+ case MEM_CANCEL_OFFLINE:
+ break;
+ }
+
+ return notifier_from_errno(ret);
+}
+
+#endif
+
+void __init page_cgroup_init(void)
+{
+ unsigned long pfn;
+ int nid;
+
+ if (mem_cgroup_disabled())
+ return;
+
+ for_each_node_state(nid, N_HIGH_MEMORY) {
+ unsigned long start_pfn, end_pfn;
+
+ start_pfn = node_start_pfn(nid);
+ end_pfn = node_end_pfn(nid);
+ /*
+ * start_pfn and end_pfn may not be aligned to SECTION and the
+ * page->flags of out of node pages are not initialized. So we
+ * scan [start_pfn, the biggest section's pfn < end_pfn) here.
+ */
+ for (pfn = start_pfn;
+ pfn < end_pfn;
+ pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) {
+
+ if (!pfn_valid(pfn))
+ continue;
+ /*
+ * Nodes's pfns can be overlapping.
+ * We know some arch can have a nodes layout such as
+ * -------------pfn-------------->
+ * N0 | N1 | N2 | N0 | N1 | N2|....
+ */
+ if (pfn_to_nid(pfn) != nid)
+ continue;
+ if (init_section_page_cgroup(pfn, nid))
+ goto oom;
+ }
+ }
+ hotplug_memory_notifier(page_cgroup_callback, 0);
+ printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
+ printk(KERN_INFO "please try 'cgroup_disable=memory' option if you "
+ "don't want memory cgroups\n");
+ return;
+oom:
+ printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
+ panic("Out of memory");
+}
+
+void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
+{
+ return;
+}
+
+#endif
+
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
+
+static DEFINE_MUTEX(swap_cgroup_mutex);
+struct swap_cgroup_ctrl {
+ struct page **map;
+ unsigned long length;
+ spinlock_t lock;
+};
+
+static struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
+
+struct swap_cgroup {
+ unsigned short id;
+};
+#define SC_PER_PAGE (PAGE_SIZE/sizeof(struct swap_cgroup))
+
+/*
+ * SwapCgroup implements "lookup" and "exchange" operations.
+ * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge
+ * against SwapCache. At swap_free(), this is accessed directly from swap.
+ *
+ * This means,
+ * - we have no race in "exchange" when we're accessed via SwapCache because
+ * SwapCache(and its swp_entry) is under lock.
+ * - When called via swap_free(), there is no user of this entry and no race.
+ * Then, we don't need lock around "exchange".
+ *
+ * TODO: we can push these buffers out to HIGHMEM.
+ */
+
+/*
+ * allocate buffer for swap_cgroup.
+ */
+static int swap_cgroup_prepare(int type)
+{
+ struct page *page;
+ struct swap_cgroup_ctrl *ctrl;
+ unsigned long idx, max;
+
+ ctrl = &swap_cgroup_ctrl[type];
+
+ for (idx = 0; idx < ctrl->length; idx++) {
+ page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!page)
+ goto not_enough_page;
+ ctrl->map[idx] = page;
+ }
+ return 0;
+not_enough_page:
+ max = idx;
+ for (idx = 0; idx < max; idx++)
+ __free_page(ctrl->map[idx]);
+
+ return -ENOMEM;
+}
+
+static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
+ struct swap_cgroup_ctrl **ctrlp)
+{
+ pgoff_t offset = swp_offset(ent);
+ struct swap_cgroup_ctrl *ctrl;
+ struct page *mappage;
+ struct swap_cgroup *sc;
+
+ ctrl = &swap_cgroup_ctrl[swp_type(ent)];
+ if (ctrlp)
+ *ctrlp = ctrl;
+
+ mappage = ctrl->map[offset / SC_PER_PAGE];
+ sc = page_address(mappage);
+ return sc + offset % SC_PER_PAGE;
+}
+
+/**
+ * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
+ * @end: swap entry to be cmpxchged
+ * @old: old id
+ * @new: new id
+ *
+ * Returns old id at success, 0 at failure.
+ * (There is no mem_cgroup using 0 as its id)
+ */
+unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
+ unsigned short old, unsigned short new)
+{
+ struct swap_cgroup_ctrl *ctrl;
+ struct swap_cgroup *sc;
+ unsigned long flags;
+ unsigned short retval;
+
+ sc = lookup_swap_cgroup(ent, &ctrl);
+
+ spin_lock_irqsave(&ctrl->lock, flags);
+ retval = sc->id;
+ if (retval == old)
+ sc->id = new;
+ else
+ retval = 0;
+ spin_unlock_irqrestore(&ctrl->lock, flags);
+ return retval;
+}
+
+/**
+ * swap_cgroup_record - record mem_cgroup for this swp_entry.
+ * @ent: swap entry to be recorded into
+ * @mem: mem_cgroup to be recorded
+ *
+ * Returns old value at success, 0 at failure.
+ * (Of course, old value can be 0.)
+ */
+unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
+{
+ struct swap_cgroup_ctrl *ctrl;
+ struct swap_cgroup *sc;
+ unsigned short old;
+ unsigned long flags;
+
+ sc = lookup_swap_cgroup(ent, &ctrl);
+
+ spin_lock_irqsave(&ctrl->lock, flags);
+ old = sc->id;
+ sc->id = id;
+ spin_unlock_irqrestore(&ctrl->lock, flags);
+
+ return old;
+}
+
+/**
+ * lookup_swap_cgroup_id - lookup mem_cgroup id tied to swap entry
+ * @ent: swap entry to be looked up.
+ *
+ * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
+ */
+unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
+{
+ return lookup_swap_cgroup(ent, NULL)->id;
+}
+
+int swap_cgroup_swapon(int type, unsigned long max_pages)
+{
+ void *array;
+ unsigned long array_size;
+ unsigned long length;
+ struct swap_cgroup_ctrl *ctrl;
+
+ if (!do_swap_account)
+ return 0;
+
+ length = DIV_ROUND_UP(max_pages, SC_PER_PAGE);
+ array_size = length * sizeof(void *);
+
+ array = vzalloc(array_size);
+ if (!array)
+ goto nomem;
+
+ ctrl = &swap_cgroup_ctrl[type];
+ mutex_lock(&swap_cgroup_mutex);
+ ctrl->length = length;
+ ctrl->map = array;
+ spin_lock_init(&ctrl->lock);
+ if (swap_cgroup_prepare(type)) {
+ /* memory shortage */
+ ctrl->map = NULL;
+ ctrl->length = 0;
+ mutex_unlock(&swap_cgroup_mutex);
+ vfree(array);
+ goto nomem;
+ }
+ mutex_unlock(&swap_cgroup_mutex);
+
+ return 0;
+nomem:
+ printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
+ printk(KERN_INFO
+ "swap_cgroup can be disabled by swapaccount=0 boot option\n");
+ return -ENOMEM;
+}
+
+void swap_cgroup_swapoff(int type)
+{
+ struct page **map;
+ unsigned long i, length;
+ struct swap_cgroup_ctrl *ctrl;
+
+ if (!do_swap_account)
+ return;
+
+ mutex_lock(&swap_cgroup_mutex);
+ ctrl = &swap_cgroup_ctrl[type];
+ map = ctrl->map;
+ length = ctrl->length;
+ ctrl->map = NULL;
+ ctrl->length = 0;
+ mutex_unlock(&swap_cgroup_mutex);
+
+ if (map) {
+ for (i = 0; i < length; i++) {
+ struct page *page = map[i];
+ if (page)
+ __free_page(page);
+ }
+ vfree(map);
+ }
+}
+
+#endif
diff --git a/ap/os/linux/linux-3.4.x/mm/page_io.c b/ap/os/linux/linux-3.4.x/mm/page_io.c
new file mode 100644
index 0000000..dc76b4d
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/page_io.c
@@ -0,0 +1,135 @@
+/*
+ * linux/mm/page_io.c
+ *
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * Swap reorganised 29.12.95,
+ * Asynchronous swapping added 30.12.95. Stephen Tweedie
+ * Removed race in async swapping. 14.4.1996. Bruno Haible
+ * Add swap of shared pages through the page cache. 20.2.1998. Stephen Tweedie
+ * Always use brw_page, life becomes simpler. 12 May 1998 Eric Biederman
+ */
+
+#include <linux/mm.h>
+#include <linux/kernel_stat.h>
+#include <linux/gfp.h>
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+#include <linux/bio.h>
+#include <linux/swapops.h>
+#include <linux/writeback.h>
+#include <asm/pgtable.h>
+
+static struct bio *get_swap_bio(gfp_t gfp_flags,
+ struct page *page, bio_end_io_t end_io)
+{
+ struct bio *bio;
+
+ bio = bio_alloc(gfp_flags, 1);
+ if (bio) {
+ bio->bi_sector = map_swap_page(page, &bio->bi_bdev);
+ bio->bi_sector <<= PAGE_SHIFT - 9;
+ bio->bi_io_vec[0].bv_page = page;
+ bio->bi_io_vec[0].bv_len = PAGE_SIZE;
+ bio->bi_io_vec[0].bv_offset = 0;
+ bio->bi_vcnt = 1;
+ bio->bi_idx = 0;
+ bio->bi_size = PAGE_SIZE;
+ bio->bi_end_io = end_io;
+ }
+ return bio;
+}
+
+static void end_swap_bio_write(struct bio *bio, int err)
+{
+ const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ struct page *page = bio->bi_io_vec[0].bv_page;
+
+ if (!uptodate) {
+ SetPageError(page);
+ /*
+ * We failed to write the page out to swap-space.
+ * Re-dirty the page in order to avoid it being reclaimed.
+ * Also print a dire warning that things will go BAD (tm)
+ * very quickly.
+ *
+ * Also clear PG_reclaim to avoid rotate_reclaimable_page()
+ */
+ set_page_dirty(page);
+ printk(KERN_ALERT "Write-error on swap-device (%u:%u:%Lu)\n",
+ imajor(bio->bi_bdev->bd_inode),
+ iminor(bio->bi_bdev->bd_inode),
+ (unsigned long long)bio->bi_sector);
+ ClearPageReclaim(page);
+ }
+ end_page_writeback(page);
+ bio_put(bio);
+}
+
+void end_swap_bio_read(struct bio *bio, int err)
+{
+ const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ struct page *page = bio->bi_io_vec[0].bv_page;
+
+ if (!uptodate) {
+ SetPageError(page);
+ ClearPageUptodate(page);
+ printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
+ imajor(bio->bi_bdev->bd_inode),
+ iminor(bio->bi_bdev->bd_inode),
+ (unsigned long long)bio->bi_sector);
+ } else {
+ SetPageUptodate(page);
+ }
+ unlock_page(page);
+ bio_put(bio);
+}
+
+/*
+ * We may have stale swap cache pages in memory: notice
+ * them here and get rid of the unnecessary final write.
+ */
+int swap_writepage(struct page *page, struct writeback_control *wbc)
+{
+ struct bio *bio;
+ int ret = 0, rw = WRITE;
+
+ if (try_to_free_swap(page)) {
+ unlock_page(page);
+ goto out;
+ }
+ bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
+ if (bio == NULL) {
+ set_page_dirty(page);
+ unlock_page(page);
+ ret = -ENOMEM;
+ goto out;
+ }
+ if (wbc->sync_mode == WB_SYNC_ALL)
+ rw |= REQ_SYNC;
+ count_vm_event(PSWPOUT);
+ set_page_writeback(page);
+ unlock_page(page);
+ submit_bio(rw, bio);
+out:
+ return ret;
+}
+
+int swap_readpage(struct page *page)
+{
+ struct bio *bio;
+ int ret = 0;
+
+ VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON(PageUptodate(page));
+ bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
+ if (bio == NULL) {
+ unlock_page(page);
+ ret = -ENOMEM;
+ goto out;
+ }
+ count_vm_event(PSWPIN);
+ submit_bio(READ, bio);
+out:
+ return ret;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/page_isolation.c b/ap/os/linux/linux-3.4.x/mm/page_isolation.c
new file mode 100644
index 0000000..4ae42bb
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/page_isolation.c
@@ -0,0 +1,141 @@
+/*
+ * linux/mm/page_isolation.c
+ */
+
+#include <linux/mm.h>
+#include <linux/page-isolation.h>
+#include <linux/pageblock-flags.h>
+#include "internal.h"
+
+static inline struct page *
+__first_valid_page(unsigned long pfn, unsigned long nr_pages)
+{
+ int i;
+ for (i = 0; i < nr_pages; i++)
+ if (pfn_valid_within(pfn + i))
+ break;
+ if (unlikely(i == nr_pages))
+ return NULL;
+ return pfn_to_page(pfn + i);
+}
+
+/*
+ * start_isolate_page_range() -- make page-allocation-type of range of pages
+ * to be MIGRATE_ISOLATE.
+ * @start_pfn: The lower PFN of the range to be isolated.
+ * @end_pfn: The upper PFN of the range to be isolated.
+ *
+ * Making page-allocation-type to be MIGRATE_ISOLATE means free pages in
+ * the range will never be allocated. Any free pages and pages freed in the
+ * future will not be allocated again.
+ *
+ * start_pfn/end_pfn must be aligned to pageblock_order.
+ * Returns 0 on success and -EBUSY if any part of range cannot be isolated.
+ */
+int
+start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn)
+{
+ unsigned long pfn;
+ unsigned long undo_pfn;
+ struct page *page;
+
+ BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
+ BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
+
+ for (pfn = start_pfn;
+ pfn < end_pfn;
+ pfn += pageblock_nr_pages) {
+ page = __first_valid_page(pfn, pageblock_nr_pages);
+ if (page && set_migratetype_isolate(page)) {
+ undo_pfn = pfn;
+ goto undo;
+ }
+ }
+ return 0;
+undo:
+ for (pfn = start_pfn;
+ pfn < undo_pfn;
+ pfn += pageblock_nr_pages)
+ unset_migratetype_isolate(pfn_to_page(pfn));
+
+ return -EBUSY;
+}
+
+/*
+ * Make isolated pages available again.
+ */
+int
+undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn)
+{
+ unsigned long pfn;
+ struct page *page;
+ BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
+ BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
+ for (pfn = start_pfn;
+ pfn < end_pfn;
+ pfn += pageblock_nr_pages) {
+ page = __first_valid_page(pfn, pageblock_nr_pages);
+ if (!page || get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
+ continue;
+ unset_migratetype_isolate(page);
+ }
+ return 0;
+}
+/*
+ * Test all pages in the range is free(means isolated) or not.
+ * all pages in [start_pfn...end_pfn) must be in the same zone.
+ * zone->lock must be held before call this.
+ *
+ * Returns 1 if all pages in the range is isolated.
+ */
+static int
+__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn)
+{
+ struct page *page;
+
+ while (pfn < end_pfn) {
+ if (!pfn_valid_within(pfn)) {
+ pfn++;
+ continue;
+ }
+ page = pfn_to_page(pfn);
+ if (PageBuddy(page))
+ pfn += 1 << page_order(page);
+ else if (page_count(page) == 0 &&
+ page_private(page) == MIGRATE_ISOLATE)
+ pfn += 1;
+ else
+ break;
+ }
+ if (pfn < end_pfn)
+ return 0;
+ return 1;
+}
+
+int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
+{
+ unsigned long pfn, flags;
+ struct page *page;
+ struct zone *zone;
+ int ret;
+
+ /*
+ * Note: pageblock_nr_page != MAX_ORDER. Then, chunks of free page
+ * is not aligned to pageblock_nr_pages.
+ * Then we just check pagetype fist.
+ */
+ for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
+ page = __first_valid_page(pfn, pageblock_nr_pages);
+ if (page && get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
+ break;
+ }
+ page = __first_valid_page(start_pfn, end_pfn - start_pfn);
+ if ((pfn < end_pfn) || !page)
+ return -EBUSY;
+ /* Check all pages are free or Marked as ISOLATED */
+ zone = page_zone(page);
+ spin_lock_irqsave(&zone->lock, flags);
+ ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn);
+ spin_unlock_irqrestore(&zone->lock, flags);
+ return ret ? 0 : -EBUSY;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/pagewalk.c b/ap/os/linux/linux-3.4.x/mm/pagewalk.c
new file mode 100644
index 0000000..1090e77
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/pagewalk.c
@@ -0,0 +1,249 @@
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/sched.h>
+#include <linux/hugetlb.h>
+
+static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ pte_t *pte;
+ int err = 0;
+
+ pte = pte_offset_map(pmd, addr);
+ for (;;) {
+ err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, walk);
+ if (err)
+ break;
+ addr += PAGE_SIZE;
+ if (addr == end)
+ break;
+ pte++;
+ }
+
+ pte_unmap(pte);
+ return err;
+}
+
+static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ pmd_t *pmd;
+ unsigned long next;
+ int err = 0;
+
+ pmd = pmd_offset(pud, addr);
+ do {
+again:
+ next = pmd_addr_end(addr, end);
+ if (pmd_none(*pmd)) {
+ if (walk->pte_hole)
+ err = walk->pte_hole(addr, next, walk);
+ if (err)
+ break;
+ continue;
+ }
+ /*
+ * This implies that each ->pmd_entry() handler
+ * needs to know about pmd_trans_huge() pmds
+ */
+ if (walk->pmd_entry)
+ err = walk->pmd_entry(pmd, addr, next, walk);
+ if (err)
+ break;
+
+ /*
+ * Check this here so we only break down trans_huge
+ * pages when we _need_ to
+ */
+ if (!walk->pte_entry)
+ continue;
+
+ split_huge_page_pmd(walk->mm, pmd);
+ if (pmd_none_or_trans_huge_or_clear_bad(pmd))
+ goto again;
+ err = walk_pte_range(pmd, addr, next, walk);
+ if (err)
+ break;
+ } while (pmd++, addr = next, addr != end);
+
+ return err;
+}
+
+static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ pud_t *pud;
+ unsigned long next;
+ int err = 0;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud)) {
+ if (walk->pte_hole)
+ err = walk->pte_hole(addr, next, walk);
+ if (err)
+ break;
+ continue;
+ }
+ if (walk->pud_entry)
+ err = walk->pud_entry(pud, addr, next, walk);
+ if (!err && (walk->pmd_entry || walk->pte_entry))
+ err = walk_pmd_range(pud, addr, next, walk);
+ if (err)
+ break;
+ } while (pud++, addr = next, addr != end);
+
+ return err;
+}
+
+#ifdef CONFIG_HUGETLB_PAGE
+static unsigned long hugetlb_entry_end(struct hstate *h, unsigned long addr,
+ unsigned long end)
+{
+ unsigned long boundary = (addr & huge_page_mask(h)) + huge_page_size(h);
+ return boundary < end ? boundary : end;
+}
+
+static int walk_hugetlb_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ struct hstate *h = hstate_vma(vma);
+ unsigned long next;
+ unsigned long hmask = huge_page_mask(h);
+ pte_t *pte;
+ int err = 0;
+
+ do {
+ next = hugetlb_entry_end(h, addr, end);
+ pte = huge_pte_offset(walk->mm, addr & hmask);
+ if (pte && walk->hugetlb_entry)
+ err = walk->hugetlb_entry(pte, hmask, addr, next, walk);
+ if (err)
+ return err;
+ } while (addr = next, addr != end);
+
+ return 0;
+}
+
+#else /* CONFIG_HUGETLB_PAGE */
+static int walk_hugetlb_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ return 0;
+}
+
+#endif /* CONFIG_HUGETLB_PAGE */
+
+
+
+/**
+ * walk_page_range - walk a memory map's page tables with a callback
+ * @mm: memory map to walk
+ * @addr: starting address
+ * @end: ending address
+ * @walk: set of callbacks to invoke for each level of the tree
+ *
+ * Recursively walk the page table for the memory area in a VMA,
+ * calling supplied callbacks. Callbacks are called in-order (first
+ * PGD, first PUD, first PMD, first PTE, second PTE... second PMD,
+ * etc.). If lower-level callbacks are omitted, walking depth is reduced.
+ *
+ * Each callback receives an entry pointer and the start and end of the
+ * associated range, and a copy of the original mm_walk for access to
+ * the ->private or ->mm fields.
+ *
+ * Usually no locks are taken, but splitting transparent huge page may
+ * take page table lock. And the bottom level iterator will map PTE
+ * directories from highmem if necessary.
+ *
+ * If any callback returns a non-zero value, the walk is aborted and
+ * the return value is propagated back to the caller. Otherwise 0 is returned.
+ *
+ * walk->mm->mmap_sem must be held for at least read if walk->hugetlb_entry
+ * is !NULL.
+ */
+int walk_page_range(unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ int err = 0;
+
+ if (addr >= end)
+ return err;
+
+ if (!walk->mm)
+ return -EINVAL;
+
+ VM_BUG_ON(!rwsem_is_locked(&walk->mm->mmap_sem));
+
+ pgd = pgd_offset(walk->mm, addr);
+ do {
+ struct vm_area_struct *vma = NULL;
+
+ next = pgd_addr_end(addr, end);
+
+ /*
+ * This function was not intended to be vma based.
+ * But there are vma special cases to be handled:
+ * - hugetlb vma's
+ * - VM_PFNMAP vma's
+ */
+ vma = find_vma(walk->mm, addr);
+ if (vma) {
+ /*
+ * There are no page structures backing a VM_PFNMAP
+ * range, so do not allow split_huge_page_pmd().
+ */
+ if ((vma->vm_start <= addr) &&
+ (vma->vm_flags & VM_PFNMAP)) {
+ next = vma->vm_end;
+ pgd = pgd_offset(walk->mm, next);
+ continue;
+ }
+ /*
+ * Handle hugetlb vma individually because pagetable
+ * walk for the hugetlb page is dependent on the
+ * architecture and we can't handled it in the same
+ * manner as non-huge pages.
+ */
+ if (walk->hugetlb_entry && (vma->vm_start <= addr) &&
+ is_vm_hugetlb_page(vma)) {
+ if (vma->vm_end < next)
+ next = vma->vm_end;
+ /*
+ * Hugepage is very tightly coupled with vma,
+ * so walk through hugetlb entries within a
+ * given vma.
+ */
+ err = walk_hugetlb_range(vma, addr, next, walk);
+ if (err)
+ break;
+ pgd = pgd_offset(walk->mm, next);
+ continue;
+ }
+ }
+
+ if (pgd_none_or_clear_bad(pgd)) {
+ if (walk->pte_hole)
+ err = walk->pte_hole(addr, next, walk);
+ if (err)
+ break;
+ pgd++;
+ continue;
+ }
+ if (walk->pgd_entry)
+ err = walk->pgd_entry(pgd, addr, next, walk);
+ if (!err &&
+ (walk->pud_entry || walk->pmd_entry || walk->pte_entry))
+ err = walk_pud_range(pgd, addr, next, walk);
+ if (err)
+ break;
+ pgd++;
+ } while (addr = next, addr != end);
+
+ return err;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/percpu-km.c b/ap/os/linux/linux-3.4.x/mm/percpu-km.c
new file mode 100644
index 0000000..89633fe
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/percpu-km.c
@@ -0,0 +1,108 @@
+/*
+ * mm/percpu-km.c - kernel memory based chunk allocation
+ *
+ * Copyright (C) 2010 SUSE Linux Products GmbH
+ * Copyright (C) 2010 Tejun Heo <tj@kernel.org>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Chunks are allocated as a contiguous kernel memory using gfp
+ * allocation. This is to be used on nommu architectures.
+ *
+ * To use percpu-km,
+ *
+ * - define CONFIG_NEED_PER_CPU_KM from the arch Kconfig.
+ *
+ * - CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK must not be defined. It's
+ * not compatible with PER_CPU_KM. EMBED_FIRST_CHUNK should work
+ * fine.
+ *
+ * - NUMA is not supported. When setting up the first chunk,
+ * @cpu_distance_fn should be NULL or report all CPUs to be nearer
+ * than or at LOCAL_DISTANCE.
+ *
+ * - It's best if the chunk size is power of two multiple of
+ * PAGE_SIZE. Because each chunk is allocated as a contiguous
+ * kernel memory block using alloc_pages(), memory will be wasted if
+ * chunk size is not aligned. percpu-km code will whine about it.
+ */
+
+#if defined(CONFIG_SMP) && defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK)
+#error "contiguous percpu allocation is incompatible with paged first chunk"
+#endif
+
+#include <linux/log2.h>
+
+static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size)
+{
+ unsigned int cpu;
+
+ for_each_possible_cpu(cpu)
+ memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
+
+ return 0;
+}
+
+static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size)
+{
+ /* nada */
+}
+
+static struct pcpu_chunk *pcpu_create_chunk(void)
+{
+ const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT;
+ struct pcpu_chunk *chunk;
+ struct page *pages;
+ int i;
+
+ chunk = pcpu_alloc_chunk();
+ if (!chunk)
+ return NULL;
+
+ pages = alloc_pages(GFP_KERNEL, order_base_2(nr_pages));
+ if (!pages) {
+ pcpu_free_chunk(chunk);
+ return NULL;
+ }
+
+ for (i = 0; i < nr_pages; i++)
+ pcpu_set_page_chunk(nth_page(pages, i), chunk);
+
+ chunk->data = pages;
+ chunk->base_addr = page_address(pages) - pcpu_group_offsets[0];
+ return chunk;
+}
+
+static void pcpu_destroy_chunk(struct pcpu_chunk *chunk)
+{
+ const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT;
+
+ if (chunk && chunk->data)
+ __free_pages(chunk->data, order_base_2(nr_pages));
+ pcpu_free_chunk(chunk);
+}
+
+static struct page *pcpu_addr_to_page(void *addr)
+{
+ return virt_to_page(addr);
+}
+
+static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai)
+{
+ size_t nr_pages, alloc_pages;
+
+ /* all units must be in a single group */
+ if (ai->nr_groups != 1) {
+ printk(KERN_CRIT "percpu: can't handle more than one groups\n");
+ return -EINVAL;
+ }
+
+ nr_pages = (ai->groups[0].nr_units * ai->unit_size) >> PAGE_SHIFT;
+ alloc_pages = roundup_pow_of_two(nr_pages);
+
+ if (alloc_pages > nr_pages)
+ printk(KERN_WARNING "percpu: wasting %zu pages per chunk\n",
+ alloc_pages - nr_pages);
+
+ return 0;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/percpu-vm.c b/ap/os/linux/linux-3.4.x/mm/percpu-vm.c
new file mode 100644
index 0000000..6f3db37
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/percpu-vm.c
@@ -0,0 +1,459 @@
+/*
+ * mm/percpu-vm.c - vmalloc area based chunk allocation
+ *
+ * Copyright (C) 2010 SUSE Linux Products GmbH
+ * Copyright (C) 2010 Tejun Heo <tj@kernel.org>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Chunks are mapped into vmalloc areas and populated page by page.
+ * This is the default chunk allocator.
+ */
+
+static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk,
+ unsigned int cpu, int page_idx)
+{
+ /* must not be used on pre-mapped chunk */
+ WARN_ON(chunk->immutable);
+
+ return vmalloc_to_page((void *)pcpu_chunk_addr(chunk, cpu, page_idx));
+}
+
+/**
+ * pcpu_get_pages_and_bitmap - get temp pages array and bitmap
+ * @chunk: chunk of interest
+ * @bitmapp: output parameter for bitmap
+ * @may_alloc: may allocate the array
+ *
+ * Returns pointer to array of pointers to struct page and bitmap,
+ * both of which can be indexed with pcpu_page_idx(). The returned
+ * array is cleared to zero and *@bitmapp is copied from
+ * @chunk->populated. Note that there is only one array and bitmap
+ * and access exclusion is the caller's responsibility.
+ *
+ * CONTEXT:
+ * pcpu_alloc_mutex and does GFP_KERNEL allocation if @may_alloc.
+ * Otherwise, don't care.
+ *
+ * RETURNS:
+ * Pointer to temp pages array on success, NULL on failure.
+ */
+static struct page **pcpu_get_pages_and_bitmap(struct pcpu_chunk *chunk,
+ unsigned long **bitmapp,
+ bool may_alloc)
+{
+ static struct page **pages;
+ static unsigned long *bitmap;
+ size_t pages_size = pcpu_nr_units * pcpu_unit_pages * sizeof(pages[0]);
+ size_t bitmap_size = BITS_TO_LONGS(pcpu_unit_pages) *
+ sizeof(unsigned long);
+
+ if (!pages || !bitmap) {
+ if (may_alloc && !pages)
+ pages = pcpu_mem_zalloc(pages_size);
+ if (may_alloc && !bitmap)
+ bitmap = pcpu_mem_zalloc(bitmap_size);
+ if (!pages || !bitmap)
+ return NULL;
+ }
+
+ bitmap_copy(bitmap, chunk->populated, pcpu_unit_pages);
+
+ *bitmapp = bitmap;
+ return pages;
+}
+
+/**
+ * pcpu_free_pages - free pages which were allocated for @chunk
+ * @chunk: chunk pages were allocated for
+ * @pages: array of pages to be freed, indexed by pcpu_page_idx()
+ * @populated: populated bitmap
+ * @page_start: page index of the first page to be freed
+ * @page_end: page index of the last page to be freed + 1
+ *
+ * Free pages [@page_start and @page_end) in @pages for all units.
+ * The pages were allocated for @chunk.
+ */
+static void pcpu_free_pages(struct pcpu_chunk *chunk,
+ struct page **pages, unsigned long *populated,
+ int page_start, int page_end)
+{
+ unsigned int cpu;
+ int i;
+
+ for_each_possible_cpu(cpu) {
+ for (i = page_start; i < page_end; i++) {
+ struct page *page = pages[pcpu_page_idx(cpu, i)];
+
+ if (page)
+ __free_page(page);
+ }
+ }
+}
+
+/**
+ * pcpu_alloc_pages - allocates pages for @chunk
+ * @chunk: target chunk
+ * @pages: array to put the allocated pages into, indexed by pcpu_page_idx()
+ * @populated: populated bitmap
+ * @page_start: page index of the first page to be allocated
+ * @page_end: page index of the last page to be allocated + 1
+ *
+ * Allocate pages [@page_start,@page_end) into @pages for all units.
+ * The allocation is for @chunk. Percpu core doesn't care about the
+ * content of @pages and will pass it verbatim to pcpu_map_pages().
+ */
+static int pcpu_alloc_pages(struct pcpu_chunk *chunk,
+ struct page **pages, unsigned long *populated,
+ int page_start, int page_end)
+{
+ const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD;
+ unsigned int cpu, tcpu;
+ int i;
+
+ for_each_possible_cpu(cpu) {
+ for (i = page_start; i < page_end; i++) {
+ struct page **pagep = &pages[pcpu_page_idx(cpu, i)];
+
+ *pagep = alloc_pages_node(cpu_to_node(cpu), gfp, 0);
+ if (!*pagep)
+ goto err;
+ }
+ }
+ return 0;
+
+err:
+ while (--i >= page_start)
+ __free_page(pages[pcpu_page_idx(cpu, i)]);
+
+ for_each_possible_cpu(tcpu) {
+ if (tcpu == cpu)
+ break;
+ for (i = page_start; i < page_end; i++)
+ __free_page(pages[pcpu_page_idx(tcpu, i)]);
+ }
+ return -ENOMEM;
+}
+
+/**
+ * pcpu_pre_unmap_flush - flush cache prior to unmapping
+ * @chunk: chunk the regions to be flushed belongs to
+ * @page_start: page index of the first page to be flushed
+ * @page_end: page index of the last page to be flushed + 1
+ *
+ * Pages in [@page_start,@page_end) of @chunk are about to be
+ * unmapped. Flush cache. As each flushing trial can be very
+ * expensive, issue flush on the whole region at once rather than
+ * doing it for each cpu. This could be an overkill but is more
+ * scalable.
+ */
+static void pcpu_pre_unmap_flush(struct pcpu_chunk *chunk,
+ int page_start, int page_end)
+{
+ flush_cache_vunmap(
+ pcpu_chunk_addr(chunk, pcpu_low_unit_cpu, page_start),
+ pcpu_chunk_addr(chunk, pcpu_high_unit_cpu, page_end));
+}
+
+static void __pcpu_unmap_pages(unsigned long addr, int nr_pages)
+{
+ unmap_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT);
+}
+
+/**
+ * pcpu_unmap_pages - unmap pages out of a pcpu_chunk
+ * @chunk: chunk of interest
+ * @pages: pages array which can be used to pass information to free
+ * @populated: populated bitmap
+ * @page_start: page index of the first page to unmap
+ * @page_end: page index of the last page to unmap + 1
+ *
+ * For each cpu, unmap pages [@page_start,@page_end) out of @chunk.
+ * Corresponding elements in @pages were cleared by the caller and can
+ * be used to carry information to pcpu_free_pages() which will be
+ * called after all unmaps are finished. The caller should call
+ * proper pre/post flush functions.
+ */
+static void pcpu_unmap_pages(struct pcpu_chunk *chunk,
+ struct page **pages, unsigned long *populated,
+ int page_start, int page_end)
+{
+ unsigned int cpu;
+ int i;
+
+ for_each_possible_cpu(cpu) {
+ for (i = page_start; i < page_end; i++) {
+ struct page *page;
+
+ page = pcpu_chunk_page(chunk, cpu, i);
+ WARN_ON(!page);
+ pages[pcpu_page_idx(cpu, i)] = page;
+ }
+ __pcpu_unmap_pages(pcpu_chunk_addr(chunk, cpu, page_start),
+ page_end - page_start);
+ }
+
+ bitmap_clear(populated, page_start, page_end - page_start);
+}
+
+/**
+ * pcpu_post_unmap_tlb_flush - flush TLB after unmapping
+ * @chunk: pcpu_chunk the regions to be flushed belong to
+ * @page_start: page index of the first page to be flushed
+ * @page_end: page index of the last page to be flushed + 1
+ *
+ * Pages [@page_start,@page_end) of @chunk have been unmapped. Flush
+ * TLB for the regions. This can be skipped if the area is to be
+ * returned to vmalloc as vmalloc will handle TLB flushing lazily.
+ *
+ * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once
+ * for the whole region.
+ */
+static void pcpu_post_unmap_tlb_flush(struct pcpu_chunk *chunk,
+ int page_start, int page_end)
+{
+ flush_tlb_kernel_range(
+ pcpu_chunk_addr(chunk, pcpu_low_unit_cpu, page_start),
+ pcpu_chunk_addr(chunk, pcpu_high_unit_cpu, page_end));
+}
+
+static int __pcpu_map_pages(unsigned long addr, struct page **pages,
+ int nr_pages)
+{
+ return map_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT,
+ PAGE_KERNEL, pages);
+}
+
+/**
+ * pcpu_map_pages - map pages into a pcpu_chunk
+ * @chunk: chunk of interest
+ * @pages: pages array containing pages to be mapped
+ * @populated: populated bitmap
+ * @page_start: page index of the first page to map
+ * @page_end: page index of the last page to map + 1
+ *
+ * For each cpu, map pages [@page_start,@page_end) into @chunk. The
+ * caller is responsible for calling pcpu_post_map_flush() after all
+ * mappings are complete.
+ *
+ * This function is responsible for setting corresponding bits in
+ * @chunk->populated bitmap and whatever is necessary for reverse
+ * lookup (addr -> chunk).
+ */
+static int pcpu_map_pages(struct pcpu_chunk *chunk,
+ struct page **pages, unsigned long *populated,
+ int page_start, int page_end)
+{
+ unsigned int cpu, tcpu;
+ int i, err;
+
+ for_each_possible_cpu(cpu) {
+ err = __pcpu_map_pages(pcpu_chunk_addr(chunk, cpu, page_start),
+ &pages[pcpu_page_idx(cpu, page_start)],
+ page_end - page_start);
+ if (err < 0)
+ goto err;
+ }
+
+ /* mapping successful, link chunk and mark populated */
+ for (i = page_start; i < page_end; i++) {
+ for_each_possible_cpu(cpu)
+ pcpu_set_page_chunk(pages[pcpu_page_idx(cpu, i)],
+ chunk);
+ __set_bit(i, populated);
+ }
+
+ return 0;
+
+err:
+ for_each_possible_cpu(tcpu) {
+ if (tcpu == cpu)
+ break;
+ __pcpu_unmap_pages(pcpu_chunk_addr(chunk, tcpu, page_start),
+ page_end - page_start);
+ }
+ pcpu_post_unmap_tlb_flush(chunk, page_start, page_end);
+ return err;
+}
+
+/**
+ * pcpu_post_map_flush - flush cache after mapping
+ * @chunk: pcpu_chunk the regions to be flushed belong to
+ * @page_start: page index of the first page to be flushed
+ * @page_end: page index of the last page to be flushed + 1
+ *
+ * Pages [@page_start,@page_end) of @chunk have been mapped. Flush
+ * cache.
+ *
+ * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once
+ * for the whole region.
+ */
+static void pcpu_post_map_flush(struct pcpu_chunk *chunk,
+ int page_start, int page_end)
+{
+ flush_cache_vmap(
+ pcpu_chunk_addr(chunk, pcpu_low_unit_cpu, page_start),
+ pcpu_chunk_addr(chunk, pcpu_high_unit_cpu, page_end));
+}
+
+/**
+ * pcpu_populate_chunk - populate and map an area of a pcpu_chunk
+ * @chunk: chunk of interest
+ * @off: offset to the area to populate
+ * @size: size of the area to populate in bytes
+ *
+ * For each cpu, populate and map pages [@page_start,@page_end) into
+ * @chunk. The area is cleared on return.
+ *
+ * CONTEXT:
+ * pcpu_alloc_mutex, does GFP_KERNEL allocation.
+ */
+static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size)
+{
+ int page_start = PFN_DOWN(off);
+ int page_end = PFN_UP(off + size);
+ int free_end = page_start, unmap_end = page_start;
+ struct page **pages;
+ unsigned long *populated;
+ unsigned int cpu;
+ int rs, re, rc;
+
+ /* quick path, check whether all pages are already there */
+ rs = page_start;
+ pcpu_next_pop(chunk, &rs, &re, page_end);
+ if (rs == page_start && re == page_end)
+ goto clear;
+
+ /* need to allocate and map pages, this chunk can't be immutable */
+ WARN_ON(chunk->immutable);
+
+ pages = pcpu_get_pages_and_bitmap(chunk, &populated, true);
+ if (!pages)
+ return -ENOMEM;
+
+ /* alloc and map */
+ pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) {
+ rc = pcpu_alloc_pages(chunk, pages, populated, rs, re);
+ if (rc)
+ goto err_free;
+ free_end = re;
+ }
+
+ pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) {
+ rc = pcpu_map_pages(chunk, pages, populated, rs, re);
+ if (rc)
+ goto err_unmap;
+ unmap_end = re;
+ }
+ pcpu_post_map_flush(chunk, page_start, page_end);
+
+ /* commit new bitmap */
+ bitmap_copy(chunk->populated, populated, pcpu_unit_pages);
+clear:
+ for_each_possible_cpu(cpu)
+ memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
+ return 0;
+
+err_unmap:
+ pcpu_pre_unmap_flush(chunk, page_start, unmap_end);
+ pcpu_for_each_unpop_region(chunk, rs, re, page_start, unmap_end)
+ pcpu_unmap_pages(chunk, pages, populated, rs, re);
+ pcpu_post_unmap_tlb_flush(chunk, page_start, unmap_end);
+err_free:
+ pcpu_for_each_unpop_region(chunk, rs, re, page_start, free_end)
+ pcpu_free_pages(chunk, pages, populated, rs, re);
+ return rc;
+}
+
+/**
+ * pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk
+ * @chunk: chunk to depopulate
+ * @off: offset to the area to depopulate
+ * @size: size of the area to depopulate in bytes
+ * @flush: whether to flush cache and tlb or not
+ *
+ * For each cpu, depopulate and unmap pages [@page_start,@page_end)
+ * from @chunk. If @flush is true, vcache is flushed before unmapping
+ * and tlb after.
+ *
+ * CONTEXT:
+ * pcpu_alloc_mutex.
+ */
+static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size)
+{
+ int page_start = PFN_DOWN(off);
+ int page_end = PFN_UP(off + size);
+ struct page **pages;
+ unsigned long *populated;
+ int rs, re;
+
+ /* quick path, check whether it's empty already */
+ rs = page_start;
+ pcpu_next_unpop(chunk, &rs, &re, page_end);
+ if (rs == page_start && re == page_end)
+ return;
+
+ /* immutable chunks can't be depopulated */
+ WARN_ON(chunk->immutable);
+
+ /*
+ * If control reaches here, there must have been at least one
+ * successful population attempt so the temp pages array must
+ * be available now.
+ */
+ pages = pcpu_get_pages_and_bitmap(chunk, &populated, false);
+ BUG_ON(!pages);
+
+ /* unmap and free */
+ pcpu_pre_unmap_flush(chunk, page_start, page_end);
+
+ pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end)
+ pcpu_unmap_pages(chunk, pages, populated, rs, re);
+
+ /* no need to flush tlb, vmalloc will handle it lazily */
+
+ pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end)
+ pcpu_free_pages(chunk, pages, populated, rs, re);
+
+ /* commit new bitmap */
+ bitmap_copy(chunk->populated, populated, pcpu_unit_pages);
+}
+
+static struct pcpu_chunk *pcpu_create_chunk(void)
+{
+ struct pcpu_chunk *chunk;
+ struct vm_struct **vms;
+
+ chunk = pcpu_alloc_chunk();
+ if (!chunk)
+ return NULL;
+
+ vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes,
+ pcpu_nr_groups, pcpu_atom_size);
+ if (!vms) {
+ pcpu_free_chunk(chunk);
+ return NULL;
+ }
+
+ chunk->data = vms;
+ chunk->base_addr = vms[0]->addr - pcpu_group_offsets[0];
+ return chunk;
+}
+
+static void pcpu_destroy_chunk(struct pcpu_chunk *chunk)
+{
+ if (chunk && chunk->data)
+ pcpu_free_vm_areas(chunk->data, pcpu_nr_groups);
+ pcpu_free_chunk(chunk);
+}
+
+static struct page *pcpu_addr_to_page(void *addr)
+{
+ return vmalloc_to_page(addr);
+}
+
+static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai)
+{
+ /* no extra restriction */
+ return 0;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/percpu.c b/ap/os/linux/linux-3.4.x/mm/percpu.c
new file mode 100644
index 0000000..13b2eef
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/percpu.c
@@ -0,0 +1,1942 @@
+/*
+ * mm/percpu.c - percpu memory allocator
+ *
+ * Copyright (C) 2009 SUSE Linux Products GmbH
+ * Copyright (C) 2009 Tejun Heo <tj@kernel.org>
+ *
+ * This file is released under the GPLv2.
+ *
+ * This is percpu allocator which can handle both static and dynamic
+ * areas. Percpu areas are allocated in chunks. Each chunk is
+ * consisted of boot-time determined number of units and the first
+ * chunk is used for static percpu variables in the kernel image
+ * (special boot time alloc/init handling necessary as these areas
+ * need to be brought up before allocation services are running).
+ * Unit grows as necessary and all units grow or shrink in unison.
+ * When a chunk is filled up, another chunk is allocated.
+ *
+ * c0 c1 c2
+ * ------------------- ------------------- ------------
+ * | u0 | u1 | u2 | u3 | | u0 | u1 | u2 | u3 | | u0 | u1 | u
+ * ------------------- ...... ------------------- .... ------------
+ *
+ * Allocation is done in offset-size areas of single unit space. Ie,
+ * an area of 512 bytes at 6k in c1 occupies 512 bytes at 6k of c1:u0,
+ * c1:u1, c1:u2 and c1:u3. On UMA, units corresponds directly to
+ * cpus. On NUMA, the mapping can be non-linear and even sparse.
+ * Percpu access can be done by configuring percpu base registers
+ * according to cpu to unit mapping and pcpu_unit_size.
+ *
+ * There are usually many small percpu allocations many of them being
+ * as small as 4 bytes. The allocator organizes chunks into lists
+ * according to free size and tries to allocate from the fullest one.
+ * Each chunk keeps the maximum contiguous area size hint which is
+ * guaranteed to be equal to or larger than the maximum contiguous
+ * area in the chunk. This helps the allocator not to iterate the
+ * chunk maps unnecessarily.
+ *
+ * Allocation state in each chunk is kept using an array of integers
+ * on chunk->map. A positive value in the map represents a free
+ * region and negative allocated. Allocation inside a chunk is done
+ * by scanning this map sequentially and serving the first matching
+ * entry. This is mostly copied from the percpu_modalloc() allocator.
+ * Chunks can be determined from the address using the index field
+ * in the page struct. The index field contains a pointer to the chunk.
+ *
+ * To use this allocator, arch code should do the followings.
+ *
+ * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate
+ * regular address to percpu pointer and back if they need to be
+ * different from the default
+ *
+ * - use pcpu_setup_first_chunk() during percpu area initialization to
+ * setup the first chunk containing the kernel static percpu area
+ */
+
+#include <linux/bitmap.h>
+#include <linux/bootmem.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/log2.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/percpu.h>
+#include <linux/pfn.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include <linux/workqueue.h>
+#include <linux/kmemleak.h>
+
+#include <asm/cacheflush.h>
+#include <asm/sections.h>
+#include <asm/tlbflush.h>
+#include <asm/io.h>
+
+#define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */
+#define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */
+
+#ifdef CONFIG_SMP
+/* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */
+#ifndef __addr_to_pcpu_ptr
+#define __addr_to_pcpu_ptr(addr) \
+ (void __percpu *)((unsigned long)(addr) - \
+ (unsigned long)pcpu_base_addr + \
+ (unsigned long)__per_cpu_start)
+#endif
+#ifndef __pcpu_ptr_to_addr
+#define __pcpu_ptr_to_addr(ptr) \
+ (void __force *)((unsigned long)(ptr) + \
+ (unsigned long)pcpu_base_addr - \
+ (unsigned long)__per_cpu_start)
+#endif
+#else /* CONFIG_SMP */
+/* on UP, it's always identity mapped */
+#define __addr_to_pcpu_ptr(addr) (void __percpu *)(addr)
+#define __pcpu_ptr_to_addr(ptr) (void __force *)(ptr)
+#endif /* CONFIG_SMP */
+
+struct pcpu_chunk {
+ struct list_head list; /* linked to pcpu_slot lists */
+ int free_size; /* free bytes in the chunk */
+ int contig_hint; /* max contiguous size hint */
+ void *base_addr; /* base address of this chunk */
+ int map_used; /* # of map entries used */
+ int map_alloc; /* # of map entries allocated */
+ int *map; /* allocation map */
+ void *data; /* chunk data */
+ bool immutable; /* no [de]population allowed */
+ unsigned long populated[]; /* populated bitmap */
+};
+
+static int pcpu_unit_pages __read_mostly;
+static int pcpu_unit_size __read_mostly;
+static int pcpu_nr_units __read_mostly;
+static int pcpu_atom_size __read_mostly;
+static int pcpu_nr_slots __read_mostly;
+static size_t pcpu_chunk_struct_size __read_mostly;
+
+/* cpus with the lowest and highest unit addresses */
+static unsigned int pcpu_low_unit_cpu __read_mostly;
+static unsigned int pcpu_high_unit_cpu __read_mostly;
+
+/* the address of the first chunk which starts with the kernel static area */
+void *pcpu_base_addr __read_mostly;
+EXPORT_SYMBOL_GPL(pcpu_base_addr);
+
+static const int *pcpu_unit_map __read_mostly; /* cpu -> unit */
+const unsigned long *pcpu_unit_offsets __read_mostly; /* cpu -> unit offset */
+
+/* group information, used for vm allocation */
+static int pcpu_nr_groups __read_mostly;
+static const unsigned long *pcpu_group_offsets __read_mostly;
+static const size_t *pcpu_group_sizes __read_mostly;
+
+/*
+ * The first chunk which always exists. Note that unlike other
+ * chunks, this one can be allocated and mapped in several different
+ * ways and thus often doesn't live in the vmalloc area.
+ */
+static struct pcpu_chunk *pcpu_first_chunk;
+
+/*
+ * Optional reserved chunk. This chunk reserves part of the first
+ * chunk and serves it for reserved allocations. The amount of
+ * reserved offset is in pcpu_reserved_chunk_limit. When reserved
+ * area doesn't exist, the following variables contain NULL and 0
+ * respectively.
+ */
+static struct pcpu_chunk *pcpu_reserved_chunk;
+static int pcpu_reserved_chunk_limit;
+
+/*
+ * Synchronization rules.
+ *
+ * There are two locks - pcpu_alloc_mutex and pcpu_lock. The former
+ * protects allocation/reclaim paths, chunks, populated bitmap and
+ * vmalloc mapping. The latter is a spinlock and protects the index
+ * data structures - chunk slots, chunks and area maps in chunks.
+ *
+ * During allocation, pcpu_alloc_mutex is kept locked all the time and
+ * pcpu_lock is grabbed and released as necessary. All actual memory
+ * allocations are done using GFP_KERNEL with pcpu_lock released. In
+ * general, percpu memory can't be allocated with irq off but
+ * irqsave/restore are still used in alloc path so that it can be used
+ * from early init path - sched_init() specifically.
+ *
+ * Free path accesses and alters only the index data structures, so it
+ * can be safely called from atomic context. When memory needs to be
+ * returned to the system, free path schedules reclaim_work which
+ * grabs both pcpu_alloc_mutex and pcpu_lock, unlinks chunks to be
+ * reclaimed, release both locks and frees the chunks. Note that it's
+ * necessary to grab both locks to remove a chunk from circulation as
+ * allocation path might be referencing the chunk with only
+ * pcpu_alloc_mutex locked.
+ */
+static DEFINE_MUTEX(pcpu_alloc_mutex); /* protects whole alloc and reclaim */
+static DEFINE_SPINLOCK(pcpu_lock); /* protects index data structures */
+
+static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */
+
+/* reclaim work to release fully free chunks, scheduled from free path */
+static void pcpu_reclaim(struct work_struct *work);
+static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim);
+
+static bool pcpu_addr_in_first_chunk(void *addr)
+{
+ void *first_start = pcpu_first_chunk->base_addr;
+
+ return addr >= first_start && addr < first_start + pcpu_unit_size;
+}
+
+static bool pcpu_addr_in_reserved_chunk(void *addr)
+{
+ void *first_start = pcpu_first_chunk->base_addr;
+
+ return addr >= first_start &&
+ addr < first_start + pcpu_reserved_chunk_limit;
+}
+
+static int __pcpu_size_to_slot(int size)
+{
+ int highbit = fls(size); /* size is in bytes */
+ return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1);
+}
+
+static int pcpu_size_to_slot(int size)
+{
+ if (size == pcpu_unit_size)
+ return pcpu_nr_slots - 1;
+ return __pcpu_size_to_slot(size);
+}
+
+static int pcpu_chunk_slot(const struct pcpu_chunk *chunk)
+{
+ if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int))
+ return 0;
+
+ return pcpu_size_to_slot(chunk->free_size);
+}
+
+/* set the pointer to a chunk in a page struct */
+static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu)
+{
+ page->index = (unsigned long)pcpu;
+}
+
+/* obtain pointer to a chunk from a page struct */
+static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page)
+{
+ return (struct pcpu_chunk *)page->index;
+}
+
+static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx)
+{
+ return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx;
+}
+
+static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk,
+ unsigned int cpu, int page_idx)
+{
+ return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] +
+ (page_idx << PAGE_SHIFT);
+}
+
+static void __maybe_unused pcpu_next_unpop(struct pcpu_chunk *chunk,
+ int *rs, int *re, int end)
+{
+ *rs = find_next_zero_bit(chunk->populated, end, *rs);
+ *re = find_next_bit(chunk->populated, end, *rs + 1);
+}
+
+static void __maybe_unused pcpu_next_pop(struct pcpu_chunk *chunk,
+ int *rs, int *re, int end)
+{
+ *rs = find_next_bit(chunk->populated, end, *rs);
+ *re = find_next_zero_bit(chunk->populated, end, *rs + 1);
+}
+
+/*
+ * (Un)populated page region iterators. Iterate over (un)populated
+ * page regions between @start and @end in @chunk. @rs and @re should
+ * be integer variables and will be set to start and end page index of
+ * the current region.
+ */
+#define pcpu_for_each_unpop_region(chunk, rs, re, start, end) \
+ for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \
+ (rs) < (re); \
+ (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end)))
+
+#define pcpu_for_each_pop_region(chunk, rs, re, start, end) \
+ for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end)); \
+ (rs) < (re); \
+ (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end)))
+
+/**
+ * pcpu_mem_zalloc - allocate memory
+ * @size: bytes to allocate
+ *
+ * Allocate @size bytes. If @size is smaller than PAGE_SIZE,
+ * kzalloc() is used; otherwise, vzalloc() is used. The returned
+ * memory is always zeroed.
+ *
+ * CONTEXT:
+ * Does GFP_KERNEL allocation.
+ *
+ * RETURNS:
+ * Pointer to the allocated area on success, NULL on failure.
+ */
+static void *pcpu_mem_zalloc(size_t size)
+{
+ if (WARN_ON_ONCE(!slab_is_available()))
+ return NULL;
+
+ if (size <= PAGE_SIZE)
+ return kzalloc(size, GFP_KERNEL);
+ else
+ return vzalloc(size);
+}
+
+/**
+ * pcpu_mem_free - free memory
+ * @ptr: memory to free
+ * @size: size of the area
+ *
+ * Free @ptr. @ptr should have been allocated using pcpu_mem_zalloc().
+ */
+static void pcpu_mem_free(void *ptr, size_t size)
+{
+ if (size <= PAGE_SIZE)
+ kfree(ptr);
+ else
+ vfree(ptr);
+}
+
+/**
+ * pcpu_chunk_relocate - put chunk in the appropriate chunk slot
+ * @chunk: chunk of interest
+ * @oslot: the previous slot it was on
+ *
+ * This function is called after an allocation or free changed @chunk.
+ * New slot according to the changed state is determined and @chunk is
+ * moved to the slot. Note that the reserved chunk is never put on
+ * chunk slots.
+ *
+ * CONTEXT:
+ * pcpu_lock.
+ */
+static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot)
+{
+ int nslot = pcpu_chunk_slot(chunk);
+
+ if (chunk != pcpu_reserved_chunk && oslot != nslot) {
+ if (oslot < nslot)
+ list_move(&chunk->list, &pcpu_slot[nslot]);
+ else
+ list_move_tail(&chunk->list, &pcpu_slot[nslot]);
+ }
+}
+
+/**
+ * pcpu_need_to_extend - determine whether chunk area map needs to be extended
+ * @chunk: chunk of interest
+ *
+ * Determine whether area map of @chunk needs to be extended to
+ * accommodate a new allocation.
+ *
+ * CONTEXT:
+ * pcpu_lock.
+ *
+ * RETURNS:
+ * New target map allocation length if extension is necessary, 0
+ * otherwise.
+ */
+static int pcpu_need_to_extend(struct pcpu_chunk *chunk)
+{
+ int new_alloc;
+
+ if (chunk->map_alloc >= chunk->map_used + 2)
+ return 0;
+
+ new_alloc = PCPU_DFL_MAP_ALLOC;
+ while (new_alloc < chunk->map_used + 2)
+ new_alloc *= 2;
+
+ return new_alloc;
+}
+
+/**
+ * pcpu_extend_area_map - extend area map of a chunk
+ * @chunk: chunk of interest
+ * @new_alloc: new target allocation length of the area map
+ *
+ * Extend area map of @chunk to have @new_alloc entries.
+ *
+ * CONTEXT:
+ * Does GFP_KERNEL allocation. Grabs and releases pcpu_lock.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc)
+{
+ int *old = NULL, *new = NULL;
+ size_t old_size = 0, new_size = new_alloc * sizeof(new[0]);
+ unsigned long flags;
+
+ new = pcpu_mem_zalloc(new_size);
+ if (!new)
+ return -ENOMEM;
+
+ /* acquire pcpu_lock and switch to new area map */
+ spin_lock_irqsave(&pcpu_lock, flags);
+
+ if (new_alloc <= chunk->map_alloc)
+ goto out_unlock;
+
+ old_size = chunk->map_alloc * sizeof(chunk->map[0]);
+ old = chunk->map;
+
+ memcpy(new, old, old_size);
+
+ chunk->map_alloc = new_alloc;
+ chunk->map = new;
+ new = NULL;
+
+out_unlock:
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+
+ /*
+ * pcpu_mem_free() might end up calling vfree() which uses
+ * IRQ-unsafe lock and thus can't be called under pcpu_lock.
+ */
+ pcpu_mem_free(old, old_size);
+ pcpu_mem_free(new, new_size);
+
+ return 0;
+}
+
+/**
+ * pcpu_split_block - split a map block
+ * @chunk: chunk of interest
+ * @i: index of map block to split
+ * @head: head size in bytes (can be 0)
+ * @tail: tail size in bytes (can be 0)
+ *
+ * Split the @i'th map block into two or three blocks. If @head is
+ * non-zero, @head bytes block is inserted before block @i moving it
+ * to @i+1 and reducing its size by @head bytes.
+ *
+ * If @tail is non-zero, the target block, which can be @i or @i+1
+ * depending on @head, is reduced by @tail bytes and @tail byte block
+ * is inserted after the target block.
+ *
+ * @chunk->map must have enough free slots to accommodate the split.
+ *
+ * CONTEXT:
+ * pcpu_lock.
+ */
+static void pcpu_split_block(struct pcpu_chunk *chunk, int i,
+ int head, int tail)
+{
+ int nr_extra = !!head + !!tail;
+
+ BUG_ON(chunk->map_alloc < chunk->map_used + nr_extra);
+
+ /* insert new subblocks */
+ memmove(&chunk->map[i + nr_extra], &chunk->map[i],
+ sizeof(chunk->map[0]) * (chunk->map_used - i));
+ chunk->map_used += nr_extra;
+
+ if (head) {
+ chunk->map[i + 1] = chunk->map[i] - head;
+ chunk->map[i++] = head;
+ }
+ if (tail) {
+ chunk->map[i++] -= tail;
+ chunk->map[i] = tail;
+ }
+}
+
+/**
+ * pcpu_alloc_area - allocate area from a pcpu_chunk
+ * @chunk: chunk of interest
+ * @size: wanted size in bytes
+ * @align: wanted align
+ *
+ * Try to allocate @size bytes area aligned at @align from @chunk.
+ * Note that this function only allocates the offset. It doesn't
+ * populate or map the area.
+ *
+ * @chunk->map must have at least two free slots.
+ *
+ * CONTEXT:
+ * pcpu_lock.
+ *
+ * RETURNS:
+ * Allocated offset in @chunk on success, -1 if no matching area is
+ * found.
+ */
+static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align)
+{
+ int oslot = pcpu_chunk_slot(chunk);
+ int max_contig = 0;
+ int i, off;
+
+ for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) {
+ bool is_last = i + 1 == chunk->map_used;
+ int head, tail;
+
+ /* extra for alignment requirement */
+ head = ALIGN(off, align) - off;
+ BUG_ON(i == 0 && head != 0);
+
+ if (chunk->map[i] < 0)
+ continue;
+ if (chunk->map[i] < head + size) {
+ max_contig = max(chunk->map[i], max_contig);
+ continue;
+ }
+
+ /*
+ * If head is small or the previous block is free,
+ * merge'em. Note that 'small' is defined as smaller
+ * than sizeof(int), which is very small but isn't too
+ * uncommon for percpu allocations.
+ */
+ if (head && (head < sizeof(int) || chunk->map[i - 1] > 0)) {
+ if (chunk->map[i - 1] > 0)
+ chunk->map[i - 1] += head;
+ else {
+ chunk->map[i - 1] -= head;
+ chunk->free_size -= head;
+ }
+ chunk->map[i] -= head;
+ off += head;
+ head = 0;
+ }
+
+ /* if tail is small, just keep it around */
+ tail = chunk->map[i] - head - size;
+ if (tail < sizeof(int))
+ tail = 0;
+
+ /* split if warranted */
+ if (head || tail) {
+ pcpu_split_block(chunk, i, head, tail);
+ if (head) {
+ i++;
+ off += head;
+ max_contig = max(chunk->map[i - 1], max_contig);
+ }
+ if (tail)
+ max_contig = max(chunk->map[i + 1], max_contig);
+ }
+
+ /* update hint and mark allocated */
+ if (is_last)
+ chunk->contig_hint = max_contig; /* fully scanned */
+ else
+ chunk->contig_hint = max(chunk->contig_hint,
+ max_contig);
+
+ chunk->free_size -= chunk->map[i];
+ chunk->map[i] = -chunk->map[i];
+
+ pcpu_chunk_relocate(chunk, oslot);
+ return off;
+ }
+
+ chunk->contig_hint = max_contig; /* fully scanned */
+ pcpu_chunk_relocate(chunk, oslot);
+
+ /* tell the upper layer that this chunk has no matching area */
+ return -1;
+}
+
+/**
+ * pcpu_free_area - free area to a pcpu_chunk
+ * @chunk: chunk of interest
+ * @freeme: offset of area to free
+ *
+ * Free area starting from @freeme to @chunk. Note that this function
+ * only modifies the allocation map. It doesn't depopulate or unmap
+ * the area.
+ *
+ * CONTEXT:
+ * pcpu_lock.
+ */
+static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme)
+{
+ int oslot = pcpu_chunk_slot(chunk);
+ int i, off;
+
+ for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++]))
+ if (off == freeme)
+ break;
+ BUG_ON(off != freeme);
+ BUG_ON(chunk->map[i] > 0);
+
+ chunk->map[i] = -chunk->map[i];
+ chunk->free_size += chunk->map[i];
+
+ /* merge with previous? */
+ if (i > 0 && chunk->map[i - 1] >= 0) {
+ chunk->map[i - 1] += chunk->map[i];
+ chunk->map_used--;
+ memmove(&chunk->map[i], &chunk->map[i + 1],
+ (chunk->map_used - i) * sizeof(chunk->map[0]));
+ i--;
+ }
+ /* merge with next? */
+ if (i + 1 < chunk->map_used && chunk->map[i + 1] >= 0) {
+ chunk->map[i] += chunk->map[i + 1];
+ chunk->map_used--;
+ memmove(&chunk->map[i + 1], &chunk->map[i + 2],
+ (chunk->map_used - (i + 1)) * sizeof(chunk->map[0]));
+ }
+
+ chunk->contig_hint = max(chunk->map[i], chunk->contig_hint);
+ pcpu_chunk_relocate(chunk, oslot);
+}
+
+static struct pcpu_chunk *pcpu_alloc_chunk(void)
+{
+ struct pcpu_chunk *chunk;
+
+ chunk = pcpu_mem_zalloc(pcpu_chunk_struct_size);
+ if (!chunk)
+ return NULL;
+
+ chunk->map = pcpu_mem_zalloc(PCPU_DFL_MAP_ALLOC *
+ sizeof(chunk->map[0]));
+ if (!chunk->map) {
+ pcpu_mem_free(chunk, pcpu_chunk_struct_size);
+ return NULL;
+ }
+
+ chunk->map_alloc = PCPU_DFL_MAP_ALLOC;
+ chunk->map[chunk->map_used++] = pcpu_unit_size;
+
+ INIT_LIST_HEAD(&chunk->list);
+ chunk->free_size = pcpu_unit_size;
+ chunk->contig_hint = pcpu_unit_size;
+
+ return chunk;
+}
+
+static void pcpu_free_chunk(struct pcpu_chunk *chunk)
+{
+ if (!chunk)
+ return;
+ pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0]));
+ kfree(chunk);
+}
+
+/*
+ * Chunk management implementation.
+ *
+ * To allow different implementations, chunk alloc/free and
+ * [de]population are implemented in a separate file which is pulled
+ * into this file and compiled together. The following functions
+ * should be implemented.
+ *
+ * pcpu_populate_chunk - populate the specified range of a chunk
+ * pcpu_depopulate_chunk - depopulate the specified range of a chunk
+ * pcpu_create_chunk - create a new chunk
+ * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop
+ * pcpu_addr_to_page - translate address to physical address
+ * pcpu_verify_alloc_info - check alloc_info is acceptable during init
+ */
+static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size);
+static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size);
+static struct pcpu_chunk *pcpu_create_chunk(void);
+static void pcpu_destroy_chunk(struct pcpu_chunk *chunk);
+static struct page *pcpu_addr_to_page(void *addr);
+static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai);
+
+#ifdef CONFIG_NEED_PER_CPU_KM
+#include "percpu-km.c"
+#else
+#include "percpu-vm.c"
+#endif
+
+/**
+ * pcpu_chunk_addr_search - determine chunk containing specified address
+ * @addr: address for which the chunk needs to be determined.
+ *
+ * RETURNS:
+ * The address of the found chunk.
+ */
+static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
+{
+ /* is it in the first chunk? */
+ if (pcpu_addr_in_first_chunk(addr)) {
+ /* is it in the reserved area? */
+ if (pcpu_addr_in_reserved_chunk(addr))
+ return pcpu_reserved_chunk;
+ return pcpu_first_chunk;
+ }
+
+ /*
+ * The address is relative to unit0 which might be unused and
+ * thus unmapped. Offset the address to the unit space of the
+ * current processor before looking it up in the vmalloc
+ * space. Note that any possible cpu id can be used here, so
+ * there's no need to worry about preemption or cpu hotplug.
+ */
+ addr += pcpu_unit_offsets[raw_smp_processor_id()];
+ return pcpu_get_page_chunk(pcpu_addr_to_page(addr));
+}
+
+/**
+ * pcpu_alloc - the percpu allocator
+ * @size: size of area to allocate in bytes
+ * @align: alignment of area (max PAGE_SIZE)
+ * @reserved: allocate from the reserved chunk if available
+ *
+ * Allocate percpu area of @size bytes aligned at @align.
+ *
+ * CONTEXT:
+ * Does GFP_KERNEL allocation.
+ *
+ * RETURNS:
+ * Percpu pointer to the allocated area on success, NULL on failure.
+ */
+static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved)
+{
+ static int warn_limit = 10;
+ struct pcpu_chunk *chunk;
+ const char *err;
+ int slot, off, new_alloc;
+ unsigned long flags;
+ void __percpu *ptr;
+
+ if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) {
+ WARN(true, "illegal size (%zu) or align (%zu) for "
+ "percpu allocation\n", size, align);
+ return NULL;
+ }
+
+ mutex_lock(&pcpu_alloc_mutex);
+ spin_lock_irqsave(&pcpu_lock, flags);
+
+ /* serve reserved allocations from the reserved chunk if available */
+ if (reserved && pcpu_reserved_chunk) {
+ chunk = pcpu_reserved_chunk;
+
+ if (size > chunk->contig_hint) {
+ err = "alloc from reserved chunk failed";
+ goto fail_unlock;
+ }
+
+ while ((new_alloc = pcpu_need_to_extend(chunk))) {
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+ if (pcpu_extend_area_map(chunk, new_alloc) < 0) {
+ err = "failed to extend area map of reserved chunk";
+ goto fail_unlock_mutex;
+ }
+ spin_lock_irqsave(&pcpu_lock, flags);
+ }
+
+ off = pcpu_alloc_area(chunk, size, align);
+ if (off >= 0)
+ goto area_found;
+
+ err = "alloc from reserved chunk failed";
+ goto fail_unlock;
+ }
+
+restart:
+ /* search through normal chunks */
+ for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) {
+ list_for_each_entry(chunk, &pcpu_slot[slot], list) {
+ if (size > chunk->contig_hint)
+ continue;
+
+ new_alloc = pcpu_need_to_extend(chunk);
+ if (new_alloc) {
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+ if (pcpu_extend_area_map(chunk,
+ new_alloc) < 0) {
+ err = "failed to extend area map";
+ goto fail_unlock_mutex;
+ }
+ spin_lock_irqsave(&pcpu_lock, flags);
+ /*
+ * pcpu_lock has been dropped, need to
+ * restart cpu_slot list walking.
+ */
+ goto restart;
+ }
+
+ off = pcpu_alloc_area(chunk, size, align);
+ if (off >= 0)
+ goto area_found;
+ }
+ }
+
+ /* hmmm... no space left, create a new chunk */
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+
+ chunk = pcpu_create_chunk();
+ if (!chunk) {
+ err = "failed to allocate new chunk";
+ goto fail_unlock_mutex;
+ }
+
+ spin_lock_irqsave(&pcpu_lock, flags);
+ pcpu_chunk_relocate(chunk, -1);
+ goto restart;
+
+area_found:
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+
+ /* populate, map and clear the area */
+ if (pcpu_populate_chunk(chunk, off, size)) {
+ spin_lock_irqsave(&pcpu_lock, flags);
+ pcpu_free_area(chunk, off);
+ err = "failed to populate";
+ goto fail_unlock;
+ }
+
+ mutex_unlock(&pcpu_alloc_mutex);
+
+ /* return address relative to base address */
+ ptr = __addr_to_pcpu_ptr(chunk->base_addr + off);
+ kmemleak_alloc_percpu(ptr, size);
+ return ptr;
+
+fail_unlock:
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+fail_unlock_mutex:
+ mutex_unlock(&pcpu_alloc_mutex);
+ if (warn_limit) {
+ pr_warning("PERCPU: allocation failed, size=%zu align=%zu, "
+ "%s\n", size, align, err);
+ dump_stack();
+ if (!--warn_limit)
+ pr_info("PERCPU: limit reached, disable warning\n");
+ }
+ return NULL;
+}
+
+/**
+ * __alloc_percpu - allocate dynamic percpu area
+ * @size: size of area to allocate in bytes
+ * @align: alignment of area (max PAGE_SIZE)
+ *
+ * Allocate zero-filled percpu area of @size bytes aligned at @align.
+ * Might sleep. Might trigger writeouts.
+ *
+ * CONTEXT:
+ * Does GFP_KERNEL allocation.
+ *
+ * RETURNS:
+ * Percpu pointer to the allocated area on success, NULL on failure.
+ */
+void __percpu *__alloc_percpu(size_t size, size_t align)
+{
+ return pcpu_alloc(size, align, false);
+}
+EXPORT_SYMBOL_GPL(__alloc_percpu);
+
+/**
+ * __alloc_reserved_percpu - allocate reserved percpu area
+ * @size: size of area to allocate in bytes
+ * @align: alignment of area (max PAGE_SIZE)
+ *
+ * Allocate zero-filled percpu area of @size bytes aligned at @align
+ * from reserved percpu area if arch has set it up; otherwise,
+ * allocation is served from the same dynamic area. Might sleep.
+ * Might trigger writeouts.
+ *
+ * CONTEXT:
+ * Does GFP_KERNEL allocation.
+ *
+ * RETURNS:
+ * Percpu pointer to the allocated area on success, NULL on failure.
+ */
+void __percpu *__alloc_reserved_percpu(size_t size, size_t align)
+{
+ return pcpu_alloc(size, align, true);
+}
+
+/**
+ * pcpu_reclaim - reclaim fully free chunks, workqueue function
+ * @work: unused
+ *
+ * Reclaim all fully free chunks except for the first one.
+ *
+ * CONTEXT:
+ * workqueue context.
+ */
+static void pcpu_reclaim(struct work_struct *work)
+{
+ LIST_HEAD(todo);
+ struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1];
+ struct pcpu_chunk *chunk, *next;
+
+ mutex_lock(&pcpu_alloc_mutex);
+ spin_lock_irq(&pcpu_lock);
+
+ list_for_each_entry_safe(chunk, next, head, list) {
+ WARN_ON(chunk->immutable);
+
+ /* spare the first one */
+ if (chunk == list_first_entry(head, struct pcpu_chunk, list))
+ continue;
+
+ list_move(&chunk->list, &todo);
+ }
+
+ spin_unlock_irq(&pcpu_lock);
+
+ list_for_each_entry_safe(chunk, next, &todo, list) {
+ pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size);
+ pcpu_destroy_chunk(chunk);
+ }
+
+ mutex_unlock(&pcpu_alloc_mutex);
+}
+
+/**
+ * free_percpu - free percpu area
+ * @ptr: pointer to area to free
+ *
+ * Free percpu area @ptr.
+ *
+ * CONTEXT:
+ * Can be called from atomic context.
+ */
+void free_percpu(void __percpu *ptr)
+{
+ void *addr;
+ struct pcpu_chunk *chunk;
+ unsigned long flags;
+ int off;
+
+ if (!ptr)
+ return;
+
+ kmemleak_free_percpu(ptr);
+
+ addr = __pcpu_ptr_to_addr(ptr);
+
+ spin_lock_irqsave(&pcpu_lock, flags);
+
+ chunk = pcpu_chunk_addr_search(addr);
+ off = addr - chunk->base_addr;
+
+ pcpu_free_area(chunk, off);
+
+ /* if there are more than one fully free chunks, wake up grim reaper */
+ if (chunk->free_size == pcpu_unit_size) {
+ struct pcpu_chunk *pos;
+
+ list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list)
+ if (pos != chunk) {
+ schedule_work(&pcpu_reclaim_work);
+ break;
+ }
+ }
+
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+}
+EXPORT_SYMBOL_GPL(free_percpu);
+
+/**
+ * is_kernel_percpu_address - test whether address is from static percpu area
+ * @addr: address to test
+ *
+ * Test whether @addr belongs to in-kernel static percpu area. Module
+ * static percpu areas are not considered. For those, use
+ * is_module_percpu_address().
+ *
+ * RETURNS:
+ * %true if @addr is from in-kernel static percpu area, %false otherwise.
+ */
+bool is_kernel_percpu_address(unsigned long addr)
+{
+#ifdef CONFIG_SMP
+ const size_t static_size = __per_cpu_end - __per_cpu_start;
+ void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr);
+ unsigned int cpu;
+
+ for_each_possible_cpu(cpu) {
+ void *start = per_cpu_ptr(base, cpu);
+
+ if ((void *)addr >= start && (void *)addr < start + static_size)
+ return true;
+ }
+#endif
+ /* on UP, can't distinguish from other static vars, always false */
+ return false;
+}
+
+/**
+ * per_cpu_ptr_to_phys - convert translated percpu address to physical address
+ * @addr: the address to be converted to physical address
+ *
+ * Given @addr which is dereferenceable address obtained via one of
+ * percpu access macros, this function translates it into its physical
+ * address. The caller is responsible for ensuring @addr stays valid
+ * until this function finishes.
+ *
+ * percpu allocator has special setup for the first chunk, which currently
+ * supports either embedding in linear address space or vmalloc mapping,
+ * and, from the second one, the backing allocator (currently either vm or
+ * km) provides translation.
+ *
+ * The addr can be tranlated simply without checking if it falls into the
+ * first chunk. But the current code reflects better how percpu allocator
+ * actually works, and the verification can discover both bugs in percpu
+ * allocator itself and per_cpu_ptr_to_phys() callers. So we keep current
+ * code.
+ *
+ * RETURNS:
+ * The physical address for @addr.
+ */
+phys_addr_t per_cpu_ptr_to_phys(void *addr)
+{
+ void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr);
+ bool in_first_chunk = false;
+ unsigned long first_low, first_high;
+ unsigned int cpu;
+
+ /*
+ * The following test on unit_low/high isn't strictly
+ * necessary but will speed up lookups of addresses which
+ * aren't in the first chunk.
+ */
+ first_low = pcpu_chunk_addr(pcpu_first_chunk, pcpu_low_unit_cpu, 0);
+ first_high = pcpu_chunk_addr(pcpu_first_chunk, pcpu_high_unit_cpu,
+ pcpu_unit_pages);
+ if ((unsigned long)addr >= first_low &&
+ (unsigned long)addr < first_high) {
+ for_each_possible_cpu(cpu) {
+ void *start = per_cpu_ptr(base, cpu);
+
+ if (addr >= start && addr < start + pcpu_unit_size) {
+ in_first_chunk = true;
+ break;
+ }
+ }
+ }
+
+ if (in_first_chunk) {
+ if (!is_vmalloc_addr(addr))
+ return __pa(addr);
+ else
+ return page_to_phys(vmalloc_to_page(addr)) +
+ offset_in_page(addr);
+ } else
+ return page_to_phys(pcpu_addr_to_page(addr)) +
+ offset_in_page(addr);
+}
+
+/**
+ * pcpu_alloc_alloc_info - allocate percpu allocation info
+ * @nr_groups: the number of groups
+ * @nr_units: the number of units
+ *
+ * Allocate ai which is large enough for @nr_groups groups containing
+ * @nr_units units. The returned ai's groups[0].cpu_map points to the
+ * cpu_map array which is long enough for @nr_units and filled with
+ * NR_CPUS. It's the caller's responsibility to initialize cpu_map
+ * pointer of other groups.
+ *
+ * RETURNS:
+ * Pointer to the allocated pcpu_alloc_info on success, NULL on
+ * failure.
+ */
+struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
+ int nr_units)
+{
+ struct pcpu_alloc_info *ai;
+ size_t base_size, ai_size;
+ void *ptr;
+ int unit;
+
+ base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]),
+ __alignof__(ai->groups[0].cpu_map[0]));
+ ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]);
+
+ ptr = alloc_bootmem_nopanic(PFN_ALIGN(ai_size));
+ if (!ptr)
+ return NULL;
+ ai = ptr;
+ ptr += base_size;
+
+ ai->groups[0].cpu_map = ptr;
+
+ for (unit = 0; unit < nr_units; unit++)
+ ai->groups[0].cpu_map[unit] = NR_CPUS;
+
+ ai->nr_groups = nr_groups;
+ ai->__ai_size = PFN_ALIGN(ai_size);
+
+ return ai;
+}
+
+/**
+ * pcpu_free_alloc_info - free percpu allocation info
+ * @ai: pcpu_alloc_info to free
+ *
+ * Free @ai which was allocated by pcpu_alloc_alloc_info().
+ */
+void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai)
+{
+ free_bootmem(__pa(ai), ai->__ai_size);
+}
+
+/**
+ * pcpu_dump_alloc_info - print out information about pcpu_alloc_info
+ * @lvl: loglevel
+ * @ai: allocation info to dump
+ *
+ * Print out information about @ai using loglevel @lvl.
+ */
+static void pcpu_dump_alloc_info(const char *lvl,
+ const struct pcpu_alloc_info *ai)
+{
+ int group_width = 1, cpu_width = 1, width;
+ char empty_str[] = "--------";
+ int alloc = 0, alloc_end = 0;
+ int group, v;
+ int upa, apl; /* units per alloc, allocs per line */
+
+ v = ai->nr_groups;
+ while (v /= 10)
+ group_width++;
+
+ v = num_possible_cpus();
+ while (v /= 10)
+ cpu_width++;
+ empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0';
+
+ upa = ai->alloc_size / ai->unit_size;
+ width = upa * (cpu_width + 1) + group_width + 3;
+ apl = rounddown_pow_of_two(max(60 / width, 1));
+
+ printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu",
+ lvl, ai->static_size, ai->reserved_size, ai->dyn_size,
+ ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size);
+
+ for (group = 0; group < ai->nr_groups; group++) {
+ const struct pcpu_group_info *gi = &ai->groups[group];
+ int unit = 0, unit_end = 0;
+
+ BUG_ON(gi->nr_units % upa);
+ for (alloc_end += gi->nr_units / upa;
+ alloc < alloc_end; alloc++) {
+ if (!(alloc % apl)) {
+ printk(KERN_CONT "\n");
+ printk("%spcpu-alloc: ", lvl);
+ }
+ printk(KERN_CONT "[%0*d] ", group_width, group);
+
+ for (unit_end += upa; unit < unit_end; unit++)
+ if (gi->cpu_map[unit] != NR_CPUS)
+ printk(KERN_CONT "%0*d ", cpu_width,
+ gi->cpu_map[unit]);
+ else
+ printk(KERN_CONT "%s ", empty_str);
+ }
+ }
+ printk(KERN_CONT "\n");
+}
+
+/**
+ * pcpu_setup_first_chunk - initialize the first percpu chunk
+ * @ai: pcpu_alloc_info describing how to percpu area is shaped
+ * @base_addr: mapped address
+ *
+ * Initialize the first percpu chunk which contains the kernel static
+ * perpcu area. This function is to be called from arch percpu area
+ * setup path.
+ *
+ * @ai contains all information necessary to initialize the first
+ * chunk and prime the dynamic percpu allocator.
+ *
+ * @ai->static_size is the size of static percpu area.
+ *
+ * @ai->reserved_size, if non-zero, specifies the amount of bytes to
+ * reserve after the static area in the first chunk. This reserves
+ * the first chunk such that it's available only through reserved
+ * percpu allocation. This is primarily used to serve module percpu
+ * static areas on architectures where the addressing model has
+ * limited offset range for symbol relocations to guarantee module
+ * percpu symbols fall inside the relocatable range.
+ *
+ * @ai->dyn_size determines the number of bytes available for dynamic
+ * allocation in the first chunk. The area between @ai->static_size +
+ * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused.
+ *
+ * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE
+ * and equal to or larger than @ai->static_size + @ai->reserved_size +
+ * @ai->dyn_size.
+ *
+ * @ai->atom_size is the allocation atom size and used as alignment
+ * for vm areas.
+ *
+ * @ai->alloc_size is the allocation size and always multiple of
+ * @ai->atom_size. This is larger than @ai->atom_size if
+ * @ai->unit_size is larger than @ai->atom_size.
+ *
+ * @ai->nr_groups and @ai->groups describe virtual memory layout of
+ * percpu areas. Units which should be colocated are put into the
+ * same group. Dynamic VM areas will be allocated according to these
+ * groupings. If @ai->nr_groups is zero, a single group containing
+ * all units is assumed.
+ *
+ * The caller should have mapped the first chunk at @base_addr and
+ * copied static data to each unit.
+ *
+ * If the first chunk ends up with both reserved and dynamic areas, it
+ * is served by two chunks - one to serve the core static and reserved
+ * areas and the other for the dynamic area. They share the same vm
+ * and page map but uses different area allocation map to stay away
+ * from each other. The latter chunk is circulated in the chunk slots
+ * and available for dynamic allocation like any other chunks.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
+ void *base_addr)
+{
+ static char cpus_buf[4096] __initdata;
+ static int smap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata;
+ static int dmap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata;
+ size_t dyn_size = ai->dyn_size;
+ size_t size_sum = ai->static_size + ai->reserved_size + dyn_size;
+ struct pcpu_chunk *schunk, *dchunk = NULL;
+ unsigned long *group_offsets;
+ size_t *group_sizes;
+ unsigned long *unit_off;
+ unsigned int cpu;
+ int *unit_map;
+ int group, unit, i;
+
+ cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask);
+
+#define PCPU_SETUP_BUG_ON(cond) do { \
+ if (unlikely(cond)) { \
+ pr_emerg("PERCPU: failed to initialize, %s", #cond); \
+ pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \
+ pcpu_dump_alloc_info(KERN_EMERG, ai); \
+ BUG(); \
+ } \
+} while (0)
+
+ /* sanity checks */
+ PCPU_SETUP_BUG_ON(ai->nr_groups <= 0);
+#ifdef CONFIG_SMP
+ PCPU_SETUP_BUG_ON(!ai->static_size);
+ PCPU_SETUP_BUG_ON((unsigned long)__per_cpu_start & ~PAGE_MASK);
+#endif
+ PCPU_SETUP_BUG_ON(!base_addr);
+ PCPU_SETUP_BUG_ON((unsigned long)base_addr & ~PAGE_MASK);
+ PCPU_SETUP_BUG_ON(ai->unit_size < size_sum);
+ PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK);
+ PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE);
+ PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE);
+ PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0);
+
+ /* process group information and build config tables accordingly */
+ group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0]));
+ group_sizes = alloc_bootmem(ai->nr_groups * sizeof(group_sizes[0]));
+ unit_map = alloc_bootmem(nr_cpu_ids * sizeof(unit_map[0]));
+ unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0]));
+
+ for (cpu = 0; cpu < nr_cpu_ids; cpu++)
+ unit_map[cpu] = UINT_MAX;
+
+ pcpu_low_unit_cpu = NR_CPUS;
+ pcpu_high_unit_cpu = NR_CPUS;
+
+ for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) {
+ const struct pcpu_group_info *gi = &ai->groups[group];
+
+ group_offsets[group] = gi->base_offset;
+ group_sizes[group] = gi->nr_units * ai->unit_size;
+
+ for (i = 0; i < gi->nr_units; i++) {
+ cpu = gi->cpu_map[i];
+ if (cpu == NR_CPUS)
+ continue;
+
+ PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids);
+ PCPU_SETUP_BUG_ON(!cpu_possible(cpu));
+ PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX);
+
+ unit_map[cpu] = unit + i;
+ unit_off[cpu] = gi->base_offset + i * ai->unit_size;
+
+ /* determine low/high unit_cpu */
+ if (pcpu_low_unit_cpu == NR_CPUS ||
+ unit_off[cpu] < unit_off[pcpu_low_unit_cpu])
+ pcpu_low_unit_cpu = cpu;
+ if (pcpu_high_unit_cpu == NR_CPUS ||
+ unit_off[cpu] > unit_off[pcpu_high_unit_cpu])
+ pcpu_high_unit_cpu = cpu;
+ }
+ }
+ pcpu_nr_units = unit;
+
+ for_each_possible_cpu(cpu)
+ PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX);
+
+ /* we're done parsing the input, undefine BUG macro and dump config */
+#undef PCPU_SETUP_BUG_ON
+ pcpu_dump_alloc_info(KERN_DEBUG, ai);
+
+ pcpu_nr_groups = ai->nr_groups;
+ pcpu_group_offsets = group_offsets;
+ pcpu_group_sizes = group_sizes;
+ pcpu_unit_map = unit_map;
+ pcpu_unit_offsets = unit_off;
+
+ /* determine basic parameters */
+ pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT;
+ pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT;
+ pcpu_atom_size = ai->atom_size;
+ pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) +
+ BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long);
+
+ /*
+ * Allocate chunk slots. The additional last slot is for
+ * empty chunks.
+ */
+ pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2;
+ pcpu_slot = alloc_bootmem(pcpu_nr_slots * sizeof(pcpu_slot[0]));
+ for (i = 0; i < pcpu_nr_slots; i++)
+ INIT_LIST_HEAD(&pcpu_slot[i]);
+
+ /*
+ * Initialize static chunk. If reserved_size is zero, the
+ * static chunk covers static area + dynamic allocation area
+ * in the first chunk. If reserved_size is not zero, it
+ * covers static area + reserved area (mostly used for module
+ * static percpu allocation).
+ */
+ schunk = alloc_bootmem(pcpu_chunk_struct_size);
+ INIT_LIST_HEAD(&schunk->list);
+ schunk->base_addr = base_addr;
+ schunk->map = smap;
+ schunk->map_alloc = ARRAY_SIZE(smap);
+ schunk->immutable = true;
+ bitmap_fill(schunk->populated, pcpu_unit_pages);
+
+ if (ai->reserved_size) {
+ schunk->free_size = ai->reserved_size;
+ pcpu_reserved_chunk = schunk;
+ pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size;
+ } else {
+ schunk->free_size = dyn_size;
+ dyn_size = 0; /* dynamic area covered */
+ }
+ schunk->contig_hint = schunk->free_size;
+
+ schunk->map[schunk->map_used++] = -ai->static_size;
+ if (schunk->free_size)
+ schunk->map[schunk->map_used++] = schunk->free_size;
+
+ /* init dynamic chunk if necessary */
+ if (dyn_size) {
+ dchunk = alloc_bootmem(pcpu_chunk_struct_size);
+ INIT_LIST_HEAD(&dchunk->list);
+ dchunk->base_addr = base_addr;
+ dchunk->map = dmap;
+ dchunk->map_alloc = ARRAY_SIZE(dmap);
+ dchunk->immutable = true;
+ bitmap_fill(dchunk->populated, pcpu_unit_pages);
+
+ dchunk->contig_hint = dchunk->free_size = dyn_size;
+ dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit;
+ dchunk->map[dchunk->map_used++] = dchunk->free_size;
+ }
+
+ /* link the first chunk in */
+ pcpu_first_chunk = dchunk ?: schunk;
+ pcpu_chunk_relocate(pcpu_first_chunk, -1);
+
+ /* we're done */
+ pcpu_base_addr = base_addr;
+ return 0;
+}
+
+#ifdef CONFIG_SMP
+
+const char *pcpu_fc_names[PCPU_FC_NR] __initdata = {
+ [PCPU_FC_AUTO] = "auto",
+ [PCPU_FC_EMBED] = "embed",
+ [PCPU_FC_PAGE] = "page",
+};
+
+enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO;
+
+static int __init percpu_alloc_setup(char *str)
+{
+ if (0)
+ /* nada */;
+#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
+ else if (!strcmp(str, "embed"))
+ pcpu_chosen_fc = PCPU_FC_EMBED;
+#endif
+#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
+ else if (!strcmp(str, "page"))
+ pcpu_chosen_fc = PCPU_FC_PAGE;
+#endif
+ else
+ pr_warning("PERCPU: unknown allocator %s specified\n", str);
+
+ return 0;
+}
+early_param("percpu_alloc", percpu_alloc_setup);
+
+/*
+ * pcpu_embed_first_chunk() is used by the generic percpu setup.
+ * Build it if needed by the arch config or the generic setup is going
+ * to be used.
+ */
+#if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \
+ !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
+#define BUILD_EMBED_FIRST_CHUNK
+#endif
+
+/* build pcpu_page_first_chunk() iff needed by the arch config */
+#if defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK)
+#define BUILD_PAGE_FIRST_CHUNK
+#endif
+
+/* pcpu_build_alloc_info() is used by both embed and page first chunk */
+#if defined(BUILD_EMBED_FIRST_CHUNK) || defined(BUILD_PAGE_FIRST_CHUNK)
+/**
+ * pcpu_build_alloc_info - build alloc_info considering distances between CPUs
+ * @reserved_size: the size of reserved percpu area in bytes
+ * @dyn_size: minimum free size for dynamic allocation in bytes
+ * @atom_size: allocation atom size
+ * @cpu_distance_fn: callback to determine distance between cpus, optional
+ *
+ * This function determines grouping of units, their mappings to cpus
+ * and other parameters considering needed percpu size, allocation
+ * atom size and distances between CPUs.
+ *
+ * Groups are always mutliples of atom size and CPUs which are of
+ * LOCAL_DISTANCE both ways are grouped together and share space for
+ * units in the same group. The returned configuration is guaranteed
+ * to have CPUs on different nodes on different groups and >=75% usage
+ * of allocated virtual address space.
+ *
+ * RETURNS:
+ * On success, pointer to the new allocation_info is returned. On
+ * failure, ERR_PTR value is returned.
+ */
+static struct pcpu_alloc_info * __init pcpu_build_alloc_info(
+ size_t reserved_size, size_t dyn_size,
+ size_t atom_size,
+ pcpu_fc_cpu_distance_fn_t cpu_distance_fn)
+{
+ static int group_map[NR_CPUS] __initdata;
+ static int group_cnt[NR_CPUS] __initdata;
+ const size_t static_size = __per_cpu_end - __per_cpu_start;
+ int nr_groups = 1, nr_units = 0;
+ size_t size_sum, min_unit_size, alloc_size;
+ int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */
+ int last_allocs, group, unit;
+ unsigned int cpu, tcpu;
+ struct pcpu_alloc_info *ai;
+ unsigned int *cpu_map;
+
+ /* this function may be called multiple times */
+ memset(group_map, 0, sizeof(group_map));
+ memset(group_cnt, 0, sizeof(group_cnt));
+
+ /* calculate size_sum and ensure dyn_size is enough for early alloc */
+ size_sum = PFN_ALIGN(static_size + reserved_size +
+ max_t(size_t, dyn_size, PERCPU_DYNAMIC_EARLY_SIZE));
+ dyn_size = size_sum - static_size - reserved_size;
+
+ /*
+ * Determine min_unit_size, alloc_size and max_upa such that
+ * alloc_size is multiple of atom_size and is the smallest
+ * which can accommodate 4k aligned segments which are equal to
+ * or larger than min_unit_size.
+ */
+ min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE);
+
+ alloc_size = roundup(min_unit_size, atom_size);
+ upa = alloc_size / min_unit_size;
+ while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK))
+ upa--;
+ max_upa = upa;
+
+ /* group cpus according to their proximity */
+ for_each_possible_cpu(cpu) {
+ group = 0;
+ next_group:
+ for_each_possible_cpu(tcpu) {
+ if (cpu == tcpu)
+ break;
+ if (group_map[tcpu] == group && cpu_distance_fn &&
+ (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE ||
+ cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) {
+ group++;
+ nr_groups = max(nr_groups, group + 1);
+ goto next_group;
+ }
+ }
+ group_map[cpu] = group;
+ group_cnt[group]++;
+ }
+
+ /*
+ * Expand unit size until address space usage goes over 75%
+ * and then as much as possible without using more address
+ * space.
+ */
+ last_allocs = INT_MAX;
+ for (upa = max_upa; upa; upa--) {
+ int allocs = 0, wasted = 0;
+
+ if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK))
+ continue;
+
+ for (group = 0; group < nr_groups; group++) {
+ int this_allocs = DIV_ROUND_UP(group_cnt[group], upa);
+ allocs += this_allocs;
+ wasted += this_allocs * upa - group_cnt[group];
+ }
+
+ /*
+ * Don't accept if wastage is over 1/3. The
+ * greater-than comparison ensures upa==1 always
+ * passes the following check.
+ */
+ if (wasted > num_possible_cpus() / 3)
+ continue;
+
+ /* and then don't consume more memory */
+ if (allocs > last_allocs)
+ break;
+ last_allocs = allocs;
+ best_upa = upa;
+ }
+ upa = best_upa;
+
+ /* allocate and fill alloc_info */
+ for (group = 0; group < nr_groups; group++)
+ nr_units += roundup(group_cnt[group], upa);
+
+ ai = pcpu_alloc_alloc_info(nr_groups, nr_units);
+ if (!ai)
+ return ERR_PTR(-ENOMEM);
+ cpu_map = ai->groups[0].cpu_map;
+
+ for (group = 0; group < nr_groups; group++) {
+ ai->groups[group].cpu_map = cpu_map;
+ cpu_map += roundup(group_cnt[group], upa);
+ }
+
+ ai->static_size = static_size;
+ ai->reserved_size = reserved_size;
+ ai->dyn_size = dyn_size;
+ ai->unit_size = alloc_size / upa;
+ ai->atom_size = atom_size;
+ ai->alloc_size = alloc_size;
+
+ for (group = 0, unit = 0; group_cnt[group]; group++) {
+ struct pcpu_group_info *gi = &ai->groups[group];
+
+ /*
+ * Initialize base_offset as if all groups are located
+ * back-to-back. The caller should update this to
+ * reflect actual allocation.
+ */
+ gi->base_offset = unit * ai->unit_size;
+
+ for_each_possible_cpu(cpu)
+ if (group_map[cpu] == group)
+ gi->cpu_map[gi->nr_units++] = cpu;
+ gi->nr_units = roundup(gi->nr_units, upa);
+ unit += gi->nr_units;
+ }
+ BUG_ON(unit != nr_units);
+
+ return ai;
+}
+#endif /* BUILD_EMBED_FIRST_CHUNK || BUILD_PAGE_FIRST_CHUNK */
+
+#if defined(BUILD_EMBED_FIRST_CHUNK)
+/**
+ * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem
+ * @reserved_size: the size of reserved percpu area in bytes
+ * @dyn_size: minimum free size for dynamic allocation in bytes
+ * @atom_size: allocation atom size
+ * @cpu_distance_fn: callback to determine distance between cpus, optional
+ * @alloc_fn: function to allocate percpu page
+ * @free_fn: function to free percpu page
+ *
+ * This is a helper to ease setting up embedded first percpu chunk and
+ * can be called where pcpu_setup_first_chunk() is expected.
+ *
+ * If this function is used to setup the first chunk, it is allocated
+ * by calling @alloc_fn and used as-is without being mapped into
+ * vmalloc area. Allocations are always whole multiples of @atom_size
+ * aligned to @atom_size.
+ *
+ * This enables the first chunk to piggy back on the linear physical
+ * mapping which often uses larger page size. Please note that this
+ * can result in very sparse cpu->unit mapping on NUMA machines thus
+ * requiring large vmalloc address space. Don't use this allocator if
+ * vmalloc space is not orders of magnitude larger than distances
+ * between node memory addresses (ie. 32bit NUMA machines).
+ *
+ * @dyn_size specifies the minimum dynamic area size.
+ *
+ * If the needed size is smaller than the minimum or specified unit
+ * size, the leftover is returned using @free_fn.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
+ size_t atom_size,
+ pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
+ pcpu_fc_alloc_fn_t alloc_fn,
+ pcpu_fc_free_fn_t free_fn)
+{
+ void *base = (void *)ULONG_MAX;
+ void **areas = NULL;
+ struct pcpu_alloc_info *ai;
+ size_t size_sum, areas_size, max_distance;
+ int group, i, rc;
+
+ ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size,
+ cpu_distance_fn);
+ if (IS_ERR(ai))
+ return PTR_ERR(ai);
+
+ size_sum = ai->static_size + ai->reserved_size + ai->dyn_size;
+ areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *));
+
+ areas = alloc_bootmem_nopanic(areas_size);
+ if (!areas) {
+ rc = -ENOMEM;
+ goto out_free;
+ }
+
+ /* allocate, copy and determine base address */
+ for (group = 0; group < ai->nr_groups; group++) {
+ struct pcpu_group_info *gi = &ai->groups[group];
+ unsigned int cpu = NR_CPUS;
+ void *ptr;
+
+ for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++)
+ cpu = gi->cpu_map[i];
+ BUG_ON(cpu == NR_CPUS);
+
+ /* allocate space for the whole group */
+ ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size);
+ if (!ptr) {
+ rc = -ENOMEM;
+ goto out_free_areas;
+ }
+ /* kmemleak tracks the percpu allocations separately */
+ kmemleak_free(ptr);
+ areas[group] = ptr;
+
+ base = min(ptr, base);
+ }
+
+ /*
+ * Copy data and free unused parts. This should happen after all
+ * allocations are complete; otherwise, we may end up with
+ * overlapping groups.
+ */
+ for (group = 0; group < ai->nr_groups; group++) {
+ struct pcpu_group_info *gi = &ai->groups[group];
+ void *ptr = areas[group];
+
+ for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) {
+ if (gi->cpu_map[i] == NR_CPUS) {
+ /* unused unit, free whole */
+ free_fn(ptr, ai->unit_size);
+ continue;
+ }
+ /* copy and return the unused part */
+ memcpy(ptr, __per_cpu_load, ai->static_size);
+ free_fn(ptr + size_sum, ai->unit_size - size_sum);
+ }
+ }
+
+ /* base address is now known, determine group base offsets */
+ max_distance = 0;
+ for (group = 0; group < ai->nr_groups; group++) {
+ ai->groups[group].base_offset = areas[group] - base;
+ max_distance = max_t(size_t, max_distance,
+ ai->groups[group].base_offset);
+ }
+ max_distance += ai->unit_size;
+
+ /* warn if maximum distance is further than 75% of vmalloc space */
+ if (max_distance > (VMALLOC_END - VMALLOC_START) * 3 / 4) {
+ pr_warning("PERCPU: max_distance=0x%zx too large for vmalloc "
+ "space 0x%lx\n", max_distance,
+ (unsigned long)(VMALLOC_END - VMALLOC_START));
+#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
+ /* and fail if we have fallback */
+ rc = -EINVAL;
+ goto out_free;
+#endif
+ }
+
+ pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n",
+ PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size,
+ ai->dyn_size, ai->unit_size);
+
+ rc = pcpu_setup_first_chunk(ai, base);
+ goto out_free;
+
+out_free_areas:
+ for (group = 0; group < ai->nr_groups; group++)
+ free_fn(areas[group],
+ ai->groups[group].nr_units * ai->unit_size);
+out_free:
+ pcpu_free_alloc_info(ai);
+ if (areas)
+ free_bootmem(__pa(areas), areas_size);
+ return rc;
+}
+#endif /* BUILD_EMBED_FIRST_CHUNK */
+
+#ifdef BUILD_PAGE_FIRST_CHUNK
+/**
+ * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages
+ * @reserved_size: the size of reserved percpu area in bytes
+ * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE
+ * @free_fn: function to free percpu page, always called with PAGE_SIZE
+ * @populate_pte_fn: function to populate pte
+ *
+ * This is a helper to ease setting up page-remapped first percpu
+ * chunk and can be called where pcpu_setup_first_chunk() is expected.
+ *
+ * This is the basic allocator. Static percpu area is allocated
+ * page-by-page into vmalloc area.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int __init pcpu_page_first_chunk(size_t reserved_size,
+ pcpu_fc_alloc_fn_t alloc_fn,
+ pcpu_fc_free_fn_t free_fn,
+ pcpu_fc_populate_pte_fn_t populate_pte_fn)
+{
+ static struct vm_struct vm;
+ struct pcpu_alloc_info *ai;
+ char psize_str[16];
+ int unit_pages;
+ size_t pages_size;
+ struct page **pages;
+ int unit, i, j, rc;
+
+ snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10);
+
+ ai = pcpu_build_alloc_info(reserved_size, 0, PAGE_SIZE, NULL);
+ if (IS_ERR(ai))
+ return PTR_ERR(ai);
+ BUG_ON(ai->nr_groups != 1);
+ BUG_ON(ai->groups[0].nr_units != num_possible_cpus());
+
+ unit_pages = ai->unit_size >> PAGE_SHIFT;
+
+ /* unaligned allocations can't be freed, round up to page size */
+ pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() *
+ sizeof(pages[0]));
+ pages = alloc_bootmem(pages_size);
+
+ /* allocate pages */
+ j = 0;
+ for (unit = 0; unit < num_possible_cpus(); unit++)
+ for (i = 0; i < unit_pages; i++) {
+ unsigned int cpu = ai->groups[0].cpu_map[unit];
+ void *ptr;
+
+ ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE);
+ if (!ptr) {
+ pr_warning("PERCPU: failed to allocate %s page "
+ "for cpu%u\n", psize_str, cpu);
+ goto enomem;
+ }
+ /* kmemleak tracks the percpu allocations separately */
+ kmemleak_free(ptr);
+ pages[j++] = virt_to_page(ptr);
+ }
+
+ /* allocate vm area, map the pages and copy static data */
+ vm.flags = VM_ALLOC;
+ vm.size = num_possible_cpus() * ai->unit_size;
+ vm_area_register_early(&vm, PAGE_SIZE);
+
+ for (unit = 0; unit < num_possible_cpus(); unit++) {
+ unsigned long unit_addr =
+ (unsigned long)vm.addr + unit * ai->unit_size;
+
+ for (i = 0; i < unit_pages; i++)
+ populate_pte_fn(unit_addr + (i << PAGE_SHIFT));
+
+ /* pte already populated, the following shouldn't fail */
+ rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages],
+ unit_pages);
+ if (rc < 0)
+ panic("failed to map percpu area, err=%d\n", rc);
+
+ /*
+ * FIXME: Archs with virtual cache should flush local
+ * cache for the linear mapping here - something
+ * equivalent to flush_cache_vmap() on the local cpu.
+ * flush_cache_vmap() can't be used as most supporting
+ * data structures are not set up yet.
+ */
+
+ /* copy static data */
+ memcpy((void *)unit_addr, __per_cpu_load, ai->static_size);
+ }
+
+ /* we're ready, commit */
+ pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n",
+ unit_pages, psize_str, vm.addr, ai->static_size,
+ ai->reserved_size, ai->dyn_size);
+
+ rc = pcpu_setup_first_chunk(ai, vm.addr);
+ goto out_free_ar;
+
+enomem:
+ while (--j >= 0)
+ free_fn(page_address(pages[j]), PAGE_SIZE);
+ rc = -ENOMEM;
+out_free_ar:
+ free_bootmem(__pa(pages), pages_size);
+ pcpu_free_alloc_info(ai);
+ return rc;
+}
+#endif /* BUILD_PAGE_FIRST_CHUNK */
+
+#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
+/*
+ * Generic SMP percpu area setup.
+ *
+ * The embedding helper is used because its behavior closely resembles
+ * the original non-dynamic generic percpu area setup. This is
+ * important because many archs have addressing restrictions and might
+ * fail if the percpu area is located far away from the previous
+ * location. As an added bonus, in non-NUMA cases, embedding is
+ * generally a good idea TLB-wise because percpu area can piggy back
+ * on the physical linear memory mapping which uses large page
+ * mappings on applicable archs.
+ */
+unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
+EXPORT_SYMBOL(__per_cpu_offset);
+
+static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size,
+ size_t align)
+{
+ return __alloc_bootmem_nopanic(size, align, __pa(MAX_DMA_ADDRESS));
+}
+
+static void __init pcpu_dfl_fc_free(void *ptr, size_t size)
+{
+ free_bootmem(__pa(ptr), size);
+}
+
+void __init setup_per_cpu_areas(void)
+{
+ unsigned long delta;
+ unsigned int cpu;
+ int rc;
+
+ /*
+ * Always reserve area for module percpu variables. That's
+ * what the legacy allocator did.
+ */
+ rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
+ PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL,
+ pcpu_dfl_fc_alloc, pcpu_dfl_fc_free);
+ if (rc < 0)
+ panic("Failed to initialize percpu areas.");
+
+ delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
+ for_each_possible_cpu(cpu)
+ __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
+}
+#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
+
+#else /* CONFIG_SMP */
+
+/*
+ * UP percpu area setup.
+ *
+ * UP always uses km-based percpu allocator with identity mapping.
+ * Static percpu variables are indistinguishable from the usual static
+ * variables and don't require any special preparation.
+ */
+void __init setup_per_cpu_areas(void)
+{
+ const size_t unit_size =
+ roundup_pow_of_two(max_t(size_t, PCPU_MIN_UNIT_SIZE,
+ PERCPU_DYNAMIC_RESERVE));
+ struct pcpu_alloc_info *ai;
+ void *fc;
+
+ ai = pcpu_alloc_alloc_info(1, 1);
+ fc = __alloc_bootmem(unit_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
+ if (!ai || !fc)
+ panic("Failed to allocate memory for percpu areas.");
+ /* kmemleak tracks the percpu allocations separately */
+ kmemleak_free(fc);
+
+ ai->dyn_size = unit_size;
+ ai->unit_size = unit_size;
+ ai->atom_size = unit_size;
+ ai->alloc_size = unit_size;
+ ai->groups[0].nr_units = 1;
+ ai->groups[0].cpu_map[0] = 0;
+
+ if (pcpu_setup_first_chunk(ai, fc) < 0)
+ panic("Failed to initialize percpu areas.");
+}
+
+#endif /* CONFIG_SMP */
+
+/*
+ * First and reserved chunks are initialized with temporary allocation
+ * map in initdata so that they can be used before slab is online.
+ * This function is called after slab is brought up and replaces those
+ * with properly allocated maps.
+ */
+void __init percpu_init_late(void)
+{
+ struct pcpu_chunk *target_chunks[] =
+ { pcpu_first_chunk, pcpu_reserved_chunk, NULL };
+ struct pcpu_chunk *chunk;
+ unsigned long flags;
+ int i;
+
+ for (i = 0; (chunk = target_chunks[i]); i++) {
+ int *map;
+ const size_t size = PERCPU_DYNAMIC_EARLY_SLOTS * sizeof(map[0]);
+
+ BUILD_BUG_ON(size > PAGE_SIZE);
+
+ map = pcpu_mem_zalloc(size);
+ BUG_ON(!map);
+
+ spin_lock_irqsave(&pcpu_lock, flags);
+ memcpy(map, chunk->map, size);
+ chunk->map = map;
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+ }
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/pgtable-generic.c b/ap/os/linux/linux-3.4.x/mm/pgtable-generic.c
new file mode 100644
index 0000000..5a74fea
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/pgtable-generic.c
@@ -0,0 +1,122 @@
+/*
+ * mm/pgtable-generic.c
+ *
+ * Generic pgtable methods declared in asm-generic/pgtable.h
+ *
+ * Copyright (C) 2010 Linus Torvalds
+ */
+
+#include <linux/pagemap.h>
+#include <asm/tlb.h>
+#include <asm-generic/pgtable.h>
+
+#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
+/*
+ * Only sets the access flags (dirty, accessed, and
+ * writable). Furthermore, we know it always gets set to a "more
+ * permissive" setting, which allows most architectures to optimize
+ * this. We return whether the PTE actually changed, which in turn
+ * instructs the caller to do things like update__mmu_cache. This
+ * used to be done in the caller, but sparc needs minor faults to
+ * force that call on sun4c so we changed this macro slightly
+ */
+int ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep,
+ pte_t entry, int dirty)
+{
+ int changed = !pte_same(*ptep, entry);
+ if (changed) {
+ set_pte_at(vma->vm_mm, address, ptep, entry);
+ flush_tlb_page(vma, address);
+ }
+ return changed;
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
+int pmdp_set_access_flags(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp,
+ pmd_t entry, int dirty)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ int changed = !pmd_same(*pmdp, entry);
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+ if (changed) {
+ set_pmd_at(vma->vm_mm, address, pmdp, entry);
+ flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+ }
+ return changed;
+#else /* CONFIG_TRANSPARENT_HUGEPAGE */
+ BUG();
+ return 0;
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+}
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
+int ptep_clear_flush_young(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep)
+{
+ int young;
+ young = ptep_test_and_clear_young(vma, address, ptep);
+ if (young)
+ flush_tlb_page(vma, address);
+ return young;
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
+int pmdp_clear_flush_young(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp)
+{
+ int young;
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+#else
+ BUG();
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+ young = pmdp_test_and_clear_young(vma, address, pmdp);
+ if (young)
+ flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+ return young;
+}
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
+pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
+ pte_t *ptep)
+{
+ pte_t pte;
+ pte = ptep_get_and_clear((vma)->vm_mm, address, ptep);
+ flush_tlb_page(vma, address);
+ return pte;
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp)
+{
+ pmd_t pmd;
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+ pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
+ flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+ return pmd;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+pmd_t pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp)
+{
+ pmd_t pmd = pmd_mksplitting(*pmdp);
+ VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+ set_pmd_at(vma->vm_mm, address, pmdp, pmd);
+ /* tlb flush only to serialize against gup-fast */
+ flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
diff --git a/ap/os/linux/linux-3.4.x/mm/prio_tree.c b/ap/os/linux/linux-3.4.x/mm/prio_tree.c
new file mode 100644
index 0000000..799dcfd
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/prio_tree.c
@@ -0,0 +1,208 @@
+/*
+ * mm/prio_tree.c - priority search tree for mapping->i_mmap
+ *
+ * Copyright (C) 2004, Rajesh Venkatasubramanian <vrajesh@umich.edu>
+ *
+ * This file is released under the GPL v2.
+ *
+ * Based on the radix priority search tree proposed by Edward M. McCreight
+ * SIAM Journal of Computing, vol. 14, no.2, pages 257-276, May 1985
+ *
+ * 02Feb2004 Initial version
+ */
+
+#include <linux/mm.h>
+#include <linux/prio_tree.h>
+#include <linux/prefetch.h>
+
+/*
+ * See lib/prio_tree.c for details on the general radix priority search tree
+ * code.
+ */
+
+/*
+ * The following #defines are mirrored from lib/prio_tree.c. They're only used
+ * for debugging, and should be removed (along with the debugging code using
+ * them) when switching also VMAs to the regular prio_tree code.
+ */
+
+#define RADIX_INDEX(vma) ((vma)->vm_pgoff)
+#define VMA_SIZE(vma) (((vma)->vm_end - (vma)->vm_start) >> PAGE_SHIFT)
+/* avoid overflow */
+#define HEAP_INDEX(vma) ((vma)->vm_pgoff + (VMA_SIZE(vma) - 1))
+
+/*
+ * Radix priority search tree for address_space->i_mmap
+ *
+ * For each vma that map a unique set of file pages i.e., unique [radix_index,
+ * heap_index] value, we have a corresponding priority search tree node. If
+ * multiple vmas have identical [radix_index, heap_index] value, then one of
+ * them is used as a tree node and others are stored in a vm_set list. The tree
+ * node points to the first vma (head) of the list using vm_set.head.
+ *
+ * prio_tree_root
+ * |
+ * A vm_set.head
+ * / \ /
+ * L R -> H-I-J-K-M-N-O-P-Q-S
+ * ^ ^ <-- vm_set.list -->
+ * tree nodes
+ *
+ * We need some way to identify whether a vma is a tree node, head of a vm_set
+ * list, or just a member of a vm_set list. We cannot use vm_flags to store
+ * such information. The reason is, in the above figure, it is possible that
+ * vm_flags' of R and H are covered by the different mmap_sems. When R is
+ * removed under R->mmap_sem, H replaces R as a tree node. Since we do not hold
+ * H->mmap_sem, we cannot use H->vm_flags for marking that H is a tree node now.
+ * That's why some trick involving shared.vm_set.parent is used for identifying
+ * tree nodes and list head nodes.
+ *
+ * vma radix priority search tree node rules:
+ *
+ * vma->shared.vm_set.parent != NULL ==> a tree node
+ * vma->shared.vm_set.head != NULL ==> list of others mapping same range
+ * vma->shared.vm_set.head == NULL ==> no others map the same range
+ *
+ * vma->shared.vm_set.parent == NULL
+ * vma->shared.vm_set.head != NULL ==> list head of vmas mapping same range
+ * vma->shared.vm_set.head == NULL ==> a list node
+ */
+
+/*
+ * Add a new vma known to map the same set of pages as the old vma:
+ * useful for fork's dup_mmap as well as vma_prio_tree_insert below.
+ * Note that it just happens to work correctly on i_mmap_nonlinear too.
+ */
+void vma_prio_tree_add(struct vm_area_struct *vma, struct vm_area_struct *old)
+{
+ /* Leave these BUG_ONs till prio_tree patch stabilizes */
+ BUG_ON(RADIX_INDEX(vma) != RADIX_INDEX(old));
+ BUG_ON(HEAP_INDEX(vma) != HEAP_INDEX(old));
+
+ vma->shared.vm_set.head = NULL;
+ vma->shared.vm_set.parent = NULL;
+
+ if (!old->shared.vm_set.parent)
+ list_add(&vma->shared.vm_set.list,
+ &old->shared.vm_set.list);
+ else if (old->shared.vm_set.head)
+ list_add_tail(&vma->shared.vm_set.list,
+ &old->shared.vm_set.head->shared.vm_set.list);
+ else {
+ INIT_LIST_HEAD(&vma->shared.vm_set.list);
+ vma->shared.vm_set.head = old;
+ old->shared.vm_set.head = vma;
+ }
+}
+
+void vma_prio_tree_insert(struct vm_area_struct *vma,
+ struct prio_tree_root *root)
+{
+ struct prio_tree_node *ptr;
+ struct vm_area_struct *old;
+
+ vma->shared.vm_set.head = NULL;
+
+ ptr = raw_prio_tree_insert(root, &vma->shared.prio_tree_node);
+ if (ptr != (struct prio_tree_node *) &vma->shared.prio_tree_node) {
+ old = prio_tree_entry(ptr, struct vm_area_struct,
+ shared.prio_tree_node);
+ vma_prio_tree_add(vma, old);
+ }
+}
+
+void vma_prio_tree_remove(struct vm_area_struct *vma,
+ struct prio_tree_root *root)
+{
+ struct vm_area_struct *node, *head, *new_head;
+
+ if (!vma->shared.vm_set.head) {
+ if (!vma->shared.vm_set.parent)
+ list_del_init(&vma->shared.vm_set.list);
+ else
+ raw_prio_tree_remove(root, &vma->shared.prio_tree_node);
+ } else {
+ /* Leave this BUG_ON till prio_tree patch stabilizes */
+ BUG_ON(vma->shared.vm_set.head->shared.vm_set.head != vma);
+ if (vma->shared.vm_set.parent) {
+ head = vma->shared.vm_set.head;
+ if (!list_empty(&head->shared.vm_set.list)) {
+ new_head = list_entry(
+ head->shared.vm_set.list.next,
+ struct vm_area_struct,
+ shared.vm_set.list);
+ list_del_init(&head->shared.vm_set.list);
+ } else
+ new_head = NULL;
+
+ raw_prio_tree_replace(root, &vma->shared.prio_tree_node,
+ &head->shared.prio_tree_node);
+ head->shared.vm_set.head = new_head;
+ if (new_head)
+ new_head->shared.vm_set.head = head;
+
+ } else {
+ node = vma->shared.vm_set.head;
+ if (!list_empty(&vma->shared.vm_set.list)) {
+ new_head = list_entry(
+ vma->shared.vm_set.list.next,
+ struct vm_area_struct,
+ shared.vm_set.list);
+ list_del_init(&vma->shared.vm_set.list);
+ node->shared.vm_set.head = new_head;
+ new_head->shared.vm_set.head = node;
+ } else
+ node->shared.vm_set.head = NULL;
+ }
+ }
+}
+
+/*
+ * Helper function to enumerate vmas that map a given file page or a set of
+ * contiguous file pages. The function returns vmas that at least map a single
+ * page in the given range of contiguous file pages.
+ */
+struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma,
+ struct prio_tree_iter *iter)
+{
+ struct prio_tree_node *ptr;
+ struct vm_area_struct *next;
+
+ if (!vma) {
+ /*
+ * First call is with NULL vma
+ */
+ ptr = prio_tree_next(iter);
+ if (ptr) {
+ next = prio_tree_entry(ptr, struct vm_area_struct,
+ shared.prio_tree_node);
+ prefetch(next->shared.vm_set.head);
+ return next;
+ } else
+ return NULL;
+ }
+
+ if (vma->shared.vm_set.parent) {
+ if (vma->shared.vm_set.head) {
+ next = vma->shared.vm_set.head;
+ prefetch(next->shared.vm_set.list.next);
+ return next;
+ }
+ } else {
+ next = list_entry(vma->shared.vm_set.list.next,
+ struct vm_area_struct, shared.vm_set.list);
+ if (!next->shared.vm_set.head) {
+ prefetch(next->shared.vm_set.list.next);
+ return next;
+ }
+ }
+
+ ptr = prio_tree_next(iter);
+ if (ptr) {
+ next = prio_tree_entry(ptr, struct vm_area_struct,
+ shared.prio_tree_node);
+ prefetch(next->shared.vm_set.head);
+ return next;
+ } else
+ return NULL;
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/process_vm_access.c b/ap/os/linux/linux-3.4.x/mm/process_vm_access.c
new file mode 100644
index 0000000..b63e84a
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/process_vm_access.c
@@ -0,0 +1,483 @@
+/*
+ * linux/mm/process_vm_access.c
+ *
+ * Copyright (C) 2010-2011 Christopher Yeoh <cyeoh@au1.ibm.com>, IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/mm.h>
+#include <linux/uio.h>
+#include <linux/sched.h>
+#include <linux/highmem.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+
+#ifdef CONFIG_COMPAT
+#include <linux/compat.h>
+#endif
+
+/**
+ * process_vm_rw_pages - read/write pages from task specified
+ * @task: task to read/write from
+ * @mm: mm for task
+ * @process_pages: struct pages area that can store at least
+ * nr_pages_to_copy struct page pointers
+ * @pa: address of page in task to start copying from/to
+ * @start_offset: offset in page to start copying from/to
+ * @len: number of bytes to copy
+ * @lvec: iovec array specifying where to copy to/from
+ * @lvec_cnt: number of elements in iovec array
+ * @lvec_current: index in iovec array we are up to
+ * @lvec_offset: offset in bytes from current iovec iov_base we are up to
+ * @vm_write: 0 means copy from, 1 means copy to
+ * @nr_pages_to_copy: number of pages to copy
+ * @bytes_copied: returns number of bytes successfully copied
+ * Returns 0 on success, error code otherwise
+ */
+static int process_vm_rw_pages(struct task_struct *task,
+ struct mm_struct *mm,
+ struct page **process_pages,
+ unsigned long pa,
+ unsigned long start_offset,
+ unsigned long len,
+ const struct iovec *lvec,
+ unsigned long lvec_cnt,
+ unsigned long *lvec_current,
+ size_t *lvec_offset,
+ int vm_write,
+ unsigned int nr_pages_to_copy,
+ ssize_t *bytes_copied)
+{
+ int pages_pinned;
+ void *target_kaddr;
+ int pgs_copied = 0;
+ int j;
+ int ret;
+ ssize_t bytes_to_copy;
+ ssize_t rc = 0;
+
+ *bytes_copied = 0;
+
+ /* Get the pages we're interested in */
+ down_read(&mm->mmap_sem);
+ pages_pinned = get_user_pages(task, mm, pa,
+ nr_pages_to_copy,
+ vm_write, 0, process_pages, NULL);
+ up_read(&mm->mmap_sem);
+
+ if (pages_pinned != nr_pages_to_copy) {
+ rc = -EFAULT;
+ goto end;
+ }
+
+ /* Do the copy for each page */
+ for (pgs_copied = 0;
+ (pgs_copied < nr_pages_to_copy) && (*lvec_current < lvec_cnt);
+ pgs_copied++) {
+ /* Make sure we have a non zero length iovec */
+ while (*lvec_current < lvec_cnt
+ && lvec[*lvec_current].iov_len == 0)
+ (*lvec_current)++;
+ if (*lvec_current == lvec_cnt)
+ break;
+
+ /*
+ * Will copy smallest of:
+ * - bytes remaining in page
+ * - bytes remaining in destination iovec
+ */
+ bytes_to_copy = min_t(ssize_t, PAGE_SIZE - start_offset,
+ len - *bytes_copied);
+ bytes_to_copy = min_t(ssize_t, bytes_to_copy,
+ lvec[*lvec_current].iov_len
+ - *lvec_offset);
+
+ target_kaddr = kmap(process_pages[pgs_copied]) + start_offset;
+
+ if (vm_write)
+ ret = copy_from_user(target_kaddr,
+ lvec[*lvec_current].iov_base
+ + *lvec_offset,
+ bytes_to_copy);
+ else
+ ret = copy_to_user(lvec[*lvec_current].iov_base
+ + *lvec_offset,
+ target_kaddr, bytes_to_copy);
+ kunmap(process_pages[pgs_copied]);
+ if (ret) {
+ *bytes_copied += bytes_to_copy - ret;
+ pgs_copied++;
+ rc = -EFAULT;
+ goto end;
+ }
+ *bytes_copied += bytes_to_copy;
+ *lvec_offset += bytes_to_copy;
+ if (*lvec_offset == lvec[*lvec_current].iov_len) {
+ /*
+ * Need to copy remaining part of page into the
+ * next iovec if there are any bytes left in page
+ */
+ (*lvec_current)++;
+ *lvec_offset = 0;
+ start_offset = (start_offset + bytes_to_copy)
+ % PAGE_SIZE;
+ if (start_offset)
+ pgs_copied--;
+ } else {
+ start_offset = 0;
+ }
+ }
+
+end:
+ if (vm_write) {
+ for (j = 0; j < pages_pinned; j++) {
+ if (j < pgs_copied)
+ set_page_dirty_lock(process_pages[j]);
+ put_page(process_pages[j]);
+ }
+ } else {
+ for (j = 0; j < pages_pinned; j++)
+ put_page(process_pages[j]);
+ }
+
+ return rc;
+}
+
+/* Maximum number of pages kmalloc'd to hold struct page's during copy */
+#define PVM_MAX_KMALLOC_PAGES (PAGE_SIZE * 2)
+
+/**
+ * process_vm_rw_single_vec - read/write pages from task specified
+ * @addr: start memory address of target process
+ * @len: size of area to copy to/from
+ * @lvec: iovec array specifying where to copy to/from locally
+ * @lvec_cnt: number of elements in iovec array
+ * @lvec_current: index in iovec array we are up to
+ * @lvec_offset: offset in bytes from current iovec iov_base we are up to
+ * @process_pages: struct pages area that can store at least
+ * nr_pages_to_copy struct page pointers
+ * @mm: mm for task
+ * @task: task to read/write from
+ * @vm_write: 0 means copy from, 1 means copy to
+ * @bytes_copied: returns number of bytes successfully copied
+ * Returns 0 on success or on failure error code
+ */
+static int process_vm_rw_single_vec(unsigned long addr,
+ unsigned long len,
+ const struct iovec *lvec,
+ unsigned long lvec_cnt,
+ unsigned long *lvec_current,
+ size_t *lvec_offset,
+ struct page **process_pages,
+ struct mm_struct *mm,
+ struct task_struct *task,
+ int vm_write,
+ ssize_t *bytes_copied)
+{
+ unsigned long pa = addr & PAGE_MASK;
+ unsigned long start_offset = addr - pa;
+ unsigned long nr_pages;
+ ssize_t bytes_copied_loop;
+ ssize_t rc = 0;
+ unsigned long nr_pages_copied = 0;
+ unsigned long nr_pages_to_copy;
+ unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES
+ / sizeof(struct pages *);
+
+ *bytes_copied = 0;
+
+ /* Work out address and page range required */
+ if (len == 0)
+ return 0;
+ nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1;
+
+ while ((nr_pages_copied < nr_pages) && (*lvec_current < lvec_cnt)) {
+ nr_pages_to_copy = min(nr_pages - nr_pages_copied,
+ max_pages_per_loop);
+
+ rc = process_vm_rw_pages(task, mm, process_pages, pa,
+ start_offset, len,
+ lvec, lvec_cnt,
+ lvec_current, lvec_offset,
+ vm_write, nr_pages_to_copy,
+ &bytes_copied_loop);
+ start_offset = 0;
+ *bytes_copied += bytes_copied_loop;
+
+ if (rc < 0) {
+ return rc;
+ } else {
+ len -= bytes_copied_loop;
+ nr_pages_copied += nr_pages_to_copy;
+ pa += nr_pages_to_copy * PAGE_SIZE;
+ }
+ }
+
+ return rc;
+}
+
+/* Maximum number of entries for process pages array
+ which lives on stack */
+#define PVM_MAX_PP_ARRAY_COUNT 16
+
+/**
+ * process_vm_rw_core - core of reading/writing pages from task specified
+ * @pid: PID of process to read/write from/to
+ * @lvec: iovec array specifying where to copy to/from locally
+ * @liovcnt: size of lvec array
+ * @rvec: iovec array specifying where to copy to/from in the other process
+ * @riovcnt: size of rvec array
+ * @flags: currently unused
+ * @vm_write: 0 if reading from other process, 1 if writing to other process
+ * Returns the number of bytes read/written or error code. May
+ * return less bytes than expected if an error occurs during the copying
+ * process.
+ */
+static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec,
+ unsigned long liovcnt,
+ const struct iovec *rvec,
+ unsigned long riovcnt,
+ unsigned long flags, int vm_write)
+{
+ struct task_struct *task;
+ struct page *pp_stack[PVM_MAX_PP_ARRAY_COUNT];
+ struct page **process_pages = pp_stack;
+ struct mm_struct *mm;
+ unsigned long i;
+ ssize_t rc = 0;
+ ssize_t bytes_copied_loop;
+ ssize_t bytes_copied = 0;
+ unsigned long nr_pages = 0;
+ unsigned long nr_pages_iov;
+ unsigned long iov_l_curr_idx = 0;
+ size_t iov_l_curr_offset = 0;
+ ssize_t iov_len;
+
+ /*
+ * Work out how many pages of struct pages we're going to need
+ * when eventually calling get_user_pages
+ */
+ for (i = 0; i < riovcnt; i++) {
+ iov_len = rvec[i].iov_len;
+ if (iov_len > 0) {
+ nr_pages_iov = ((unsigned long)rvec[i].iov_base
+ + iov_len)
+ / PAGE_SIZE - (unsigned long)rvec[i].iov_base
+ / PAGE_SIZE + 1;
+ nr_pages = max(nr_pages, nr_pages_iov);
+ }
+ }
+
+ if (nr_pages == 0)
+ return 0;
+
+ if (nr_pages > PVM_MAX_PP_ARRAY_COUNT) {
+ /* For reliability don't try to kmalloc more than
+ 2 pages worth */
+ process_pages = kmalloc(min_t(size_t, PVM_MAX_KMALLOC_PAGES,
+ sizeof(struct pages *)*nr_pages),
+ GFP_KERNEL);
+
+ if (!process_pages)
+ return -ENOMEM;
+ }
+
+ /* Get process information */
+ rcu_read_lock();
+ task = find_task_by_vpid(pid);
+ if (task)
+ get_task_struct(task);
+ rcu_read_unlock();
+ if (!task) {
+ rc = -ESRCH;
+ goto free_proc_pages;
+ }
+
+ mm = mm_access(task, PTRACE_MODE_ATTACH);
+ if (!mm || IS_ERR(mm)) {
+ rc = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH;
+ /*
+ * Explicitly map EACCES to EPERM as EPERM is a more a
+ * appropriate error code for process_vw_readv/writev
+ */
+ if (rc == -EACCES)
+ rc = -EPERM;
+ goto put_task_struct;
+ }
+
+ for (i = 0; i < riovcnt && iov_l_curr_idx < liovcnt; i++) {
+ rc = process_vm_rw_single_vec(
+ (unsigned long)rvec[i].iov_base, rvec[i].iov_len,
+ lvec, liovcnt, &iov_l_curr_idx, &iov_l_curr_offset,
+ process_pages, mm, task, vm_write, &bytes_copied_loop);
+ bytes_copied += bytes_copied_loop;
+ if (rc != 0) {
+ /* If we have managed to copy any data at all then
+ we return the number of bytes copied. Otherwise
+ we return the error code */
+ if (bytes_copied)
+ rc = bytes_copied;
+ goto put_mm;
+ }
+ }
+
+ rc = bytes_copied;
+put_mm:
+ mmput(mm);
+
+put_task_struct:
+ put_task_struct(task);
+
+free_proc_pages:
+ if (process_pages != pp_stack)
+ kfree(process_pages);
+ return rc;
+}
+
+/**
+ * process_vm_rw - check iovecs before calling core routine
+ * @pid: PID of process to read/write from/to
+ * @lvec: iovec array specifying where to copy to/from locally
+ * @liovcnt: size of lvec array
+ * @rvec: iovec array specifying where to copy to/from in the other process
+ * @riovcnt: size of rvec array
+ * @flags: currently unused
+ * @vm_write: 0 if reading from other process, 1 if writing to other process
+ * Returns the number of bytes read/written or error code. May
+ * return less bytes than expected if an error occurs during the copying
+ * process.
+ */
+static ssize_t process_vm_rw(pid_t pid,
+ const struct iovec __user *lvec,
+ unsigned long liovcnt,
+ const struct iovec __user *rvec,
+ unsigned long riovcnt,
+ unsigned long flags, int vm_write)
+{
+ struct iovec iovstack_l[UIO_FASTIOV];
+ struct iovec iovstack_r[UIO_FASTIOV];
+ struct iovec *iov_l = iovstack_l;
+ struct iovec *iov_r = iovstack_r;
+ ssize_t rc;
+
+ if (flags != 0)
+ return -EINVAL;
+
+ /* Check iovecs */
+ if (vm_write)
+ rc = rw_copy_check_uvector(WRITE, lvec, liovcnt, UIO_FASTIOV,
+ iovstack_l, &iov_l, 1);
+ else
+ rc = rw_copy_check_uvector(READ, lvec, liovcnt, UIO_FASTIOV,
+ iovstack_l, &iov_l, 1);
+ if (rc <= 0)
+ goto free_iovecs;
+
+ rc = rw_copy_check_uvector(READ, rvec, riovcnt, UIO_FASTIOV,
+ iovstack_r, &iov_r, 0);
+ if (rc <= 0)
+ goto free_iovecs;
+
+ rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags,
+ vm_write);
+
+free_iovecs:
+ if (iov_r != iovstack_r)
+ kfree(iov_r);
+ if (iov_l != iovstack_l)
+ kfree(iov_l);
+
+ return rc;
+}
+
+SYSCALL_DEFINE6(process_vm_readv, pid_t, pid, const struct iovec __user *, lvec,
+ unsigned long, liovcnt, const struct iovec __user *, rvec,
+ unsigned long, riovcnt, unsigned long, flags)
+{
+ return process_vm_rw(pid, lvec, liovcnt, rvec, riovcnt, flags, 0);
+}
+
+SYSCALL_DEFINE6(process_vm_writev, pid_t, pid,
+ const struct iovec __user *, lvec,
+ unsigned long, liovcnt, const struct iovec __user *, rvec,
+ unsigned long, riovcnt, unsigned long, flags)
+{
+ return process_vm_rw(pid, lvec, liovcnt, rvec, riovcnt, flags, 1);
+}
+
+#ifdef CONFIG_COMPAT
+
+asmlinkage ssize_t
+compat_process_vm_rw(compat_pid_t pid,
+ const struct compat_iovec __user *lvec,
+ unsigned long liovcnt,
+ const struct compat_iovec __user *rvec,
+ unsigned long riovcnt,
+ unsigned long flags, int vm_write)
+{
+ struct iovec iovstack_l[UIO_FASTIOV];
+ struct iovec iovstack_r[UIO_FASTIOV];
+ struct iovec *iov_l = iovstack_l;
+ struct iovec *iov_r = iovstack_r;
+ ssize_t rc = -EFAULT;
+
+ if (flags != 0)
+ return -EINVAL;
+
+ if (vm_write)
+ rc = compat_rw_copy_check_uvector(WRITE, lvec, liovcnt,
+ UIO_FASTIOV, iovstack_l,
+ &iov_l, 1);
+ else
+ rc = compat_rw_copy_check_uvector(READ, lvec, liovcnt,
+ UIO_FASTIOV, iovstack_l,
+ &iov_l, 1);
+ if (rc <= 0)
+ goto free_iovecs;
+ rc = compat_rw_copy_check_uvector(READ, rvec, riovcnt,
+ UIO_FASTIOV, iovstack_r,
+ &iov_r, 0);
+ if (rc <= 0)
+ goto free_iovecs;
+
+ rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags,
+ vm_write);
+
+free_iovecs:
+ if (iov_r != iovstack_r)
+ kfree(iov_r);
+ if (iov_l != iovstack_l)
+ kfree(iov_l);
+ return rc;
+}
+
+asmlinkage ssize_t
+compat_sys_process_vm_readv(compat_pid_t pid,
+ const struct compat_iovec __user *lvec,
+ unsigned long liovcnt,
+ const struct compat_iovec __user *rvec,
+ unsigned long riovcnt,
+ unsigned long flags)
+{
+ return compat_process_vm_rw(pid, lvec, liovcnt, rvec,
+ riovcnt, flags, 0);
+}
+
+asmlinkage ssize_t
+compat_sys_process_vm_writev(compat_pid_t pid,
+ const struct compat_iovec __user *lvec,
+ unsigned long liovcnt,
+ const struct compat_iovec __user *rvec,
+ unsigned long riovcnt,
+ unsigned long flags)
+{
+ return compat_process_vm_rw(pid, lvec, liovcnt, rvec,
+ riovcnt, flags, 1);
+}
+
+#endif
diff --git a/ap/os/linux/linux-3.4.x/mm/quicklist.c b/ap/os/linux/linux-3.4.x/mm/quicklist.c
new file mode 100644
index 0000000..9422129
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/quicklist.c
@@ -0,0 +1,102 @@
+/*
+ * Quicklist support.
+ *
+ * Quicklists are light weight lists of pages that have a defined state
+ * on alloc and free. Pages must be in the quicklist specific defined state
+ * (zero by default) when the page is freed. It seems that the initial idea
+ * for such lists first came from Dave Miller and then various other people
+ * improved on it.
+ *
+ * Copyright (C) 2007 SGI,
+ * Christoph Lameter <clameter@sgi.com>
+ * Generalized, added support for multiple lists and
+ * constructors / destructors.
+ */
+#include <linux/kernel.h>
+
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/quicklist.h>
+
+DEFINE_PER_CPU(struct quicklist [CONFIG_NR_QUICK], quicklist);
+
+#define FRACTION_OF_NODE_MEM 16
+
+static unsigned long max_pages(unsigned long min_pages)
+{
+ unsigned long node_free_pages, max;
+ int node = numa_node_id();
+ struct zone *zones = NODE_DATA(node)->node_zones;
+ int num_cpus_on_node;
+
+ node_free_pages =
+#ifdef CONFIG_ZONE_DMA
+ zone_page_state(&zones[ZONE_DMA], NR_FREE_PAGES) +
+#endif
+#ifdef CONFIG_ZONE_DMA32
+ zone_page_state(&zones[ZONE_DMA32], NR_FREE_PAGES) +
+#endif
+ zone_page_state(&zones[ZONE_NORMAL], NR_FREE_PAGES);
+
+ max = node_free_pages / FRACTION_OF_NODE_MEM;
+
+ num_cpus_on_node = cpumask_weight(cpumask_of_node(node));
+ max /= num_cpus_on_node;
+
+ return max(max, min_pages);
+}
+
+static long min_pages_to_free(struct quicklist *q,
+ unsigned long min_pages, long max_free)
+{
+ long pages_to_free;
+
+ pages_to_free = q->nr_pages - max_pages(min_pages);
+
+ return min(pages_to_free, max_free);
+}
+
+/*
+ * Trim down the number of pages in the quicklist
+ */
+void quicklist_trim(int nr, void (*dtor)(void *),
+ unsigned long min_pages, unsigned long max_free)
+{
+ long pages_to_free;
+ struct quicklist *q;
+
+ q = &get_cpu_var(quicklist)[nr];
+ if (q->nr_pages > min_pages) {
+ pages_to_free = min_pages_to_free(q, min_pages, max_free);
+
+ while (pages_to_free > 0) {
+ /*
+ * We pass a gfp_t of 0 to quicklist_alloc here
+ * because we will never call into the page allocator.
+ */
+ void *p = quicklist_alloc(nr, 0, NULL);
+
+ if (dtor)
+ dtor(p);
+ free_page((unsigned long)p);
+ pages_to_free--;
+ }
+ }
+ put_cpu_var(quicklist);
+}
+
+unsigned long quicklist_total_size(void)
+{
+ unsigned long count = 0;
+ int cpu;
+ struct quicklist *ql, *q;
+
+ for_each_online_cpu(cpu) {
+ ql = per_cpu(quicklist, cpu);
+ for (q = ql; q < ql + CONFIG_NR_QUICK; q++)
+ count += q->nr_pages;
+ }
+ return count;
+}
+
diff --git a/ap/os/linux/linux-3.4.x/mm/ramdump/Makefile b/ap/os/linux/linux-3.4.x/mm/ramdump/Makefile
new file mode 100755
index 0000000..eb6eab5
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/ramdump/Makefile
@@ -0,0 +1,36 @@
+#
+# Makefile for the linux ramdump
+#
+ifeq ($(CONFIG_MMU),y)
+ccflags-y += -D__USE_MMU__
+endif
+
+ifeq ($(CONFIG_MPU),y)
+ccflags-y += -D__USE_MPU__
+endif
+
+ifeq ($(CONFIG_TRANS_WITH_COLLECT),y)
+ccflags-y += -D__USE_TRANS_WITH_COLLECT__
+endif
+
+ifeq ($(CONFIG_RAMDUMP_TRANS_SERVER),y)
+ccflags-y += -D__USE_RAMDUMP_TRANS_SERVER__
+endif
+
+ifeq ($(CONFIG_RAMDUMP_CLIENT),y)
+ccflags-y += -D__USE_RAMDUMP_CLIENT__
+endif
+
+ifeq ($(CONFIG_CLIENT_WITH_COLLECT),y)
+ccflags-y += -D__USE_CLIENT_WITH_COLLECT__
+endif
+
+ccflags-y += -D_OS_LINUX
+
+ccflags-y += -I$(srctree)/include/linux/ramdump
+obj-$(CONFIG_RAMDUMP_TRANS_SERVER) += ramdump_oss.o
+#obj-$(CONFIG_RAMDUMP) += ramdump_oss.o
+obj-$(CONFIG_TRANS_WITH_COLLECT) += ramdump_collect_server.o
+obj-$(CONFIG_RAMDUMP_TRANS_SERVER) += ramdump_trans_server.o
+obj-$(CONFIG_RAMDUMP_CLIENT) += ramdump_client.o
+obj-$(CONFIG_SYSTEM_CAP) += ramdump_client_cap.o
\ No newline at end of file
diff --git a/ap/os/linux/linux-3.4.x/mm/ramdump/ramdump_client_cap.c b/ap/os/linux/linux-3.4.x/mm/ramdump/ramdump_client_cap.c
new file mode 100755
index 0000000..f1c79b3
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/ramdump/ramdump_client_cap.c
@@ -0,0 +1,330 @@
+/*******************************************************************************
+* °æȨËùÓÐ (C)2016, ÖÐÐËͨѶ¹É·ÝÓÐÏÞ¹«Ë¾¡£
+*
+* ÎļþÃû³Æ: ramdump_client_cap.c
+* Îļþ±êʶ: ramdump_client_cap.c
+* ÄÚÈÝÕªÒª: ramdump cap¿Í»§¶ËÒì³£ËÀ»úÏÖ³¡Êý¾Ýµ¼³öʵÏÖ
+*
+* ÐÞ¸ÄÈÕÆÚ °æ±¾ºÅ Ð޸ıê¼Ç ÐÞ¸ÄÈË ÐÞ¸ÄÄÚÈÝ
+* ------------------------------------------------------------------------------
+* 2019/10/10 V1.0 Create 00130574 ´´½¨
+*
+*******************************************************************************/
+
+/*******************************************************************************
+* Í·Îļþ *
+*******************************************************************************/
+#include "ramdump_pub.h"
+#include "ramdump_oss.h"
+#include <linux/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*******************************************************************************
+* ³£Á¿¶¨Òå *
+*******************************************************************************/
+
+/*******************************************************************************
+* ºê¶¨Òå *
+*******************************************************************************/
+
+/*******************************************************************************
+* Êý¾ÝÀàÐͶ¨Òå *
+*******************************************************************************/
+
+/*******************************************************************************
+* º¯ÊýÉùÃ÷ *
+*******************************************************************************/
+
+/*******************************************************************************
+* ¾Ö²¿¾²Ì¬±äÁ¿¶¨Òå *
+*******************************************************************************/
+static int ramdump_cap_init_flag;
+static int ramdump_count;
+
+#define RAMDUMP_ON_DEFAULT_VAL (1)
+#define ramdump_cap_cmm_buf (ZX_DDR_CAPBUF_BASE + ICP_CAP_BUF_LEN + TOOL_CAP_BUF_LEN)
+
+/*******************************************************************************
+* È«¾Ö±äÁ¿¶¨Òå *
+*******************************************************************************/
+/*
+ * run time control dump or not, use ( echo "0" > ramdump_on ) to close ramdump
+ */
+int sysctl_ramdump_on_panic = RAMDUMP_ON_DEFAULT_VAL;
+
+/*******************************************************************************
+* ¾Ö²¿º¯ÊýʵÏÖ *
+*******************************************************************************/
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_cap_icp_handle
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) buf: icp msg addr
+* len: icp msg len
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for ramdump client icp msg handle, common entry
+*******************************************************************************/
+static void ramdump_cap_icp_handle(void *buf, unsigned int len)
+{
+ ramdump_msg_t *icp_msg = (ramdump_msg_t *)buf;
+
+ switch(icp_msg->msg_id)
+ {
+ case RAMDUMP_MSG_EXCEPT:
+ {
+ OSS_PANIC("trans server received forced dump request from Ap server!\n");
+
+ break;
+ }
+
+ default:
+ {
+ OSS_PANIC("trans server received forced dump request from Ap server!\n");
+
+ break;
+ }
+ }
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_icp_create_channel
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) actorID: icp send core id
+ chID: icp channel id
+ size: icp channel size
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: int: if msg send success
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+static int ramdump_cap_icp_create_channel(
+ ramdump_oss_icp_actorid actorID,
+ ramdump_oss_icp_channelid chID,
+ unsigned int size)
+{
+ return zDrvRpMsg_CreateChannel(actorID, chID, size);
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_icp_regcallback
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) actorID: icp send core id
+ chID: icp channel id
+ callback:icp callback fun
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: int: if msg send success
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+static int ramdump_cap_icp_regcallback (
+ ramdump_oss_icp_actorid actorID,
+ unsigned int chID,
+ ramdump_oss_icp_callback callback)
+{
+ return zDrvRpMsg_RegCallBack(actorID,chID,callback);
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_cap_icp_init
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for ramdump client icp init
+*******************************************************************************/
+static int ramdump_cap_icp_init(void)
+{
+ int ret = 0;
+
+ ret = ramdump_cap_icp_create_channel(
+ AP_ID,
+ RAMDUMP_CHANNEL,
+ RAMDUMP_CHANNEL_SIZE);
+
+ if (ret != RAMDUMP_SUCCESS)
+ return ret;
+ ret = ramdump_cap_icp_regcallback(
+ AP_ID,
+ RAMDUMP_CHANNEL,
+ ramdump_cap_icp_handle);
+
+ if (ret != RAMDUMP_SUCCESS)
+ return ret;
+
+ return RAMDUMP_SUCCESS;
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_notify_server_panic
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for cap notify ramdump server to panic
+*******************************************************************************/
+static void ramdump_notify_server_panic()
+{
+ int Rlt = 0;
+
+ T_ZDrvRpMsg_Msg tMsg ={AP_ID, RAMDUMP_CHANNEL, 1, NULL, 0};
+
+ Rlt = zDrvRpMsg_WriteLockIrq(&tMsg);
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_cap_store_ram_conf
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) mem: addr
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: unsigend char*: changed addr
+* ÆäËü˵Ã÷: This function is used to store ram conf
+*******************************************************************************/
+static unsigned char *ramdump_cap_store_ram_conf(unsigned char *mem)
+{
+ unsigned long cap_cmm_phy = 0;
+
+ cap_cmm_phy = RAMDUMP_CAP_CMM_BUF_ADDR;
+
+ mem += sprintf(
+ mem,
+ "data.load.binary &ramdump_dir\\%s 0x%x--0x%x /noclear\n",
+ "cap_ddr",
+ (unsigned long)DDR_BASE_CAP_ADDR_PA,
+ (unsigned int)(DDR_BASE_CAP_ADDR_PA + DDR_BASE_LEN_CAP));
+ mem += sprintf(
+ mem,
+ "data.load.binary &ramdump_dir\\%s 0x%x--0x%x /noclear\n",
+ "cap.cmm",
+ cap_cmm_phy,
+ (unsigned int)(cap_cmm_phy + RAMDUMP_CAP_CMM_BUF_LEN));
+ return mem;
+}
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_cap_cmm_create
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for server to generate cmm scripts
+*******************************************************************************/
+static void ramdump_cap_cmm_create(void)
+{
+ unsigned char *pcmm_buf = ramdump_cap_cmm_buf;
+
+ // store the cmm BEGIN
+ pcmm_buf += sprintf(pcmm_buf, "ENTRY &ramdump_dir\n");
+
+ // store procmodes regs
+ pcmm_buf = ramdump_arch_store_modes_regs(pcmm_buf);
+
+ // store ram config
+ pcmm_buf = ramdump_cap_store_ram_conf(pcmm_buf);
+
+ // store memory map control regs
+ pcmm_buf = ramdump_arch_store_mm_regs(pcmm_buf);
+
+ // store end symbol
+ pcmm_buf += sprintf(pcmm_buf, "ENDDO\n");
+
+}
+/*******************************************************************************
+* È«¾Öº¯ÊýʵÏÖ *
+*******************************************************************************/
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_ram_conf_table_add
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) ram_name: dump ram name
+ ram_start: dump ram start(virtual addr)
+ ram_size: dump ram size
+ ram_virt: dump ram virt addr
+ ram_flag: dump ram flag(copy/exter/callback)
+ ram_extra: dump ram extra access addr
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used to add dump ram conf into public table
+*******************************************************************************/
+void ramdump_ram_conf_table_add(
+ char *ram_name,
+ unsigned long ram_phy,
+ unsigned long ram_size,
+ unsigned long ram_virt,
+ unsigned long ram_flag,
+ unsigned long ram_extra)
+{
+ ;
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_init
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: RAMDUMP_SUCCESS or RAMDUMP_FAILED
+* ÆäËü˵Ã÷: This function is used for ramdump init
+*******************************************************************************/
+int ramdump_init(void)
+{
+ int ret = 0;
+
+ if (ramdump_cap_init_flag == RAMDUMP_TRUE)
+ return RAMDUMP_SUCCESS;
+
+ ret = ramdump_cap_icp_init();
+ if (ret != RAMDUMP_ICP_SUCCESS)
+ return ret;
+
+ OSS_PRINTF("Ramdump cap init success!\n");
+ ramdump_cap_init_flag = RAMDUMP_TRUE;
+
+ return RAMDUMP_SUCCESS;
+}
+module_init(ramdump_init);
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_entry
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for ramdump entry
+*******************************************************************************/
+void ramdump_entry (void)
+{
+ unsigned long flags;
+ if (sysctl_ramdump_on_panic == FALSE)
+ return;
+
+ /*
+ * we need lock the irq, this can`t be interrupt.
+ */
+ OSS_LOCK(flags);
+
+ if (!ramdump_cap_init_flag)
+ while(TRUE); /* endless circle */
+
+ if (++ramdump_count > 1)
+ while(TRUE); /* endless circle */
+
+ /*
+ * save all regs first.
+ */
+ ramdump_arch_save_all_regs();
+
+ //Éú³Écmm½Å±¾µÄµ¼³öÅäÖÃ
+ ramdump_cap_cmm_create();
+ /* notify client ramdump */
+ ramdump_notify_server_panic();
+ ramdump_arch_clean_caches();
+
+ while(TRUE);
+
+ OSS_UNLOCK(flags);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+
+MODULE_LICENSE("GPL");
diff --git a/ap/os/linux/linux-3.4.x/mm/ramdump/ramdump_oss.c b/ap/os/linux/linux-3.4.x/mm/ramdump/ramdump_oss.c
new file mode 100755
index 0000000..f59e646
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/ramdump/ramdump_oss.c
@@ -0,0 +1,448 @@
+/*******************************************************************************
+* °æȨËùÓÐ (C)2016, ÖÐÐËͨѶ¹É·ÝÓÐÏÞ¹«Ë¾¡£
+*
+* ÎļþÃû³Æ: ramdump_oss.c
+* Îļþ±êʶ: ramdump_oss.c
+* ÄÚÈÝÕªÒª: ramdump²Ù×÷ϵͳÒÀÀµ½Ó¿Ú/Êý¾Ý½á¹¹¶¨ÒåÍ·Îļþ
+* ʹÓ÷½·¨: Èç¹û¸ü»»²Ù×÷ϵͳ£¬¸ÄÍ·ÎļþÄÚ½Ó¿Ú»òÕßÊý¾Ý¶¨ÒåÐèÒªÖØÐÂÊÊÅä
+*
+* ÐÞ¸ÄÈÕÆÚ °æ±¾ºÅ Ð޸ıê¼Ç ÐÞ¸ÄÈË ÐÞ¸ÄÄÚÈÝ
+* ------------------------------------------------------------------------------
+* 2016/6/10 V1.0 Create ÕÔ¾ü¿ü ´´½¨
+*
+*******************************************************************************/
+
+/*******************************************************************************
+* Í·Îļþ *
+*******************************************************************************/
+#include "ramdump_pub.h"
+#include "ramdump_oss.h"
+#include <linux/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*******************************************************************************
+* Íⲿº¯ÊýÉùÃ÷ *
+*******************************************************************************/
+
+/*******************************************************************************
+* ºê¶¨Òå *
+*******************************************************************************/
+
+/*******************************************************************************
+* Êý¾ÝÀàÐͶ¨Òå *
+*******************************************************************************/
+
+/*******************************************************************************
+* È«¾Ö±äÁ¿ÉùÃ÷ *
+*******************************************************************************/
+
+/*******************************************************************************
+* È«¾Öº¯ÊýÉùÃ÷ *
+*******************************************************************************/
+
+#ifdef _OS_LINUX
+/* icp api */
+extern int zDrvRpMsg_CreateChannel(
+ T_ZDrvRpMsg_ActorID actorID,
+ T_ZDrvRpMsg_ChID chID,
+ unsigned int size);
+extern int zDrvRpMsg_RegCallBack(
+ T_ZDrvRpMsg_ActorID actorID,
+ unsigned int chID,
+ T_ZDrvRpMsg_CallbackFunction callback);
+extern int zDrvRpMsg_WriteLockIrq(const T_ZDrvRpMsg_Msg *pMsg);
+extern void panic(const char *fmt, ...);
+
+extern int zDrvUsbPoll_Init(void);
+extern int zDrvUsbPoll_Isr(void);
+extern bool zDrvUsbPoll_isConnect(void);
+extern int zDrvUsbPoll_Read(unsigned char* pBuf,unsigned long length);
+extern int zDrvUsbPoll_Write(unsigned char* pBuf,unsigned long length);
+#if defined CONFIG_PRINTK
+extern void get_logbuf_info(unsigned long *addr, unsigned long *size);
+#endif
+#endif //#ifdef _OS_LINUX
+
+/*******************************************************************************
+* È«¾Öº¯ÊýʵÏÖ *
+*******************************************************************************/
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_create_thread
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+void ramdump_oss_create_thread (
+ unsigned char *name,
+ ramdump_oss_thread_entry_t entry)
+{
+#ifdef _OS_TOS
+#define RAMDUMP_THREAD_STACK_DEF_SIZE 2048
+#define RAMDUMP_THREAD_DEF_PRIO 20
+#define RAMDUMP_THREAD_DEF_ARG 0
+#define RAMDUMP_THREAD_AUTORUN 1
+#define RAMDUMP_THREAD_PREEMPT 1
+
+ zOss_CreateThread(
+ name,entry,
+ RAMDUMP_THREAD_DEF_ARG,
+ RAMDUMP_THREAD_STACK_DEF_SIZE,
+ RAMDUMP_THREAD_DEF_PRIO,
+ RAMDUMP_THREAD_PREEMPT,
+ RAMDUMP_THREAD_AUTORUN);
+#endif
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_mmap
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+unsigned long ramdump_oss_mmap (unsigned long addr, unsigned long size)
+{
+#ifdef _OS_LINUX
+ return ioremap(addr,size);
+#elif defined (_OS_TOS)
+
+#ifdef __USE_MMU__
+ T_zTos_MmuRamdumpTable mmuTable = {0};
+ zTos_MmuGetMappingRegion(addr, size, &mmuTable);
+ /*
+ * TODO!
+ * current tos mmap one to one
+ * need new API like ioremap realize
+ */
+ return addr;
+#endif
+
+#endif
+}
+
+#ifdef _USE_CAP_SYS
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_icp_send_cap
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) icp_msg: msg info
+ client_id: client id
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: int: if msg send success
+* ÆäËü˵Ã÷: This function is used for server to send msg to client
+*******************************************************************************/
+int ramdump_oss_icp_send_cap(ramdump_oss_msg_t *icp_msg, unsigned int client_id)
+{
+ int ret;
+ ramdump_oss_icp_msg rpmsg = {0};
+
+ rpmsg.actorID = client_id;
+ rpmsg.chID = channel_10;
+ rpmsg.flag = 1;
+ rpmsg.buf = icp_msg;
+ rpmsg.len = sizeof(*icp_msg);
+
+ /*
+ * clean all the caches to make sure all data in ddr
+ */
+ ramdump_arch_clean_caches();
+
+ ret = zDrvRpMsg_Write_Cap(&rpmsg);
+
+ if (ret != rpmsg.len)
+ {
+ OSS_PRINTF(
+ "[ramdump] icpmsg send fail, ret != rpmsg.len[ret:%d], [client_id:%d]\n",
+ ret,
+ client_id);
+ return ret;
+ }
+
+ return RAMDUMP_ICP_SUCCESS;
+}
+#endif
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_icp_send
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) icp_msg: msg info
+ client_id: client id
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: int: if msg send success
+* ÆäËü˵Ã÷: This function is used for server to send msg to client
+*******************************************************************************/
+int ramdump_oss_icp_send(ramdump_oss_msg_t *icp_msg, unsigned int client_id)
+{
+ int ret;
+ ramdump_oss_icp_msg rpmsg = {0};
+
+ rpmsg.actorID = client_id;
+ rpmsg.chID = channel_40;
+ rpmsg.flag = 1;
+ rpmsg.buf = icp_msg;
+ rpmsg.len = sizeof(*icp_msg);
+
+ /*
+ * clean all the caches to make sure all data in ddr
+ */
+ ramdump_arch_clean_caches();
+
+ ret = ramdump_oss_icp_write(&rpmsg);
+
+ if (ret != rpmsg.len)
+ {
+#ifdef _OS_LINUX
+ OSS_PRINTF(
+ "[ramdump] icpmsg send fail, ret != rpmsg.len[ret:%d], [client_id:%d]\n",
+ ret,
+ client_id);
+#elif defined (_OS_TOS)
+ OSS_PRINTF(
+ SUBMDL_TEST,
+ PRINT_LEVEL_NORMAL,
+ "[ramdump] icpmsg send fail, ret != rpmsg.len[ret:%d], [client_id:%d]\n",
+ ret,
+ client_id);
+#endif
+ return ret;
+ }
+
+ return RAMDUMP_ICP_SUCCESS;
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_error_log_creat
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) buf : addr point
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+void ramdump_oss_error_log_creat(char *buf)
+{
+#ifdef _OS_LINUX
+ if (current->mm != NULL)
+ sprintf(
+ buf,
+ " dump at user, app name is: %s, load addr is: %lu \n",
+ current->comm,
+ current->mm->start_code);
+ else
+ sprintf(
+ buf,
+ " dump at kernel, app name is: %s \n",
+ current->comm);
+#endif
+
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_icp_create_channel
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) actorID: icp send core id
+ chID: icp channel id
+ size: icp channel size
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: int: if msg send success
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+int ramdump_oss_icp_create_channel(
+ ramdump_oss_icp_actorid actorID,
+ ramdump_oss_icp_channelid chID,
+ unsigned int size)
+{
+#ifdef _OS_LINUX
+ return CPPS_FUNC(cpps_callbacks, zDrvRpMsg_CreateChannel)(actorID, chID, size);
+#elif defined (_OS_TOS)
+ if (actorID == ramdump_cpu_id[RAMDUMP_CPU_2])
+ return 0;
+ else
+ return zDrvRpMsg_CreateChannel(actorID, chID, size);
+#endif
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_icp_regcallback
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) actorID: icp send core id
+ chID: icp channel id
+ callback:icp callback fun
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: int: if msg send success
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+int ramdump_oss_icp_regcallback (
+ ramdump_oss_icp_actorid actorID,
+ unsigned int chID,
+ ramdump_oss_icp_callback callback)
+{
+#ifdef _OS_LINUX
+ return CPPS_FUNC(cpps_callbacks, zDrvRpMsg_RegCallBack)(actorID,chID,callback);
+#elif defined (_OS_TOS)
+ if (actorID == ramdump_cpu_id[RAMDUMP_CPU_2])
+ return zDrvIcp_RegCallback(
+ ICP_ARM0_MODULE_ID_OS,
+ actorID,
+ callback,
+ ICP_ISR_CALLBACK);
+ else
+ return zDrvRpMsg_RegCallBack(actorID,chID,callback);
+#endif
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_icp_write
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) pMsg: icp send msg
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: int: if msg send success
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+int ramdump_oss_icp_write(const ramdump_oss_icp_msg *pMsg)
+{
+#ifdef _OS_LINUX
+ return CPPS_FUNC(cpps_callbacks, zDrvRpMsg_Write)(pMsg);
+#elif defined (_OS_TOS)
+ if ((ramdump_msg_t *)pMsg->actorID == ramdump_cpu_id[RAMDUMP_CPU_2])
+ {
+ switch (((ramdump_msg_t *)(pMsg->buf))->msg_id)
+ {
+ case RAMDUMP_MSG_EXCEPT:
+ {
+ T_HalIcp_Msg icpMsg = { 0 };
+ icpMsg.SrcModId = ICP_ARM0_MODULE_ID_OS;
+ icpMsg.desModId = ICP_ARM1_MODULE_ID_OS;
+ icpMsg.IntInfo.high_word = ZPLAT_PS2PHY_RAMDUMP_INT_ICP_CF;
+ zDrvIcp_SendMsg((const T_HalIcp_Msg *)&icpMsg);
+ }
+ case RAMDUMP_MSG_SYNC:
+ default:
+ return pMsg->len;
+ }
+ }
+ else
+ return zDrvRpMsg_WriteLockIrq(pMsg);
+#endif
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_data_trans_init
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+void ramdump_oss_data_trans_init(void)
+{
+#ifdef _OS_LINUX
+ zDrvUsbPoll_Init(); /* ³õʼ»¯USB */
+ while (!zDrvUsbPoll_isConnect()) ; /* ²éѯUSBÊÇ·ñÁ¬½Ó */
+#endif
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_data_trans_read
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) buffer: data buff
+ size: data size
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+void ramdump_oss_data_trans_read(unsigned char *buffer, unsigned int size)
+{
+#ifdef _OS_LINUX
+ unsigned int count = 0;
+
+ do
+ {
+ zDrvUsbPoll_Isr();
+ count = (unsigned int)zDrvUsbPoll_Read(buffer, size);
+ if ( size <= count)
+ {
+ break;
+ }
+ buffer += count;
+ size -=count;
+ }
+ while (size > 0);
+#endif
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_data_trans_write
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) buffer: data buff
+ size: data size
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+void ramdump_oss_data_trans_write(unsigned char *buffer, unsigned int size)
+{
+#ifdef _OS_LINUX
+ unsigned int count = 0;
+
+ while (size > 0)
+ {
+ zDrvUsbPoll_Isr();
+ count = (unsigned int)zDrvUsbPoll_Write(buffer, size);
+ if ( size <= count)
+ {
+ break;
+ }
+
+ buffer += count;
+ size -=count;
+ }
+#endif
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_oss_data_trans_done
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷:
+*******************************************************************************/
+void ramdump_oss_data_trans_done(void)
+{
+#ifdef _OS_LINUX
+ /* µÈ´ýÊý¾Ý·¢ËÍÍêºó£¬ÔÙÖØÆô */
+ zDrvUsbPoll_Isr();
+#endif
+}
+
+void ramdump_oss_logbuf_create(void)
+{
+#ifdef _OS_LINUX
+#if defined CONFIG_PRINTK
+
+ unsigned long addr;
+ unsigned long size;
+
+ get_logbuf_info(&addr, &size);
+
+ ramdump_ram_conf_table_add(
+ "ap_log_buf",
+ (unsigned long)OSS_VIRT_TO_PHY(addr),
+ size,
+ addr,
+ RAMDUMP_FLAG_NONE,
+ 0);
+#endif
+#endif
+}
+
+#ifdef __cplusplus
+}
+#endif
+
diff --git a/ap/os/linux/linux-3.4.x/mm/ramdump/ramdump_trans_server.c b/ap/os/linux/linux-3.4.x/mm/ramdump/ramdump_trans_server.c
new file mode 100755
index 0000000..b112efd
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/ramdump/ramdump_trans_server.c
@@ -0,0 +1,1237 @@
+/*******************************************************************************
+* °æȨËùÓÐ (C)2016, ÖÐÐËͨѶ¹É·ÝÓÐÏÞ¹«Ë¾¡£
+*
+* ÎļþÃû³Æ: ramdump_server_trans.c
+* Îļþ±êʶ: ramdump_server_trans.c
+* ÄÚÈÝÕªÒª: ramdump·þÎñ¶ËÒì³£ËÀ»úÏÖ³¡Êý¾Ýµ¼³öʵÏÖ
+*
+* ÐÞ¸ÄÈÕÆÚ °æ±¾ºÅ Ð޸ıê¼Ç ÐÞ¸ÄÈË ÐÞ¸ÄÄÚÈÝ
+* ------------------------------------------------------------------------------
+* 2016/3/10 V1.0 Create ÕÔ¾ü¿ü ´´½¨
+*
+*******************************************************************************/
+
+/*******************************************************************************
+* Í·Îļþ *
+*******************************************************************************/
+#include "ramdump_pub.h"
+#include "ramdump_oss.h"
+#include <linux/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*******************************************************************************
+* ³£Á¿¶¨Òå *
+*******************************************************************************/
+#define __USE_TRANS_WITH_COLLECT__ 1
+
+/*******************************************************************************
+* ºê¶¨Òå *
+*******************************************************************************/
+#define RAMDUMP_ON_DEFAULT_VAL (1)
+
+#define RAMDUMP_MMAP_SUCCESS (RAMDUMP_SUCCESS)
+#define RAMDUMP_MMAP_FAILED (RAMDUMP_FAILED)
+
+#define RP_MSG_PS_PHY_RAMDUMP_CHANNEL channel_40 //arm¡¢zspÖ®¼äµÄramdumpͨµÀ
+#define RP_MSG_PS_PHY_RAMDUMP_SIZE 0x40 //arm¡¢zspÖ®¼äµÄramdumpͨµÀ
+
+#ifdef _USE_CAP_SYS
+#define RAMDUMP_ICP_MSG_CAP_SIZE 0x40
+#endif
+
+/* ramdump ºÍ PCÇý¶¯´úÀí½»»¥ÃüÁîÔ¼¶¨ */
+/*ͬ²½ÇëÇó*/
+#define RAMDUMP_PC_INTERACTIVE_REQ 1
+/*ͬ²½ÇëÇóÓ¦´ð,´«ÊäramdumpµÄÎļþÊýÄ¿*/
+#define RAMDUMP_TRANS_SERVER_INTERACTIVE_RSP 2
+/*ÇëÇó´«µÝÖ¸¶¨Îļþ±àºÅµÄÎļþÐÅÏ¢*/
+#define RAMDUMP_PC_FILE_INFO_READ_REQ 3
+/*ÇëÇó´«µÝÖ¸¶¨Îļþ±àºÅµÄÎļþÐÅÏ¢µÄÓ¦´ð£¬´«ÊäÎļþÃû¼°´óС*/
+#define RAMDUMP_TRANS_SERVER_FILE_INFO_READ_RSP 4
+/*ÇëÇó¶ÁÈ¡Ö¸¶¨Îļþ±àºÅµÄÎļþÄÚÈÝ*/
+#define RAMDUMP_PC_FILE_DATA_TRANS_REQ 5
+/*ÇëÇó¶ÁÈ¡Ö¸¶¨Îļþ±àºÅµÄÎļþÄÚÈݵÄÓ¦´ð£¬´«ÊäÎļþÄÚÈÝ*/
+#define RAMDUMP_TRANS_SERVER_FILE_DATA_TRANS_RSP 6
+/*´«Êä½áÊø*/
+#define RAMDUMP_PC_FILE_TRANS_DONE_REQ 7
+/*´«Êä½áÊøÓ¦´ð*/
+#define RAMDUMP_TRANS_SERVER_FILE_TRANS_DONE_RSP 8
+
+/* ´íÎóÀàÐÍ */
+/*Ö¸Áî´íÎó*/
+#define RAMDUMP_INTERACTIVE_CMD_ERROR 9
+/*ÇëÇó´«µÝÖ¸¶¨Îļþ±àºÅ´í*/
+#define RAMDUMP_FILE_NUMBER_ERROR 10
+/*ÇëÇó´«µÝÖ¸¶¨ÎļþλÖôóС´í*/
+#define RAMDUMP_FILE_SIZE_ERROR 11
+/*Ö¸ÁîÖ¡³¤¶È */
+#define RAMDUMP_INTERACTIVE_DATA_LEN 16
+
+#define RAMDUMP_TRANS_SERVER_DDR_BINNAME "trans_server_ddr.bin"
+#define RAMDUMP_TRANS_SERVER_CMM_SCRNAME "trans_server_cmm.cmm"
+#define RAMDUMP_TRANS_SERVER_ERR_LOG "trans_server_error_log.txt"
+#define RAMDUMP_TRANS_SERVER_DEF_BINNAME "trans_server_"
+
+#define RAMDUMP_CAP_CMM_BUF_ADDR_PHY (RAMDUMP_CAP_CMM_BUF_ADDR_PA)
+#define RAMDUMP_CAP_CMM_BUF_LEN_REAL ((3 * 1024UL)>>CPU_SHIFT)
+#define RAMDUMP_CAP_LOG_BUF_ADDR (RAMDUMP_CAP_CMM_BUF_ADDR_PHY + RAMDUMP_CAP_CMM_BUF_LEN_REAL)
+#define RAMDUMP_CAP_LOG_BUF_LEN ((1 * 1024UL)>>CPU_SHIFT)
+
+/*******************************************************************************
+* Êý¾ÝÀàÐͶ¨Òå *
+*******************************************************************************/
+
+/*
+ * struct TRANS WITH PC
+ */
+
+/* trans_server rsp pc, interactive msg struct */
+typedef struct
+{
+ unsigned long cmd;
+ unsigned long file_num;
+} ramdump_trans_server_interactive_rsp;
+
+/* trans_server rsp pc, file info msg struct */
+typedef struct
+{
+ unsigned long cmd;
+ char file_name[RAMDUMP_RAMCONF_FILENAME_MAXLEN];
+ unsigned long file_size;
+} ramdump_trans_server_file_info_rsp;
+
+/* pc req trans_server, file info msg struct */
+typedef struct
+{
+ unsigned long cmd;
+ unsigned long file_id;
+} ramdump_pc_file_info_req;
+
+/* trans_server rsp pc, trans data msg struct */
+typedef struct
+{
+ unsigned long cmd;
+ unsigned long buf_addr;
+ unsigned long buf_left_size;
+} ramdump_trans_server_data_trans_rsp;
+
+/* pc req trans_server, trans data msg struct */
+typedef struct
+{
+ unsigned long cmd;
+ unsigned long file_id; /* Îļþ±àºÅ */
+ unsigned long offset; /* offsetΪÊý¾ÝÆ«ÒÆ */
+ unsigned long length; /* lengthΪÊý¾Ý³¤¶È */
+} ramdump_pc_trans_data_req;
+
+
+/*******************************************************************************
+* º¯ÊýÉùÃ÷ *
+*******************************************************************************/
+#ifndef CONFIG_SYSTEM_RECOVERY
+extern unsigned int zOss_GetExceptResetFlag(void);
+extern int zSys_ExceptReboot(unsigned int except_cpu);
+#else
+extern void emergency_restart(void);
+#endif
+
+extern void zx_wdt_m0_stop(void);
+extern struct meminfo meminfo;
+
+/*******************************************************************************
+* ¾Ö²¿¾²Ì¬±äÁ¿¶¨Òå *
+*******************************************************************************/
+static int ramdump_server_init_flag;
+static int ramdump_count;
+static int ramdump_file_num;
+
+static DEFINE_MUTEX(ramdump_mutex);
+
+/* Cmm file content */
+static unsigned char ramdump_server_cmm_buf[RAMDUMP_CMM_SIZE];
+/* err log file */
+static char ramdump_server_error_log[RAMDUMP_ERROR_LOG_SIZE];
+
+/* trans server ram conf table */
+static ramdump_ram_config_t ramdump_trans_server_ram_conf[RAMDUMP_RAMCONF_TABLE_MAX_ENTRYS];
+static unsigned int ddr_ap_size;
+
+#ifndef __USE_TRANS_WITH_COLLECT__
+/* trans server ram conf data done flag*/
+static unsigned long ramdump_trans_server_data_done_flag = RAMDUMP_SYNC_RESET;
+/* collect server ram conf addr */
+static ramdump_ram_config_sync_msg_t ramdump_collect_server_ram_conf;
+
+static ramdump_ram_config_msg_t ramdump_ap_config;
+static int ramdump_ap_file_num;
+
+#endif
+
+/*******************************************************************************
+* È«¾Ö±äÁ¿¶¨Òå *
+*******************************************************************************/
+/*
+ * run time control dump or not, use ( echo "0" > ramdump_on ) to close ramdump
+ */
+int sysctl_ramdump_on_panic = RAMDUMP_ON_DEFAULT_VAL;
+
+/* diff server crash or client crash */
+int ramdump_trans_server_force_panic_flag = RAMDUMP_FALSE;
+
+/*******************************************************************************
+* ¾Ö²¿º¯ÊýʵÏÖ *
+*******************************************************************************/
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_trans_server_dynamic_ram_conf_collect
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used to collect server ram conf before client mmap
+*******************************************************************************/
+static unsigned long ramdump_phy_to_vir(ramdump_ram_config_t * ram_config)
+{
+ unsigned long pfn = 0;
+ unsigned long vir_addr = 0;
+
+ if(ram_config->vir != 0)
+ return ram_config->vir;
+
+ pfn = OSS_PHY_TO_PFN((unsigned long)(ram_config->phy));
+ if (OSS_PFN_VALID(pfn))
+ vir_addr = OSS_PHY_TO_VIRT((unsigned long)ram_config->phy);
+ else
+ if (ram_config->copy != 0 &&
+ ram_config->copy != ram_config->phy)
+ {
+ vir_addr =(unsigned long)ram_config->copy;
+ }
+ else if (ram_config->exter != 0 && ram_config->exter != ram_config->phy)
+ {
+ vir_addr = (unsigned long)ram_config->exter;
+ }
+ else
+ vir_addr = (unsigned long)OSS_MMAP(ram_config->phy, ram_config->size);
+
+ return vir_addr;
+}
+
+#ifndef __USE_TRANS_WITH_COLLECT__
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_trans_server_ram_conf_table_mmap
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) array: ram conf table addr
+* nr: ram conf table size
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for ramdump trans to mmap addr table space
+*******************************************************************************/
+static void ramdump_trans_server_ram_conf_table_mmap(
+ void *array,
+ unsigned int nr)
+{
+ unsigned long cpu_id = 0;
+ unsigned long vir_addr = 0;
+ unsigned long pfn = 0;
+ while (cpu_id < nr)
+ {
+ vir_addr = 0;
+ pfn = 0;
+ ramdump_ram_config_msg_t *array_entry =
+ (ramdump_ram_config_msg_t *)(&(ramdump_collect_server_ram_conf.array[cpu_id]));
+ if (((((ramdump_ram_config_msg_t *)array)[cpu_id]).array) == NULL ||
+ ((((ramdump_ram_config_msg_t *)array)[cpu_id]).nr) == 0)
+ {
+ cpu_id++;
+ continue;
+ }
+
+ pfn = OSS_PHY_TO_PFN((unsigned long)((((ramdump_ram_config_msg_t *)array)[cpu_id]).array));
+ if (OSS_PFN_VALID(pfn))
+ vir_addr = OSS_PHY_TO_VIRT((unsigned long)((((ramdump_ram_config_msg_t *)array)[cpu_id]).array));
+ else
+ vir_addr = (unsigned long)OSS_MMAP(
+ (unsigned long)((((ramdump_ram_config_msg_t *)array)[cpu_id]).array),
+ ((((ramdump_ram_config_msg_t *)array)[cpu_id].nr) * sizeof(ramdump_ram_config_t)));
+ if (vir_addr == 0)
+ {
+ OSS_PRINTF("[ramdump] trans server mmap collect server ram conf table entry failed!\n");
+ cpu_id++;
+ continue;
+ }
+ else
+ {
+ array_entry->array = (ramdump_ram_config_t *)vir_addr;
+ array_entry->nr = (((ramdump_ram_config_msg_t *)array)[cpu_id].nr);
+ }
+
+ /* mmap collect ram conf table space sync done flag */
+ vir_addr = 0;
+ pfn = OSS_PHY_TO_PFN((unsigned long)((((ramdump_ram_config_msg_t *)array)[cpu_id]).done_flag));
+ if (OSS_PFN_VALID(pfn))
+ vir_addr = OSS_PHY_TO_VIRT((unsigned long)((((ramdump_ram_config_msg_t *)array)[cpu_id]).done_flag));
+ else
+ vir_addr = (unsigned long)OSS_MMAP(
+ (unsigned long)((((ramdump_ram_config_msg_t *)array)[cpu_id]).done_flag),
+ sizeof(*((((ramdump_ram_config_msg_t *)array)[cpu_id]).done_flag)));
+ if (vir_addr == 0)
+ {
+ OSS_PRINTF("[ramdump] trans server mmap collect server table entry done flag failed!\n");
+ cpu_id++;
+ continue;
+ }
+ else
+ {
+ array_entry->done_flag = vir_addr;
+ }
+ cpu_id++;
+ }
+
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_dump_ram_conf_mmap_init
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for ramdump client mmap init
+*******************************************************************************/
+static void ramdump_dump_ram_conf_mmap_init(void)
+{
+ unsigned long vir_addr = 0;
+ int cpu_id = 0;
+
+ /* iterate all cpu */
+ while (cpu_id < ramdump_collect_server_ram_conf.nr)
+ {
+ int tb_index = 0;
+ unsigned long pfn = 0;
+ ramdump_ram_config_msg_t *array_entry =
+ (ramdump_ram_config_msg_t *)(&(ramdump_collect_server_ram_conf.array[cpu_id]));
+ if (array_entry->array == NULL || array_entry->nr == 0 || array_entry->done_flag == NULL)
+ {
+ OSS_PRINTF("Ramdump maybe happens before collect server init done, please check!\n");
+ cpu_id++;
+ continue;
+ }
+
+ /* wait collect data done */
+ while (*(array_entry->done_flag) == RAMDUMP_SYNC_RESET)
+ ramdump_wait_done_delay(
+ RAMDUMP_WAIT_TIMELEN,
+ (volatile unsigned long *)array_entry->done_flag,
+ RAMDUMP_SYNC_RAM_CONFIG_DONE);
+
+ /* iterate all ram conf table entry */
+ while (tb_index < array_entry->nr)
+ {
+ if (array_entry->array[tb_index].phy == 0 ||
+ array_entry->array[tb_index].size == 0)
+ {
+ tb_index++;
+ continue;
+ }
+
+ vir_addr = ramdump_phy_to_vir(&array_entry->array[tb_index]);
+ if (vir_addr == 0)
+ OSS_PRINTF("Ramdump init failed, client mem mmap init wrong!\n");
+ else
+ array_entry->array[tb_index].vir = vir_addr;
+ tb_index++;
+ }
+ cpu_id++;
+ }
+
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_dump_file_num_recalc
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used to create err log file
+*******************************************************************************/
+static void ramdump_dump_file_num_recalc(void)
+{
+ unsigned long cpu_id = 0;
+ if (ramdump_collect_server_ram_conf.nr == 0 ||
+ ramdump_collect_server_ram_conf.array == NULL)
+ while(TRUE); /* except happends before sync with other core done */
+
+ while (cpu_id < ramdump_collect_server_ram_conf.nr)
+ {
+ unsigned long arr_num = 0;
+ unsigned long file_num = 0;
+ while(arr_num < ramdump_collect_server_ram_conf.array[cpu_id].nr)
+ {
+ /* ram conf have contents,need to dump */
+ if (ramdump_collect_server_ram_conf.array[cpu_id].array[arr_num].vir != 0 &&
+ ramdump_collect_server_ram_conf.array[cpu_id].array[arr_num].size != 0)
+ file_num++;
+ arr_num++;
+ }
+ ramdump_collect_server_ram_conf.array[cpu_id].nr = file_num;
+ cpu_id++;
+ }
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_find_collect_ram_conf_entry_id
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) file_id: file number
+* (´«³ö²ÎÊý) cpu_id : cpu index
+* ·µ »Ø Öµ: unsigned long: file id
+* ÆäËü˵Ã÷: This function is used for ramdump to
+*******************************************************************************/
+static unsigned long ramdump_find_collect_ram_conf_entry_id(
+ unsigned long file_id,
+ unsigned long* cpu_id)
+{
+ unsigned long cpu_index = 0;
+ while (cpu_index < RAMDUMP_CPU_MAX)
+ {
+ if (file_id >= ramdump_collect_server_ram_conf.array[cpu_index].nr)
+ file_id -= ramdump_collect_server_ram_conf.array[cpu_index].nr;
+ else
+ break;
+ cpu_index++;
+ }
+
+ *cpu_id = cpu_index;
+ return file_id;
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_wait_clients_dump_done
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for ramdump client dump done charge
+*******************************************************************************/
+static void ramdump_wait_clients_dump_done(void)
+{
+ unsigned long cpu_id = 0;
+ while (cpu_id < RAMDUMP_CPU_MAX)
+ {
+ if (ramdump_collect_server_ram_conf.array[cpu_id].array == NULL ||
+ ramdump_collect_server_ram_conf.array[cpu_id].nr == NULL ||
+ ramdump_collect_server_ram_conf.array[cpu_id].done_flag == NULL)
+ break;
+ while (*(ramdump_collect_server_ram_conf.array[cpu_id].done_flag) == RAMDUMP_SYNC_RESET)
+ ramdump_wait_done_delay(
+ RAMDUMP_WAIT_TIMELEN,
+ (volatile unsigned long *)(ramdump_collect_server_ram_conf.array[cpu_id].done_flag),
+ RAMDUMP_SYNC_RAM_CONTENT_DONE);
+ cpu_id++;
+ }
+}
+#endif //#ifndef __USE_TRANS_WITH_COLLECT__
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_do_panic
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for ramdump client icp msg handle, do panic
+*******************************************************************************/
+static void ramdump_do_panic(void)
+{
+ if (ramdump_trans_server_force_panic_flag == RAMDUMP_CLIENT_ZSP)
+ OSS_PANIC("trans server received forced dump request from zsp client!\n");
+ else if (ramdump_trans_server_force_panic_flag == RAMDUMP_CLIENT_CAP)
+ OSS_PANIC("trans server received forced dump request from cap client!\n");
+ else
+ OSS_PANIC("AP server recv error icp msg\n");
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_clients_icp_handle
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) buf: icp msg addr
+* len: icp msg len
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for ramdump client icp msg handle, common entry
+*******************************************************************************/
+static void ramdump_clients_icp_handle(void *buf, unsigned int len)
+{
+ unsigned long vir_addr = 0;
+ ramdump_msg_t *icp_msg = (ramdump_msg_t *)buf;
+ switch(icp_msg->msg_id)
+ {
+#ifndef __USE_TRANS_WITH_COLLECT__
+ case RAMDUMP_MSG_INIT_REQ:
+ {
+ /* trans ram conf send to collect server */
+ ramdump_msg_t icp_msg_to_server = {0};
+ icp_msg_to_server.msg_id = RAMDUMP_MSG_INIT_RSP;
+ icp_msg_to_server.cpu_id = ramdump_cpu_id[RAMDUMP_CPU_1];
+ icp_msg_to_server.msg_data_t.ram_config.array =
+ OSS_VIRT_TO_PHY(ramdump_trans_server_ram_conf);
+ icp_msg_to_server.msg_data_t.ram_config.nr =
+ RAMDUMP_ARRAY_NR(ramdump_trans_server_ram_conf);
+ icp_msg_to_server.msg_data_t.ram_config.done_flag =
+ OSS_VIRT_TO_PHY((unsigned long*)&ramdump_trans_server_data_done_flag);
+
+ ramdump_oss_icp_send(&icp_msg_to_server, ramdump_cpu_id[RAMDUMP_CPU_0]);
+ break;
+ }
+ case RAMDUMP_MSG_SYNC: /* handle collect ram conf */
+ {
+ unsigned long addr = RAMDUMP_SYNC_RESET;
+ if (icp_msg->msg_data_t.ram_config_sync.array == NULL ||
+ icp_msg->msg_data_t.ram_config_sync.nr == 0)
+ break;
+
+ /* mmap collect ram conf table space */
+ vir_addr = (unsigned long)OSS_MMAP(
+ (unsigned long)icp_msg->msg_data_t.ram_config_sync.array,
+ ((icp_msg->msg_data_t.ram_config_sync.nr) * sizeof(ramdump_ram_config_msg_t)));
+ if (vir_addr == 0)
+ {
+ OSS_PRINTF("[ramdump] trans server mmap collect server ram conf table failed!\n");
+ break;
+ }
+ ramdump_collect_server_ram_conf.array = (ramdump_ram_config_msg_t *)vir_addr;
+ ramdump_collect_server_ram_conf.nr = icp_msg->msg_data_t.ram_config_sync.nr;
+
+ /* mmap collect ram conf table entry space */
+ ramdump_trans_server_ram_conf_table_mmap(
+ ramdump_collect_server_ram_conf.array,
+ ramdump_collect_server_ram_conf.nr);
+
+ /* wait ioremap work */
+ ramdump_wait_done_delay(RAMDUMP_WAIT_TIMELEN, &addr, RAMDUMP_SYNC_RAM_CONFIG_DONE);
+
+ /* we have to mmap first,sometime except happend in interrupt
+ handlers , then we can`t mmap - -! */
+ ramdump_dump_ram_conf_mmap_init();
+
+ break;
+ }
+#endif
+ case RAMDUMP_MSG_EXCEPT:
+ {
+ ramdump_do_panic();
+ break;
+ }
+ default:
+ {
+ ramdump_do_panic();
+ break;
+ }
+ }
+}
+
+/**************************************************************************
+ * º¯ÊýÃû³Æ£º ramdump_icp_msg_from_zsp
+ * ¹¦ÄÜÃèÊö£º server ´¦ÀízspµÄICPÏûÏ¢º¯Êý
+ * ²ÎÊý˵Ã÷£º
+* (´«Èë²ÎÊý) pMsg: ic msg buf
+* (´«³ö²ÎÊý) void
+ * ·µ »Ø Öµ£º void
+ * ÆäËü˵Ã÷£º void
+**************************************************************************/
+static void ramdump_icp_msg_from_zsp(void *buf, unsigned int len)
+{
+ ramdump_trans_server_force_panic_flag = RAMDUMP_CLIENT_ZSP;
+
+ ramdump_clients_icp_handle(buf, len);
+}
+
+/**************************************************************************
+ * º¯ÊýÃû³Æ£º ramdump_icp_msg_from_cap
+ * ¹¦ÄÜÃèÊö£º server ´¦ÀízspµÄICPÏûÏ¢º¯Êý
+ * ²ÎÊý˵Ã÷£º
+* (´«Èë²ÎÊý) pMsg: ic msg buf
+* (´«³ö²ÎÊý) void
+ * ·µ »Ø Öµ£º void
+ * ÆäËü˵Ã÷£º void
+**************************************************************************/
+static void ramdump_icp_msg_from_cap(void *buf, unsigned int len)
+{
+ ramdump_trans_server_force_panic_flag = RAMDUMP_CLIENT_CAP;
+
+ ramdump_clients_icp_handle(buf, len);
+}
+
+/**************************************************************************
+ * º¯ÊýÃû³Æ£º ramdump_icp_msg_from_m0
+ * ¹¦ÄÜÃèÊö£º server ´¦ÀízspµÄICPÏûÏ¢º¯Êý
+ * ²ÎÊý˵Ã÷£º
+* (´«Èë²ÎÊý) pMsg: ic msg buf
+* (´«³ö²ÎÊý) void
+ * ·µ »Ø Öµ£º void
+ * ÆäËü˵Ã÷£º void
+**************************************************************************/
+void ramdump_icp_msg_from_m0(void *buf, int len)
+{
+ ramdump_trans_server_force_panic_flag = RAMDUMP_CLIENT_M0;
+ OSS_PANIC("trans server received forced dump request from M0 client!\n");
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_icp_init
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for ramdump client icp init
+*******************************************************************************/
+static int ramdump_icp_init(void)
+{
+ int ret = 0;
+#ifndef __USE_TRANS_WITH_COLLECT__
+ ret = ramdump_oss_icp_create_channel(
+ ramdump_cpu_id[RAMDUMP_CPU_0],
+ RAMDUMP_CHANNEL,
+ RAMDUMP_CHANNEL_SIZE);
+ if (ret != RAMDUMP_SUCCESS)
+ return ret;
+
+ ret = ramdump_oss_icp_regcallback(
+ ramdump_cpu_id[RAMDUMP_CPU_0],
+ RAMDUMP_CHANNEL,
+ ramdump_collect_server_icp_handle);
+ if (ret != RAMDUMP_SUCCESS)
+ return ret;
+#else
+#ifdef _USE_CAP_SYS
+ ret = zDrvRpMsg_CreateChannel_Cap(
+ CAP_ID,
+ RAMDUMP_CHANNEL,
+ RAMDUMP_ICP_MSG_CAP_SIZE);
+ if (ret != RAMDUMP_SUCCESS)
+ return ret;
+ ret = zDrvRpMsg_RegCallBack_Cap(
+ CAP_ID,
+ RAMDUMP_CHANNEL,
+ ramdump_icp_msg_from_cap);
+ if (ret != RAMDUMP_SUCCESS)
+ return ret;
+#endif
+ ret = ramdump_oss_icp_create_channel(
+ ramdump_cpu_id[RAMDUMP_CPU_2],
+ RP_MSG_PS_PHY_RAMDUMP_CHANNEL,
+ RP_MSG_PS_PHY_RAMDUMP_SIZE);
+ if (ret != RAMDUMP_SUCCESS)
+ return ret;
+
+ ret = ramdump_oss_icp_regcallback(
+ ramdump_cpu_id[RAMDUMP_CPU_2],
+ RP_MSG_PS_PHY_RAMDUMP_CHANNEL,
+ ramdump_icp_msg_from_zsp);
+ if (ret != RAMDUMP_SUCCESS)
+ return ret;
+
+ ret = ramdump_oss_icp_create_channel(
+ M0_ID,
+ channel_3,
+ 0x14);
+ if (ret != RAMDUMP_SUCCESS)
+ return ret;
+
+ ret = ramdump_oss_icp_regcallback(
+ M0_ID,
+ channel_3,
+ ramdump_icp_msg_from_m0);
+
+ if (ret != RAMDUMP_SUCCESS)
+ return ret;
+
+#endif
+
+ return RAMDUMP_SUCCESS;
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_notify_client_dump
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for
+*******************************************************************************/
+static void ramdump_notify_client_dump(void)
+{
+ ramdump_msg_t icp_msg = {0};
+#ifndef __USE_TRANS_WITH_COLLECT__
+
+ /* client except interactive */
+ icp_msg.msg_id = RAMDUMP_MSG_EXCEPT;
+ icp_msg.cpu_id = RAMDUMP_CPU_1;
+ ramdump_oss_icp_send(&icp_msg, ramdump_cpu_id[RAMDUMP_CPU_0]);
+#else
+#ifdef _USE_CAP_SYS
+ /* client except interactive */
+ icp_msg.msg_id = RAMDUMP_MSG_EXCEPT;
+ icp_msg.cpu_id = RAMDUMP_CPU_0;
+ ramdump_oss_icp_send_cap(&icp_msg, CAP_ID);
+#endif
+ /* client except interactive */
+ icp_msg.msg_id = RAMDUMP_MSG_EXCEPT;
+ icp_msg.cpu_id = RAMDUMP_CPU_0;
+ ramdump_oss_icp_send(&icp_msg, ramdump_cpu_id[RAMDUMP_CPU_2]);
+#endif
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_server_store_ram_conf
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) mem: addr
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: unsigend char*: changed addr
+* ÆäËü˵Ã÷: This function is used to store ram conf
+*******************************************************************************/
+static unsigned char *ramdump_server_store_ram_conf(unsigned char *mem)
+{
+ unsigned long i_ram_conf = 0;
+ while (ramdump_trans_server_ram_conf[i_ram_conf].vir != 0 &&
+ ramdump_trans_server_ram_conf[i_ram_conf].size != 0)
+ {
+ ramdump_ram_config_t *config_entry = &(ramdump_trans_server_ram_conf[i_ram_conf]);
+ /* session can be access */
+ if (config_entry->callback == NULL ||
+ (config_entry->callback != NULL &&
+ (*(config_entry->callback))() == RAMDUMP_TRUE))
+ mem += sprintf(
+ mem,
+ "data.load.binary &ramdump_dir\\%s 0x%x--0x%x /noclear\n",
+ (config_entry->name),
+ (unsigned int)config_entry->phy,
+ (unsigned int)(config_entry->phy + config_entry->size));
+ i_ram_conf++;
+ }
+
+ return mem;
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_trans_server_cmm_create
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for server to generate cmm scripts
+*******************************************************************************/
+static void ramdump_trans_server_cmm_create(void)
+{
+ unsigned char *pcmm_buf = ramdump_server_cmm_buf;
+ unsigned int cmm_buf_len = 0;
+ char cmm_name[RAMDUMP_RAMCONF_FILENAME_MAXLEN] = {0};
+
+ // store the cmm BEGIN
+ pcmm_buf += sprintf(pcmm_buf, "ENTRY &ramdump_dir\n");
+ // store procmodes regs
+ pcmm_buf = ramdump_arch_store_modes_regs(pcmm_buf);
+ // store ram config
+ pcmm_buf = ramdump_server_store_ram_conf(pcmm_buf);
+ // store memory map control regs
+ pcmm_buf = ramdump_arch_store_mm_regs(pcmm_buf);
+
+ // store end symbol
+ pcmm_buf += sprintf(pcmm_buf, "ENDDO\n");
+
+ // generate cmm name
+ sprintf(
+ cmm_name,
+ "%s-%s",
+ ramdump_cpu_name[RAMDUMP_CPU_1],
+ RAMDUMP_TRANS_SERVER_CMM_SCRNAME);
+
+ //if out of buf, since we can`t stop it, then cut it
+ cmm_buf_len = ((unsigned int)pcmm_buf - (unsigned int)ramdump_server_cmm_buf);
+ if (cmm_buf_len <= RAMDUMP_CMM_SIZE)
+ ramdump_ram_conf_table_add(
+ cmm_name,
+ (unsigned long)OSS_VIRT_TO_PHY(ramdump_server_cmm_buf),
+ cmm_buf_len,
+ (unsigned long)ramdump_server_cmm_buf,
+ RAMDUMP_FLAG_NONE,
+ 0);
+ else
+ ramdump_ram_conf_table_add(
+ cmm_name,
+ (unsigned long)OSS_VIRT_TO_PHY(ramdump_server_cmm_buf),
+ RAMDUMP_CMM_SIZE,
+ (unsigned long)ramdump_server_cmm_buf,
+ RAMDUMP_FLAG_NONE,
+ 0);
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_trans_server_error_log_create
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used to create err log file
+*******************************************************************************/
+static void ramdump_trans_server_error_log_create(void)
+{
+ int offset = 0;
+ char err_log_name[RAMDUMP_RAMCONF_FILENAME_MAXLEN] = {0};
+
+ if (ramdump_trans_server_force_panic_flag == RAMDUMP_CLIENT_ZSP)
+ offset = sprintf(ramdump_server_error_log, "trans server received force dump request from ZSP client !\n");
+ else if (ramdump_trans_server_force_panic_flag == RAMDUMP_CLIENT_M0)
+ offset = sprintf(ramdump_server_error_log, "trans server received force dump request from M0 client !\n");
+ else if (ramdump_trans_server_force_panic_flag == RAMDUMP_CLIENT_CAP)
+ offset = sprintf(ramdump_server_error_log, "trans server received force dump request from CAP client !\n");
+ else
+ offset = sprintf(ramdump_server_error_log, "AP server breakdown happens !\n");
+
+ ramdump_oss_error_log_creat(ramdump_server_error_log + offset);
+ // generate err_log name
+ sprintf(
+ err_log_name,
+ "%s-%s",
+ ramdump_cpu_name[RAMDUMP_CPU_1],
+ RAMDUMP_TRANS_SERVER_ERR_LOG);
+ ramdump_ram_conf_table_add(
+ err_log_name,
+ (unsigned long)OSS_VIRT_TO_PHY(ramdump_server_error_log),
+ ((strlen(ramdump_server_error_log) >= RAMDUMP_ERROR_LOG_SIZE) ?
+ RAMDUMP_ERROR_LOG_SIZE : strlen(ramdump_server_error_log)),
+ (unsigned long)ramdump_server_error_log,
+ RAMDUMP_FLAG_NONE,
+ 0);
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_data_transfer_to_pc
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for ramdump to trans dump data to PC
+*******************************************************************************/
+static void ramdump_data_transfer_to_pc(void)
+{
+ char req_buf[RAMDUMP_INTERACTIVE_DATA_LEN] = {0};
+
+ /* interactive begin */
+ ramdump_oss_data_trans_init();
+
+ for(;;)
+ {
+ ramdump_oss_data_trans_read((unsigned char *)req_buf, RAMDUMP_INTERACTIVE_DATA_LEN);
+ switch (*(unsigned long *)req_buf)
+ {
+ case RAMDUMP_PC_INTERACTIVE_REQ:
+ {
+ ramdump_trans_server_interactive_rsp server_to_pc_msg = {0};
+ server_to_pc_msg.cmd = RAMDUMP_TRANS_SERVER_INTERACTIVE_RSP;
+ server_to_pc_msg.file_num = ramdump_file_num;
+
+ ramdump_oss_data_trans_write(
+ (unsigned char*)(&server_to_pc_msg),
+ sizeof(server_to_pc_msg));
+
+ break;
+ }
+ case RAMDUMP_PC_FILE_INFO_READ_REQ:
+ {
+ ramdump_trans_server_file_info_rsp server_to_pc_msg = {0};
+ /* data from pc to server */
+ ramdump_pc_file_info_req *pc_to_server_msg = (ramdump_pc_file_info_req *)req_buf;
+
+ /* data respond pc from server */
+ server_to_pc_msg.cmd = RAMDUMP_TRANS_SERVER_FILE_INFO_READ_RSP;
+ strncpy(server_to_pc_msg.file_name,
+ ramdump_trans_server_ram_conf[pc_to_server_msg->file_id].name,
+ RAMDUMP_RAMCONF_FILENAME_MAXLEN - 1);
+ server_to_pc_msg.file_name[RAMDUMP_RAMCONF_FILENAME_MAXLEN - 1] = '\0';
+ server_to_pc_msg.file_size = ramdump_trans_server_ram_conf[pc_to_server_msg->file_id].size;
+ if (ramdump_trans_server_ram_conf[pc_to_server_msg->file_id].callback != NULL &&
+ (ramdump_trans_server_ram_conf[pc_to_server_msg->file_id].callback)() == RAMDUMP_FALSE)
+ server_to_pc_msg.file_size = 0;
+ /* interactive data trans */
+ ramdump_oss_data_trans_write(
+ (unsigned char*)(&server_to_pc_msg),
+ sizeof(server_to_pc_msg));
+
+ break;
+ }
+ case RAMDUMP_PC_FILE_DATA_TRANS_REQ:
+ {
+ ramdump_trans_server_data_trans_rsp server_to_pc_msg = {0};
+ /* data from pc to server */
+ ramdump_pc_trans_data_req *pc_to_server_msg = (ramdump_pc_trans_data_req *)req_buf;
+
+ /* data respond pc from server */
+ server_to_pc_msg.cmd = RAMDUMP_TRANS_SERVER_FILE_DATA_TRANS_RSP;
+ server_to_pc_msg.buf_addr =
+ (ramdump_trans_server_ram_conf[pc_to_server_msg->file_id].vir +
+ pc_to_server_msg->offset);
+ server_to_pc_msg.buf_left_size = pc_to_server_msg->length;
+ /* interactive data trans */
+ /*
+ * TODO!
+ * now multiplex old interactive flow.
+ * need to be optimize, write once is better.
+ * like this ramdump_oss_data_trans_write((unsigned char *)(&server_to_pc_msg),
+ * sizeof(server_to_pc_msg));
+ */
+ ramdump_oss_data_trans_write(
+ (unsigned char *)(&(server_to_pc_msg.cmd)),
+ sizeof(server_to_pc_msg.cmd));
+ ramdump_oss_data_trans_write(
+ (unsigned char *)(server_to_pc_msg.buf_addr),
+ server_to_pc_msg.buf_left_size);
+
+ continue;
+ }
+ case RAMDUMP_PC_FILE_TRANS_DONE_REQ:
+ {
+ unsigned long finish_cmd = RAMDUMP_TRANS_SERVER_FILE_TRANS_DONE_RSP;
+ /* interactive data trans */
+ ramdump_oss_data_trans_write(
+ (unsigned char *)(&finish_cmd),
+ sizeof(finish_cmd));
+ ramdump_oss_data_trans_done();
+ return;
+ }
+ default:
+ {
+ unsigned long error_cmd = RAMDUMP_INTERACTIVE_CMD_ERROR;
+ /* interactive data trans */
+ ramdump_oss_data_trans_write((unsigned char *)(&error_cmd),
+ sizeof(error_cmd));
+ break;
+ }
+ }
+ }
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_client_copy_data
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used to create err log file
+*******************************************************************************/
+static void ramdump_trans_copy_data(void)
+{
+ unsigned long i_ram_conf = 0;
+
+ while (ramdump_trans_server_ram_conf[i_ram_conf].phy != 0 &&
+ ramdump_trans_server_ram_conf[i_ram_conf].size != 0)
+ {
+ if (ramdump_trans_server_ram_conf[i_ram_conf].flag == RAMDUMP_FLAG_NEED_COPY &&
+ ramdump_trans_server_ram_conf[i_ram_conf].copy != 0 &&
+ (ramdump_trans_server_ram_conf[i_ram_conf].phy !=
+ ramdump_trans_server_ram_conf[i_ram_conf].copy))
+ memcpy(
+ ramdump_trans_server_ram_conf[i_ram_conf].copy,
+ ramdump_trans_server_ram_conf[i_ram_conf].phy,
+ ramdump_trans_server_ram_conf[i_ram_conf].size);
+ i_ram_conf++;
+ }
+}
+
+/*******************************************************************************
+* È«¾Öº¯ÊýʵÏÖ *
+*******************************************************************************/
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_ram_conf_table_add
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) ram_name: dump ram name
+ ram_start: dump ram start(virtual addr)
+ ram_size: dump ram size
+ ram_virt: dump ram virt addr
+ ram_flag: dump ram flag(copy/exter/callback)
+ ram_extra: dump ram extra access addr
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used to add dump ram conf into public table
+*******************************************************************************/
+void ramdump_ram_conf_table_add(
+ char *ram_name,
+ unsigned long ram_phy,
+ unsigned long ram_size,
+ unsigned long ram_virt,
+ unsigned long ram_flag,
+ unsigned long ram_extra)
+{
+ static unsigned int i_entry = 0;
+
+ if ((ram_phy == 0) && (ram_size == 0))
+ return;
+
+ mutex_lock(&ramdump_mutex);
+
+ strncpy(ramdump_trans_server_ram_conf[i_entry].name,
+ ram_name,
+ RAMDUMP_RAMCONF_FILENAME_MAXLEN - 1);
+ ramdump_trans_server_ram_conf[i_entry].name[RAMDUMP_RAMCONF_FILENAME_MAXLEN - 1] = '\0';
+ ramdump_trans_server_ram_conf[i_entry].phy = ram_phy;
+ ramdump_trans_server_ram_conf[i_entry].size = ram_size;
+ ramdump_trans_server_ram_conf[i_entry].vir = ram_virt;
+ ramdump_trans_server_ram_conf[i_entry].flag = ram_flag;
+
+ switch (ram_flag)
+ {
+ case RAMDUMP_FLAG_NEED_COPY:
+ ramdump_trans_server_ram_conf[i_entry].exter = ram_extra;
+ ramdump_trans_server_ram_conf[i_entry].flag = RAMDUMP_FLAG_HAS_EXTERNAL;
+ break;
+ case RAMDUMP_FLAG_HAS_EXTERNAL:
+ ramdump_trans_server_ram_conf[i_entry].exter = ram_extra;
+ break;
+ case RAMDUMP_FLAG_HAS_CALLBACK:
+ ramdump_trans_server_ram_conf[i_entry].callback = ram_extra;
+ break;
+ default:
+ break;
+ }
+
+ if (ram_phy != 0 && ram_size != 0)
+ ramdump_trans_server_ram_conf[i_entry].vir = ramdump_phy_to_vir(&ramdump_trans_server_ram_conf[i_entry]);
+
+ i_entry++;
+
+ if (i_entry >= RAMDUMP_RAMCONF_TABLE_MAX_ENTRYS)
+ i_entry = 0;
+
+ ramdump_file_num ++;
+ mutex_unlock(&ramdump_mutex);
+}
+EXPORT_SYMBOL(ramdump_ram_conf_table_add);
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_init
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: RAMDUMP_SUCCESS or RAMDUMP_FAILED
+* ÆäËü˵Ã÷: This function is used for ramdump init
+*******************************************************************************/
+static int test_fun(void)
+{
+ return RAMDUMP_TRUE;
+}
+
+int ramdump_init(void)
+{
+ if (ramdump_server_init_flag == RAMDUMP_TRUE)
+ return RAMDUMP_SUCCESS;
+
+ int ret = 0;
+ int i = 0;
+ char bin_name[RAMDUMP_RAMCONF_FILENAME_MAXLEN] = {0};
+
+ for(i = 0;i < meminfo.nr_banks;i++) {
+ if(meminfo.bank[i].start == RAMDUMP_SERVER_DDR_BASE)
+ ddr_ap_size = meminfo.bank[i].size;
+ }
+ BUG_ON(ddr_ap_size == 0);
+
+ /* change the interactive cpu value */
+ ramdump_cpu_id[RAMDUMP_CPU_2] = ICP_MSG_ACTOR_ZSP;
+
+ /* client icp init */
+ ret = ramdump_icp_init();
+ if (ret != RAMDUMP_ICP_SUCCESS)
+ return ret;
+
+ sprintf(
+ bin_name,
+ "%s-%s",
+ ramdump_cpu_name[RAMDUMP_CPU_1],
+ RAMDUMP_TRANS_SERVER_DDR_BINNAME);
+ ramdump_ram_conf_table_add(
+ bin_name,
+ RAMDUMP_SERVER_DDR_BASE,
+ ddr_ap_size,
+ (unsigned long)OSS_PHY_TO_VIRT(RAMDUMP_SERVER_DDR_BASE),
+ RAMDUMP_FLAG_NONE,
+ 0);
+
+ ramdump_ram_conf_table_add(
+ "AP_test_bus_call_false.bin",
+ RAMDUMP_SERVER_DDR_BASE,
+ 0x1000,
+ (unsigned long)OSS_PHY_TO_VIRT(RAMDUMP_SERVER_DDR_BASE),
+ RAMDUMP_FLAG_HAS_CALLBACK,
+ test_fun);
+
+#ifdef CONFIG_MEM_TRACKER
+ ramdump_ram_conf_table_add(
+ "mem_tracker.bin",
+ ZX29_MEM_TRACKER_PHYS,
+ ZX_MEM_TRACKER_SIZE,
+ ZX_MEM_TRACKER_BASE,
+ RAMDUMP_FLAG_NONE,
+ 0);
+ ramdump_ram_conf_table_add(
+ "kmalloc_tracker.bin",
+ ZX29_KMALLOC_TRACKER_PHYS,
+ ZX_KMALLOC_TRACKER_SIZE,
+ ZX_KMALLOC_TRACKER_BASE,
+ RAMDUMP_FLAG_NONE,
+ 0);
+#endif
+#ifdef _USE_CAP_SYS
+ /* cap ramdump cmm */
+ ramdump_ram_conf_table_add(
+ "cap_ddr.bin",
+ DDR_BASE_CAP_ADDR_PA,
+ DDR_BASE_LEN_CAP,
+ 0,
+ RAMDUMP_FLAG_NONE,
+ 0);
+ ramdump_ram_conf_table_add(
+ "cap.cmm",
+ RAMDUMP_CAP_CMM_BUF_ADDR_PHY,
+ RAMDUMP_CAP_CMM_BUF_LEN_REAL,
+ 0,
+ RAMDUMP_FLAG_NONE,
+ 0);
+ ramdump_ram_conf_table_add(
+ "cap_err_log.txt",
+ RAMDUMP_CAP_LOG_BUF_ADDR,
+ RAMDUMP_CAP_LOG_BUF_LEN,
+ 0,
+ RAMDUMP_FLAG_NONE,
+ 0);
+#endif
+ /* set trans ram data done flag */
+// ramdump_trans_server_data_done_flag = RAMDUMP_SYNC_RAM_CONTENT_DONE;
+
+ OSS_PRINTF("Ramdump server init success!\n");
+ ramdump_server_init_flag = RAMDUMP_TRUE;
+
+ return RAMDUMP_SUCCESS;
+}
+//OSS_INIT(ramdump_init);
+EXPORT_SYMBOL(ramdump_init);
+extern void show_stack_state();
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_info
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for print ramdump info
+*******************************************************************************/
+void ramdump_info(void)
+{
+ if(CPPS_FUNC(cpps_callbacks, zOss_GetExceptResetFlag)() == 1)
+ printk(KERN_EMERG "Ramdump info: Ramdump Except Reboot enabled!\n");
+ else if(CPPS_FUNC(cpps_callbacks, zOss_GetExceptResetFlag)() == 2)
+ printk(KERN_EMERG "Ramdump info: Ramdump Except Reboot after export!\n");
+ if (sysctl_ramdump_on_panic == FALSE)
+ printk(KERN_EMERG "Ramdump info: Ramdump disabled!\n");
+ printk(KERN_EMERG "Ramdump info: Current Process is: %s, pid is %i!\n", current->comm, current->pid);
+}
+
+/*******************************************************************************
+* ¹¦ÄÜÃèÊö: ramdump_entry
+* ²ÎÊý˵Ã÷:
+* (´«Èë²ÎÊý) void
+* (´«³ö²ÎÊý) void
+* ·µ »Ø Öµ: void
+* ÆäËü˵Ã÷: This function is used for ramdump entry
+*******************************************************************************/
+void ramdump_entry (void)
+{
+ unsigned long flags;
+
+#ifndef CONFIG_SYSTEM_RECOVERY
+ if (CPPS_FUNC(cpps_callbacks, zOss_GetExceptResetFlag) != NULL)
+ {
+ if(CPPS_FUNC(cpps_callbacks, zOss_GetExceptResetFlag)() == 1)
+ CPPS_FUNC(cpps_callbacks, zSys_ExceptReboot)(0);
+ }
+#else
+ emergency_restart();
+#endif
+
+#ifdef CONFIG_ZX29_WATCHDOG
+ zx_wdt_m0_stop();
+#endif
+
+ if (sysctl_ramdump_on_panic == FALSE)
+ return;
+
+ /*
+ * we need lock the irq, this can`t be interrupt.
+ */
+ OSS_LOCK(flags);
+#ifdef CONFIG_STACK_SIZE
+ show_stack_state();
+#endif
+ if (!ramdump_server_init_flag)
+ while(TRUE); /* endless circle */
+
+ if (++ramdump_count > 1)
+ while(TRUE); /* endless circle */
+
+ /*
+ * save all regs first.
+ */
+ ramdump_arch_save_all_regs();
+
+ //Éú³Écmm½Å±¾µÄµ¼³öÅäÖÃ
+ ramdump_trans_server_cmm_create();
+
+ /* error log file */
+ ramdump_trans_server_error_log_create();
+
+ /* log buf */
+ ramdump_oss_logbuf_create();
+
+ /* notify client ramdump */
+ ramdump_notify_client_dump();
+
+ /* special data copy to the copy addr
+ * then other core read from the copy addr
+ */
+ ramdump_trans_copy_data();
+
+#ifndef __USE_TRANS_WITH_COLLECT__ // if not collect server, need to do this
+ /* wait client all data done */
+ ramdump_wait_clients_dump_done();
+#endif
+
+ /* caculate the true dump file num */
+ //ramdump_dump_file_num_recalc();
+ /* ram data trans to pc */
+ ramdump_data_transfer_to_pc();
+
+ /*
+ * TODO!
+ * now endless circle, e.g., config restart or not is more better.
+ */
+#ifndef CONFIG_SYSTEM_RECOVERY
+ if (CPPS_FUNC(cpps_callbacks, zOss_GetExceptResetFlag) != NULL)
+ {
+ if(CPPS_FUNC(cpps_callbacks, zOss_GetExceptResetFlag)() == 2)
+ CPPS_FUNC(cpps_callbacks, zSys_ExceptReboot)(0);
+ else
+ while(TRUE);
+ }
+#endif
+ while(TRUE);
+
+ OSS_UNLOCK(flags);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+
+MODULE_LICENSE("GPL");
diff --git a/ap/os/linux/linux-3.4.x/mm/readahead.c b/ap/os/linux/linux-3.4.x/mm/readahead.c
new file mode 100644
index 0000000..cbcbb02
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/readahead.c
@@ -0,0 +1,564 @@
+/*
+ * mm/readahead.c - address_space-level file readahead.
+ *
+ * Copyright (C) 2002, Linus Torvalds
+ *
+ * 09Apr2002 Andrew Morton
+ * Initial version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/export.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/pagevec.h>
+#include <linux/pagemap.h>
+
+/*
+ * Initialise a struct file's readahead state. Assumes that the caller has
+ * memset *ra to zero.
+ */
+void
+file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping)
+{
+ ra->ra_pages = mapping->backing_dev_info->ra_pages;
+ ra->prev_pos = -1;
+}
+EXPORT_SYMBOL_GPL(file_ra_state_init);
+
+#define list_to_page(head) (list_entry((head)->prev, struct page, lru))
+
+/*
+ * see if a page needs releasing upon read_cache_pages() failure
+ * - the caller of read_cache_pages() may have set PG_private or PG_fscache
+ * before calling, such as the NFS fs marking pages that are cached locally
+ * on disk, thus we need to give the fs a chance to clean up in the event of
+ * an error
+ */
+static void read_cache_pages_invalidate_page(struct address_space *mapping,
+ struct page *page)
+{
+ if (page_has_private(page)) {
+ if (!trylock_page(page))
+ BUG();
+ page->mapping = mapping;
+ do_invalidatepage(page, 0);
+ page->mapping = NULL;
+ unlock_page(page);
+ }
+ page_cache_release(page);
+}
+
+/*
+ * release a list of pages, invalidating them first if need be
+ */
+static void read_cache_pages_invalidate_pages(struct address_space *mapping,
+ struct list_head *pages)
+{
+ struct page *victim;
+
+ while (!list_empty(pages)) {
+ victim = list_to_page(pages);
+ list_del(&victim->lru);
+ read_cache_pages_invalidate_page(mapping, victim);
+ }
+}
+
+/**
+ * read_cache_pages - populate an address space with some pages & start reads against them
+ * @mapping: the address_space
+ * @pages: The address of a list_head which contains the target pages. These
+ * pages have their ->index populated and are otherwise uninitialised.
+ * @filler: callback routine for filling a single page.
+ * @data: private data for the callback routine.
+ *
+ * Hides the details of the LRU cache etc from the filesystems.
+ */
+int read_cache_pages(struct address_space *mapping, struct list_head *pages,
+ int (*filler)(void *, struct page *), void *data)
+{
+ struct page *page;
+ int ret = 0;
+
+ while (!list_empty(pages)) {
+ page = list_to_page(pages);
+ list_del(&page->lru);
+ if (add_to_page_cache_lru(page, mapping,
+ page->index, GFP_KERNEL)) {
+ read_cache_pages_invalidate_page(mapping, page);
+ continue;
+ }
+ page_cache_release(page);
+
+ ret = filler(data, page);
+ if (unlikely(ret)) {
+ read_cache_pages_invalidate_pages(mapping, pages);
+ break;
+ }
+ task_io_account_read(PAGE_CACHE_SIZE);
+ }
+ return ret;
+}
+
+EXPORT_SYMBOL(read_cache_pages);
+
+static int read_pages(struct address_space *mapping, struct file *filp,
+ struct list_head *pages, unsigned nr_pages)
+{
+ struct blk_plug plug;
+ unsigned page_idx;
+ int ret;
+
+ blk_start_plug(&plug);
+
+ if (mapping->a_ops->readpages) {
+ ret = mapping->a_ops->readpages(filp, mapping, pages, nr_pages);
+ /* Clean up the remaining pages */
+ put_pages_list(pages);
+ goto out;
+ }
+
+ for (page_idx = 0; page_idx < nr_pages; page_idx++) {
+ struct page *page = list_to_page(pages);
+ list_del(&page->lru);
+ if (!add_to_page_cache_lru(page, mapping,
+ page->index, GFP_KERNEL)) {
+ mapping->a_ops->readpage(filp, page);
+ }
+ page_cache_release(page);
+ }
+ ret = 0;
+
+out:
+ blk_finish_plug(&plug);
+
+ return ret;
+}
+
+/*
+ * __do_page_cache_readahead() actually reads a chunk of disk. It allocates all
+ * the pages first, then submits them all for I/O. This avoids the very bad
+ * behaviour which would occur if page allocations are causing VM writeback.
+ * We really don't want to intermingle reads and writes like that.
+ *
+ * Returns the number of pages requested, or the maximum amount of I/O allowed.
+ */
+static int
+__do_page_cache_readahead(struct address_space *mapping, struct file *filp,
+ pgoff_t offset, unsigned long nr_to_read,
+ unsigned long lookahead_size)
+{
+ struct inode *inode = mapping->host;
+ struct page *page;
+ unsigned long end_index; /* The last page we want to read */
+ LIST_HEAD(page_pool);
+ int page_idx;
+ int ret = 0;
+ loff_t isize = i_size_read(inode);
+
+ if (isize == 0)
+ goto out;
+
+ end_index = ((isize - 1) >> PAGE_CACHE_SHIFT);
+
+ /*
+ * Preallocate as many pages as we will need.
+ */
+ for (page_idx = 0; page_idx < nr_to_read; page_idx++) {
+ pgoff_t page_offset = offset + page_idx;
+
+ if (page_offset > end_index)
+ break;
+
+ rcu_read_lock();
+ page = radix_tree_lookup(&mapping->page_tree, page_offset);
+ rcu_read_unlock();
+ if (page)
+ continue;
+
+ page = page_cache_alloc_readahead(mapping);
+ if (!page)
+ break;
+ page->index = page_offset;
+ list_add(&page->lru, &page_pool);
+ if (page_idx == nr_to_read - lookahead_size)
+ SetPageReadahead(page);
+ ret++;
+ }
+
+ /*
+ * Now start the IO. We ignore I/O errors - if the page is not
+ * uptodate then the caller will launch readpage again, and
+ * will then handle the error.
+ */
+ if (ret)
+ read_pages(mapping, filp, &page_pool, ret);
+ BUG_ON(!list_empty(&page_pool));
+out:
+ return ret;
+}
+
+/*
+ * Chunk the readahead into 2 megabyte units, so that we don't pin too much
+ * memory at once.
+ */
+int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
+ pgoff_t offset, unsigned long nr_to_read)
+{
+ int ret = 0;
+
+ if (unlikely(!mapping->a_ops->readpage && !mapping->a_ops->readpages))
+ return -EINVAL;
+
+ nr_to_read = max_sane_readahead(nr_to_read);
+ while (nr_to_read) {
+ int err;
+
+ unsigned long this_chunk = (2 * 1024 * 1024) / PAGE_CACHE_SIZE;
+
+ if (this_chunk > nr_to_read)
+ this_chunk = nr_to_read;
+ err = __do_page_cache_readahead(mapping, filp,
+ offset, this_chunk, 0);
+ if (err < 0) {
+ ret = err;
+ break;
+ }
+ ret += err;
+ offset += this_chunk;
+ nr_to_read -= this_chunk;
+ }
+ return ret;
+}
+
+/*
+ * Given a desired number of PAGE_CACHE_SIZE readahead pages, return a
+ * sensible upper limit.
+ */
+unsigned long max_sane_readahead(unsigned long nr)
+{
+ return min(nr, (node_page_state(numa_node_id(), NR_INACTIVE_FILE)
+ + node_page_state(numa_node_id(), NR_FREE_PAGES)) / 2);
+}
+
+/*
+ * Submit IO for the read-ahead request in file_ra_state.
+ */
+unsigned long ra_submit(struct file_ra_state *ra,
+ struct address_space *mapping, struct file *filp)
+{
+ int actual;
+
+ actual = __do_page_cache_readahead(mapping, filp,
+ ra->start, ra->size, ra->async_size);
+
+ return actual;
+}
+
+/*
+ * Set the initial window size, round to next power of 2 and square
+ * for small size, x 4 for medium, and x 2 for large
+ * for 128k (32 page) max ra
+ * 1-8 page = 32k initial, > 8 page = 128k initial
+ */
+static unsigned long get_init_ra_size(unsigned long size, unsigned long max)
+{
+ unsigned long newsize = roundup_pow_of_two(size);
+
+ if (newsize <= max / 32)
+ newsize = newsize * 4;
+ else if (newsize <= max / 4)
+ newsize = newsize * 2;
+ else
+ newsize = max;
+
+ return newsize;
+}
+
+/*
+ * Get the previous window size, ramp it up, and
+ * return it as the new window size.
+ */
+static unsigned long get_next_ra_size(struct file_ra_state *ra,
+ unsigned long max)
+{
+ unsigned long cur = ra->size;
+ unsigned long newsize;
+
+ if (cur < max / 16)
+ newsize = 4 * cur;
+ else
+ newsize = 2 * cur;
+
+ return min(newsize, max);
+}
+
+/*
+ * On-demand readahead design.
+ *
+ * The fields in struct file_ra_state represent the most-recently-executed
+ * readahead attempt:
+ *
+ * |<----- async_size ---------|
+ * |------------------- size -------------------->|
+ * |==================#===========================|
+ * ^start ^page marked with PG_readahead
+ *
+ * To overlap application thinking time and disk I/O time, we do
+ * `readahead pipelining': Do not wait until the application consumed all
+ * readahead pages and stalled on the missing page at readahead_index;
+ * Instead, submit an asynchronous readahead I/O as soon as there are
+ * only async_size pages left in the readahead window. Normally async_size
+ * will be equal to size, for maximum pipelining.
+ *
+ * In interleaved sequential reads, concurrent streams on the same fd can
+ * be invalidating each other's readahead state. So we flag the new readahead
+ * page at (start+size-async_size) with PG_readahead, and use it as readahead
+ * indicator. The flag won't be set on already cached pages, to avoid the
+ * readahead-for-nothing fuss, saving pointless page cache lookups.
+ *
+ * prev_pos tracks the last visited byte in the _previous_ read request.
+ * It should be maintained by the caller, and will be used for detecting
+ * small random reads. Note that the readahead algorithm checks loosely
+ * for sequential patterns. Hence interleaved reads might be served as
+ * sequential ones.
+ *
+ * There is a special-case: if the first page which the application tries to
+ * read happens to be the first page of the file, it is assumed that a linear
+ * read is about to happen and the window is immediately set to the initial size
+ * based on I/O request size and the max_readahead.
+ *
+ * The code ramps up the readahead size aggressively at first, but slow down as
+ * it approaches max_readhead.
+ */
+
+/*
+ * Count contiguously cached pages from @offset-1 to @offset-@max,
+ * this count is a conservative estimation of
+ * - length of the sequential read sequence, or
+ * - thrashing threshold in memory tight systems
+ */
+static pgoff_t count_history_pages(struct address_space *mapping,
+ struct file_ra_state *ra,
+ pgoff_t offset, unsigned long max)
+{
+ pgoff_t head;
+
+ rcu_read_lock();
+ head = radix_tree_prev_hole(&mapping->page_tree, offset - 1, max);
+ rcu_read_unlock();
+
+ return offset - 1 - head;
+}
+
+/*
+ * page cache context based read-ahead
+ */
+static int try_context_readahead(struct address_space *mapping,
+ struct file_ra_state *ra,
+ pgoff_t offset,
+ unsigned long req_size,
+ unsigned long max)
+{
+ pgoff_t size;
+
+ size = count_history_pages(mapping, ra, offset, max);
+
+ /*
+ * no history pages:
+ * it could be a random read
+ */
+ if (!size)
+ return 0;
+
+ /*
+ * starts from beginning of file:
+ * it is a strong indication of long-run stream (or whole-file-read)
+ */
+ if (size >= offset)
+ size *= 2;
+
+ ra->start = offset;
+ ra->size = get_init_ra_size(size + req_size, max);
+ ra->async_size = ra->size;
+
+ return 1;
+}
+
+/*
+ * A minimal readahead algorithm for trivial sequential/random reads.
+ */
+static unsigned long
+ondemand_readahead(struct address_space *mapping,
+ struct file_ra_state *ra, struct file *filp,
+ bool hit_readahead_marker, pgoff_t offset,
+ unsigned long req_size)
+{
+ unsigned long max = max_sane_readahead(ra->ra_pages);
+
+ /*
+ * start of file
+ */
+ if (!offset)
+ goto initial_readahead;
+
+ /*
+ * It's the expected callback offset, assume sequential access.
+ * Ramp up sizes, and push forward the readahead window.
+ */
+ if ((offset == (ra->start + ra->size - ra->async_size) ||
+ offset == (ra->start + ra->size))) {
+ ra->start += ra->size;
+ ra->size = get_next_ra_size(ra, max);
+ ra->async_size = ra->size;
+ goto readit;
+ }
+
+ /*
+ * Hit a marked page without valid readahead state.
+ * E.g. interleaved reads.
+ * Query the pagecache for async_size, which normally equals to
+ * readahead size. Ramp it up and use it as the new readahead size.
+ */
+ if (hit_readahead_marker) {
+ pgoff_t start;
+
+ rcu_read_lock();
+ start = radix_tree_next_hole(&mapping->page_tree, offset+1,max);
+ rcu_read_unlock();
+
+ if (!start || start - offset > max)
+ return 0;
+
+ ra->start = start;
+ ra->size = start - offset; /* old async_size */
+ ra->size += req_size;
+ ra->size = get_next_ra_size(ra, max);
+ ra->async_size = ra->size;
+ goto readit;
+ }
+
+ /*
+ * oversize read
+ */
+ if (req_size > max)
+ goto initial_readahead;
+
+ /*
+ * sequential cache miss
+ */
+ if (offset - (ra->prev_pos >> PAGE_CACHE_SHIFT) <= 1UL)
+ goto initial_readahead;
+
+ /*
+ * Query the page cache and look for the traces(cached history pages)
+ * that a sequential stream would leave behind.
+ */
+ if (try_context_readahead(mapping, ra, offset, req_size, max))
+ goto readit;
+
+ /*
+ * standalone, small random read
+ * Read as is, and do not pollute the readahead state.
+ */
+ return __do_page_cache_readahead(mapping, filp, offset, req_size, 0);
+
+initial_readahead:
+ ra->start = offset;
+ ra->size = get_init_ra_size(req_size, max);
+ ra->async_size = ra->size > req_size ? ra->size - req_size : ra->size;
+
+readit:
+ /*
+ * Will this read hit the readahead marker made by itself?
+ * If so, trigger the readahead marker hit now, and merge
+ * the resulted next readahead window into the current one.
+ */
+ if (offset == ra->start && ra->size == ra->async_size) {
+ ra->async_size = get_next_ra_size(ra, max);
+ ra->size += ra->async_size;
+ }
+
+ return ra_submit(ra, mapping, filp);
+}
+
+/**
+ * page_cache_sync_readahead - generic file readahead
+ * @mapping: address_space which holds the pagecache and I/O vectors
+ * @ra: file_ra_state which holds the readahead state
+ * @filp: passed on to ->readpage() and ->readpages()
+ * @offset: start offset into @mapping, in pagecache page-sized units
+ * @req_size: hint: total size of the read which the caller is performing in
+ * pagecache pages
+ *
+ * page_cache_sync_readahead() should be called when a cache miss happened:
+ * it will submit the read. The readahead logic may decide to piggyback more
+ * pages onto the read request if access patterns suggest it will improve
+ * performance.
+ */
+void page_cache_sync_readahead(struct address_space *mapping,
+ struct file_ra_state *ra, struct file *filp,
+ pgoff_t offset, unsigned long req_size)
+{
+ /* no read-ahead */
+ if (!ra->ra_pages)
+ return;
+
+ /* be dumb */
+ if (filp && (filp->f_mode & FMODE_RANDOM)) {
+ force_page_cache_readahead(mapping, filp, offset, req_size);
+ return;
+ }
+
+ /* do read-ahead */
+ ondemand_readahead(mapping, ra, filp, false, offset, req_size);
+}
+EXPORT_SYMBOL_GPL(page_cache_sync_readahead);
+
+/**
+ * page_cache_async_readahead - file readahead for marked pages
+ * @mapping: address_space which holds the pagecache and I/O vectors
+ * @ra: file_ra_state which holds the readahead state
+ * @filp: passed on to ->readpage() and ->readpages()
+ * @page: the page at @offset which has the PG_readahead flag set
+ * @offset: start offset into @mapping, in pagecache page-sized units
+ * @req_size: hint: total size of the read which the caller is performing in
+ * pagecache pages
+ *
+ * page_cache_async_readahead() should be called when a page is used which
+ * has the PG_readahead flag; this is a marker to suggest that the application
+ * has used up enough of the readahead window that we should start pulling in
+ * more pages.
+ */
+void
+page_cache_async_readahead(struct address_space *mapping,
+ struct file_ra_state *ra, struct file *filp,
+ struct page *page, pgoff_t offset,
+ unsigned long req_size)
+{
+ /* no read-ahead */
+ if (!ra->ra_pages)
+ return;
+
+ /*
+ * Same bit is used for PG_readahead and PG_reclaim.
+ */
+ if (PageWriteback(page))
+ return;
+
+ ClearPageReadahead(page);
+
+ /*
+ * Defer asynchronous read-ahead on IO congestion.
+ */
+ if (bdi_read_congested(mapping->backing_dev_info))
+ return;
+
+ /* do read-ahead */
+ ondemand_readahead(mapping, ra, filp, true, offset, req_size);
+}
+EXPORT_SYMBOL_GPL(page_cache_async_readahead);
diff --git a/ap/os/linux/linux-3.4.x/mm/rmap.c b/ap/os/linux/linux-3.4.x/mm/rmap.c
new file mode 100644
index 0000000..57f503b
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/rmap.c
@@ -0,0 +1,1910 @@
+/*
+ * mm/rmap.c - physical to virtual reverse mappings
+ *
+ * Copyright 2001, Rik van Riel <riel@conectiva.com.br>
+ * Released under the General Public License (GPL).
+ *
+ * Simple, low overhead reverse mapping scheme.
+ * Please try to keep this thing as modular as possible.
+ *
+ * Provides methods for unmapping each kind of mapped page:
+ * the anon methods track anonymous pages, and
+ * the file methods track pages belonging to an inode.
+ *
+ * Original design by Rik van Riel <riel@conectiva.com.br> 2001
+ * File methods by Dave McCracken <dmccr@us.ibm.com> 2003, 2004
+ * Anonymous methods by Andrea Arcangeli <andrea@suse.de> 2004
+ * Contributions by Hugh Dickins 2003, 2004
+ */
+
+/*
+ * Lock ordering in mm:
+ *
+ * inode->i_mutex (while writing or truncating, not reading or faulting)
+ * mm->mmap_sem
+ * page->flags PG_locked (lock_page)
+ * mapping->i_mmap_mutex
+ * anon_vma->mutex
+ * mm->page_table_lock or pte_lock
+ * zone->lru_lock (in mark_page_accessed, isolate_lru_page)
+ * swap_lock (in swap_duplicate, swap_info_get)
+ * mmlist_lock (in mmput, drain_mmlist and others)
+ * mapping->private_lock (in __set_page_dirty_buffers)
+ * inode->i_lock (in set_page_dirty's __mark_inode_dirty)
+ * bdi.wb->list_lock (in set_page_dirty's __mark_inode_dirty)
+ * sb_lock (within inode_lock in fs/fs-writeback.c)
+ * mapping->tree_lock (widely used, in set_page_dirty,
+ * in arch-dependent flush_dcache_mmap_lock,
+ * within bdi.wb->list_lock in __sync_single_inode)
+ *
+ * anon_vma->mutex,mapping->i_mutex (memory_failure, collect_procs_anon)
+ * ->tasklist_lock
+ * pte map lock
+ */
+
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/ksm.h>
+#include <linux/rmap.h>
+#include <linux/rcupdate.h>
+#include <linux/export.h>
+#include <linux/memcontrol.h>
+#include <linux/mmu_notifier.h>
+#include <linux/migrate.h>
+#include <linux/hugetlb.h>
+#include <linux/backing-dev.h>
+
+#include <asm/tlbflush.h>
+
+#include "internal.h"
+
+static struct kmem_cache *anon_vma_cachep;
+static struct kmem_cache *anon_vma_chain_cachep;
+
+static inline struct anon_vma *anon_vma_alloc(void)
+{
+ struct anon_vma *anon_vma;
+
+ anon_vma = kmem_cache_alloc(anon_vma_cachep, GFP_KERNEL);
+ if (anon_vma) {
+ atomic_set(&anon_vma->refcount, 1);
+ anon_vma->degree = 1; /* Reference for first vma */
+ anon_vma->parent = anon_vma;
+ /*
+ * Initialise the anon_vma root to point to itself. If called
+ * from fork, the root will be reset to the parents anon_vma.
+ */
+ anon_vma->root = anon_vma;
+ }
+
+ return anon_vma;
+}
+
+static inline void anon_vma_free(struct anon_vma *anon_vma)
+{
+ VM_BUG_ON(atomic_read(&anon_vma->refcount));
+
+ /*
+ * Synchronize against page_lock_anon_vma() such that
+ * we can safely hold the lock without the anon_vma getting
+ * freed.
+ *
+ * Relies on the full mb implied by the atomic_dec_and_test() from
+ * put_anon_vma() against the acquire barrier implied by
+ * mutex_trylock() from page_lock_anon_vma(). This orders:
+ *
+ * page_lock_anon_vma() VS put_anon_vma()
+ * mutex_trylock() atomic_dec_and_test()
+ * LOCK MB
+ * atomic_read() mutex_is_locked()
+ *
+ * LOCK should suffice since the actual taking of the lock must
+ * happen _before_ what follows.
+ */
+ might_sleep();
+ if (mutex_is_locked(&anon_vma->root->mutex)) {
+ anon_vma_lock(anon_vma);
+ anon_vma_unlock(anon_vma);
+ }
+
+ kmem_cache_free(anon_vma_cachep, anon_vma);
+}
+
+static inline struct anon_vma_chain *anon_vma_chain_alloc(gfp_t gfp)
+{
+ return kmem_cache_alloc(anon_vma_chain_cachep, gfp);
+}
+
+static void anon_vma_chain_free(struct anon_vma_chain *anon_vma_chain)
+{
+ kmem_cache_free(anon_vma_chain_cachep, anon_vma_chain);
+}
+
+static void anon_vma_chain_link(struct vm_area_struct *vma,
+ struct anon_vma_chain *avc,
+ struct anon_vma *anon_vma)
+{
+ avc->vma = vma;
+ avc->anon_vma = anon_vma;
+ list_add(&avc->same_vma, &vma->anon_vma_chain);
+
+ /*
+ * It's critical to add new vmas to the tail of the anon_vma,
+ * see comment in huge_memory.c:__split_huge_page().
+ */
+ list_add_tail(&avc->same_anon_vma, &anon_vma->head);
+}
+
+/**
+ * anon_vma_prepare - attach an anon_vma to a memory region
+ * @vma: the memory region in question
+ *
+ * This makes sure the memory mapping described by 'vma' has
+ * an 'anon_vma' attached to it, so that we can associate the
+ * anonymous pages mapped into it with that anon_vma.
+ *
+ * The common case will be that we already have one, but if
+ * not we either need to find an adjacent mapping that we
+ * can re-use the anon_vma from (very common when the only
+ * reason for splitting a vma has been mprotect()), or we
+ * allocate a new one.
+ *
+ * Anon-vma allocations are very subtle, because we may have
+ * optimistically looked up an anon_vma in page_lock_anon_vma()
+ * and that may actually touch the spinlock even in the newly
+ * allocated vma (it depends on RCU to make sure that the
+ * anon_vma isn't actually destroyed).
+ *
+ * As a result, we need to do proper anon_vma locking even
+ * for the new allocation. At the same time, we do not want
+ * to do any locking for the common case of already having
+ * an anon_vma.
+ *
+ * This must be called with the mmap_sem held for reading.
+ */
+int anon_vma_prepare(struct vm_area_struct *vma)
+{
+ struct anon_vma *anon_vma = vma->anon_vma;
+ struct anon_vma_chain *avc;
+
+ might_sleep();
+ if (unlikely(!anon_vma)) {
+ struct mm_struct *mm = vma->vm_mm;
+ struct anon_vma *allocated;
+
+ avc = anon_vma_chain_alloc(GFP_KERNEL);
+ if (!avc)
+ goto out_enomem;
+
+ anon_vma = find_mergeable_anon_vma(vma);
+ allocated = NULL;
+ if (!anon_vma) {
+ anon_vma = anon_vma_alloc();
+ if (unlikely(!anon_vma))
+ goto out_enomem_free_avc;
+ allocated = anon_vma;
+ }
+
+ anon_vma_lock(anon_vma);
+ /* page_table_lock to protect against threads */
+ spin_lock(&mm->page_table_lock);
+ if (likely(!vma->anon_vma)) {
+ vma->anon_vma = anon_vma;
+ anon_vma_chain_link(vma, avc, anon_vma);
+ /* vma reference or self-parent link for new root */
+ anon_vma->degree++;
+ allocated = NULL;
+ avc = NULL;
+ }
+ spin_unlock(&mm->page_table_lock);
+ anon_vma_unlock(anon_vma);
+
+ if (unlikely(allocated))
+ put_anon_vma(allocated);
+ if (unlikely(avc))
+ anon_vma_chain_free(avc);
+ }
+ return 0;
+
+ out_enomem_free_avc:
+ anon_vma_chain_free(avc);
+ out_enomem:
+ return -ENOMEM;
+}
+
+/*
+ * This is a useful helper function for locking the anon_vma root as
+ * we traverse the vma->anon_vma_chain, looping over anon_vma's that
+ * have the same vma.
+ *
+ * Such anon_vma's should have the same root, so you'd expect to see
+ * just a single mutex_lock for the whole traversal.
+ */
+static inline struct anon_vma *lock_anon_vma_root(struct anon_vma *root, struct anon_vma *anon_vma)
+{
+ struct anon_vma *new_root = anon_vma->root;
+ if (new_root != root) {
+ if (WARN_ON_ONCE(root))
+ mutex_unlock(&root->mutex);
+ root = new_root;
+ mutex_lock(&root->mutex);
+ }
+ return root;
+}
+
+static inline void unlock_anon_vma_root(struct anon_vma *root)
+{
+ if (root)
+ mutex_unlock(&root->mutex);
+}
+
+/*
+ * Attach the anon_vmas from src to dst.
+ * Returns 0 on success, -ENOMEM on failure.
+ *
+ * If dst->anon_vma is NULL this function tries to find and reuse existing
+ * anon_vma which has no vmas and only one child anon_vma. This prevents
+ * degradation of anon_vma hierarchy to endless linear chain in case of
+ * constantly forking task. On the other hand, an anon_vma with more than one
+ * child isn't reused even if there was no alive vma, thus rmap walker has a
+ * good chance of avoiding scanning the whole hierarchy when it searches where
+ * page is mapped.
+ */
+int anon_vma_clone(struct vm_area_struct *dst, struct vm_area_struct *src)
+{
+ struct anon_vma_chain *avc, *pavc;
+ struct anon_vma *root = NULL;
+
+ list_for_each_entry_reverse(pavc, &src->anon_vma_chain, same_vma) {
+ struct anon_vma *anon_vma;
+
+ avc = anon_vma_chain_alloc(GFP_NOWAIT | __GFP_NOWARN);
+ if (unlikely(!avc)) {
+ unlock_anon_vma_root(root);
+ root = NULL;
+ avc = anon_vma_chain_alloc(GFP_KERNEL);
+ if (!avc)
+ goto enomem_failure;
+ }
+ anon_vma = pavc->anon_vma;
+ root = lock_anon_vma_root(root, anon_vma);
+ anon_vma_chain_link(dst, avc, anon_vma);
+
+ /*
+ * Reuse existing anon_vma if its degree lower than two,
+ * that means it has no vma and only one anon_vma child.
+ *
+ * Do not chose parent anon_vma, otherwise first child
+ * will always reuse it. Root anon_vma is never reused:
+ * it has self-parent reference and at least one child.
+ */
+ if (!dst->anon_vma && anon_vma != src->anon_vma &&
+ anon_vma->degree < 2)
+ dst->anon_vma = anon_vma;
+ }
+ if (dst->anon_vma)
+ dst->anon_vma->degree++;
+ unlock_anon_vma_root(root);
+ return 0;
+
+ enomem_failure:
+ /*
+ * dst->anon_vma is dropped here otherwise its degree can be incorrectly
+ * decremented in unlink_anon_vmas().
+ * We can safely do this because callers of anon_vma_clone() don't care
+ * about dst->anon_vma if anon_vma_clone() failed.
+ */
+ dst->anon_vma = NULL;
+ unlink_anon_vmas(dst);
+ return -ENOMEM;
+}
+
+/*
+ * Some rmap walk that needs to find all ptes/hugepmds without false
+ * negatives (like migrate and split_huge_page) running concurrent
+ * with operations that copy or move pagetables (like mremap() and
+ * fork()) to be safe. They depend on the anon_vma "same_anon_vma"
+ * list to be in a certain order: the dst_vma must be placed after the
+ * src_vma in the list. This is always guaranteed by fork() but
+ * mremap() needs to call this function to enforce it in case the
+ * dst_vma isn't newly allocated and chained with the anon_vma_clone()
+ * function but just an extension of a pre-existing vma through
+ * vma_merge.
+ *
+ * NOTE: the same_anon_vma list can still be changed by other
+ * processes while mremap runs because mremap doesn't hold the
+ * anon_vma mutex to prevent modifications to the list while it
+ * runs. All we need to enforce is that the relative order of this
+ * process vmas isn't changing (we don't care about other vmas
+ * order). Each vma corresponds to an anon_vma_chain structure so
+ * there's no risk that other processes calling anon_vma_moveto_tail()
+ * and changing the same_anon_vma list under mremap() will screw with
+ * the relative order of this process vmas in the list, because we
+ * they can't alter the order of any vma that belongs to this
+ * process. And there can't be another anon_vma_moveto_tail() running
+ * concurrently with mremap() coming from this process because we hold
+ * the mmap_sem for the whole mremap(). fork() ordering dependency
+ * also shouldn't be affected because fork() only cares that the
+ * parent vmas are placed in the list before the child vmas and
+ * anon_vma_moveto_tail() won't reorder vmas from either the fork()
+ * parent or child.
+ */
+void anon_vma_moveto_tail(struct vm_area_struct *dst)
+{
+ struct anon_vma_chain *pavc;
+ struct anon_vma *root = NULL;
+
+ list_for_each_entry_reverse(pavc, &dst->anon_vma_chain, same_vma) {
+ struct anon_vma *anon_vma = pavc->anon_vma;
+ VM_BUG_ON(pavc->vma != dst);
+ root = lock_anon_vma_root(root, anon_vma);
+ list_del(&pavc->same_anon_vma);
+ list_add_tail(&pavc->same_anon_vma, &anon_vma->head);
+ }
+ unlock_anon_vma_root(root);
+}
+
+/*
+ * Attach vma to its own anon_vma, as well as to the anon_vmas that
+ * the corresponding VMA in the parent process is attached to.
+ * Returns 0 on success, non-zero on failure.
+ */
+int anon_vma_fork(struct vm_area_struct *vma, struct vm_area_struct *pvma)
+{
+ struct anon_vma_chain *avc;
+ struct anon_vma *anon_vma;
+
+ /* Don't bother if the parent process has no anon_vma here. */
+ if (!pvma->anon_vma)
+ return 0;
+
+ /* Drop inherited anon_vma, we'll reuse existing or allocate new. */
+ vma->anon_vma = NULL;
+
+ /*
+ * First, attach the new VMA to the parent VMA's anon_vmas,
+ * so rmap can find non-COWed pages in child processes.
+ */
+ if (anon_vma_clone(vma, pvma))
+ return -ENOMEM;
+
+ /* An existing anon_vma has been reused, all done then. */
+ if (vma->anon_vma)
+ return 0;
+
+ /* Then add our own anon_vma. */
+ anon_vma = anon_vma_alloc();
+ if (!anon_vma)
+ goto out_error;
+ avc = anon_vma_chain_alloc(GFP_KERNEL);
+ if (!avc)
+ goto out_error_free_anon_vma;
+
+ /*
+ * The root anon_vma's spinlock is the lock actually used when we
+ * lock any of the anon_vmas in this anon_vma tree.
+ */
+ anon_vma->root = pvma->anon_vma->root;
+ anon_vma->parent = pvma->anon_vma;
+ /*
+ * With refcounts, an anon_vma can stay around longer than the
+ * process it belongs to. The root anon_vma needs to be pinned until
+ * this anon_vma is freed, because the lock lives in the root.
+ */
+ get_anon_vma(anon_vma->root);
+ /* Mark this anon_vma as the one where our new (COWed) pages go. */
+ vma->anon_vma = anon_vma;
+ anon_vma_lock(anon_vma);
+ anon_vma_chain_link(vma, avc, anon_vma);
+ anon_vma->parent->degree++;
+ anon_vma_unlock(anon_vma);
+
+ return 0;
+
+ out_error_free_anon_vma:
+ put_anon_vma(anon_vma);
+ out_error:
+ unlink_anon_vmas(vma);
+ return -ENOMEM;
+}
+
+void unlink_anon_vmas(struct vm_area_struct *vma)
+{
+ struct anon_vma_chain *avc, *next;
+ struct anon_vma *root = NULL;
+
+ /*
+ * Unlink each anon_vma chained to the VMA. This list is ordered
+ * from newest to oldest, ensuring the root anon_vma gets freed last.
+ */
+ list_for_each_entry_safe(avc, next, &vma->anon_vma_chain, same_vma) {
+ struct anon_vma *anon_vma = avc->anon_vma;
+
+ root = lock_anon_vma_root(root, anon_vma);
+ list_del(&avc->same_anon_vma);
+
+ /*
+ * Leave empty anon_vmas on the list - we'll need
+ * to free them outside the lock.
+ */
+ if (list_empty(&anon_vma->head)) {
+ anon_vma->parent->degree--;
+ continue;
+ }
+
+ list_del(&avc->same_vma);
+ anon_vma_chain_free(avc);
+ }
+ if (vma->anon_vma)
+ vma->anon_vma->degree--;
+ unlock_anon_vma_root(root);
+
+ /*
+ * Iterate the list once more, it now only contains empty and unlinked
+ * anon_vmas, destroy them. Could not do before due to __put_anon_vma()
+ * needing to acquire the anon_vma->root->mutex.
+ */
+ list_for_each_entry_safe(avc, next, &vma->anon_vma_chain, same_vma) {
+ struct anon_vma *anon_vma = avc->anon_vma;
+
+ BUG_ON(anon_vma->degree);
+ put_anon_vma(anon_vma);
+
+ list_del(&avc->same_vma);
+ anon_vma_chain_free(avc);
+ }
+}
+
+static void anon_vma_ctor(void *data)
+{
+ struct anon_vma *anon_vma = data;
+
+ mutex_init(&anon_vma->mutex);
+ atomic_set(&anon_vma->refcount, 0);
+ INIT_LIST_HEAD(&anon_vma->head);
+}
+
+void __init anon_vma_init(void)
+{
+ anon_vma_cachep = kmem_cache_create("anon_vma", sizeof(struct anon_vma),
+ 0, SLAB_DESTROY_BY_RCU|SLAB_PANIC, anon_vma_ctor);
+ anon_vma_chain_cachep = KMEM_CACHE(anon_vma_chain, SLAB_PANIC);
+}
+
+/*
+ * Getting a lock on a stable anon_vma from a page off the LRU is tricky!
+ *
+ * Since there is no serialization what so ever against page_remove_rmap()
+ * the best this function can do is return a locked anon_vma that might
+ * have been relevant to this page.
+ *
+ * The page might have been remapped to a different anon_vma or the anon_vma
+ * returned may already be freed (and even reused).
+ *
+ * In case it was remapped to a different anon_vma, the new anon_vma will be a
+ * child of the old anon_vma, and the anon_vma lifetime rules will therefore
+ * ensure that any anon_vma obtained from the page will still be valid for as
+ * long as we observe page_mapped() [ hence all those page_mapped() tests ].
+ *
+ * All users of this function must be very careful when walking the anon_vma
+ * chain and verify that the page in question is indeed mapped in it
+ * [ something equivalent to page_mapped_in_vma() ].
+ *
+ * Since anon_vma's slab is DESTROY_BY_RCU and we know from page_remove_rmap()
+ * that the anon_vma pointer from page->mapping is valid if there is a
+ * mapcount, we can dereference the anon_vma after observing those.
+ */
+struct anon_vma *page_get_anon_vma(struct page *page)
+{
+ struct anon_vma *anon_vma = NULL;
+ unsigned long anon_mapping;
+
+ rcu_read_lock();
+ anon_mapping = (unsigned long) ACCESS_ONCE(page->mapping);
+ if ((anon_mapping & PAGE_MAPPING_FLAGS) != PAGE_MAPPING_ANON)
+ goto out;
+ if (!page_mapped(page))
+ goto out;
+
+ anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);
+ if (!atomic_inc_not_zero(&anon_vma->refcount)) {
+ anon_vma = NULL;
+ goto out;
+ }
+
+ /*
+ * If this page is still mapped, then its anon_vma cannot have been
+ * freed. But if it has been unmapped, we have no security against the
+ * anon_vma structure being freed and reused (for another anon_vma:
+ * SLAB_DESTROY_BY_RCU guarantees that - so the atomic_inc_not_zero()
+ * above cannot corrupt).
+ */
+ if (!page_mapped(page)) {
+ rcu_read_unlock();
+ put_anon_vma(anon_vma);
+ return NULL;
+ }
+out:
+ rcu_read_unlock();
+
+ return anon_vma;
+}
+
+/*
+ * Similar to page_get_anon_vma() except it locks the anon_vma.
+ *
+ * Its a little more complex as it tries to keep the fast path to a single
+ * atomic op -- the trylock. If we fail the trylock, we fall back to getting a
+ * reference like with page_get_anon_vma() and then block on the mutex.
+ */
+struct anon_vma *page_lock_anon_vma(struct page *page)
+{
+ struct anon_vma *anon_vma = NULL;
+ struct anon_vma *root_anon_vma;
+ unsigned long anon_mapping;
+
+ rcu_read_lock();
+ anon_mapping = (unsigned long) ACCESS_ONCE(page->mapping);
+ if ((anon_mapping & PAGE_MAPPING_FLAGS) != PAGE_MAPPING_ANON)
+ goto out;
+ if (!page_mapped(page))
+ goto out;
+
+ anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);
+ root_anon_vma = ACCESS_ONCE(anon_vma->root);
+ if (mutex_trylock(&root_anon_vma->mutex)) {
+ /*
+ * If the page is still mapped, then this anon_vma is still
+ * its anon_vma, and holding the mutex ensures that it will
+ * not go away, see anon_vma_free().
+ */
+ if (!page_mapped(page)) {
+ mutex_unlock(&root_anon_vma->mutex);
+ anon_vma = NULL;
+ }
+ goto out;
+ }
+
+ /* trylock failed, we got to sleep */
+ if (!atomic_inc_not_zero(&anon_vma->refcount)) {
+ anon_vma = NULL;
+ goto out;
+ }
+
+ if (!page_mapped(page)) {
+ rcu_read_unlock();
+ put_anon_vma(anon_vma);
+ return NULL;
+ }
+
+ /* we pinned the anon_vma, its safe to sleep */
+ rcu_read_unlock();
+ anon_vma_lock(anon_vma);
+
+ if (atomic_dec_and_test(&anon_vma->refcount)) {
+ /*
+ * Oops, we held the last refcount, release the lock
+ * and bail -- can't simply use put_anon_vma() because
+ * we'll deadlock on the anon_vma_lock() recursion.
+ */
+ anon_vma_unlock(anon_vma);
+ __put_anon_vma(anon_vma);
+ anon_vma = NULL;
+ }
+
+ return anon_vma;
+
+out:
+ rcu_read_unlock();
+ return anon_vma;
+}
+
+void page_unlock_anon_vma(struct anon_vma *anon_vma)
+{
+ anon_vma_unlock(anon_vma);
+}
+
+/*
+ * At what user virtual address is page expected in @vma?
+ * Returns virtual address or -EFAULT if page's index/offset is not
+ * within the range mapped the @vma.
+ */
+inline unsigned long
+vma_address(struct page *page, struct vm_area_struct *vma)
+{
+ pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ unsigned long address;
+
+ if (unlikely(is_vm_hugetlb_page(vma)))
+ pgoff = page->index << huge_page_order(page_hstate(page));
+ address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+ if (unlikely(address < vma->vm_start || address >= vma->vm_end)) {
+ /* page should be within @vma mapping range */
+ return -EFAULT;
+ }
+ return address;
+}
+
+/*
+ * At what user virtual address is page expected in vma?
+ * Caller should check the page is actually part of the vma.
+ */
+unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
+{
+ if (PageAnon(page)) {
+ struct anon_vma *page__anon_vma = page_anon_vma(page);
+ /*
+ * Note: swapoff's unuse_vma() is more efficient with this
+ * check, and needs it to match anon_vma when KSM is active.
+ */
+ if (!vma->anon_vma || !page__anon_vma ||
+ vma->anon_vma->root != page__anon_vma->root)
+ return -EFAULT;
+ } else if (page->mapping && !(vma->vm_flags & VM_NONLINEAR)) {
+ if (!vma->vm_file ||
+ vma->vm_file->f_mapping != page->mapping)
+ return -EFAULT;
+ } else
+ return -EFAULT;
+ return vma_address(page, vma);
+}
+
+/*
+ * Check that @page is mapped at @address into @mm.
+ *
+ * If @sync is false, page_check_address may perform a racy check to avoid
+ * the page table lock when the pte is not present (helpful when reclaiming
+ * highly shared pages).
+ *
+ * On success returns with pte mapped and locked.
+ */
+pte_t *__page_check_address(struct page *page, struct mm_struct *mm,
+ unsigned long address, spinlock_t **ptlp, int sync)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ if (unlikely(PageHuge(page))) {
+ /* when pud is not present, pte will be NULL */
+ pte = huge_pte_offset(mm, address);
+ if (!pte)
+ return NULL;
+
+ ptl = &mm->page_table_lock;
+ goto check;
+ }
+
+ pgd = pgd_offset(mm, address);
+ if (!pgd_present(*pgd))
+ return NULL;
+
+ pud = pud_offset(pgd, address);
+ if (!pud_present(*pud))
+ return NULL;
+
+ pmd = pmd_offset(pud, address);
+ if (!pmd_present(*pmd))
+ return NULL;
+ if (pmd_trans_huge(*pmd))
+ return NULL;
+
+ pte = pte_offset_map(pmd, address);
+ /* Make a quick check before getting the lock */
+ if (!sync && !pte_present(*pte)) {
+ pte_unmap(pte);
+ return NULL;
+ }
+
+ ptl = pte_lockptr(mm, pmd);
+check:
+ spin_lock(ptl);
+ if (pte_present(*pte) && page_to_pfn(page) == pte_pfn(*pte)) {
+ *ptlp = ptl;
+ return pte;
+ }
+ pte_unmap_unlock(pte, ptl);
+ return NULL;
+}
+
+/**
+ * page_mapped_in_vma - check whether a page is really mapped in a VMA
+ * @page: the page to test
+ * @vma: the VMA to test
+ *
+ * Returns 1 if the page is mapped into the page tables of the VMA, 0
+ * if the page is not mapped into the page tables of this VMA. Only
+ * valid for normal file or anonymous VMAs.
+ */
+int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
+{
+ unsigned long address;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ address = vma_address(page, vma);
+ if (address == -EFAULT) /* out of vma range */
+ return 0;
+ pte = page_check_address(page, vma->vm_mm, address, &ptl, 1);
+ if (!pte) /* the page is not in this mm */
+ return 0;
+ pte_unmap_unlock(pte, ptl);
+
+ return 1;
+}
+
+/*
+ * Subfunctions of page_referenced: page_referenced_one called
+ * repeatedly from either page_referenced_anon or page_referenced_file.
+ */
+int page_referenced_one(struct page *page, struct vm_area_struct *vma,
+ unsigned long address, unsigned int *mapcount,
+ unsigned long *vm_flags)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int referenced = 0;
+
+ if (unlikely(PageTransHuge(page))) {
+ pmd_t *pmd;
+
+ spin_lock(&mm->page_table_lock);
+ /*
+ * rmap might return false positives; we must filter
+ * these out using page_check_address_pmd().
+ */
+ pmd = page_check_address_pmd(page, mm, address,
+ PAGE_CHECK_ADDRESS_PMD_FLAG);
+ if (!pmd) {
+ spin_unlock(&mm->page_table_lock);
+ goto out;
+ }
+
+ if (vma->vm_flags & VM_LOCKED) {
+ spin_unlock(&mm->page_table_lock);
+ *mapcount = 0; /* break early from loop */
+ *vm_flags |= VM_LOCKED;
+ goto out;
+ }
+
+ /* go ahead even if the pmd is pmd_trans_splitting() */
+ if (pmdp_clear_flush_young_notify(vma, address, pmd))
+ referenced++;
+ spin_unlock(&mm->page_table_lock);
+ } else {
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ /*
+ * rmap might return false positives; we must filter
+ * these out using page_check_address().
+ */
+ pte = page_check_address(page, mm, address, &ptl, 0);
+ if (!pte)
+ goto out;
+
+ if (vma->vm_flags & VM_LOCKED) {
+ pte_unmap_unlock(pte, ptl);
+ *mapcount = 0; /* break early from loop */
+ *vm_flags |= VM_LOCKED;
+ goto out;
+ }
+
+ if (ptep_clear_flush_young_notify(vma, address, pte)) {
+ /*
+ * Don't treat a reference through a sequentially read
+ * mapping as such. If the page has been used in
+ * another mapping, we will catch it; if this other
+ * mapping is already gone, the unmap path will have
+ * set PG_referenced or activated the page.
+ */
+ if (likely(!VM_SequentialReadHint(vma)))
+ referenced++;
+ }
+ pte_unmap_unlock(pte, ptl);
+ }
+
+ /* Pretend the page is referenced if the task has the
+ swap token and is in the middle of a page fault. */
+ if (mm != current->mm && has_swap_token(mm) &&
+ rwsem_is_locked(&mm->mmap_sem))
+ referenced++;
+
+ (*mapcount)--;
+
+ if (referenced)
+ *vm_flags |= vma->vm_flags;
+out:
+ return referenced;
+}
+
+static int page_referenced_anon(struct page *page,
+ struct mem_cgroup *memcg,
+ unsigned long *vm_flags)
+{
+ unsigned int mapcount;
+ struct anon_vma *anon_vma;
+ struct anon_vma_chain *avc;
+ int referenced = 0;
+
+ anon_vma = page_lock_anon_vma(page);
+ if (!anon_vma)
+ return referenced;
+
+ mapcount = page_mapcount(page);
+ list_for_each_entry(avc, &anon_vma->head, same_anon_vma) {
+ struct vm_area_struct *vma = avc->vma;
+ unsigned long address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
+ /*
+ * If we are reclaiming on behalf of a cgroup, skip
+ * counting on behalf of references from different
+ * cgroups
+ */
+ if (memcg && !mm_match_cgroup(vma->vm_mm, memcg))
+ continue;
+ referenced += page_referenced_one(page, vma, address,
+ &mapcount, vm_flags);
+ if (!mapcount)
+ break;
+ }
+
+ page_unlock_anon_vma(anon_vma);
+ return referenced;
+}
+
+/**
+ * page_referenced_file - referenced check for object-based rmap
+ * @page: the page we're checking references on.
+ * @memcg: target memory control group
+ * @vm_flags: collect encountered vma->vm_flags who actually referenced the page
+ *
+ * For an object-based mapped page, find all the places it is mapped and
+ * check/clear the referenced flag. This is done by following the page->mapping
+ * pointer, then walking the chain of vmas it holds. It returns the number
+ * of references it found.
+ *
+ * This function is only called from page_referenced for object-based pages.
+ */
+static int page_referenced_file(struct page *page,
+ struct mem_cgroup *memcg,
+ unsigned long *vm_flags)
+{
+ unsigned int mapcount;
+ struct address_space *mapping = page->mapping;
+ pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ struct vm_area_struct *vma;
+ struct prio_tree_iter iter;
+ int referenced = 0;
+
+ /*
+ * The caller's checks on page->mapping and !PageAnon have made
+ * sure that this is a file page: the check for page->mapping
+ * excludes the case just before it gets set on an anon page.
+ */
+ BUG_ON(PageAnon(page));
+
+ /*
+ * The page lock not only makes sure that page->mapping cannot
+ * suddenly be NULLified by truncation, it makes sure that the
+ * structure at mapping cannot be freed and reused yet,
+ * so we can safely take mapping->i_mmap_mutex.
+ */
+ BUG_ON(!PageLocked(page));
+
+ mutex_lock(&mapping->i_mmap_mutex);
+
+ /*
+ * i_mmap_mutex does not stabilize mapcount at all, but mapcount
+ * is more likely to be accurate if we note it after spinning.
+ */
+ mapcount = page_mapcount(page);
+
+ vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+ unsigned long address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
+ /*
+ * If we are reclaiming on behalf of a cgroup, skip
+ * counting on behalf of references from different
+ * cgroups
+ */
+ if (memcg && !mm_match_cgroup(vma->vm_mm, memcg))
+ continue;
+ referenced += page_referenced_one(page, vma, address,
+ &mapcount, vm_flags);
+ if (!mapcount)
+ break;
+ }
+
+ mutex_unlock(&mapping->i_mmap_mutex);
+ return referenced;
+}
+
+/**
+ * page_referenced - test if the page was referenced
+ * @page: the page to test
+ * @is_locked: caller holds lock on the page
+ * @memcg: target memory cgroup
+ * @vm_flags: collect encountered vma->vm_flags who actually referenced the page
+ *
+ * Quick test_and_clear_referenced for all mappings to a page,
+ * returns the number of ptes which referenced the page.
+ */
+int page_referenced(struct page *page,
+ int is_locked,
+ struct mem_cgroup *memcg,
+ unsigned long *vm_flags)
+{
+ int referenced = 0;
+ int we_locked = 0;
+
+ *vm_flags = 0;
+ if (page_mapped(page) && page_rmapping(page)) {
+ if (!is_locked && (!PageAnon(page) || PageKsm(page))) {
+ we_locked = trylock_page(page);
+ if (!we_locked) {
+ referenced++;
+ goto out;
+ }
+ }
+ if (unlikely(PageKsm(page)))
+ referenced += page_referenced_ksm(page, memcg,
+ vm_flags);
+ else if (PageAnon(page))
+ referenced += page_referenced_anon(page, memcg,
+ vm_flags);
+ else if (page->mapping)
+ referenced += page_referenced_file(page, memcg,
+ vm_flags);
+ if (we_locked)
+ unlock_page(page);
+
+ if (page_test_and_clear_young(page_to_pfn(page)))
+ referenced++;
+ }
+out:
+ return referenced;
+}
+
+static int page_mkclean_one(struct page *page, struct vm_area_struct *vma,
+ unsigned long address)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pte_t *pte;
+ spinlock_t *ptl;
+ int ret = 0;
+
+ pte = page_check_address(page, mm, address, &ptl, 1);
+ if (!pte)
+ goto out;
+
+ if (pte_dirty(*pte) || pte_write(*pte)) {
+ pte_t entry;
+
+ flush_cache_page(vma, address, pte_pfn(*pte));
+ entry = ptep_clear_flush_notify(vma, address, pte);
+ entry = pte_wrprotect(entry);
+ entry = pte_mkclean(entry);
+ set_pte_at(mm, address, pte, entry);
+ ret = 1;
+ }
+
+ pte_unmap_unlock(pte, ptl);
+out:
+ return ret;
+}
+
+static int page_mkclean_file(struct address_space *mapping, struct page *page)
+{
+ pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ struct vm_area_struct *vma;
+ struct prio_tree_iter iter;
+ int ret = 0;
+
+ BUG_ON(PageAnon(page));
+
+ mutex_lock(&mapping->i_mmap_mutex);
+ vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+ if (vma->vm_flags & VM_SHARED) {
+ unsigned long address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
+ ret += page_mkclean_one(page, vma, address);
+ }
+ }
+ mutex_unlock(&mapping->i_mmap_mutex);
+ return ret;
+}
+
+int page_mkclean(struct page *page)
+{
+ int ret = 0;
+
+ BUG_ON(!PageLocked(page));
+
+ if (page_mapped(page)) {
+ struct address_space *mapping = page_mapping(page);
+ if (mapping)
+ ret = page_mkclean_file(mapping, page);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(page_mkclean);
+
+/**
+ * page_move_anon_rmap - move a page to our anon_vma
+ * @page: the page to move to our anon_vma
+ * @vma: the vma the page belongs to
+ * @address: the user virtual address mapped
+ *
+ * When a page belongs exclusively to one process after a COW event,
+ * that page can be moved into the anon_vma that belongs to just that
+ * process, so the rmap code will not search the parent or sibling
+ * processes.
+ */
+void page_move_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ struct anon_vma *anon_vma = vma->anon_vma;
+
+ VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON(!anon_vma);
+ VM_BUG_ON(page->index != linear_page_index(vma, address));
+
+ anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
+ page->mapping = (struct address_space *) anon_vma;
+}
+
+/**
+ * __page_set_anon_rmap - set up new anonymous rmap
+ * @page: Page to add to rmap
+ * @vma: VM area to add page to.
+ * @address: User virtual address of the mapping
+ * @exclusive: the page is exclusively owned by the current process
+ */
+static void __page_set_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address, int exclusive)
+{
+ struct anon_vma *anon_vma = vma->anon_vma;
+
+ BUG_ON(!anon_vma);
+
+ if (PageAnon(page))
+ return;
+
+ /*
+ * If the page isn't exclusively mapped into this vma,
+ * we must use the _oldest_ possible anon_vma for the
+ * page mapping!
+ */
+ if (!exclusive)
+ anon_vma = anon_vma->root;
+
+ anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
+ page->mapping = (struct address_space *) anon_vma;
+ page->index = linear_page_index(vma, address);
+}
+
+/**
+ * __page_check_anon_rmap - sanity check anonymous rmap addition
+ * @page: the page to add the mapping to
+ * @vma: the vm area in which the mapping is added
+ * @address: the user virtual address mapped
+ */
+static void __page_check_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address)
+{
+#ifdef CONFIG_DEBUG_VM
+ /*
+ * The page's anon-rmap details (mapping and index) are guaranteed to
+ * be set up correctly at this point.
+ *
+ * We have exclusion against page_add_anon_rmap because the caller
+ * always holds the page locked, except if called from page_dup_rmap,
+ * in which case the page is already known to be setup.
+ *
+ * We have exclusion against page_add_new_anon_rmap because those pages
+ * are initially only visible via the pagetables, and the pte is locked
+ * over the call to page_add_new_anon_rmap.
+ */
+ BUG_ON(page_anon_vma(page)->root != vma->anon_vma->root);
+ BUG_ON(page->index != linear_page_index(vma, address));
+#endif
+}
+
+/**
+ * page_add_anon_rmap - add pte mapping to an anonymous page
+ * @page: the page to add the mapping to
+ * @vma: the vm area in which the mapping is added
+ * @address: the user virtual address mapped
+ *
+ * The caller needs to hold the pte lock, and the page must be locked in
+ * the anon_vma case: to serialize mapping,index checking after setting,
+ * and to ensure that PageAnon is not being upgraded racily to PageKsm
+ * (but PageKsm is never downgraded to PageAnon).
+ */
+void page_add_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ do_page_add_anon_rmap(page, vma, address, 0);
+}
+
+/*
+ * Special version of the above for do_swap_page, which often runs
+ * into pages that are exclusively owned by the current process.
+ * Everybody else should continue to use page_add_anon_rmap above.
+ */
+void do_page_add_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address, int exclusive)
+{
+ int first = atomic_inc_and_test(&page->_mapcount);
+ if (first) {
+ if (!PageTransHuge(page))
+ __inc_zone_page_state(page, NR_ANON_PAGES);
+ else
+ __inc_zone_page_state(page,
+ NR_ANON_TRANSPARENT_HUGEPAGES);
+ }
+ if (unlikely(PageKsm(page)))
+ return;
+
+ VM_BUG_ON(!PageLocked(page));
+ /* address might be in next vma when migration races vma_adjust */
+ if (first)
+ __page_set_anon_rmap(page, vma, address, exclusive);
+ else
+ __page_check_anon_rmap(page, vma, address);
+}
+
+/**
+ * page_add_new_anon_rmap - add pte mapping to a new anonymous page
+ * @page: the page to add the mapping to
+ * @vma: the vm area in which the mapping is added
+ * @address: the user virtual address mapped
+ *
+ * Same as page_add_anon_rmap but must only be called on *new* pages.
+ * This means the inc-and-test can be bypassed.
+ * Page does not have to be locked.
+ */
+void page_add_new_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+ SetPageSwapBacked(page);
+ atomic_set(&page->_mapcount, 0); /* increment count (starts at -1) */
+ if (!PageTransHuge(page))
+ __inc_zone_page_state(page, NR_ANON_PAGES);
+ else
+ __inc_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
+ __page_set_anon_rmap(page, vma, address, 1);
+ if (page_evictable(page, vma))
+ lru_cache_add_lru(page, LRU_ACTIVE_ANON);
+ else
+ add_page_to_unevictable_list(page);
+}
+
+/**
+ * page_add_file_rmap - add pte mapping to a file page
+ * @page: the page to add the mapping to
+ *
+ * The caller needs to hold the pte lock.
+ */
+void page_add_file_rmap(struct page *page)
+{
+ bool locked;
+ unsigned long flags;
+
+ mem_cgroup_begin_update_page_stat(page, &locked, &flags);
+ if (atomic_inc_and_test(&page->_mapcount)) {
+ __inc_zone_page_state(page, NR_FILE_MAPPED);
+ mem_cgroup_inc_page_stat(page, MEMCG_NR_FILE_MAPPED);
+ }
+ mem_cgroup_end_update_page_stat(page, &locked, &flags);
+}
+
+/**
+ * page_remove_rmap - take down pte mapping from a page
+ * @page: page to remove mapping from
+ *
+ * The caller needs to hold the pte lock.
+ */
+void page_remove_rmap(struct page *page)
+{
+ struct address_space *mapping = page_mapping(page);
+ bool anon = PageAnon(page);
+ bool locked;
+ unsigned long flags;
+
+ /*
+ * The anon case has no mem_cgroup page_stat to update; but may
+ * uncharge_page() below, where the lock ordering can deadlock if
+ * we hold the lock against page_stat move: so avoid it on anon.
+ */
+ if (!anon)
+ mem_cgroup_begin_update_page_stat(page, &locked, &flags);
+
+ /* page still mapped by someone else? */
+ if (!atomic_add_negative(-1, &page->_mapcount))
+ goto out;
+
+ /*
+ * Now that the last pte has gone, s390 must transfer dirty
+ * flag from storage key to struct page. We can usually skip
+ * this if the page is anon, so about to be freed; but perhaps
+ * not if it's in swapcache - there might be another pte slot
+ * containing the swap entry, but page not yet written to swap.
+ *
+ * And we can skip it on file pages, so long as the filesystem
+ * participates in dirty tracking; but need to catch shm and tmpfs
+ * and ramfs pages which have been modified since creation by read
+ * fault.
+ *
+ * Note that mapping must be decided above, before decrementing
+ * mapcount (which luckily provides a barrier): once page is unmapped,
+ * it could be truncated and page->mapping reset to NULL at any moment.
+ * Note also that we are relying on page_mapping(page) to set mapping
+ * to &swapper_space when PageSwapCache(page).
+ */
+ if (mapping && !mapping_cap_account_dirty(mapping) &&
+ page_test_and_clear_dirty(page_to_pfn(page), 1))
+ set_page_dirty(page);
+ /*
+ * Hugepages are not counted in NR_ANON_PAGES nor NR_FILE_MAPPED
+ * and not charged by memcg for now.
+ */
+ if (unlikely(PageHuge(page)))
+ goto out;
+ if (anon) {
+ mem_cgroup_uncharge_page(page);
+ if (!PageTransHuge(page))
+ __dec_zone_page_state(page, NR_ANON_PAGES);
+ else
+ __dec_zone_page_state(page,
+ NR_ANON_TRANSPARENT_HUGEPAGES);
+ } else {
+ __dec_zone_page_state(page, NR_FILE_MAPPED);
+ mem_cgroup_dec_page_stat(page, MEMCG_NR_FILE_MAPPED);
+ }
+ /*
+ * It would be tidy to reset the PageAnon mapping here,
+ * but that might overwrite a racing page_add_anon_rmap
+ * which increments mapcount after us but sets mapping
+ * before us: so leave the reset to free_hot_cold_page,
+ * and remember that it's only reliable while mapped.
+ * Leaving it set also helps swapoff to reinstate ptes
+ * faster for those pages still in swapcache.
+ */
+out:
+ if (!anon)
+ mem_cgroup_end_update_page_stat(page, &locked, &flags);
+}
+
+/*
+ * Subfunctions of try_to_unmap: try_to_unmap_one called
+ * repeatedly from try_to_unmap_ksm, try_to_unmap_anon or try_to_unmap_file.
+ */
+int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
+ unsigned long address, enum ttu_flags flags)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pte_t *pte;
+ pte_t pteval;
+ spinlock_t *ptl;
+ int ret = SWAP_AGAIN;
+
+ pte = page_check_address(page, mm, address, &ptl, 0);
+ if (!pte)
+ goto out;
+
+ /*
+ * If the page is mlock()d, we cannot swap it out.
+ * If it's recently referenced (perhaps page_referenced
+ * skipped over this mm) then we should reactivate it.
+ */
+ if (!(flags & TTU_IGNORE_MLOCK)) {
+ if (vma->vm_flags & VM_LOCKED)
+ goto out_mlock;
+
+ if (TTU_ACTION(flags) == TTU_MUNLOCK)
+ goto out_unmap;
+ }
+ if (!(flags & TTU_IGNORE_ACCESS)) {
+ if (ptep_clear_flush_young_notify(vma, address, pte)) {
+ ret = SWAP_FAIL;
+ goto out_unmap;
+ }
+ }
+
+ /* Nuke the page table entry. */
+ flush_cache_page(vma, address, page_to_pfn(page));
+ pteval = ptep_clear_flush_notify(vma, address, pte);
+
+ /* Move the dirty bit to the physical page now the pte is gone. */
+ if (pte_dirty(pteval))
+ set_page_dirty(page);
+
+ /* Update high watermark before we lower rss */
+ update_hiwater_rss(mm);
+
+ if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
+ if (PageAnon(page))
+ dec_mm_counter(mm, MM_ANONPAGES);
+ else
+ dec_mm_counter(mm, MM_FILEPAGES);
+ set_pte_at(mm, address, pte,
+ swp_entry_to_pte(make_hwpoison_entry(page)));
+ } else if (PageAnon(page)) {
+ swp_entry_t entry = { .val = page_private(page) };
+
+ if (PageSwapCache(page)) {
+ /*
+ * Store the swap location in the pte.
+ * See handle_pte_fault() ...
+ */
+ if (swap_duplicate(entry) < 0) {
+ set_pte_at(mm, address, pte, pteval);
+ ret = SWAP_FAIL;
+ goto out_unmap;
+ }
+ if (list_empty(&mm->mmlist)) {
+ spin_lock(&mmlist_lock);
+ if (list_empty(&mm->mmlist))
+ list_add(&mm->mmlist, &init_mm.mmlist);
+ spin_unlock(&mmlist_lock);
+ }
+ dec_mm_counter(mm, MM_ANONPAGES);
+ inc_mm_counter(mm, MM_SWAPENTS);
+ } else if (IS_ENABLED(CONFIG_MIGRATION)) {
+ /*
+ * Store the pfn of the page in a special migration
+ * pte. do_swap_page() will wait until the migration
+ * pte is removed and then restart fault handling.
+ */
+ BUG_ON(TTU_ACTION(flags) != TTU_MIGRATION);
+ entry = make_migration_entry(page, pte_write(pteval));
+ }
+ set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
+ BUG_ON(pte_file(*pte));
+ } else if (IS_ENABLED(CONFIG_MIGRATION) &&
+ (TTU_ACTION(flags) == TTU_MIGRATION)) {
+ /* Establish migration entry for a file page */
+ swp_entry_t entry;
+ entry = make_migration_entry(page, pte_write(pteval));
+ set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
+ } else
+ dec_mm_counter(mm, MM_FILEPAGES);
+
+ page_remove_rmap(page);
+ page_cache_release(page);
+
+out_unmap:
+ pte_unmap_unlock(pte, ptl);
+out:
+ return ret;
+
+out_mlock:
+ pte_unmap_unlock(pte, ptl);
+
+
+ /*
+ * We need mmap_sem locking, Otherwise VM_LOCKED check makes
+ * unstable result and race. Plus, We can't wait here because
+ * we now hold anon_vma->mutex or mapping->i_mmap_mutex.
+ * if trylock failed, the page remain in evictable lru and later
+ * vmscan could retry to move the page to unevictable lru if the
+ * page is actually mlocked.
+ */
+ if (down_read_trylock(&vma->vm_mm->mmap_sem)) {
+ if (vma->vm_flags & VM_LOCKED) {
+ mlock_vma_page(page);
+ ret = SWAP_MLOCK;
+ }
+ up_read(&vma->vm_mm->mmap_sem);
+ }
+ return ret;
+}
+
+/*
+ * objrmap doesn't work for nonlinear VMAs because the assumption that
+ * offset-into-file correlates with offset-into-virtual-addresses does not hold.
+ * Consequently, given a particular page and its ->index, we cannot locate the
+ * ptes which are mapping that page without an exhaustive linear search.
+ *
+ * So what this code does is a mini "virtual scan" of each nonlinear VMA which
+ * maps the file to which the target page belongs. The ->vm_private_data field
+ * holds the current cursor into that scan. Successive searches will circulate
+ * around the vma's virtual address space.
+ *
+ * So as more replacement pressure is applied to the pages in a nonlinear VMA,
+ * more scanning pressure is placed against them as well. Eventually pages
+ * will become fully unmapped and are eligible for eviction.
+ *
+ * For very sparsely populated VMAs this is a little inefficient - chances are
+ * there there won't be many ptes located within the scan cluster. In this case
+ * maybe we could scan further - to the end of the pte page, perhaps.
+ *
+ * Mlocked pages: check VM_LOCKED under mmap_sem held for read, if we can
+ * acquire it without blocking. If vma locked, mlock the pages in the cluster,
+ * rather than unmapping them. If we encounter the "check_page" that vmscan is
+ * trying to unmap, return SWAP_MLOCK, else default SWAP_AGAIN.
+ */
+#define CLUSTER_SIZE min(32*PAGE_SIZE, PMD_SIZE)
+#define CLUSTER_MASK (~(CLUSTER_SIZE - 1))
+
+static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
+ struct vm_area_struct *vma, struct page *check_page)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+ pte_t pteval;
+ spinlock_t *ptl;
+ struct page *page;
+ unsigned long address;
+ unsigned long end;
+ int ret = SWAP_AGAIN;
+ int locked_vma = 0;
+
+ address = (vma->vm_start + cursor) & CLUSTER_MASK;
+ end = address + CLUSTER_SIZE;
+ if (address < vma->vm_start)
+ address = vma->vm_start;
+ if (end > vma->vm_end)
+ end = vma->vm_end;
+
+ pgd = pgd_offset(mm, address);
+ if (!pgd_present(*pgd))
+ return ret;
+
+ pud = pud_offset(pgd, address);
+ if (!pud_present(*pud))
+ return ret;
+
+ pmd = pmd_offset(pud, address);
+ if (!pmd_present(*pmd))
+ return ret;
+
+ /*
+ * If we can acquire the mmap_sem for read, and vma is VM_LOCKED,
+ * keep the sem while scanning the cluster for mlocking pages.
+ */
+ if (down_read_trylock(&vma->vm_mm->mmap_sem)) {
+ locked_vma = (vma->vm_flags & VM_LOCKED);
+ if (!locked_vma)
+ up_read(&vma->vm_mm->mmap_sem); /* don't need it */
+ }
+
+ pte = pte_offset_map_lock(mm, pmd, address, &ptl);
+
+ /* Update high watermark before we lower rss */
+ update_hiwater_rss(mm);
+
+ for (; address < end; pte++, address += PAGE_SIZE) {
+ if (!pte_present(*pte))
+ continue;
+ page = vm_normal_page(vma, address, *pte);
+ BUG_ON(!page || PageAnon(page));
+
+ if (locked_vma) {
+ if (page == check_page) {
+ /* we know we have check_page locked */
+ mlock_vma_page(page);
+ ret = SWAP_MLOCK;
+ } else if (trylock_page(page)) {
+ /*
+ * If we can lock the page, perform mlock.
+ * Otherwise leave the page alone, it will be
+ * eventually encountered again later.
+ */
+ mlock_vma_page(page);
+ unlock_page(page);
+ }
+ continue; /* don't unmap */
+ }
+
+ if (ptep_clear_flush_young_notify(vma, address, pte))
+ continue;
+
+ /* Nuke the page table entry. */
+ flush_cache_page(vma, address, pte_pfn(*pte));
+ pteval = ptep_clear_flush_notify(vma, address, pte);
+
+ /* If nonlinear, store the file page offset in the pte. */
+ if (page->index != linear_page_index(vma, address))
+ set_pte_at(mm, address, pte, pgoff_to_pte(page->index));
+
+ /* Move the dirty bit to the physical page now the pte is gone. */
+ if (pte_dirty(pteval))
+ set_page_dirty(page);
+
+ page_remove_rmap(page);
+ page_cache_release(page);
+ dec_mm_counter(mm, MM_FILEPAGES);
+ (*mapcount)--;
+ }
+ pte_unmap_unlock(pte - 1, ptl);
+ if (locked_vma)
+ up_read(&vma->vm_mm->mmap_sem);
+ return ret;
+}
+
+bool is_vma_temporary_stack(struct vm_area_struct *vma)
+{
+ int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
+
+ if (!maybe_stack)
+ return false;
+
+ if ((vma->vm_flags & VM_STACK_INCOMPLETE_SETUP) ==
+ VM_STACK_INCOMPLETE_SETUP)
+ return true;
+
+ return false;
+}
+
+/**
+ * try_to_unmap_anon - unmap or unlock anonymous page using the object-based
+ * rmap method
+ * @page: the page to unmap/unlock
+ * @flags: action and flags
+ *
+ * Find all the mappings of a page using the mapping pointer and the vma chains
+ * contained in the anon_vma struct it points to.
+ *
+ * This function is only called from try_to_unmap/try_to_munlock for
+ * anonymous pages.
+ * When called from try_to_munlock(), the mmap_sem of the mm containing the vma
+ * where the page was found will be held for write. So, we won't recheck
+ * vm_flags for that VMA. That should be OK, because that vma shouldn't be
+ * 'LOCKED.
+ */
+static int try_to_unmap_anon(struct page *page, enum ttu_flags flags)
+{
+ struct anon_vma *anon_vma;
+ struct anon_vma_chain *avc;
+ int ret = SWAP_AGAIN;
+
+ anon_vma = page_lock_anon_vma(page);
+ if (!anon_vma)
+ return ret;
+
+ list_for_each_entry(avc, &anon_vma->head, same_anon_vma) {
+ struct vm_area_struct *vma = avc->vma;
+ unsigned long address;
+
+ /*
+ * During exec, a temporary VMA is setup and later moved.
+ * The VMA is moved under the anon_vma lock but not the
+ * page tables leading to a race where migration cannot
+ * find the migration ptes. Rather than increasing the
+ * locking requirements of exec(), migration skips
+ * temporary VMAs until after exec() completes.
+ */
+ if (IS_ENABLED(CONFIG_MIGRATION) && (flags & TTU_MIGRATION) &&
+ is_vma_temporary_stack(vma))
+ continue;
+
+ address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
+ ret = try_to_unmap_one(page, vma, address, flags);
+ if (ret != SWAP_AGAIN || !page_mapped(page))
+ break;
+ }
+
+ page_unlock_anon_vma(anon_vma);
+ return ret;
+}
+
+/**
+ * try_to_unmap_file - unmap/unlock file page using the object-based rmap method
+ * @page: the page to unmap/unlock
+ * @flags: action and flags
+ *
+ * Find all the mappings of a page using the mapping pointer and the vma chains
+ * contained in the address_space struct it points to.
+ *
+ * This function is only called from try_to_unmap/try_to_munlock for
+ * object-based pages.
+ * When called from try_to_munlock(), the mmap_sem of the mm containing the vma
+ * where the page was found will be held for write. So, we won't recheck
+ * vm_flags for that VMA. That should be OK, because that vma shouldn't be
+ * 'LOCKED.
+ */
+static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
+{
+ struct address_space *mapping = page->mapping;
+ pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ struct vm_area_struct *vma;
+ struct prio_tree_iter iter;
+ int ret = SWAP_AGAIN;
+ unsigned long cursor;
+ unsigned long max_nl_cursor = 0;
+ unsigned long max_nl_size = 0;
+ unsigned int mapcount;
+
+ mutex_lock(&mapping->i_mmap_mutex);
+ vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+ unsigned long address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
+ ret = try_to_unmap_one(page, vma, address, flags);
+ if (ret != SWAP_AGAIN || !page_mapped(page))
+ goto out;
+ }
+
+ if (list_empty(&mapping->i_mmap_nonlinear))
+ goto out;
+
+ /*
+ * We don't bother to try to find the munlocked page in nonlinears.
+ * It's costly. Instead, later, page reclaim logic may call
+ * try_to_unmap(TTU_MUNLOCK) and recover PG_mlocked lazily.
+ */
+ if (TTU_ACTION(flags) == TTU_MUNLOCK)
+ goto out;
+
+ list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
+ shared.vm_set.list) {
+ cursor = (unsigned long) vma->vm_private_data;
+ if (cursor > max_nl_cursor)
+ max_nl_cursor = cursor;
+ cursor = vma->vm_end - vma->vm_start;
+ if (cursor > max_nl_size)
+ max_nl_size = cursor;
+ }
+
+ if (max_nl_size == 0) { /* all nonlinears locked or reserved ? */
+ ret = SWAP_FAIL;
+ goto out;
+ }
+
+ /*
+ * We don't try to search for this page in the nonlinear vmas,
+ * and page_referenced wouldn't have found it anyway. Instead
+ * just walk the nonlinear vmas trying to age and unmap some.
+ * The mapcount of the page we came in with is irrelevant,
+ * but even so use it as a guide to how hard we should try?
+ */
+ mapcount = page_mapcount(page);
+ if (!mapcount)
+ goto out;
+ cond_resched();
+
+ max_nl_size = (max_nl_size + CLUSTER_SIZE - 1) & CLUSTER_MASK;
+ if (max_nl_cursor == 0)
+ max_nl_cursor = CLUSTER_SIZE;
+
+ do {
+ list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
+ shared.vm_set.list) {
+ cursor = (unsigned long) vma->vm_private_data;
+ while ( cursor < max_nl_cursor &&
+ cursor < vma->vm_end - vma->vm_start) {
+ if (try_to_unmap_cluster(cursor, &mapcount,
+ vma, page) == SWAP_MLOCK)
+ ret = SWAP_MLOCK;
+ cursor += CLUSTER_SIZE;
+ vma->vm_private_data = (void *) cursor;
+ if ((int)mapcount <= 0)
+ goto out;
+ }
+ vma->vm_private_data = (void *) max_nl_cursor;
+ }
+ cond_resched();
+ max_nl_cursor += CLUSTER_SIZE;
+ } while (max_nl_cursor <= max_nl_size);
+
+ /*
+ * Don't loop forever (perhaps all the remaining pages are
+ * in locked vmas). Reset cursor on all unreserved nonlinear
+ * vmas, now forgetting on which ones it had fallen behind.
+ */
+ list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list)
+ vma->vm_private_data = NULL;
+out:
+ mutex_unlock(&mapping->i_mmap_mutex);
+ return ret;
+}
+
+/**
+ * try_to_unmap - try to remove all page table mappings to a page
+ * @page: the page to get unmapped
+ * @flags: action and flags
+ *
+ * Tries to remove all the page table entries which are mapping this
+ * page, used in the pageout path. Caller must hold the page lock.
+ * Return values are:
+ *
+ * SWAP_SUCCESS - we succeeded in removing all mappings
+ * SWAP_AGAIN - we missed a mapping, try again later
+ * SWAP_FAIL - the page is unswappable
+ * SWAP_MLOCK - page is mlocked.
+ */
+int try_to_unmap(struct page *page, enum ttu_flags flags)
+{
+ int ret;
+
+ BUG_ON(!PageLocked(page));
+ VM_BUG_ON(!PageHuge(page) && PageTransHuge(page));
+
+ if (unlikely(PageKsm(page)))
+ ret = try_to_unmap_ksm(page, flags);
+ else if (PageAnon(page))
+ ret = try_to_unmap_anon(page, flags);
+ else
+ ret = try_to_unmap_file(page, flags);
+ if (ret != SWAP_MLOCK && !page_mapped(page))
+ ret = SWAP_SUCCESS;
+ return ret;
+}
+
+/**
+ * try_to_munlock - try to munlock a page
+ * @page: the page to be munlocked
+ *
+ * Called from munlock code. Checks all of the VMAs mapping the page
+ * to make sure nobody else has this page mlocked. The page will be
+ * returned with PG_mlocked cleared if no other vmas have it mlocked.
+ *
+ * Return values are:
+ *
+ * SWAP_AGAIN - no vma is holding page mlocked, or,
+ * SWAP_AGAIN - page mapped in mlocked vma -- couldn't acquire mmap sem
+ * SWAP_FAIL - page cannot be located at present
+ * SWAP_MLOCK - page is now mlocked.
+ */
+int try_to_munlock(struct page *page)
+{
+ VM_BUG_ON(!PageLocked(page) || PageLRU(page));
+
+ if (unlikely(PageKsm(page)))
+ return try_to_unmap_ksm(page, TTU_MUNLOCK);
+ else if (PageAnon(page))
+ return try_to_unmap_anon(page, TTU_MUNLOCK);
+ else
+ return try_to_unmap_file(page, TTU_MUNLOCK);
+}
+
+void __put_anon_vma(struct anon_vma *anon_vma)
+{
+ struct anon_vma *root = anon_vma->root;
+
+ anon_vma_free(anon_vma);
+ if (root != anon_vma && atomic_dec_and_test(&root->refcount))
+ anon_vma_free(root);
+}
+
+#ifdef CONFIG_MIGRATION
+/*
+ * rmap_walk() and its helpers rmap_walk_anon() and rmap_walk_file():
+ * Called by migrate.c to remove migration ptes, but might be used more later.
+ */
+static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *,
+ struct vm_area_struct *, unsigned long, void *), void *arg)
+{
+ struct anon_vma *anon_vma;
+ struct anon_vma_chain *avc;
+ int ret = SWAP_AGAIN;
+
+ /*
+ * Note: remove_migration_ptes() cannot use page_lock_anon_vma()
+ * because that depends on page_mapped(); but not all its usages
+ * are holding mmap_sem. Users without mmap_sem are required to
+ * take a reference count to prevent the anon_vma disappearing
+ */
+ anon_vma = page_anon_vma(page);
+ if (!anon_vma)
+ return ret;
+ anon_vma_lock(anon_vma);
+ list_for_each_entry(avc, &anon_vma->head, same_anon_vma) {
+ struct vm_area_struct *vma = avc->vma;
+ unsigned long address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
+ ret = rmap_one(page, vma, address, arg);
+ if (ret != SWAP_AGAIN)
+ break;
+ }
+ anon_vma_unlock(anon_vma);
+ return ret;
+}
+
+static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *,
+ struct vm_area_struct *, unsigned long, void *), void *arg)
+{
+ struct address_space *mapping = page->mapping;
+ pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ struct vm_area_struct *vma;
+ struct prio_tree_iter iter;
+ int ret = SWAP_AGAIN;
+
+ if (!mapping)
+ return ret;
+ mutex_lock(&mapping->i_mmap_mutex);
+ vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+ unsigned long address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
+ ret = rmap_one(page, vma, address, arg);
+ if (ret != SWAP_AGAIN)
+ break;
+ }
+ /*
+ * No nonlinear handling: being always shared, nonlinear vmas
+ * never contain migration ptes. Decide what to do about this
+ * limitation to linear when we need rmap_walk() on nonlinear.
+ */
+ mutex_unlock(&mapping->i_mmap_mutex);
+ return ret;
+}
+
+int rmap_walk(struct page *page, int (*rmap_one)(struct page *,
+ struct vm_area_struct *, unsigned long, void *), void *arg)
+{
+ VM_BUG_ON(!PageLocked(page));
+
+ if (unlikely(PageKsm(page)))
+ return rmap_walk_ksm(page, rmap_one, arg);
+ else if (PageAnon(page))
+ return rmap_walk_anon(page, rmap_one, arg);
+ else
+ return rmap_walk_file(page, rmap_one, arg);
+}
+#endif /* CONFIG_MIGRATION */
+
+#ifdef CONFIG_HUGETLB_PAGE
+/*
+ * The following three functions are for anonymous (private mapped) hugepages.
+ * Unlike common anonymous pages, anonymous hugepages have no accounting code
+ * and no lru code, because we handle hugepages differently from common pages.
+ */
+static void __hugepage_set_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address, int exclusive)
+{
+ struct anon_vma *anon_vma = vma->anon_vma;
+
+ BUG_ON(!anon_vma);
+
+ if (PageAnon(page))
+ return;
+ if (!exclusive)
+ anon_vma = anon_vma->root;
+
+ anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
+ page->mapping = (struct address_space *) anon_vma;
+ page->index = linear_page_index(vma, address);
+}
+
+void hugepage_add_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ struct anon_vma *anon_vma = vma->anon_vma;
+ int first;
+
+ BUG_ON(!PageLocked(page));
+ BUG_ON(!anon_vma);
+ /* address might be in next vma when migration races vma_adjust */
+ first = atomic_inc_and_test(&page->_mapcount);
+ if (first)
+ __hugepage_set_anon_rmap(page, vma, address, 0);
+}
+
+void hugepage_add_new_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+ atomic_set(&page->_mapcount, 0);
+ __hugepage_set_anon_rmap(page, vma, address, 1);
+}
+#endif /* CONFIG_HUGETLB_PAGE */
diff --git a/ap/os/linux/linux-3.4.x/mm/shmem.c b/ap/os/linux/linux-3.4.x/mm/shmem.c
new file mode 100644
index 0000000..4cb1864
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/shmem.c
@@ -0,0 +1,2823 @@
+/*
+ * Resizable virtual memory filesystem for Linux.
+ *
+ * Copyright (C) 2000 Linus Torvalds.
+ * 2000 Transmeta Corp.
+ * 2000-2001 Christoph Rohland
+ * 2000-2001 SAP AG
+ * 2002 Red Hat Inc.
+ * Copyright (C) 2002-2011 Hugh Dickins.
+ * Copyright (C) 2011 Google Inc.
+ * Copyright (C) 2002-2005 VERITAS Software Corporation.
+ * Copyright (C) 2004 Andi Kleen, SuSE Labs
+ *
+ * Extended attribute support for tmpfs:
+ * Copyright (c) 2004, Luke Kenneth Casson Leighton <lkcl@lkcl.net>
+ * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
+ *
+ * tiny-shmem:
+ * Copyright (c) 2004, 2008 Matt Mackall <mpm@selenic.com>
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/vfs.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/file.h>
+#include <linux/mm.h>
+#include <linux/export.h>
+#include <linux/swap.h>
+
+static struct vfsmount *shm_mnt;
+
+#ifdef CONFIG_SHMEM
+/*
+ * This virtual memory filesystem is heavily based on the ramfs. It
+ * extends ramfs by the ability to use swap and honor resource limits
+ * which makes it a completely usable filesystem.
+ */
+
+#include <linux/xattr.h>
+#include <linux/exportfs.h>
+#include <linux/posix_acl.h>
+#include <linux/generic_acl.h>
+#include <linux/mman.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/backing-dev.h>
+#include <linux/shmem_fs.h>
+#include <linux/writeback.h>
+#include <linux/blkdev.h>
+#include <linux/pagevec.h>
+#include <linux/percpu_counter.h>
+#include <linux/splice.h>
+#include <linux/security.h>
+#include <linux/swapops.h>
+#include <linux/mempolicy.h>
+#include <linux/namei.h>
+#include <linux/ctype.h>
+#include <linux/migrate.h>
+#include <linux/highmem.h>
+#include <linux/seq_file.h>
+#include <linux/magic.h>
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+
+#define BLOCKS_PER_PAGE (PAGE_CACHE_SIZE/512)
+#define VM_ACCT(size) (PAGE_CACHE_ALIGN(size) >> PAGE_SHIFT)
+
+/* Pretend that each entry is of this size in directory's i_size */
+#define BOGO_DIRENT_SIZE 20
+
+/* Symlink up to this size is kmalloc'ed instead of using a swappable page */
+#define SHORT_SYMLINK_LEN 128
+
+/*
+ * vmtruncate_range() communicates with shmem_fault via
+ * inode->i_private (with i_mutex making sure that it has only one user at
+ * a time): we would prefer not to enlarge the shmem inode just for that.
+ */
+struct shmem_falloc {
+ wait_queue_head_t *waitq; /* faults into hole wait for punch to end */
+ pgoff_t start; /* start of range currently being fallocated */
+ pgoff_t next; /* the next page offset to be fallocated */
+};
+
+struct shmem_xattr {
+ struct list_head list; /* anchored by shmem_inode_info->xattr_list */
+ char *name; /* xattr name */
+ size_t size;
+ char value[0];
+};
+
+/* Flag allocation requirements to shmem_getpage */
+enum sgp_type {
+ SGP_READ, /* don't exceed i_size, don't allocate page */
+ SGP_CACHE, /* don't exceed i_size, may allocate page */
+ SGP_DIRTY, /* like SGP_CACHE, but set new page dirty */
+ SGP_WRITE, /* may exceed i_size, may allocate page */
+};
+
+#ifdef CONFIG_TMPFS
+static unsigned long shmem_default_max_blocks(void)
+{
+ return totalram_pages / 2;
+}
+
+static unsigned long shmem_default_max_inodes(void)
+{
+ return min(totalram_pages - totalhigh_pages, totalram_pages / 2);
+}
+#endif
+
+static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
+ struct page **pagep, enum sgp_type sgp, gfp_t gfp, int *fault_type);
+
+static inline int shmem_getpage(struct inode *inode, pgoff_t index,
+ struct page **pagep, enum sgp_type sgp, int *fault_type)
+{
+ return shmem_getpage_gfp(inode, index, pagep, sgp,
+ mapping_gfp_mask(inode->i_mapping), fault_type);
+}
+
+static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb)
+{
+ return sb->s_fs_info;
+}
+
+/*
+ * shmem_file_setup pre-accounts the whole fixed size of a VM object,
+ * for shared memory and for shared anonymous (/dev/zero) mappings
+ * (unless MAP_NORESERVE and sysctl_overcommit_memory <= 1),
+ * consistent with the pre-accounting of private mappings ...
+ */
+static inline int shmem_acct_size(unsigned long flags, loff_t size)
+{
+ return (flags & VM_NORESERVE) ?
+ 0 : security_vm_enough_memory_mm(current->mm, VM_ACCT(size));
+}
+
+static inline void shmem_unacct_size(unsigned long flags, loff_t size)
+{
+ if (!(flags & VM_NORESERVE))
+ vm_unacct_memory(VM_ACCT(size));
+}
+
+/*
+ * ... whereas tmpfs objects are accounted incrementally as
+ * pages are allocated, in order to allow huge sparse files.
+ * shmem_getpage reports shmem_acct_block failure as -ENOSPC not -ENOMEM,
+ * so that a failure on a sparse tmpfs mapping will give SIGBUS not OOM.
+ */
+static inline int shmem_acct_block(unsigned long flags)
+{
+ return (flags & VM_NORESERVE) ?
+ security_vm_enough_memory_mm(current->mm, VM_ACCT(PAGE_CACHE_SIZE)) : 0;
+}
+
+static inline void shmem_unacct_blocks(unsigned long flags, long pages)
+{
+ if (flags & VM_NORESERVE)
+ vm_unacct_memory(pages * VM_ACCT(PAGE_CACHE_SIZE));
+}
+
+static const struct super_operations shmem_ops;
+static const struct address_space_operations shmem_aops;
+static const struct file_operations shmem_file_operations;
+static const struct inode_operations shmem_inode_operations;
+static const struct inode_operations shmem_dir_inode_operations;
+static const struct inode_operations shmem_special_inode_operations;
+static const struct vm_operations_struct shmem_vm_ops;
+
+static struct backing_dev_info shmem_backing_dev_info __read_mostly = {
+ .ra_pages = 0, /* No readahead */
+ .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED,
+};
+
+static LIST_HEAD(shmem_swaplist);
+static DEFINE_MUTEX(shmem_swaplist_mutex);
+
+static int shmem_reserve_inode(struct super_block *sb)
+{
+ struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
+ if (sbinfo->max_inodes) {
+ spin_lock(&sbinfo->stat_lock);
+ if (!sbinfo->free_inodes) {
+ spin_unlock(&sbinfo->stat_lock);
+ return -ENOSPC;
+ }
+ sbinfo->free_inodes--;
+ spin_unlock(&sbinfo->stat_lock);
+ }
+ return 0;
+}
+
+static void shmem_free_inode(struct super_block *sb)
+{
+ struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
+ if (sbinfo->max_inodes) {
+ spin_lock(&sbinfo->stat_lock);
+ sbinfo->free_inodes++;
+ spin_unlock(&sbinfo->stat_lock);
+ }
+}
+
+/**
+ * shmem_recalc_inode - recalculate the block usage of an inode
+ * @inode: inode to recalc
+ *
+ * We have to calculate the free blocks since the mm can drop
+ * undirtied hole pages behind our back.
+ *
+ * But normally info->alloced == inode->i_mapping->nrpages + info->swapped
+ * So mm freed is info->alloced - (inode->i_mapping->nrpages + info->swapped)
+ *
+ * It has to be called with the spinlock held.
+ */
+static void shmem_recalc_inode(struct inode *inode)
+{
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ long freed;
+
+ freed = info->alloced - info->swapped - inode->i_mapping->nrpages;
+ if (freed > 0) {
+ struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
+ if (sbinfo->max_blocks)
+ percpu_counter_add(&sbinfo->used_blocks, -freed);
+ info->alloced -= freed;
+ inode->i_blocks -= freed * BLOCKS_PER_PAGE;
+ shmem_unacct_blocks(info->flags, freed);
+ }
+}
+
+/*
+ * Replace item expected in radix tree by a new item, while holding tree lock.
+ */
+static int shmem_radix_tree_replace(struct address_space *mapping,
+ pgoff_t index, void *expected, void *replacement)
+{
+ void **pslot;
+ void *item = NULL;
+
+ VM_BUG_ON(!expected);
+ pslot = radix_tree_lookup_slot(&mapping->page_tree, index);
+ if (pslot)
+ item = radix_tree_deref_slot_protected(pslot,
+ &mapping->tree_lock);
+ if (item != expected)
+ return -ENOENT;
+ if (replacement)
+ radix_tree_replace_slot(pslot, replacement);
+ else
+ radix_tree_delete(&mapping->page_tree, index);
+ return 0;
+}
+
+/*
+ * Like add_to_page_cache_locked, but error if expected item has gone.
+ */
+static int shmem_add_to_page_cache(struct page *page,
+ struct address_space *mapping,
+ pgoff_t index, gfp_t gfp, void *expected)
+{
+ int error = 0;
+
+ VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON(!PageSwapBacked(page));
+
+ if (!expected)
+ error = radix_tree_preload(gfp & GFP_RECLAIM_MASK);
+ if (!error) {
+ page_cache_get(page);
+ page->mapping = mapping;
+ page->index = index;
+
+ spin_lock_irq(&mapping->tree_lock);
+ if (!expected)
+ error = radix_tree_insert(&mapping->page_tree,
+ index, page);
+ else
+ error = shmem_radix_tree_replace(mapping, index,
+ expected, page);
+ if (!error) {
+ mapping->nrpages++;
+ __inc_zone_page_state(page, NR_FILE_PAGES);
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+ __inc_zone_page_state(page, NR_TMPFS_PAGES);
+#endif
+ __inc_zone_page_state(page, NR_SHMEM);
+ spin_unlock_irq(&mapping->tree_lock);
+ } else {
+ page->mapping = NULL;
+ spin_unlock_irq(&mapping->tree_lock);
+ page_cache_release(page);
+ }
+ if (!expected)
+ radix_tree_preload_end();
+ }
+ if (error)
+ mem_cgroup_uncharge_cache_page(page);
+ return error;
+}
+
+/*
+ * Like delete_from_page_cache, but substitutes swap for page.
+ */
+static void shmem_delete_from_page_cache(struct page *page, void *radswap)
+{
+ struct address_space *mapping = page->mapping;
+ int error;
+ unsigned long flags;
+
+ spin_lock_irq(&mapping->tree_lock);
+ local_irq_save(flags);
+ error = shmem_radix_tree_replace(mapping, page->index, page, radswap);
+ page->mapping = NULL;
+ mapping->nrpages--;
+ __dec_zone_page_state(page, NR_FILE_PAGES);
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+ __dec_zone_page_state(page, NR_TMPFS_PAGES);
+#endif
+ __dec_zone_page_state(page, NR_SHMEM);
+ local_irq_restore(flags);
+ spin_unlock_irq(&mapping->tree_lock);
+ page_cache_release(page);
+ BUG_ON(error);
+}
+
+/*
+ * Like find_get_pages, but collecting swap entries as well as pages.
+ */
+static unsigned shmem_find_get_pages_and_swap(struct address_space *mapping,
+ pgoff_t start, unsigned int nr_pages,
+ struct page **pages, pgoff_t *indices)
+{
+ unsigned int i;
+ unsigned int ret;
+ unsigned int nr_found;
+
+ rcu_read_lock();
+restart:
+ nr_found = radix_tree_gang_lookup_slot(&mapping->page_tree,
+ (void ***)pages, indices, start, nr_pages);
+ ret = 0;
+ for (i = 0; i < nr_found; i++) {
+ struct page *page;
+repeat:
+ page = radix_tree_deref_slot((void **)pages[i]);
+ if (unlikely(!page))
+ continue;
+ if (radix_tree_exception(page)) {
+ if (radix_tree_deref_retry(page))
+ goto restart;
+ /*
+ * Otherwise, we must be storing a swap entry
+ * here as an exceptional entry: so return it
+ * without attempting to raise page count.
+ */
+ goto export;
+ }
+ if (!page_cache_get_speculative(page))
+ goto repeat;
+
+ /* Has the page moved? */
+ if (unlikely(page != *((void **)pages[i]))) {
+ page_cache_release(page);
+ goto repeat;
+ }
+export:
+ indices[ret] = indices[i];
+ pages[ret] = page;
+ ret++;
+ }
+ if (unlikely(!ret && nr_found))
+ goto restart;
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Remove swap entry from radix tree, free the swap and its page cache.
+ */
+static int shmem_free_swap(struct address_space *mapping,
+ pgoff_t index, void *radswap)
+{
+ int error;
+
+ spin_lock_irq(&mapping->tree_lock);
+ error = shmem_radix_tree_replace(mapping, index, radswap, NULL);
+ spin_unlock_irq(&mapping->tree_lock);
+ if (!error)
+ free_swap_and_cache(radix_to_swp_entry(radswap));
+ return error;
+}
+
+/*
+ * Pagevec may contain swap entries, so shuffle up pages before releasing.
+ */
+static void shmem_deswap_pagevec(struct pagevec *pvec)
+{
+ int i, j;
+
+ for (i = 0, j = 0; i < pagevec_count(pvec); i++) {
+ struct page *page = pvec->pages[i];
+ if (!radix_tree_exceptional_entry(page))
+ pvec->pages[j++] = page;
+ }
+ pvec->nr = j;
+}
+
+/*
+ * SysV IPC SHM_UNLOCK restore Unevictable pages to their evictable lists.
+ */
+void shmem_unlock_mapping(struct address_space *mapping)
+{
+ struct pagevec pvec;
+ pgoff_t indices[PAGEVEC_SIZE];
+ pgoff_t index = 0;
+
+ pagevec_init(&pvec, 0);
+ /*
+ * Minor point, but we might as well stop if someone else SHM_LOCKs it.
+ */
+ while (!mapping_unevictable(mapping)) {
+ /*
+ * Avoid pagevec_lookup(): find_get_pages() returns 0 as if it
+ * has finished, if it hits a row of PAGEVEC_SIZE swap entries.
+ */
+ pvec.nr = shmem_find_get_pages_and_swap(mapping, index,
+ PAGEVEC_SIZE, pvec.pages, indices);
+ if (!pvec.nr)
+ break;
+ index = indices[pvec.nr - 1] + 1;
+ shmem_deswap_pagevec(&pvec);
+ check_move_unevictable_pages(pvec.pages, pvec.nr);
+ pagevec_release(&pvec);
+ cond_resched();
+ }
+}
+
+/*
+ * Remove range of pages and swap entries from radix tree, and free them.
+ */
+void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
+{
+ struct address_space *mapping = inode->i_mapping;
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ pgoff_t start = (lstart + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ unsigned partial = lstart & (PAGE_CACHE_SIZE - 1);
+ pgoff_t end = (lend >> PAGE_CACHE_SHIFT);
+ struct pagevec pvec;
+ pgoff_t indices[PAGEVEC_SIZE];
+ long nr_swaps_freed = 0;
+ pgoff_t index;
+ int i;
+
+ BUG_ON((lend & (PAGE_CACHE_SIZE - 1)) != (PAGE_CACHE_SIZE - 1));
+
+ pagevec_init(&pvec, 0);
+ index = start;
+ while (index <= end) {
+ pvec.nr = shmem_find_get_pages_and_swap(mapping, index,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1,
+ pvec.pages, indices);
+ if (!pvec.nr)
+ break;
+ mem_cgroup_uncharge_start();
+ for (i = 0; i < pagevec_count(&pvec); i++) {
+ struct page *page = pvec.pages[i];
+
+ index = indices[i];
+ if (index > end)
+ break;
+
+ if (radix_tree_exceptional_entry(page)) {
+ nr_swaps_freed += !shmem_free_swap(mapping,
+ index, page);
+ continue;
+ }
+
+ if (!trylock_page(page))
+ continue;
+ if (page->mapping == mapping) {
+ VM_BUG_ON(PageWriteback(page));
+ truncate_inode_page(mapping, page);
+ }
+ unlock_page(page);
+ }
+ shmem_deswap_pagevec(&pvec);
+ pagevec_release(&pvec);
+ mem_cgroup_uncharge_end();
+ cond_resched();
+ index++;
+ }
+
+ if (partial) {
+ struct page *page = NULL;
+ shmem_getpage(inode, start - 1, &page, SGP_READ, NULL);
+ if (page) {
+ zero_user_segment(page, partial, PAGE_CACHE_SIZE);
+ set_page_dirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ }
+
+ index = start;
+ while (index <= end) {
+ cond_resched();
+ pvec.nr = shmem_find_get_pages_and_swap(mapping, index,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1,
+ pvec.pages, indices);
+ if (!pvec.nr) {
+ /* If all gone or hole-punch, we're done */
+ if (index == start || end != -1)
+ break;
+ /* But if truncating, restart to make sure all gone */
+ index = start;
+ continue;
+ }
+ mem_cgroup_uncharge_start();
+ for (i = 0; i < pagevec_count(&pvec); i++) {
+ struct page *page = pvec.pages[i];
+
+ index = indices[i];
+ if (index > end)
+ break;
+
+ if (radix_tree_exceptional_entry(page)) {
+ if (shmem_free_swap(mapping, index, page)) {
+ /* Swap was replaced by page: retry */
+ index--;
+ break;
+ }
+ nr_swaps_freed++;
+ continue;
+ }
+
+ lock_page(page);
+ if (page->mapping == mapping) {
+ VM_BUG_ON(PageWriteback(page));
+ truncate_inode_page(mapping, page);
+ } else {
+ /* Page was replaced by swap: retry */
+ unlock_page(page);
+ index--;
+ break;
+ }
+ unlock_page(page);
+ }
+ shmem_deswap_pagevec(&pvec);
+ pagevec_release(&pvec);
+ mem_cgroup_uncharge_end();
+ index++;
+ }
+
+ spin_lock(&info->lock);
+ info->swapped -= nr_swaps_freed;
+ shmem_recalc_inode(inode);
+ spin_unlock(&info->lock);
+
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+}
+EXPORT_SYMBOL_GPL(shmem_truncate_range);
+
+static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ error = inode_change_ok(inode, attr);
+ if (error)
+ return error;
+
+ if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
+ loff_t oldsize = inode->i_size;
+ loff_t newsize = attr->ia_size;
+
+ if (newsize != oldsize) {
+ i_size_write(inode, newsize);
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+ }
+ if (newsize < oldsize) {
+ loff_t holebegin = round_up(newsize, PAGE_SIZE);
+ unmap_mapping_range(inode->i_mapping, holebegin, 0, 1);
+ shmem_truncate_range(inode, newsize, (loff_t)-1);
+ /* unmap again to remove racily COWed private pages */
+ unmap_mapping_range(inode->i_mapping, holebegin, 0, 1);
+ }
+ }
+
+ setattr_copy(inode, attr);
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ if (attr->ia_valid & ATTR_MODE)
+ error = generic_acl_chmod(inode);
+#endif
+ return error;
+}
+
+static void shmem_evict_inode(struct inode *inode)
+{
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ struct shmem_xattr *xattr, *nxattr;
+
+ if (inode->i_mapping->a_ops == &shmem_aops) {
+ shmem_unacct_size(info->flags, inode->i_size);
+ inode->i_size = 0;
+ shmem_truncate_range(inode, 0, (loff_t)-1);
+ if (!list_empty(&info->swaplist)) {
+ mutex_lock(&shmem_swaplist_mutex);
+ list_del_init(&info->swaplist);
+ mutex_unlock(&shmem_swaplist_mutex);
+ }
+ } else
+ kfree(info->symlink);
+
+ list_for_each_entry_safe(xattr, nxattr, &info->xattr_list, list) {
+ kfree(xattr->name);
+ kfree(xattr);
+ }
+ WARN_ON(inode->i_blocks);
+ shmem_free_inode(inode->i_sb);
+ end_writeback(inode);
+}
+
+/*
+ * If swap found in inode, free it and move page from swapcache to filecache.
+ */
+static int shmem_unuse_inode(struct shmem_inode_info *info,
+ swp_entry_t swap, struct page *page)
+{
+ struct address_space *mapping = info->vfs_inode.i_mapping;
+ void *radswap;
+ pgoff_t index;
+ int error;
+
+ radswap = swp_to_radix_entry(swap);
+ index = radix_tree_locate_item(&mapping->page_tree, radswap);
+ if (index == -1)
+ return 0;
+
+ /*
+ * Move _head_ to start search for next from here.
+ * But be careful: shmem_evict_inode checks list_empty without taking
+ * mutex, and there's an instant in list_move_tail when info->swaplist
+ * would appear empty, if it were the only one on shmem_swaplist.
+ */
+ if (shmem_swaplist.next != &info->swaplist)
+ list_move_tail(&shmem_swaplist, &info->swaplist);
+
+ /*
+ * We rely on shmem_swaplist_mutex, not only to protect the swaplist,
+ * but also to hold up shmem_evict_inode(): so inode cannot be freed
+ * beneath us (pagelock doesn't help until the page is in pagecache).
+ */
+ error = shmem_add_to_page_cache(page, mapping, index,
+ GFP_NOWAIT, radswap);
+ /* which does mem_cgroup_uncharge_cache_page on error */
+
+ if (error != -ENOMEM) {
+ /*
+ * Truncation and eviction use free_swap_and_cache(), which
+ * only does trylock page: if we raced, best clean up here.
+ */
+ delete_from_swap_cache(page);
+ set_page_dirty(page);
+ if (!error) {
+ spin_lock(&info->lock);
+ info->swapped--;
+ spin_unlock(&info->lock);
+ swap_free(swap);
+ }
+ error = 1; /* not an error, but entry was found */
+ }
+ return error;
+}
+
+/*
+ * Search through swapped inodes to find and replace swap by page.
+ */
+int shmem_unuse(swp_entry_t swap, struct page *page)
+{
+ struct list_head *this, *next;
+ struct shmem_inode_info *info;
+ int found = 0;
+ int error;
+
+ /*
+ * Charge page using GFP_KERNEL while we can wait, before taking
+ * the shmem_swaplist_mutex which might hold up shmem_writepage().
+ * Charged back to the user (not to caller) when swap account is used.
+ */
+ error = mem_cgroup_cache_charge(page, current->mm, GFP_KERNEL);
+ if (error)
+ goto out;
+ /* No radix_tree_preload: swap entry keeps a place for page in tree */
+
+ mutex_lock(&shmem_swaplist_mutex);
+ list_for_each_safe(this, next, &shmem_swaplist) {
+ info = list_entry(this, struct shmem_inode_info, swaplist);
+ if (info->swapped)
+ found = shmem_unuse_inode(info, swap, page);
+ else
+ list_del_init(&info->swaplist);
+ cond_resched();
+ if (found)
+ break;
+ }
+ mutex_unlock(&shmem_swaplist_mutex);
+
+ if (!found)
+ mem_cgroup_uncharge_cache_page(page);
+ if (found < 0)
+ error = found;
+out:
+ unlock_page(page);
+ page_cache_release(page);
+ return error;
+}
+
+/*
+ * Move the page from the page cache to the swap cache.
+ */
+static int shmem_writepage(struct page *page, struct writeback_control *wbc)
+{
+ struct shmem_inode_info *info;
+ struct address_space *mapping;
+ struct inode *inode;
+ swp_entry_t swap;
+ pgoff_t index;
+
+ BUG_ON(!PageLocked(page));
+ mapping = page->mapping;
+ index = page->index;
+ inode = mapping->host;
+ info = SHMEM_I(inode);
+ if (info->flags & VM_LOCKED)
+ goto redirty;
+ if (!total_swap_pages)
+ goto redirty;
+
+ /*
+ * shmem_backing_dev_info's capabilities prevent regular writeback or
+ * sync from ever calling shmem_writepage; but a stacking filesystem
+ * might use ->writepage of its underlying filesystem, in which case
+ * tmpfs should write out to swap only in response to memory pressure,
+ * and not for the writeback threads or sync.
+ */
+ if (!wbc->for_reclaim) {
+ WARN_ON_ONCE(1); /* Still happens? Tell us about it! */
+ goto redirty;
+ }
+ swap = get_swap_page();
+ if (!swap.val)
+ goto redirty;
+
+ /*
+ * Add inode to shmem_unuse()'s list of swapped-out inodes,
+ * if it's not already there. Do it now before the page is
+ * moved to swap cache, when its pagelock no longer protects
+ * the inode from eviction. But don't unlock the mutex until
+ * we've incremented swapped, because shmem_unuse_inode() will
+ * prune a !swapped inode from the swaplist under this mutex.
+ */
+ mutex_lock(&shmem_swaplist_mutex);
+ if (list_empty(&info->swaplist))
+ list_add_tail(&info->swaplist, &shmem_swaplist);
+
+ if (add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) {
+ swap_shmem_alloc(swap);
+ shmem_delete_from_page_cache(page, swp_to_radix_entry(swap));
+
+ spin_lock(&info->lock);
+ info->swapped++;
+ shmem_recalc_inode(inode);
+ spin_unlock(&info->lock);
+
+ mutex_unlock(&shmem_swaplist_mutex);
+ BUG_ON(page_mapped(page));
+ swap_writepage(page, wbc);
+ return 0;
+ }
+
+ mutex_unlock(&shmem_swaplist_mutex);
+ swapcache_free(swap, NULL);
+redirty:
+ set_page_dirty(page);
+ if (wbc->for_reclaim)
+ return AOP_WRITEPAGE_ACTIVATE; /* Return with page locked */
+ unlock_page(page);
+ return 0;
+}
+
+#ifdef CONFIG_NUMA
+#ifdef CONFIG_TMPFS
+static void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol)
+{
+ char buffer[64];
+
+ if (!mpol || mpol->mode == MPOL_DEFAULT)
+ return; /* show nothing */
+
+ mpol_to_str(buffer, sizeof(buffer), mpol, 1);
+
+ seq_printf(seq, ",mpol=%s", buffer);
+}
+
+static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo)
+{
+ struct mempolicy *mpol = NULL;
+ if (sbinfo->mpol) {
+ spin_lock(&sbinfo->stat_lock); /* prevent replace/use races */
+ mpol = sbinfo->mpol;
+ mpol_get(mpol);
+ spin_unlock(&sbinfo->stat_lock);
+ }
+ return mpol;
+}
+#endif /* CONFIG_TMPFS */
+
+static struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp,
+ struct shmem_inode_info *info, pgoff_t index)
+{
+ struct vm_area_struct pvma;
+ struct page *page;
+
+ /* Create a pseudo vma that just contains the policy */
+ pvma.vm_start = 0;
+ pvma.vm_pgoff = index;
+ pvma.vm_ops = NULL;
+ pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index);
+
+ page = swapin_readahead(swap, gfp, &pvma, 0);
+
+ /* Drop reference taken by mpol_shared_policy_lookup() */
+ mpol_cond_put(pvma.vm_policy);
+
+ return page;
+}
+
+static struct page *shmem_alloc_page(gfp_t gfp,
+ struct shmem_inode_info *info, pgoff_t index)
+{
+ struct vm_area_struct pvma;
+ struct page *page;
+
+ /* Create a pseudo vma that just contains the policy */
+ pvma.vm_start = 0;
+ pvma.vm_pgoff = index;
+ pvma.vm_ops = NULL;
+ pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index);
+
+ page = alloc_page_vma(gfp, &pvma, 0);
+
+ /* Drop reference taken by mpol_shared_policy_lookup() */
+ mpol_cond_put(pvma.vm_policy);
+
+ return page;
+}
+#else /* !CONFIG_NUMA */
+#ifdef CONFIG_TMPFS
+static inline void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol)
+{
+}
+#endif /* CONFIG_TMPFS */
+
+static inline struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp,
+ struct shmem_inode_info *info, pgoff_t index)
+{
+ return swapin_readahead(swap, gfp, NULL, 0);
+}
+
+static inline struct page *shmem_alloc_page(gfp_t gfp,
+ struct shmem_inode_info *info, pgoff_t index)
+{
+ return alloc_page(gfp);
+}
+#endif /* CONFIG_NUMA */
+
+#if !defined(CONFIG_NUMA) || !defined(CONFIG_TMPFS)
+static inline struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo)
+{
+ return NULL;
+}
+#endif
+
+/*
+ * shmem_getpage_gfp - find page in cache, or get from swap, or allocate
+ *
+ * If we allocate a new one we do not mark it dirty. That's up to the
+ * vm. If we swap it in we mark it dirty since we also free the swap
+ * entry since a page cannot live in both the swap and page cache
+ */
+static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
+ struct page **pagep, enum sgp_type sgp, gfp_t gfp, int *fault_type)
+{
+ struct address_space *mapping = inode->i_mapping;
+ struct shmem_inode_info *info;
+ struct shmem_sb_info *sbinfo;
+ struct page *page;
+ swp_entry_t swap;
+ int error;
+ int once = 0;
+
+ if (index > (MAX_LFS_FILESIZE >> PAGE_CACHE_SHIFT))
+ return -EFBIG;
+repeat:
+ swap.val = 0;
+ page = find_lock_page(mapping, index);
+ if (radix_tree_exceptional_entry(page)) {
+ swap = radix_to_swp_entry(page);
+ page = NULL;
+ }
+
+ if (sgp != SGP_WRITE &&
+ ((loff_t)index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) {
+ error = -EINVAL;
+ goto failed;
+ }
+
+ if (page || (sgp == SGP_READ && !swap.val)) {
+ /*
+ * Once we can get the page lock, it must be uptodate:
+ * if there were an error in reading back from swap,
+ * the page would not be inserted into the filecache.
+ */
+ BUG_ON(page && !PageUptodate(page));
+ *pagep = page;
+ return 0;
+ }
+
+ /*
+ * Fast cache lookup did not find it:
+ * bring it back from swap or allocate.
+ */
+ info = SHMEM_I(inode);
+ sbinfo = SHMEM_SB(inode->i_sb);
+
+ if (swap.val) {
+ /* Look it up and read it in.. */
+ page = lookup_swap_cache(swap);
+ if (!page) {
+ /* here we actually do the io */
+ if (fault_type)
+ *fault_type |= VM_FAULT_MAJOR;
+ page = shmem_swapin(swap, gfp, info, index);
+ if (!page) {
+ error = -ENOMEM;
+ goto failed;
+ }
+ }
+
+ /* We have to do this with page locked to prevent races */
+ lock_page(page);
+ if (!PageUptodate(page)) {
+ error = -EIO;
+ goto failed;
+ }
+ wait_on_page_writeback(page);
+
+ /* Someone may have already done it for us */
+ if (page->mapping) {
+ if (page->mapping == mapping &&
+ page->index == index)
+ goto done;
+ error = -EEXIST;
+ goto failed;
+ }
+
+ error = mem_cgroup_cache_charge(page, current->mm,
+ gfp & GFP_RECLAIM_MASK);
+ if (!error)
+ error = shmem_add_to_page_cache(page, mapping, index,
+ gfp, swp_to_radix_entry(swap));
+ if (error)
+ goto failed;
+
+ spin_lock(&info->lock);
+ info->swapped--;
+ shmem_recalc_inode(inode);
+ spin_unlock(&info->lock);
+
+ delete_from_swap_cache(page);
+ set_page_dirty(page);
+ swap_free(swap);
+
+ } else {
+ if (shmem_acct_block(info->flags)) {
+ error = -ENOSPC;
+ goto failed;
+ }
+ if (sbinfo->max_blocks) {
+ if (percpu_counter_compare(&sbinfo->used_blocks,
+ sbinfo->max_blocks) >= 0) {
+ error = -ENOSPC;
+ goto unacct;
+ }
+ percpu_counter_inc(&sbinfo->used_blocks);
+ }
+
+ page = shmem_alloc_page(gfp, info, index);
+ if (!page) {
+ error = -ENOMEM;
+ goto decused;
+ }
+
+ SetPageSwapBacked(page);
+ __set_page_locked(page);
+ error = mem_cgroup_cache_charge(page, current->mm,
+ gfp & GFP_RECLAIM_MASK);
+ if (!error)
+ error = shmem_add_to_page_cache(page, mapping, index,
+ gfp, NULL);
+ if (error)
+ goto decused;
+ lru_cache_add_anon(page);
+
+ spin_lock(&info->lock);
+ info->alloced++;
+ inode->i_blocks += BLOCKS_PER_PAGE;
+ shmem_recalc_inode(inode);
+ spin_unlock(&info->lock);
+
+ clear_highpage(page);
+ flush_dcache_page(page);
+ SetPageUptodate(page);
+ if (sgp == SGP_DIRTY)
+ set_page_dirty(page);
+ }
+done:
+ /* Perhaps the file has been truncated since we checked */
+ if (sgp != SGP_WRITE &&
+ ((loff_t)index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) {
+ error = -EINVAL;
+ goto trunc;
+ }
+ *pagep = page;
+ return 0;
+
+ /*
+ * Error recovery.
+ */
+trunc:
+ ClearPageDirty(page);
+ delete_from_page_cache(page);
+ spin_lock(&info->lock);
+ info->alloced--;
+ inode->i_blocks -= BLOCKS_PER_PAGE;
+ spin_unlock(&info->lock);
+decused:
+ if (sbinfo->max_blocks)
+ percpu_counter_add(&sbinfo->used_blocks, -1);
+unacct:
+ shmem_unacct_blocks(info->flags, 1);
+failed:
+ if (swap.val && error != -EINVAL) {
+ struct page *test = find_get_page(mapping, index);
+ if (test && !radix_tree_exceptional_entry(test))
+ page_cache_release(test);
+ /* Have another try if the entry has changed */
+ if (test != swp_to_radix_entry(swap))
+ error = -EEXIST;
+ }
+ if (page) {
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ if (error == -ENOSPC && !once++) {
+ info = SHMEM_I(inode);
+ spin_lock(&info->lock);
+ shmem_recalc_inode(inode);
+ spin_unlock(&info->lock);
+ goto repeat;
+ }
+ if (error == -EEXIST)
+ goto repeat;
+ return error;
+}
+
+static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
+ int error;
+ int ret = VM_FAULT_LOCKED;
+
+ /*
+ * Trinity finds that probing a hole which tmpfs is punching can
+ * prevent the hole-punch from ever completing: which in turn
+ * locks writers out with its hold on i_mutex. So refrain from
+ * faulting pages into the hole while it's being punched. Although
+ * shmem_truncate_range() does remove the additions, it may be unable to
+ * keep up, as each new page needs its own unmap_mapping_range() call,
+ * and the i_mmap tree grows ever slower to scan if new vmas are added.
+ *
+ * It does not matter if we sometimes reach this check just before the
+ * hole-punch begins, so that one fault then races with the punch:
+ * we just need to make racing faults a rare case.
+ *
+ * The implementation below would be much simpler if we just used a
+ * standard mutex or completion: but we cannot take i_mutex in fault,
+ * and bloating every shmem inode for this unlikely case would be sad.
+ */
+ if (unlikely(inode->i_private)) {
+ struct shmem_falloc *shmem_falloc;
+
+ spin_lock(&inode->i_lock);
+ shmem_falloc = inode->i_private;
+ if (shmem_falloc &&
+ vmf->pgoff >= shmem_falloc->start &&
+ vmf->pgoff < shmem_falloc->next) {
+ wait_queue_head_t *shmem_falloc_waitq;
+ DEFINE_WAIT(shmem_fault_wait);
+
+ ret = VM_FAULT_NOPAGE;
+ if ((vmf->flags & FAULT_FLAG_ALLOW_RETRY) &&
+ !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
+ /* It's polite to up mmap_sem if we can */
+ up_read(&vma->vm_mm->mmap_sem);
+ ret = VM_FAULT_RETRY;
+ }
+
+ shmem_falloc_waitq = shmem_falloc->waitq;
+ prepare_to_wait(shmem_falloc_waitq, &shmem_fault_wait,
+ TASK_UNINTERRUPTIBLE);
+ spin_unlock(&inode->i_lock);
+ schedule();
+
+ /*
+ * shmem_falloc_waitq points into the vmtruncate_range()
+ * stack of the hole-punching task: shmem_falloc_waitq
+ * is usually invalid by the time we reach here, but
+ * finish_wait() does not dereference it in that case;
+ * though i_lock needed lest racing with wake_up_all().
+ */
+ spin_lock(&inode->i_lock);
+ finish_wait(shmem_falloc_waitq, &shmem_fault_wait);
+ spin_unlock(&inode->i_lock);
+ return ret;
+ }
+ spin_unlock(&inode->i_lock);
+ }
+
+ error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_CACHE, &ret);
+ if (error)
+ return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS);
+
+ if (ret & VM_FAULT_MAJOR) {
+ count_vm_event(PGMAJFAULT);
+ mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT);
+ }
+ return ret;
+}
+
+int vmtruncate_range(struct inode *inode, loff_t lstart, loff_t lend)
+{
+ /*
+ * If the underlying filesystem is not going to provide
+ * a way to truncate a range of blocks (punch a hole) -
+ * we should return failure right now.
+ * Only CONFIG_SHMEM shmem.c ever supported i_op->truncate_range().
+ */
+ if (inode->i_op->truncate_range != shmem_truncate_range)
+ return -ENOSYS;
+
+ mutex_lock(&inode->i_mutex);
+ {
+ struct shmem_falloc shmem_falloc;
+ struct address_space *mapping = inode->i_mapping;
+ loff_t unmap_start = round_up(lstart, PAGE_SIZE);
+ loff_t unmap_end = round_down(1 + lend, PAGE_SIZE) - 1;
+ DECLARE_WAIT_QUEUE_HEAD_ONSTACK(shmem_falloc_waitq);
+
+ shmem_falloc.waitq = &shmem_falloc_waitq;
+ shmem_falloc.start = unmap_start >> PAGE_SHIFT;
+ shmem_falloc.next = (unmap_end + 1) >> PAGE_SHIFT;
+ spin_lock(&inode->i_lock);
+ inode->i_private = &shmem_falloc;
+ spin_unlock(&inode->i_lock);
+
+ if ((u64)unmap_end > (u64)unmap_start)
+ unmap_mapping_range(mapping, unmap_start,
+ 1 + unmap_end - unmap_start, 0);
+ shmem_truncate_range(inode, lstart, lend);
+ /* No need to unmap again: hole-punching leaves COWed pages */
+
+ spin_lock(&inode->i_lock);
+ inode->i_private = NULL;
+ wake_up_all(&shmem_falloc_waitq);
+ spin_unlock(&inode->i_lock);
+ }
+ mutex_unlock(&inode->i_mutex);
+ return 0;
+}
+
+#ifdef CONFIG_NUMA
+static int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *mpol)
+{
+ struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
+ return mpol_set_shared_policy(&SHMEM_I(inode)->policy, vma, mpol);
+}
+
+static struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
+ pgoff_t index;
+
+ index = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+ return mpol_shared_policy_lookup(&SHMEM_I(inode)->policy, index);
+}
+#endif
+
+int shmem_lock(struct file *file, int lock, struct user_struct *user)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ int retval = -ENOMEM;
+
+ spin_lock(&info->lock);
+ if (lock && !(info->flags & VM_LOCKED)) {
+ if (!user_shm_lock(inode->i_size, user))
+ goto out_nomem;
+ info->flags |= VM_LOCKED;
+ mapping_set_unevictable(file->f_mapping);
+ }
+ if (!lock && (info->flags & VM_LOCKED) && user) {
+ user_shm_unlock(inode->i_size, user);
+ info->flags &= ~VM_LOCKED;
+ mapping_clear_unevictable(file->f_mapping);
+ }
+ retval = 0;
+
+out_nomem:
+ spin_unlock(&info->lock);
+ return retval;
+}
+
+static int shmem_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ file_accessed(file);
+ vma->vm_ops = &shmem_vm_ops;
+ vma->vm_flags |= VM_CAN_NONLINEAR;
+ return 0;
+}
+
+static struct inode *shmem_get_inode(struct super_block *sb, const struct inode *dir,
+ umode_t mode, dev_t dev, unsigned long flags)
+{
+ struct inode *inode;
+ struct shmem_inode_info *info;
+ struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
+
+ if (shmem_reserve_inode(sb))
+ return NULL;
+
+ inode = new_inode(sb);
+ if (inode) {
+ inode->i_ino = get_next_ino();
+ inode_init_owner(inode, dir, mode);
+ inode->i_blocks = 0;
+ inode->i_mapping->backing_dev_info = &shmem_backing_dev_info;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ inode->i_generation = get_seconds();
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+ mapping_set_gfp_mask(inode->i_mapping,
+ mapping_gfp_mask(inode->i_mapping) | __GFP_PAGETMPFS);
+#endif
+ info = SHMEM_I(inode);
+ memset(info, 0, (char *)inode - (char *)info);
+ spin_lock_init(&info->lock);
+ info->flags = flags & VM_NORESERVE;
+ INIT_LIST_HEAD(&info->swaplist);
+ INIT_LIST_HEAD(&info->xattr_list);
+ cache_no_acl(inode);
+
+ switch (mode & S_IFMT) {
+ default:
+ inode->i_op = &shmem_special_inode_operations;
+ init_special_inode(inode, mode, dev);
+ break;
+ case S_IFREG:
+ inode->i_mapping->a_ops = &shmem_aops;
+ inode->i_op = &shmem_inode_operations;
+ inode->i_fop = &shmem_file_operations;
+ mpol_shared_policy_init(&info->policy,
+ shmem_get_sbmpol(sbinfo));
+ break;
+ case S_IFDIR:
+ inc_nlink(inode);
+ /* Some things misbehave if size == 0 on a directory */
+ inode->i_size = 2 * BOGO_DIRENT_SIZE;
+ inode->i_op = &shmem_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ break;
+ case S_IFLNK:
+ /*
+ * Must not load anything in the rbtree,
+ * mpol_free_shared_policy will not be called.
+ */
+ mpol_shared_policy_init(&info->policy, NULL);
+ break;
+ }
+ } else
+ shmem_free_inode(sb);
+ return inode;
+}
+
+#ifdef CONFIG_TMPFS
+static const struct inode_operations shmem_symlink_inode_operations;
+static const struct inode_operations shmem_short_symlink_operations;
+
+#ifdef CONFIG_TMPFS_XATTR
+static int shmem_initxattrs(struct inode *, const struct xattr *, void *);
+#else
+#define shmem_initxattrs NULL
+#endif
+
+static int
+shmem_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct inode *inode = mapping->host;
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ return shmem_getpage(inode, index, pagep, SGP_WRITE, NULL);
+}
+
+static int
+shmem_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ struct inode *inode = mapping->host;
+
+ if (pos + copied > inode->i_size)
+ i_size_write(inode, pos + copied);
+
+ set_page_dirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+
+ return copied;
+}
+
+static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc, read_actor_t actor)
+{
+ struct inode *inode = filp->f_path.dentry->d_inode;
+ struct address_space *mapping = inode->i_mapping;
+ pgoff_t index;
+ unsigned long offset;
+ enum sgp_type sgp = SGP_READ;
+
+ /*
+ * Might this read be for a stacking filesystem? Then when reading
+ * holes of a sparse file, we actually need to allocate those pages,
+ * and even mark them dirty, so it cannot exceed the max_blocks limit.
+ */
+ if (segment_eq(get_fs(), KERNEL_DS))
+ sgp = SGP_DIRTY;
+
+ index = *ppos >> PAGE_CACHE_SHIFT;
+ offset = *ppos & ~PAGE_CACHE_MASK;
+
+ for (;;) {
+ struct page *page = NULL;
+ pgoff_t end_index;
+ unsigned long nr, ret;
+ loff_t i_size = i_size_read(inode);
+
+ end_index = i_size >> PAGE_CACHE_SHIFT;
+ if (index > end_index)
+ break;
+ if (index == end_index) {
+ nr = i_size & ~PAGE_CACHE_MASK;
+ if (nr <= offset)
+ break;
+ }
+
+ desc->error = shmem_getpage(inode, index, &page, sgp, NULL);
+ if (desc->error) {
+ if (desc->error == -EINVAL)
+ desc->error = 0;
+ break;
+ }
+ if (page)
+ unlock_page(page);
+
+ /*
+ * We must evaluate after, since reads (unlike writes)
+ * are called without i_mutex protection against truncate
+ */
+ nr = PAGE_CACHE_SIZE;
+ i_size = i_size_read(inode);
+ end_index = i_size >> PAGE_CACHE_SHIFT;
+ if (index == end_index) {
+ nr = i_size & ~PAGE_CACHE_MASK;
+ if (nr <= offset) {
+ if (page)
+ page_cache_release(page);
+ break;
+ }
+ }
+ nr -= offset;
+
+ if (page) {
+ /*
+ * If users can be writing to this page using arbitrary
+ * virtual addresses, take care about potential aliasing
+ * before reading the page on the kernel side.
+ */
+ if (mapping_writably_mapped(mapping))
+ flush_dcache_page(page);
+ /*
+ * Mark the page accessed if we read the beginning.
+ */
+ if (!offset)
+ mark_page_accessed(page);
+ } else {
+ page = ZERO_PAGE(0);
+ page_cache_get(page);
+ }
+
+ /*
+ * Ok, we have the page, and it's up-to-date, so
+ * now we can copy it to user space...
+ *
+ * The actor routine returns how many bytes were actually used..
+ * NOTE! This may not be the same as how much of a user buffer
+ * we filled up (we may be padding etc), so we can only update
+ * "pos" here (the actor routine has to update the user buffer
+ * pointers and the remaining count).
+ */
+ ret = actor(desc, page, offset, nr);
+ offset += ret;
+ index += offset >> PAGE_CACHE_SHIFT;
+ offset &= ~PAGE_CACHE_MASK;
+
+ page_cache_release(page);
+ if (ret != nr || !desc->count)
+ break;
+
+ cond_resched();
+ }
+
+ *ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset;
+ file_accessed(filp);
+}
+
+static ssize_t shmem_file_aio_read(struct kiocb *iocb,
+ const struct iovec *iov, unsigned long nr_segs, loff_t pos)
+{
+ struct file *filp = iocb->ki_filp;
+ ssize_t retval;
+ unsigned long seg;
+ size_t count;
+ loff_t *ppos = &iocb->ki_pos;
+
+ retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
+ if (retval)
+ return retval;
+
+ for (seg = 0; seg < nr_segs; seg++) {
+ read_descriptor_t desc;
+
+ desc.written = 0;
+ desc.arg.buf = iov[seg].iov_base;
+ desc.count = iov[seg].iov_len;
+ if (desc.count == 0)
+ continue;
+ desc.error = 0;
+ do_shmem_file_read(filp, ppos, &desc, file_read_actor);
+ retval += desc.written;
+ if (desc.error) {
+ retval = retval ?: desc.error;
+ break;
+ }
+ if (desc.count > 0)
+ break;
+ }
+ return retval;
+}
+
+static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len,
+ unsigned int flags)
+{
+ struct address_space *mapping = in->f_mapping;
+ struct inode *inode = mapping->host;
+ unsigned int loff, nr_pages, req_pages;
+ struct page *pages[PIPE_DEF_BUFFERS];
+ struct partial_page partial[PIPE_DEF_BUFFERS];
+ struct page *page;
+ pgoff_t index, end_index;
+ loff_t isize, left;
+ int error, page_nr;
+ struct splice_pipe_desc spd = {
+ .pages = pages,
+ .partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
+ .flags = flags,
+ .ops = &page_cache_pipe_buf_ops,
+ .spd_release = spd_release_page,
+ };
+
+ isize = i_size_read(inode);
+ if (unlikely(*ppos >= isize))
+ return 0;
+
+ left = isize - *ppos;
+ if (unlikely(left < len))
+ len = left;
+
+ if (splice_grow_spd(pipe, &spd))
+ return -ENOMEM;
+
+ index = *ppos >> PAGE_CACHE_SHIFT;
+ loff = *ppos & ~PAGE_CACHE_MASK;
+ req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ nr_pages = min(req_pages, pipe->buffers);
+
+ spd.nr_pages = find_get_pages_contig(mapping, index,
+ nr_pages, spd.pages);
+ index += spd.nr_pages;
+ error = 0;
+
+ while (spd.nr_pages < nr_pages) {
+ error = shmem_getpage(inode, index, &page, SGP_CACHE, NULL);
+ if (error)
+ break;
+ unlock_page(page);
+ spd.pages[spd.nr_pages++] = page;
+ index++;
+ }
+
+ index = *ppos >> PAGE_CACHE_SHIFT;
+ nr_pages = spd.nr_pages;
+ spd.nr_pages = 0;
+
+ for (page_nr = 0; page_nr < nr_pages; page_nr++) {
+ unsigned int this_len;
+
+ if (!len)
+ break;
+
+ this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff);
+ page = spd.pages[page_nr];
+
+ if (!PageUptodate(page) || page->mapping != mapping) {
+ error = shmem_getpage(inode, index, &page,
+ SGP_CACHE, NULL);
+ if (error)
+ break;
+ unlock_page(page);
+ page_cache_release(spd.pages[page_nr]);
+ spd.pages[page_nr] = page;
+ }
+
+ isize = i_size_read(inode);
+ end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
+ if (unlikely(!isize || index > end_index))
+ break;
+
+ if (end_index == index) {
+ unsigned int plen;
+
+ plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
+ if (plen <= loff)
+ break;
+
+ this_len = min(this_len, plen - loff);
+ len = this_len;
+ }
+
+ spd.partial[page_nr].offset = loff;
+ spd.partial[page_nr].len = this_len;
+ len -= this_len;
+ loff = 0;
+ spd.nr_pages++;
+ index++;
+ }
+
+ while (page_nr < nr_pages)
+ page_cache_release(spd.pages[page_nr++]);
+
+ if (spd.nr_pages)
+ error = splice_to_pipe(pipe, &spd);
+
+ splice_shrink_spd(&spd);
+
+ if (error > 0) {
+ *ppos += error;
+ file_accessed(in);
+ }
+ return error;
+}
+
+static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct shmem_sb_info *sbinfo = SHMEM_SB(dentry->d_sb);
+
+ buf->f_type = TMPFS_MAGIC;
+ buf->f_bsize = PAGE_CACHE_SIZE;
+ buf->f_namelen = NAME_MAX;
+ if (sbinfo->max_blocks) {
+ buf->f_blocks = sbinfo->max_blocks;
+ buf->f_bavail =
+ buf->f_bfree = sbinfo->max_blocks -
+ percpu_counter_sum(&sbinfo->used_blocks);
+ }
+ if (sbinfo->max_inodes) {
+ buf->f_files = sbinfo->max_inodes;
+ buf->f_ffree = sbinfo->free_inodes;
+ }
+ /* else leave those fields 0 like simple_statfs */
+ return 0;
+}
+
+/*
+ * File creation. Allocate an inode, and we're done..
+ */
+static int
+shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
+{
+ struct inode *inode;
+ int error = -ENOSPC;
+
+ inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE);
+ if (inode) {
+ error = security_inode_init_security(inode, dir,
+ &dentry->d_name,
+ shmem_initxattrs, NULL);
+ if (error) {
+ if (error != -EOPNOTSUPP) {
+ iput(inode);
+ return error;
+ }
+ }
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ error = generic_acl_init(inode, dir);
+ if (error) {
+ iput(inode);
+ return error;
+ }
+#else
+ error = 0;
+#endif
+ dir->i_size += BOGO_DIRENT_SIZE;
+ dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+ d_instantiate(dentry, inode);
+ dget(dentry); /* Extra count - pin the dentry in core */
+ }
+ return error;
+}
+
+static int shmem_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ int error;
+
+ if ((error = shmem_mknod(dir, dentry, mode | S_IFDIR, 0)))
+ return error;
+ inc_nlink(dir);
+ return 0;
+}
+
+static int shmem_create(struct inode *dir, struct dentry *dentry, umode_t mode,
+ struct nameidata *nd)
+{
+ return shmem_mknod(dir, dentry, mode | S_IFREG, 0);
+}
+
+/*
+ * Link a file..
+ */
+static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = old_dentry->d_inode;
+ int ret;
+
+ /*
+ * No ordinary (disk based) filesystem counts links as inodes;
+ * but each new link needs a new dentry, pinning lowmem, and
+ * tmpfs dentries cannot be pruned until they are unlinked.
+ */
+ ret = shmem_reserve_inode(inode->i_sb);
+ if (ret)
+ goto out;
+
+ dir->i_size += BOGO_DIRENT_SIZE;
+ inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+ inc_nlink(inode);
+ ihold(inode); /* New dentry reference */
+ dget(dentry); /* Extra pinning count for the created dentry */
+ d_instantiate(dentry, inode);
+out:
+ return ret;
+}
+
+static int shmem_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+
+ if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode))
+ shmem_free_inode(inode->i_sb);
+
+ dir->i_size -= BOGO_DIRENT_SIZE;
+ inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+ drop_nlink(inode);
+ dput(dentry); /* Undo the count from "create" - this does all the work */
+ return 0;
+}
+
+static int shmem_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ if (!simple_empty(dentry))
+ return -ENOTEMPTY;
+
+ drop_nlink(dentry->d_inode);
+ drop_nlink(dir);
+ return shmem_unlink(dir, dentry);
+}
+
+/*
+ * The VFS layer already does all the dentry stuff for rename,
+ * we just have to decrement the usage count for the target if
+ * it exists so that the VFS layer correctly free's it when it
+ * gets overwritten.
+ */
+static int shmem_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct inode *inode = old_dentry->d_inode;
+ int they_are_dirs = S_ISDIR(inode->i_mode);
+
+ if (!simple_empty(new_dentry))
+ return -ENOTEMPTY;
+
+ if (new_dentry->d_inode) {
+ (void) shmem_unlink(new_dir, new_dentry);
+ if (they_are_dirs) {
+ drop_nlink(new_dentry->d_inode);
+ drop_nlink(old_dir);
+ }
+ } else if (they_are_dirs) {
+ drop_nlink(old_dir);
+ inc_nlink(new_dir);
+ }
+
+ old_dir->i_size -= BOGO_DIRENT_SIZE;
+ new_dir->i_size += BOGO_DIRENT_SIZE;
+ old_dir->i_ctime = old_dir->i_mtime =
+ new_dir->i_ctime = new_dir->i_mtime =
+ inode->i_ctime = CURRENT_TIME;
+ return 0;
+}
+
+static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
+{
+ int error;
+ int len;
+ struct inode *inode;
+ struct page *page;
+ char *kaddr;
+ struct shmem_inode_info *info;
+
+ len = strlen(symname) + 1;
+ if (len > PAGE_CACHE_SIZE)
+ return -ENAMETOOLONG;
+
+ inode = shmem_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE);
+ if (!inode)
+ return -ENOSPC;
+
+ error = security_inode_init_security(inode, dir, &dentry->d_name,
+ shmem_initxattrs, NULL);
+ if (error) {
+ if (error != -EOPNOTSUPP) {
+ iput(inode);
+ return error;
+ }
+ error = 0;
+ }
+
+ info = SHMEM_I(inode);
+ inode->i_size = len-1;
+ if (len <= SHORT_SYMLINK_LEN) {
+ info->symlink = kmemdup(symname, len, GFP_KERNEL);
+ if (!info->symlink) {
+ iput(inode);
+ return -ENOMEM;
+ }
+ inode->i_op = &shmem_short_symlink_operations;
+ } else {
+ error = shmem_getpage(inode, 0, &page, SGP_WRITE, NULL);
+ if (error) {
+ iput(inode);
+ return error;
+ }
+ inode->i_mapping->a_ops = &shmem_aops;
+ inode->i_op = &shmem_symlink_inode_operations;
+ kaddr = kmap_atomic(page);
+ memcpy(kaddr, symname, len);
+ kunmap_atomic(kaddr);
+ set_page_dirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ dir->i_size += BOGO_DIRENT_SIZE;
+ dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+ d_instantiate(dentry, inode);
+ dget(dentry);
+ return 0;
+}
+
+static void *shmem_follow_short_symlink(struct dentry *dentry, struct nameidata *nd)
+{
+ nd_set_link(nd, SHMEM_I(dentry->d_inode)->symlink);
+ return NULL;
+}
+
+static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ struct page *page = NULL;
+ int error = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL);
+ nd_set_link(nd, error ? ERR_PTR(error) : kmap(page));
+ if (page)
+ unlock_page(page);
+ return page;
+}
+
+static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
+{
+ if (!IS_ERR(nd_get_link(nd))) {
+ struct page *page = cookie;
+ kunmap(page);
+ mark_page_accessed(page);
+ page_cache_release(page);
+ }
+}
+
+#ifdef CONFIG_TMPFS_XATTR
+/*
+ * Superblocks without xattr inode operations may get some security.* xattr
+ * support from the LSM "for free". As soon as we have any other xattrs
+ * like ACLs, we also need to implement the security.* handlers at
+ * filesystem level, though.
+ */
+
+/*
+ * Allocate new xattr and copy in the value; but leave the name to callers.
+ */
+static struct shmem_xattr *shmem_xattr_alloc(const void *value, size_t size)
+{
+ struct shmem_xattr *new_xattr;
+ size_t len;
+
+ /* wrap around? */
+ len = sizeof(*new_xattr) + size;
+ if (len <= sizeof(*new_xattr))
+ return NULL;
+
+ new_xattr = kmalloc(len, GFP_KERNEL);
+ if (!new_xattr)
+ return NULL;
+
+ new_xattr->size = size;
+ memcpy(new_xattr->value, value, size);
+ return new_xattr;
+}
+
+/*
+ * Callback for security_inode_init_security() for acquiring xattrs.
+ */
+static int shmem_initxattrs(struct inode *inode,
+ const struct xattr *xattr_array,
+ void *fs_info)
+{
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ const struct xattr *xattr;
+ struct shmem_xattr *new_xattr;
+ size_t len;
+
+ for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+ new_xattr = shmem_xattr_alloc(xattr->value, xattr->value_len);
+ if (!new_xattr)
+ return -ENOMEM;
+
+ len = strlen(xattr->name) + 1;
+ new_xattr->name = kmalloc(XATTR_SECURITY_PREFIX_LEN + len,
+ GFP_KERNEL);
+ if (!new_xattr->name) {
+ kfree(new_xattr);
+ return -ENOMEM;
+ }
+
+ memcpy(new_xattr->name, XATTR_SECURITY_PREFIX,
+ XATTR_SECURITY_PREFIX_LEN);
+ memcpy(new_xattr->name + XATTR_SECURITY_PREFIX_LEN,
+ xattr->name, len);
+
+ spin_lock(&info->lock);
+ list_add(&new_xattr->list, &info->xattr_list);
+ spin_unlock(&info->lock);
+ }
+
+ return 0;
+}
+
+static int shmem_xattr_get(struct dentry *dentry, const char *name,
+ void *buffer, size_t size)
+{
+ struct shmem_inode_info *info;
+ struct shmem_xattr *xattr;
+ int ret = -ENODATA;
+
+ info = SHMEM_I(dentry->d_inode);
+
+ spin_lock(&info->lock);
+ list_for_each_entry(xattr, &info->xattr_list, list) {
+ if (strcmp(name, xattr->name))
+ continue;
+
+ ret = xattr->size;
+ if (buffer) {
+ if (size < xattr->size)
+ ret = -ERANGE;
+ else
+ memcpy(buffer, xattr->value, xattr->size);
+ }
+ break;
+ }
+ spin_unlock(&info->lock);
+ return ret;
+}
+
+static int shmem_xattr_set(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ struct shmem_xattr *xattr;
+ struct shmem_xattr *new_xattr = NULL;
+ int err = 0;
+
+ /* value == NULL means remove */
+ if (value) {
+ new_xattr = shmem_xattr_alloc(value, size);
+ if (!new_xattr)
+ return -ENOMEM;
+
+ new_xattr->name = kstrdup(name, GFP_KERNEL);
+ if (!new_xattr->name) {
+ kfree(new_xattr);
+ return -ENOMEM;
+ }
+ }
+
+ spin_lock(&info->lock);
+ list_for_each_entry(xattr, &info->xattr_list, list) {
+ if (!strcmp(name, xattr->name)) {
+ if (flags & XATTR_CREATE) {
+ xattr = new_xattr;
+ err = -EEXIST;
+ } else if (new_xattr) {
+ list_replace(&xattr->list, &new_xattr->list);
+ } else {
+ list_del(&xattr->list);
+ }
+ goto out;
+ }
+ }
+ if (flags & XATTR_REPLACE) {
+ xattr = new_xattr;
+ err = -ENODATA;
+ } else {
+ list_add(&new_xattr->list, &info->xattr_list);
+ xattr = NULL;
+ }
+out:
+ spin_unlock(&info->lock);
+ if (xattr)
+ kfree(xattr->name);
+ kfree(xattr);
+ return err;
+}
+
+static const struct xattr_handler *shmem_xattr_handlers[] = {
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ &generic_acl_access_handler,
+ &generic_acl_default_handler,
+#endif
+ NULL
+};
+
+static int shmem_xattr_validate(const char *name)
+{
+ struct { const char *prefix; size_t len; } arr[] = {
+ { XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN },
+ { XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN }
+ };
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(arr); i++) {
+ size_t preflen = arr[i].len;
+ if (strncmp(name, arr[i].prefix, preflen) == 0) {
+ if (!name[preflen])
+ return -EINVAL;
+ return 0;
+ }
+ }
+ return -EOPNOTSUPP;
+}
+
+static ssize_t shmem_getxattr(struct dentry *dentry, const char *name,
+ void *buffer, size_t size)
+{
+ int err;
+
+ /*
+ * If this is a request for a synthetic attribute in the system.*
+ * namespace use the generic infrastructure to resolve a handler
+ * for it via sb->s_xattr.
+ */
+ if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+ return generic_getxattr(dentry, name, buffer, size);
+
+ err = shmem_xattr_validate(name);
+ if (err)
+ return err;
+
+ return shmem_xattr_get(dentry, name, buffer, size);
+}
+
+static int shmem_setxattr(struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags)
+{
+ int err;
+
+ /*
+ * If this is a request for a synthetic attribute in the system.*
+ * namespace use the generic infrastructure to resolve a handler
+ * for it via sb->s_xattr.
+ */
+ if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+ return generic_setxattr(dentry, name, value, size, flags);
+
+ err = shmem_xattr_validate(name);
+ if (err)
+ return err;
+
+ if (size == 0)
+ value = ""; /* empty EA, do not remove */
+
+ return shmem_xattr_set(dentry->d_inode, name, value, size, flags);
+
+}
+
+static int shmem_removexattr(struct dentry *dentry, const char *name)
+{
+ int err;
+
+ /*
+ * If this is a request for a synthetic attribute in the system.*
+ * namespace use the generic infrastructure to resolve a handler
+ * for it via sb->s_xattr.
+ */
+ if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+ return generic_removexattr(dentry, name);
+
+ err = shmem_xattr_validate(name);
+ if (err)
+ return err;
+
+ return shmem_xattr_set(dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
+}
+
+static bool xattr_is_trusted(const char *name)
+{
+ return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
+}
+
+static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+ bool trusted = capable(CAP_SYS_ADMIN);
+ struct shmem_xattr *xattr;
+ struct shmem_inode_info *info;
+ size_t used = 0;
+
+ info = SHMEM_I(dentry->d_inode);
+
+ spin_lock(&info->lock);
+ list_for_each_entry(xattr, &info->xattr_list, list) {
+ size_t len;
+
+ /* skip "trusted." attributes for unprivileged callers */
+ if (!trusted && xattr_is_trusted(xattr->name))
+ continue;
+
+ len = strlen(xattr->name) + 1;
+ used += len;
+ if (buffer) {
+ if (size < used) {
+ used = -ERANGE;
+ break;
+ }
+ memcpy(buffer, xattr->name, len);
+ buffer += len;
+ }
+ }
+ spin_unlock(&info->lock);
+
+ return used;
+}
+#endif /* CONFIG_TMPFS_XATTR */
+
+static const struct inode_operations shmem_short_symlink_operations = {
+ .readlink = generic_readlink,
+ .follow_link = shmem_follow_short_symlink,
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = shmem_setxattr,
+ .getxattr = shmem_getxattr,
+ .listxattr = shmem_listxattr,
+ .removexattr = shmem_removexattr,
+#endif
+};
+
+static const struct inode_operations shmem_symlink_inode_operations = {
+ .readlink = generic_readlink,
+ .follow_link = shmem_follow_link,
+ .put_link = shmem_put_link,
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = shmem_setxattr,
+ .getxattr = shmem_getxattr,
+ .listxattr = shmem_listxattr,
+ .removexattr = shmem_removexattr,
+#endif
+};
+
+static struct dentry *shmem_get_parent(struct dentry *child)
+{
+ return ERR_PTR(-ESTALE);
+}
+
+static int shmem_match(struct inode *ino, void *vfh)
+{
+ __u32 *fh = vfh;
+ __u64 inum = fh[2];
+ inum = (inum << 32) | fh[1];
+ return ino->i_ino == inum && fh[0] == ino->i_generation;
+}
+
+static struct dentry *shmem_fh_to_dentry(struct super_block *sb,
+ struct fid *fid, int fh_len, int fh_type)
+{
+ struct inode *inode;
+ struct dentry *dentry = NULL;
+ u64 inum;
+
+ if (fh_len < 3)
+ return NULL;
+
+ inum = fid->raw[2];
+ inum = (inum << 32) | fid->raw[1];
+
+ inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]),
+ shmem_match, fid->raw);
+ if (inode) {
+ dentry = d_find_alias(inode);
+ iput(inode);
+ }
+
+ return dentry;
+}
+
+static int shmem_encode_fh(struct dentry *dentry, __u32 *fh, int *len,
+ int connectable)
+{
+ struct inode *inode = dentry->d_inode;
+
+ if (*len < 3) {
+ *len = 3;
+ return 255;
+ }
+
+ if (inode_unhashed(inode)) {
+ /* Unfortunately insert_inode_hash is not idempotent,
+ * so as we hash inodes here rather than at creation
+ * time, we need a lock to ensure we only try
+ * to do it once
+ */
+ static DEFINE_SPINLOCK(lock);
+ spin_lock(&lock);
+ if (inode_unhashed(inode))
+ __insert_inode_hash(inode,
+ inode->i_ino + inode->i_generation);
+ spin_unlock(&lock);
+ }
+
+ fh[0] = inode->i_generation;
+ fh[1] = inode->i_ino;
+ fh[2] = ((__u64)inode->i_ino) >> 32;
+
+ *len = 3;
+ return 1;
+}
+
+static const struct export_operations shmem_export_ops = {
+ .get_parent = shmem_get_parent,
+ .encode_fh = shmem_encode_fh,
+ .fh_to_dentry = shmem_fh_to_dentry,
+};
+
+static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo,
+ bool remount)
+{
+ char *this_char, *value, *rest;
+
+ while (options != NULL) {
+ this_char = options;
+ for (;;) {
+ /*
+ * NUL-terminate this option: unfortunately,
+ * mount options form a comma-separated list,
+ * but mpol's nodelist may also contain commas.
+ */
+ options = strchr(options, ',');
+ if (options == NULL)
+ break;
+ options++;
+ if (!isdigit(*options)) {
+ options[-1] = '\0';
+ break;
+ }
+ }
+ if (!*this_char)
+ continue;
+ if ((value = strchr(this_char,'=')) != NULL) {
+ *value++ = 0;
+ } else {
+ printk(KERN_ERR
+ "tmpfs: No value for mount option '%s'\n",
+ this_char);
+ return 1;
+ }
+
+ if (!strcmp(this_char,"size")) {
+ unsigned long long size;
+ size = memparse(value,&rest);
+ if (*rest == '%') {
+ size <<= PAGE_SHIFT;
+ size *= totalram_pages;
+ do_div(size, 100);
+ rest++;
+ }
+ if (*rest)
+ goto bad_val;
+ sbinfo->max_blocks =
+ DIV_ROUND_UP(size, PAGE_CACHE_SIZE);
+ } else if (!strcmp(this_char,"nr_blocks")) {
+ sbinfo->max_blocks = memparse(value, &rest);
+ if (*rest)
+ goto bad_val;
+ } else if (!strcmp(this_char,"nr_inodes")) {
+ sbinfo->max_inodes = memparse(value, &rest);
+ if (*rest)
+ goto bad_val;
+ } else if (!strcmp(this_char,"mode")) {
+ if (remount)
+ continue;
+ sbinfo->mode = simple_strtoul(value, &rest, 8) & 07777;
+ if (*rest)
+ goto bad_val;
+ } else if (!strcmp(this_char,"uid")) {
+ if (remount)
+ continue;
+ sbinfo->uid = simple_strtoul(value, &rest, 0);
+ if (*rest)
+ goto bad_val;
+ } else if (!strcmp(this_char,"gid")) {
+ if (remount)
+ continue;
+ sbinfo->gid = simple_strtoul(value, &rest, 0);
+ if (*rest)
+ goto bad_val;
+ } else if (!strcmp(this_char,"mpol")) {
+ if (mpol_parse_str(value, &sbinfo->mpol, 1))
+ goto bad_val;
+ } else {
+ printk(KERN_ERR "tmpfs: Bad mount option %s\n",
+ this_char);
+ return 1;
+ }
+ }
+ return 0;
+
+bad_val:
+ printk(KERN_ERR "tmpfs: Bad value '%s' for mount option '%s'\n",
+ value, this_char);
+ return 1;
+
+}
+
+static int shmem_remount_fs(struct super_block *sb, int *flags, char *data)
+{
+ struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
+ struct shmem_sb_info config = *sbinfo;
+ unsigned long inodes;
+ int error = -EINVAL;
+
+ config.mpol = NULL;
+ if (shmem_parse_options(data, &config, true))
+ return error;
+
+ spin_lock(&sbinfo->stat_lock);
+ inodes = sbinfo->max_inodes - sbinfo->free_inodes;
+ if (percpu_counter_compare(&sbinfo->used_blocks, config.max_blocks) > 0)
+ goto out;
+ if (config.max_inodes < inodes)
+ goto out;
+ /*
+ * Those tests disallow limited->unlimited while any are in use;
+ * but we must separately disallow unlimited->limited, because
+ * in that case we have no record of how much is already in use.
+ */
+ if (config.max_blocks && !sbinfo->max_blocks)
+ goto out;
+ if (config.max_inodes && !sbinfo->max_inodes)
+ goto out;
+
+ error = 0;
+ sbinfo->max_blocks = config.max_blocks;
+ sbinfo->max_inodes = config.max_inodes;
+ sbinfo->free_inodes = config.max_inodes - inodes;
+
+ /*
+ * Preserve previous mempolicy unless mpol remount option was specified.
+ */
+ if (config.mpol) {
+ mpol_put(sbinfo->mpol);
+ sbinfo->mpol = config.mpol; /* transfers initial ref */
+ }
+out:
+ spin_unlock(&sbinfo->stat_lock);
+ return error;
+}
+
+static int shmem_show_options(struct seq_file *seq, struct dentry *root)
+{
+ struct shmem_sb_info *sbinfo = SHMEM_SB(root->d_sb);
+
+ if (sbinfo->max_blocks != shmem_default_max_blocks())
+ seq_printf(seq, ",size=%luk",
+ sbinfo->max_blocks << (PAGE_CACHE_SHIFT - 10));
+ if (sbinfo->max_inodes != shmem_default_max_inodes())
+ seq_printf(seq, ",nr_inodes=%lu", sbinfo->max_inodes);
+ if (sbinfo->mode != (S_IRWXUGO | S_ISVTX))
+ seq_printf(seq, ",mode=%03ho", sbinfo->mode);
+ if (sbinfo->uid != 0)
+ seq_printf(seq, ",uid=%u", sbinfo->uid);
+ if (sbinfo->gid != 0)
+ seq_printf(seq, ",gid=%u", sbinfo->gid);
+ shmem_show_mpol(seq, sbinfo->mpol);
+ return 0;
+}
+#endif /* CONFIG_TMPFS */
+
+static void shmem_put_super(struct super_block *sb)
+{
+ struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
+
+ percpu_counter_destroy(&sbinfo->used_blocks);
+ kfree(sbinfo);
+ sb->s_fs_info = NULL;
+}
+
+int shmem_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct inode *inode;
+ struct shmem_sb_info *sbinfo;
+ int err = -ENOMEM;
+
+ /* Round up to L1_CACHE_BYTES to resist false sharing */
+ sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info),
+ L1_CACHE_BYTES), GFP_KERNEL);
+ if (!sbinfo)
+ return -ENOMEM;
+
+ sbinfo->mode = S_IRWXUGO | S_ISVTX;
+ sbinfo->uid = current_fsuid();
+ sbinfo->gid = current_fsgid();
+ sb->s_fs_info = sbinfo;
+
+#ifdef CONFIG_TMPFS
+ /*
+ * Per default we only allow half of the physical ram per
+ * tmpfs instance, limiting inodes to one per page of lowmem;
+ * but the internal instance is left unlimited.
+ */
+ if (!(sb->s_flags & MS_NOUSER)) {
+ sbinfo->max_blocks = shmem_default_max_blocks();
+ sbinfo->max_inodes = shmem_default_max_inodes();
+ if (shmem_parse_options(data, sbinfo, false)) {
+ err = -EINVAL;
+ goto failed;
+ }
+ }
+ sb->s_export_op = &shmem_export_ops;
+#else
+ sb->s_flags |= MS_NOUSER;
+#endif
+
+ spin_lock_init(&sbinfo->stat_lock);
+ if (percpu_counter_init(&sbinfo->used_blocks, 0))
+ goto failed;
+ sbinfo->free_inodes = sbinfo->max_inodes;
+
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = TMPFS_MAGIC;
+ sb->s_op = &shmem_ops;
+ sb->s_time_gran = 1;
+#ifdef CONFIG_TMPFS_XATTR
+ sb->s_xattr = shmem_xattr_handlers;
+#endif
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ sb->s_flags |= MS_POSIXACL;
+#endif
+
+ inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE);
+ if (!inode)
+ goto failed;
+ inode->i_uid = sbinfo->uid;
+ inode->i_gid = sbinfo->gid;
+ sb->s_root = d_make_root(inode);
+ if (!sb->s_root)
+ goto failed;
+ return 0;
+
+failed:
+ shmem_put_super(sb);
+ return err;
+}
+
+static struct kmem_cache *shmem_inode_cachep;
+
+static struct inode *shmem_alloc_inode(struct super_block *sb)
+{
+ struct shmem_inode_info *info;
+ info = kmem_cache_alloc(shmem_inode_cachep, GFP_KERNEL);
+ if (!info)
+ return NULL;
+ return &info->vfs_inode;
+}
+
+static void shmem_destroy_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode));
+}
+
+static void shmem_destroy_inode(struct inode *inode)
+{
+ if (S_ISREG(inode->i_mode))
+ mpol_free_shared_policy(&SHMEM_I(inode)->policy);
+ call_rcu(&inode->i_rcu, shmem_destroy_callback);
+}
+
+static void shmem_init_inode(void *foo)
+{
+ struct shmem_inode_info *info = foo;
+ inode_init_once(&info->vfs_inode);
+}
+
+static int shmem_init_inodecache(void)
+{
+ shmem_inode_cachep = kmem_cache_create("shmem_inode_cache",
+ sizeof(struct shmem_inode_info),
+ 0, SLAB_PANIC, shmem_init_inode);
+ return 0;
+}
+
+static void shmem_destroy_inodecache(void)
+{
+ kmem_cache_destroy(shmem_inode_cachep);
+}
+
+static const struct address_space_operations shmem_aops = {
+ .writepage = shmem_writepage,
+ .set_page_dirty = __set_page_dirty_no_writeback,
+#ifdef CONFIG_TMPFS
+ .write_begin = shmem_write_begin,
+ .write_end = shmem_write_end,
+#endif
+ .migratepage = migrate_page,
+ .error_remove_page = generic_error_remove_page,
+};
+
+static const struct file_operations shmem_file_operations = {
+ .mmap = shmem_mmap,
+#ifdef CONFIG_TMPFS
+ .llseek = generic_file_llseek,
+ .read = do_sync_read,
+ .write = do_sync_write,
+ .aio_read = shmem_file_aio_read,
+ .aio_write = generic_file_aio_write,
+ .fsync = noop_fsync,
+ .splice_read = shmem_file_splice_read,
+ .splice_write = generic_file_splice_write,
+#endif
+};
+
+static const struct inode_operations shmem_inode_operations = {
+ .setattr = shmem_setattr,
+ .truncate_range = shmem_truncate_range,
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = shmem_setxattr,
+ .getxattr = shmem_getxattr,
+ .listxattr = shmem_listxattr,
+ .removexattr = shmem_removexattr,
+#endif
+};
+
+static const struct inode_operations shmem_dir_inode_operations = {
+#ifdef CONFIG_TMPFS
+ .create = shmem_create,
+ .lookup = simple_lookup,
+ .link = shmem_link,
+ .unlink = shmem_unlink,
+ .symlink = shmem_symlink,
+ .mkdir = shmem_mkdir,
+ .rmdir = shmem_rmdir,
+ .mknod = shmem_mknod,
+ .rename = shmem_rename,
+#endif
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = shmem_setxattr,
+ .getxattr = shmem_getxattr,
+ .listxattr = shmem_listxattr,
+ .removexattr = shmem_removexattr,
+#endif
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ .setattr = shmem_setattr,
+#endif
+};
+
+static const struct inode_operations shmem_special_inode_operations = {
+#ifdef CONFIG_TMPFS_XATTR
+ .setxattr = shmem_setxattr,
+ .getxattr = shmem_getxattr,
+ .listxattr = shmem_listxattr,
+ .removexattr = shmem_removexattr,
+#endif
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ .setattr = shmem_setattr,
+#endif
+};
+
+static const struct super_operations shmem_ops = {
+ .alloc_inode = shmem_alloc_inode,
+ .destroy_inode = shmem_destroy_inode,
+#ifdef CONFIG_TMPFS
+ .statfs = shmem_statfs,
+ .remount_fs = shmem_remount_fs,
+ .show_options = shmem_show_options,
+#endif
+ .evict_inode = shmem_evict_inode,
+ .drop_inode = generic_delete_inode,
+ .put_super = shmem_put_super,
+};
+
+static const struct vm_operations_struct shmem_vm_ops = {
+ .fault = shmem_fault,
+#ifdef CONFIG_NUMA
+ .set_policy = shmem_set_policy,
+ .get_policy = shmem_get_policy,
+#endif
+};
+
+static struct dentry *shmem_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_nodev(fs_type, flags, data, shmem_fill_super);
+}
+
+static struct file_system_type shmem_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "tmpfs",
+ .mount = shmem_mount,
+ .kill_sb = kill_litter_super,
+};
+
+int __init shmem_init(void)
+{
+ int error;
+
+ error = bdi_init(&shmem_backing_dev_info);
+ if (error)
+ goto out4;
+
+ error = shmem_init_inodecache();
+ if (error)
+ goto out3;
+
+ error = register_filesystem(&shmem_fs_type);
+ if (error) {
+ printk(KERN_ERR "Could not register tmpfs\n");
+ goto out2;
+ }
+
+ shm_mnt = vfs_kern_mount(&shmem_fs_type, MS_NOUSER,
+ shmem_fs_type.name, NULL);
+ if (IS_ERR(shm_mnt)) {
+ error = PTR_ERR(shm_mnt);
+ printk(KERN_ERR "Could not kern_mount tmpfs\n");
+ goto out1;
+ }
+ return 0;
+
+out1:
+ unregister_filesystem(&shmem_fs_type);
+out2:
+ shmem_destroy_inodecache();
+out3:
+ bdi_destroy(&shmem_backing_dev_info);
+out4:
+ shm_mnt = ERR_PTR(error);
+ return error;
+}
+
+#else /* !CONFIG_SHMEM */
+
+/*
+ * tiny-shmem: simple shmemfs and tmpfs using ramfs code
+ *
+ * This is intended for small system where the benefits of the full
+ * shmem code (swap-backed and resource-limited) are outweighed by
+ * their complexity. On systems without swap this code should be
+ * effectively equivalent, but much lighter weight.
+ */
+
+#include <linux/ramfs.h>
+
+static struct file_system_type shmem_fs_type = {
+ .name = "tmpfs",
+ .mount = ramfs_mount,
+ .kill_sb = kill_litter_super,
+};
+
+int __init shmem_init(void)
+{
+ BUG_ON(register_filesystem(&shmem_fs_type) != 0);
+
+ shm_mnt = kern_mount(&shmem_fs_type);
+ BUG_ON(IS_ERR(shm_mnt));
+
+ return 0;
+}
+
+int shmem_unuse(swp_entry_t swap, struct page *page)
+{
+ return 0;
+}
+
+int shmem_lock(struct file *file, int lock, struct user_struct *user)
+{
+ return 0;
+}
+
+void shmem_unlock_mapping(struct address_space *mapping)
+{
+}
+
+void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
+{
+ truncate_inode_pages_range(inode->i_mapping, lstart, lend);
+}
+EXPORT_SYMBOL_GPL(shmem_truncate_range);
+
+int vmtruncate_range(struct inode *inode, loff_t lstart, loff_t lend)
+{
+ /* Only CONFIG_SHMEM shmem.c ever supported i_op->truncate_range(). */
+ return -ENOSYS;
+}
+
+#define shmem_vm_ops generic_file_vm_ops
+#define shmem_file_operations ramfs_file_operations
+#define shmem_get_inode(sb, dir, mode, dev, flags) ramfs_get_inode(sb, dir, mode, dev)
+#define shmem_acct_size(flags, size) 0
+#define shmem_unacct_size(flags, size) do {} while (0)
+
+#endif /* CONFIG_SHMEM */
+
+/* common code */
+
+/**
+ * shmem_file_setup - get an unlinked file living in tmpfs
+ * @name: name for dentry (to be seen in /proc/<pid>/maps
+ * @size: size to be set for the file
+ * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size
+ */
+struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags)
+{
+ int error;
+ struct file *file;
+ struct inode *inode;
+ struct path path;
+ struct dentry *root;
+ struct qstr this;
+
+ if (IS_ERR(shm_mnt))
+ return (void *)shm_mnt;
+
+ if (size < 0 || size > MAX_LFS_FILESIZE)
+ return ERR_PTR(-EINVAL);
+
+ if (shmem_acct_size(flags, size))
+ return ERR_PTR(-ENOMEM);
+
+ error = -ENOMEM;
+ this.name = name;
+ this.len = strlen(name);
+ this.hash = 0; /* will go */
+ root = shm_mnt->mnt_root;
+ path.dentry = d_alloc(root, &this);
+ if (!path.dentry)
+ goto put_memory;
+ path.mnt = mntget(shm_mnt);
+
+ error = -ENOSPC;
+ inode = shmem_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0, flags);
+ if (!inode)
+ goto put_dentry;
+
+ d_instantiate(path.dentry, inode);
+ inode->i_size = size;
+ clear_nlink(inode); /* It is unlinked */
+#ifndef CONFIG_MMU
+ error = ramfs_nommu_expand_for_mapping(inode, size);
+ if (error)
+ goto put_dentry;
+#endif
+
+ error = -ENFILE;
+ file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
+ &shmem_file_operations);
+ if (!file)
+ goto put_dentry;
+
+ return file;
+
+put_dentry:
+ path_put(&path);
+put_memory:
+ shmem_unacct_size(flags, size);
+ return ERR_PTR(error);
+}
+EXPORT_SYMBOL_GPL(shmem_file_setup);
+
+void shmem_set_file(struct vm_area_struct *vma, struct file *file)
+{
+ if (vma->vm_file)
+ fput(vma->vm_file);
+ vma->vm_file = file;
+ vma->vm_ops = &shmem_vm_ops;
+ vma->vm_flags |= VM_CAN_NONLINEAR;
+}
+
+/**
+ * shmem_zero_setup - setup a shared anonymous mapping
+ * @vma: the vma to be mmapped is prepared by do_mmap_pgoff
+ */
+int shmem_zero_setup(struct vm_area_struct *vma)
+{
+ struct file *file;
+ loff_t size = vma->vm_end - vma->vm_start;
+
+ file = shmem_file_setup("dev/zero", size, vma->vm_flags);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+
+ shmem_set_file(vma, file);
+ return 0;
+}
+
+/**
+ * shmem_read_mapping_page_gfp - read into page cache, using specified page allocation flags.
+ * @mapping: the page's address_space
+ * @index: the page index
+ * @gfp: the page allocator flags to use if allocating
+ *
+ * This behaves as a tmpfs "read_cache_page_gfp(mapping, index, gfp)",
+ * with any new page allocations done using the specified allocation flags.
+ * But read_cache_page_gfp() uses the ->readpage() method: which does not
+ * suit tmpfs, since it may have pages in swapcache, and needs to find those
+ * for itself; although drivers/gpu/drm i915 and ttm rely upon this support.
+ *
+ * i915_gem_object_get_pages_gtt() mixes __GFP_NORETRY | __GFP_NOWARN in
+ * with the mapping_gfp_mask(), to avoid OOMing the machine unnecessarily.
+ */
+struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
+ pgoff_t index, gfp_t gfp)
+{
+#ifdef CONFIG_SHMEM
+ struct inode *inode = mapping->host;
+ struct page *page;
+ int error;
+
+ BUG_ON(mapping->a_ops != &shmem_aops);
+ error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE, gfp, NULL);
+ if (error)
+ page = ERR_PTR(error);
+ else
+ unlock_page(page);
+ return page;
+#else
+ /*
+ * The tiny !SHMEM case uses ramfs without swap
+ */
+ return read_cache_page_gfp(mapping, index, gfp);
+#endif
+}
+EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp);
diff --git a/ap/os/linux/linux-3.4.x/mm/slab.c b/ap/os/linux/linux-3.4.x/mm/slab.c
new file mode 100644
index 0000000..fae1764
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/slab.c
@@ -0,0 +1,4949 @@
+/*
+ * linux/mm/slab.c
+ * Written by Mark Hemment, 1996/97.
+ * (markhe@nextd.demon.co.uk)
+ *
+ * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
+ *
+ * Major cleanup, different bufctl logic, per-cpu arrays
+ * (c) 2000 Manfred Spraul
+ *
+ * Cleanup, make the head arrays unconditional, preparation for NUMA
+ * (c) 2002 Manfred Spraul
+ *
+ * An implementation of the Slab Allocator as described in outline in;
+ * UNIX Internals: The New Frontiers by Uresh Vahalia
+ * Pub: Prentice Hall ISBN 0-13-101908-2
+ * or with a little more detail in;
+ * The Slab Allocator: An Object-Caching Kernel Memory Allocator
+ * Jeff Bonwick (Sun Microsystems).
+ * Presented at: USENIX Summer 1994 Technical Conference
+ *
+ * The memory is organized in caches, one cache for each object type.
+ * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
+ * Each cache consists out of many slabs (they are small (usually one
+ * page long) and always contiguous), and each slab contains multiple
+ * initialized objects.
+ *
+ * This means, that your constructor is used only for newly allocated
+ * slabs and you must pass objects with the same initializations to
+ * kmem_cache_free.
+ *
+ * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
+ * normal). If you need a special memory type, then must create a new
+ * cache for that memory type.
+ *
+ * In order to reduce fragmentation, the slabs are sorted in 3 groups:
+ * full slabs with 0 free objects
+ * partial slabs
+ * empty slabs with no allocated objects
+ *
+ * If partial slabs exist, then new allocations come from these slabs,
+ * otherwise from empty slabs or new slabs are allocated.
+ *
+ * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
+ * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
+ *
+ * Each cache has a short per-cpu head array, most allocs
+ * and frees go into that array, and if that array overflows, then 1/2
+ * of the entries in the array are given back into the global cache.
+ * The head array is strictly LIFO and should improve the cache hit rates.
+ * On SMP, it additionally reduces the spinlock operations.
+ *
+ * The c_cpuarray may not be read with enabled local interrupts -
+ * it's changed with a smp_call_function().
+ *
+ * SMP synchronization:
+ * constructors and destructors are called without any locking.
+ * Several members in struct kmem_cache and struct slab never change, they
+ * are accessed without any locking.
+ * The per-cpu arrays are never accessed from the wrong cpu, no locking,
+ * and local interrupts are disabled so slab code is preempt-safe.
+ * The non-constant members are protected with a per-cache irq spinlock.
+ *
+ * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
+ * in 2000 - many ideas in the current implementation are derived from
+ * his patch.
+ *
+ * Further notes from the original documentation:
+ *
+ * 11 April '97. Started multi-threading - markhe
+ * The global cache-chain is protected by the mutex 'cache_chain_mutex'.
+ * The sem is only needed when accessing/extending the cache-chain, which
+ * can never happen inside an interrupt (kmem_cache_create(),
+ * kmem_cache_shrink() and kmem_cache_reap()).
+ *
+ * At present, each engine can be growing a cache. This should be blocked.
+ *
+ * 15 March 2005. NUMA slab allocator.
+ * Shai Fultheim <shai@scalex86.org>.
+ * Shobhit Dayal <shobhit@calsoftinc.com>
+ * Alok N Kataria <alokk@calsoftinc.com>
+ * Christoph Lameter <christoph@lameter.com>
+ *
+ * Modified the slab allocator to be node aware on NUMA systems.
+ * Each node has its own list of partial, free and full slabs.
+ * All object allocations for a node occur from node specific slab lists.
+ */
+
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/poison.h>
+#include <linux/swap.h>
+#include <linux/cache.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/compiler.h>
+#include <linux/cpuset.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/notifier.h>
+#include <linux/kallsyms.h>
+#include <linux/cpu.h>
+#include <linux/sysctl.h>
+#include <linux/module.h>
+#include <linux/rcupdate.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/nodemask.h>
+#include <linux/kmemleak.h>
+#include <linux/mempolicy.h>
+#include <linux/mutex.h>
+#include <linux/fault-inject.h>
+#include <linux/rtmutex.h>
+#include <linux/reciprocal_div.h>
+#include <linux/debugobjects.h>
+#include <linux/kmemcheck.h>
+#include <linux/memory.h>
+#include <linux/prefetch.h>
+#include <linux/locallock.h>
+
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/page.h>
+
+#include <trace/events/kmem.h>
+
+#ifdef CONFIG_KMALLOC_TRACKER
+#include <linux/mem_tracker_def.h>
+#endif
+
+/*
+ * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON.
+ * 0 for faster, smaller code (especially in the critical paths).
+ *
+ * STATS - 1 to collect stats for /proc/slabinfo.
+ * 0 for faster, smaller code (especially in the critical paths).
+ *
+ * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
+ */
+
+#ifdef CONFIG_DEBUG_SLAB
+#define DEBUG 1
+#define STATS 1
+#define FORCED_DEBUG 1
+#else
+#define DEBUG 0
+#define STATS 0
+#define FORCED_DEBUG 0
+#endif
+
+/* Shouldn't this be in a header file somewhere? */
+#define BYTES_PER_WORD sizeof(void *)
+#define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long))
+
+#ifndef ARCH_KMALLOC_FLAGS
+#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
+#endif
+
+/* Legal flag mask for kmem_cache_create(). */
+#if DEBUG
+# define CREATE_MASK (SLAB_RED_ZONE | \
+ SLAB_POISON | SLAB_HWCACHE_ALIGN | \
+ SLAB_CACHE_DMA | \
+ SLAB_STORE_USER | \
+ SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
+ SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \
+ SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK)
+#else
+# define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
+ SLAB_CACHE_DMA | \
+ SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
+ SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \
+ SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK)
+#endif
+
+/*
+ * kmem_bufctl_t:
+ *
+ * Bufctl's are used for linking objs within a slab
+ * linked offsets.
+ *
+ * This implementation relies on "struct page" for locating the cache &
+ * slab an object belongs to.
+ * This allows the bufctl structure to be small (one int), but limits
+ * the number of objects a slab (not a cache) can contain when off-slab
+ * bufctls are used. The limit is the size of the largest general cache
+ * that does not use off-slab slabs.
+ * For 32bit archs with 4 kB pages, is this 56.
+ * This is not serious, as it is only for large objects, when it is unwise
+ * to have too many per slab.
+ * Note: This limit can be raised by introducing a general cache whose size
+ * is less than 512 (PAGE_SIZE<<3), but greater than 256.
+ */
+
+typedef unsigned int kmem_bufctl_t;
+#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
+#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
+#define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2)
+#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
+
+/*
+ * struct slab_rcu
+ *
+ * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
+ * arrange for kmem_freepages to be called via RCU. This is useful if
+ * we need to approach a kernel structure obliquely, from its address
+ * obtained without the usual locking. We can lock the structure to
+ * stabilize it and check it's still at the given address, only if we
+ * can be sure that the memory has not been meanwhile reused for some
+ * other kind of object (which our subsystem's lock might corrupt).
+ *
+ * rcu_read_lock before reading the address, then rcu_read_unlock after
+ * taking the spinlock within the structure expected at that address.
+ */
+struct slab_rcu {
+ struct rcu_head head;
+ struct kmem_cache *cachep;
+ void *addr;
+};
+
+/*
+ * struct slab
+ *
+ * Manages the objs in a slab. Placed either at the beginning of mem allocated
+ * for a slab, or allocated from an general cache.
+ * Slabs are chained into three list: fully used, partial, fully free slabs.
+ */
+struct slab {
+ union {
+ struct {
+ struct list_head list;
+ unsigned long colouroff;
+ void *s_mem; /* including colour offset */
+ unsigned int inuse; /* num of objs active in slab */
+ kmem_bufctl_t free;
+ unsigned short nodeid;
+ };
+ struct slab_rcu __slab_cover_slab_rcu;
+ };
+};
+
+/*
+ * struct array_cache
+ *
+ * Purpose:
+ * - LIFO ordering, to hand out cache-warm objects from _alloc
+ * - reduce the number of linked list operations
+ * - reduce spinlock operations
+ *
+ * The limit is stored in the per-cpu structure to reduce the data cache
+ * footprint.
+ *
+ */
+struct array_cache {
+ unsigned int avail;
+ unsigned int limit;
+ unsigned int batchcount;
+ unsigned int touched;
+ spinlock_t lock;
+ void *entry[]; /*
+ * Must have this definition in here for the proper
+ * alignment of array_cache. Also simplifies accessing
+ * the entries.
+ */
+};
+
+/*
+ * bootstrap: The caches do not work without cpuarrays anymore, but the
+ * cpuarrays are allocated from the generic caches...
+ */
+#define BOOT_CPUCACHE_ENTRIES 1
+struct arraycache_init {
+ struct array_cache cache;
+ void *entries[BOOT_CPUCACHE_ENTRIES];
+};
+
+/*
+ * The slab lists for all objects.
+ */
+struct kmem_list3 {
+ struct list_head slabs_partial; /* partial list first, better asm code */
+ struct list_head slabs_full;
+ struct list_head slabs_free;
+ unsigned long free_objects;
+ unsigned int free_limit;
+ unsigned int colour_next; /* Per-node cache coloring */
+ spinlock_t list_lock;
+ struct array_cache *shared; /* shared per node */
+ struct array_cache **alien; /* on other nodes */
+ unsigned long next_reap; /* updated without locking */
+ int free_touched; /* updated without locking */
+};
+
+/*
+ * Need this for bootstrapping a per node allocator.
+ */
+#define NUM_INIT_LISTS (3 * MAX_NUMNODES)
+static struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
+#define CACHE_CACHE 0
+#define SIZE_AC MAX_NUMNODES
+#define SIZE_L3 (2 * MAX_NUMNODES)
+
+static int drain_freelist(struct kmem_cache *cache,
+ struct kmem_list3 *l3, int tofree);
+static void free_block(struct kmem_cache *cachep, void **objpp, int len,
+ int node);
+static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp);
+static void cache_reap(struct work_struct *unused);
+
+/*
+ * This function must be completely optimized away if a constant is passed to
+ * it. Mostly the same as what is in linux/slab.h except it returns an index.
+ */
+static __always_inline int index_of(const size_t size)
+{
+ extern void __bad_size(void);
+
+ if (__builtin_constant_p(size)) {
+ int i = 0;
+
+#define CACHE(x) \
+ if (size <=x) \
+ return i; \
+ else \
+ i++;
+#include <linux/kmalloc_sizes.h>
+#undef CACHE
+ __bad_size();
+ } else
+ __bad_size();
+ return 0;
+}
+
+static int slab_early_init = 1;
+
+#define INDEX_AC index_of(sizeof(struct arraycache_init))
+#define INDEX_L3 index_of(sizeof(struct kmem_list3))
+
+static void kmem_list3_init(struct kmem_list3 *parent)
+{
+ INIT_LIST_HEAD(&parent->slabs_full);
+ INIT_LIST_HEAD(&parent->slabs_partial);
+ INIT_LIST_HEAD(&parent->slabs_free);
+ parent->shared = NULL;
+ parent->alien = NULL;
+ parent->colour_next = 0;
+ spin_lock_init(&parent->list_lock);
+ parent->free_objects = 0;
+ parent->free_touched = 0;
+}
+
+#define MAKE_LIST(cachep, listp, slab, nodeid) \
+ do { \
+ INIT_LIST_HEAD(listp); \
+ list_splice(&(cachep->nodelists[nodeid]->slab), listp); \
+ } while (0)
+
+#define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
+ do { \
+ MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
+ MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
+ MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
+ } while (0)
+
+#define CFLGS_OFF_SLAB (0x80000000UL)
+#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
+
+#define BATCHREFILL_LIMIT 16
+/*
+ * Optimization question: fewer reaps means less probability for unnessary
+ * cpucache drain/refill cycles.
+ *
+ * OTOH the cpuarrays can contain lots of objects,
+ * which could lock up otherwise freeable slabs.
+ */
+#define REAPTIMEOUT_CPUC (2*HZ)
+#define REAPTIMEOUT_LIST3 (4*HZ)
+
+#if STATS
+#define STATS_INC_ACTIVE(x) ((x)->num_active++)
+#define STATS_DEC_ACTIVE(x) ((x)->num_active--)
+#define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
+#define STATS_INC_GROWN(x) ((x)->grown++)
+#define STATS_ADD_REAPED(x,y) ((x)->reaped += (y))
+#define STATS_SET_HIGH(x) \
+ do { \
+ if ((x)->num_active > (x)->high_mark) \
+ (x)->high_mark = (x)->num_active; \
+ } while (0)
+#define STATS_INC_ERR(x) ((x)->errors++)
+#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
+#define STATS_INC_NODEFREES(x) ((x)->node_frees++)
+#define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
+#define STATS_SET_FREEABLE(x, i) \
+ do { \
+ if ((x)->max_freeable < i) \
+ (x)->max_freeable = i; \
+ } while (0)
+#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
+#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
+#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
+#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
+#else
+#define STATS_INC_ACTIVE(x) do { } while (0)
+#define STATS_DEC_ACTIVE(x) do { } while (0)
+#define STATS_INC_ALLOCED(x) do { } while (0)
+#define STATS_INC_GROWN(x) do { } while (0)
+#define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0)
+#define STATS_SET_HIGH(x) do { } while (0)
+#define STATS_INC_ERR(x) do { } while (0)
+#define STATS_INC_NODEALLOCS(x) do { } while (0)
+#define STATS_INC_NODEFREES(x) do { } while (0)
+#define STATS_INC_ACOVERFLOW(x) do { } while (0)
+#define STATS_SET_FREEABLE(x, i) do { } while (0)
+#define STATS_INC_ALLOCHIT(x) do { } while (0)
+#define STATS_INC_ALLOCMISS(x) do { } while (0)
+#define STATS_INC_FREEHIT(x) do { } while (0)
+#define STATS_INC_FREEMISS(x) do { } while (0)
+#endif
+
+#if DEBUG
+
+/*
+ * memory layout of objects:
+ * 0 : objp
+ * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
+ * the end of an object is aligned with the end of the real
+ * allocation. Catches writes behind the end of the allocation.
+ * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
+ * redzone word.
+ * cachep->obj_offset: The real object.
+ * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
+ * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address
+ * [BYTES_PER_WORD long]
+ */
+static int obj_offset(struct kmem_cache *cachep)
+{
+ return cachep->obj_offset;
+}
+
+static int obj_size(struct kmem_cache *cachep)
+{
+ return cachep->obj_size;
+}
+
+static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
+{
+ BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
+ return (unsigned long long*) (objp + obj_offset(cachep) -
+ sizeof(unsigned long long));
+}
+
+static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
+{
+ BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
+ if (cachep->flags & SLAB_STORE_USER)
+ return (unsigned long long *)(objp + cachep->buffer_size -
+ sizeof(unsigned long long) -
+ REDZONE_ALIGN);
+ return (unsigned long long *) (objp + cachep->buffer_size -
+ sizeof(unsigned long long));
+}
+
+static void **dbg_userword(struct kmem_cache *cachep, void *objp)
+{
+ BUG_ON(!(cachep->flags & SLAB_STORE_USER));
+ return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
+}
+
+#else
+
+#define obj_offset(x) 0
+#define obj_size(cachep) (cachep->buffer_size)
+#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
+#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
+#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
+
+#endif
+
+#ifdef CONFIG_DEBUG_SLAB_MARK_HEAD
+void **dbg_userrecord(void *objp,int index)
+{
+ return (void **)(objp + index * BYTES_PER_RECORD);
+}
+EXPORT_SYMBOL(dbg_userrecord);
+
+void **dbg_userhead(void *objp)
+{
+ return (void **)(objp - RECORD_COUNT * BYTES_PER_RECORD);
+}
+EXPORT_SYMBOL(dbg_userhead);
+#endif
+
+void **dbg_recordtask(struct kmem_cache *cachep, void *objp)
+{
+ return (void **)(objp + cachep->buffer_size - 2*BYTES_PER_WORD);
+}
+EXPORT_SYMBOL(dbg_recordtask);
+
+void **dbg_recordcaller(struct kmem_cache *cachep, void *objp)
+{
+ return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
+}
+EXPORT_SYMBOL(dbg_recordcaller);
+
+#ifdef CONFIG_TRACING
+size_t slab_buffer_size(struct kmem_cache *cachep)
+{
+ return cachep->buffer_size;
+}
+EXPORT_SYMBOL(slab_buffer_size);
+#endif
+
+/*
+ * Do not go above this order unless 0 objects fit into the slab or
+ * overridden on the command line.
+ */
+#define SLAB_MAX_ORDER_HI 1
+#define SLAB_MAX_ORDER_LO 0
+static int slab_max_order = SLAB_MAX_ORDER_LO;
+static bool slab_max_order_set __initdata;
+
+/*
+ * Functions for storing/retrieving the cachep and or slab from the page
+ * allocator. These are used to find the slab an obj belongs to. With kfree(),
+ * these are used to find the cache which an obj belongs to.
+ */
+static inline void page_set_cache(struct page *page, struct kmem_cache *cache)
+{
+ page->lru.next = (struct list_head *)cache;
+}
+
+static inline struct kmem_cache *page_get_cache(struct page *page)
+{
+ page = compound_head(page);
+ BUG_ON(!PageSlab(page));
+ return (struct kmem_cache *)page->lru.next;
+}
+
+static inline void page_set_slab(struct page *page, struct slab *slab)
+{
+ page->lru.prev = (struct list_head *)slab;
+}
+
+static inline struct slab *page_get_slab(struct page *page)
+{
+ BUG_ON(!PageSlab(page));
+ return (struct slab *)page->lru.prev;
+}
+
+static inline struct kmem_cache *virt_to_cache(const void *obj)
+{
+ struct page *page = virt_to_head_page(obj);
+ return page_get_cache(page);
+}
+
+static inline struct slab *virt_to_slab(const void *obj)
+{
+ struct page *page = virt_to_head_page(obj);
+ return page_get_slab(page);
+}
+
+static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
+ unsigned int idx)
+{
+ return slab->s_mem + cache->buffer_size * idx;
+}
+
+/*
+ * We want to avoid an expensive divide : (offset / cache->buffer_size)
+ * Using the fact that buffer_size is a constant for a particular cache,
+ * we can replace (offset / cache->buffer_size) by
+ * reciprocal_divide(offset, cache->reciprocal_buffer_size)
+ */
+static inline unsigned int obj_to_index(const struct kmem_cache *cache,
+ const struct slab *slab, void *obj)
+{
+ u32 offset = (obj - slab->s_mem);
+ return reciprocal_divide(offset, cache->reciprocal_buffer_size);
+}
+
+/*
+ * These are the default caches for kmalloc. Custom caches can have other sizes.
+ */
+struct cache_sizes malloc_sizes[] = {
+#define CACHE(x) { .cs_size = (x) },
+#include <linux/kmalloc_sizes.h>
+ CACHE(ULONG_MAX)
+#undef CACHE
+};
+EXPORT_SYMBOL(malloc_sizes);
+
+/* Must match cache_sizes above. Out of line to keep cache footprint low. */
+struct cache_names {
+ char *name;
+ char *name_dma;
+};
+
+static struct cache_names __initdata cache_names[] = {
+#define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
+#include <linux/kmalloc_sizes.h>
+ {NULL,}
+#undef CACHE
+};
+
+static struct arraycache_init initarray_cache __initdata =
+ { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
+static struct arraycache_init initarray_generic =
+ { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
+
+/* internal cache of cache description objs */
+static struct kmem_list3 *cache_cache_nodelists[MAX_NUMNODES];
+static struct kmem_cache cache_cache = {
+ .nodelists = cache_cache_nodelists,
+ .batchcount = 1,
+ .limit = BOOT_CPUCACHE_ENTRIES,
+ .shared = 1,
+ .buffer_size = sizeof(struct kmem_cache),
+ .name = "kmem_cache",
+};
+
+#define BAD_ALIEN_MAGIC 0x01020304ul
+
+/*
+ * chicken and egg problem: delay the per-cpu array allocation
+ * until the general caches are up.
+ */
+static enum {
+ NONE,
+ PARTIAL_AC,
+ PARTIAL_L3,
+ EARLY,
+ LATE,
+ FULL
+} g_cpucache_up;
+
+/*
+ * used by boot code to determine if it can use slab based allocator
+ */
+int slab_is_available(void)
+{
+ return g_cpucache_up >= EARLY;
+}
+
+/*
+ * Guard access to the cache-chain.
+ */
+static DEFINE_MUTEX(cache_chain_mutex);
+static struct list_head cache_chain;
+
+#ifdef CONFIG_LOCKDEP
+
+/*
+ * Slab sometimes uses the kmalloc slabs to store the slab headers
+ * for other slabs "off slab".
+ * The locking for this is tricky in that it nests within the locks
+ * of all other slabs in a few places; to deal with this special
+ * locking we put on-slab caches into a separate lock-class.
+ *
+ * We set lock class for alien array caches which are up during init.
+ * The lock annotation will be lost if all cpus of a node goes down and
+ * then comes back up during hotplug
+ */
+static struct lock_class_key on_slab_l3_key;
+static struct lock_class_key on_slab_alc_key;
+
+static struct lock_class_key debugobj_l3_key;
+static struct lock_class_key debugobj_alc_key;
+
+static void slab_set_lock_classes(struct kmem_cache *cachep,
+ struct lock_class_key *l3_key, struct lock_class_key *alc_key,
+ int q)
+{
+ struct array_cache **alc;
+ struct kmem_list3 *l3;
+ int r;
+
+ l3 = cachep->nodelists[q];
+ if (!l3)
+ return;
+
+ lockdep_set_class(&l3->list_lock, l3_key);
+ alc = l3->alien;
+ /*
+ * FIXME: This check for BAD_ALIEN_MAGIC
+ * should go away when common slab code is taught to
+ * work even without alien caches.
+ * Currently, non NUMA code returns BAD_ALIEN_MAGIC
+ * for alloc_alien_cache,
+ */
+ if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC)
+ return;
+ for_each_node(r) {
+ if (alc[r])
+ lockdep_set_class(&alc[r]->lock, alc_key);
+ }
+}
+
+static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node)
+{
+ slab_set_lock_classes(cachep, &debugobj_l3_key, &debugobj_alc_key, node);
+}
+
+static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep)
+{
+ int node;
+
+ for_each_online_node(node)
+ slab_set_debugobj_lock_classes_node(cachep, node);
+}
+
+static void init_lock_keys(struct kmem_cache *cachep, int node)
+{
+ struct kmem_list3 *l3;
+
+ if (g_cpucache_up < LATE)
+ return;
+
+ l3 = cachep->nodelists[node];
+ if (!l3 || OFF_SLAB(cachep))
+ return;
+
+ slab_set_lock_classes(cachep, &on_slab_l3_key, &on_slab_alc_key, node);
+}
+
+static void init_node_lock_keys(int node)
+{
+ struct kmem_cache *cachep;
+
+ list_for_each_entry(cachep, &cache_chain, next)
+ init_lock_keys(cachep, node);
+}
+
+static inline void init_cachep_lock_keys(struct kmem_cache *cachep)
+{
+ int node;
+
+ for_each_node(node)
+ init_lock_keys(cachep, node);
+}
+#else
+static void init_node_lock_keys(int node)
+{
+}
+
+static void init_cachep_lock_keys(struct kmem_cache *cachep)
+{
+}
+
+static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node)
+{
+}
+
+static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep)
+{
+}
+#endif
+
+static DEFINE_PER_CPU(struct delayed_work, slab_reap_work);
+static DEFINE_PER_CPU(struct list_head, slab_free_list);
+static DEFINE_LOCAL_IRQ_LOCK(slab_lock);
+
+#ifndef CONFIG_PREEMPT_RT_BASE
+# define slab_on_each_cpu(func, cp) on_each_cpu(func, cp, 1)
+#else
+/*
+ * execute func() for all CPUs. On PREEMPT_RT we dont actually have
+ * to run on the remote CPUs - we only have to take their CPU-locks.
+ * (This is a rare operation, so cacheline bouncing is not an issue.)
+ */
+static void
+slab_on_each_cpu(void (*func)(void *arg, int this_cpu), void *arg)
+{
+ unsigned int i;
+
+ get_cpu_light();
+ for_each_online_cpu(i)
+ func(arg, i);
+ put_cpu_light();
+}
+
+static void lock_slab_on(unsigned int cpu)
+{
+ local_lock_irq_on(slab_lock, cpu);
+}
+
+static void unlock_slab_on(unsigned int cpu)
+{
+ local_unlock_irq_on(slab_lock, cpu);
+}
+#endif
+
+static void free_delayed(struct list_head *h)
+{
+ while(!list_empty(h)) {
+ struct page *page = list_first_entry(h, struct page, lru);
+
+ list_del(&page->lru);
+ __free_pages(page, page->index);
+ }
+}
+
+static void unlock_l3_and_free_delayed(spinlock_t *list_lock)
+{
+ LIST_HEAD(tmp);
+
+ list_splice_init(&__get_cpu_var(slab_free_list), &tmp);
+ local_spin_unlock_irq(slab_lock, list_lock);
+ free_delayed(&tmp);
+}
+
+static void unlock_slab_and_free_delayed(unsigned long flags)
+{
+ LIST_HEAD(tmp);
+
+ list_splice_init(&__get_cpu_var(slab_free_list), &tmp);
+ local_unlock_irqrestore(slab_lock, flags);
+ free_delayed(&tmp);
+}
+
+static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
+{
+ return cachep->array[smp_processor_id()];
+}
+
+static inline struct array_cache *cpu_cache_get_on_cpu(struct kmem_cache *cachep,
+ int cpu)
+{
+ return cachep->array[cpu];
+}
+
+static inline struct kmem_cache *__find_general_cachep(size_t size,
+ gfp_t gfpflags)
+{
+ struct cache_sizes *csizep = malloc_sizes;
+
+#if DEBUG
+ /* This happens if someone tries to call
+ * kmem_cache_create(), or __kmalloc(), before
+ * the generic caches are initialized.
+ */
+ BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
+#endif
+ if (!size)
+ return ZERO_SIZE_PTR;
+
+ while (size > csizep->cs_size)
+ csizep++;
+
+ /*
+ * Really subtle: The last entry with cs->cs_size==ULONG_MAX
+ * has cs_{dma,}cachep==NULL. Thus no special case
+ * for large kmalloc calls required.
+ */
+#ifdef CONFIG_ZONE_DMA
+ if (unlikely(gfpflags & GFP_DMA))
+ return csizep->cs_dmacachep;
+#endif
+ return csizep->cs_cachep;
+}
+
+static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
+{
+ return __find_general_cachep(size, gfpflags);
+}
+
+static size_t slab_mgmt_size(size_t nr_objs, size_t align)
+{
+ return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
+}
+
+/*
+ * Calculate the number of objects and left-over bytes for a given buffer size.
+ */
+static void cache_estimate(unsigned long gfporder, size_t buffer_size,
+ size_t align, int flags, size_t *left_over,
+ unsigned int *num)
+{
+ int nr_objs;
+ size_t mgmt_size;
+ size_t slab_size = PAGE_SIZE << gfporder;
+
+ /*
+ * The slab management structure can be either off the slab or
+ * on it. For the latter case, the memory allocated for a
+ * slab is used for:
+ *
+ * - The struct slab
+ * - One kmem_bufctl_t for each object
+ * - Padding to respect alignment of @align
+ * - @buffer_size bytes for each object
+ *
+ * If the slab management structure is off the slab, then the
+ * alignment will already be calculated into the size. Because
+ * the slabs are all pages aligned, the objects will be at the
+ * correct alignment when allocated.
+ */
+ if (flags & CFLGS_OFF_SLAB) {
+ mgmt_size = 0;
+ nr_objs = slab_size / buffer_size;
+
+ if (nr_objs > SLAB_LIMIT)
+ nr_objs = SLAB_LIMIT;
+ } else {
+ /*
+ * Ignore padding for the initial guess. The padding
+ * is at most @align-1 bytes, and @buffer_size is at
+ * least @align. In the worst case, this result will
+ * be one greater than the number of objects that fit
+ * into the memory allocation when taking the padding
+ * into account.
+ */
+ nr_objs = (slab_size - sizeof(struct slab)) /
+ (buffer_size + sizeof(kmem_bufctl_t));
+
+ /*
+ * This calculated number will be either the right
+ * amount, or one greater than what we want.
+ */
+ if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size
+ > slab_size)
+ nr_objs--;
+
+ if (nr_objs > SLAB_LIMIT)
+ nr_objs = SLAB_LIMIT;
+
+ mgmt_size = slab_mgmt_size(nr_objs, align);
+ }
+ *num = nr_objs;
+ *left_over = slab_size - nr_objs*buffer_size - mgmt_size;
+}
+
+#define slab_error(cachep, msg) __slab_error(__func__, cachep, msg)
+
+static void __slab_error(const char *function, struct kmem_cache *cachep,
+ char *msg)
+{
+ printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
+ function, cachep->name, msg);
+ dump_stack();
+}
+
+/*
+ * By default on NUMA we use alien caches to stage the freeing of
+ * objects allocated from other nodes. This causes massive memory
+ * inefficiencies when using fake NUMA setup to split memory into a
+ * large number of small nodes, so it can be disabled on the command
+ * line
+ */
+
+static int use_alien_caches __read_mostly = 1;
+static int __init noaliencache_setup(char *s)
+{
+ use_alien_caches = 0;
+ return 1;
+}
+__setup("noaliencache", noaliencache_setup);
+
+static int __init slab_max_order_setup(char *str)
+{
+ get_option(&str, &slab_max_order);
+ slab_max_order = slab_max_order < 0 ? 0 :
+ min(slab_max_order, MAX_ORDER - 1);
+ slab_max_order_set = true;
+
+ return 1;
+}
+__setup("slab_max_order=", slab_max_order_setup);
+
+#ifdef CONFIG_NUMA
+/*
+ * Special reaping functions for NUMA systems called from cache_reap().
+ * These take care of doing round robin flushing of alien caches (containing
+ * objects freed on different nodes from which they were allocated) and the
+ * flushing of remote pcps by calling drain_node_pages.
+ */
+static DEFINE_PER_CPU(unsigned long, slab_reap_node);
+
+static void init_reap_node(int cpu)
+{
+ int node;
+
+ node = next_node(cpu_to_mem(cpu), node_online_map);
+ if (node == MAX_NUMNODES)
+ node = first_node(node_online_map);
+
+ per_cpu(slab_reap_node, cpu) = node;
+}
+
+static void next_reap_node(void)
+{
+ int node = __this_cpu_read(slab_reap_node);
+
+ node = next_node(node, node_online_map);
+ if (unlikely(node >= MAX_NUMNODES))
+ node = first_node(node_online_map);
+ __this_cpu_write(slab_reap_node, node);
+}
+
+#else
+#define init_reap_node(cpu) do { } while (0)
+#define next_reap_node(void) do { } while (0)
+#endif
+
+/*
+ * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
+ * via the workqueue/eventd.
+ * Add the CPU number into the expiration time to minimize the possibility of
+ * the CPUs getting into lockstep and contending for the global cache chain
+ * lock.
+ */
+static void __cpuinit start_cpu_timer(int cpu)
+{
+ struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu);
+
+ /*
+ * When this gets called from do_initcalls via cpucache_init(),
+ * init_workqueues() has already run, so keventd will be setup
+ * at that time.
+ */
+ if (keventd_up() && reap_work->work.func == NULL) {
+ init_reap_node(cpu);
+ INIT_DELAYED_WORK_DEFERRABLE(reap_work, cache_reap);
+ schedule_delayed_work_on(cpu, reap_work,
+ __round_jiffies_relative(HZ, cpu));
+ }
+}
+
+static struct array_cache *alloc_arraycache(int node, int entries,
+ int batchcount, gfp_t gfp)
+{
+ int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
+ struct array_cache *nc = NULL;
+
+ nc = kmalloc_node(memsize, gfp, node);
+ /*
+ * The array_cache structures contain pointers to free object.
+ * However, when such objects are allocated or transferred to another
+ * cache the pointers are not cleared and they could be counted as
+ * valid references during a kmemleak scan. Therefore, kmemleak must
+ * not scan such objects.
+ */
+ kmemleak_no_scan(nc);
+ if (nc) {
+ nc->avail = 0;
+ nc->limit = entries;
+ nc->batchcount = batchcount;
+ nc->touched = 0;
+ spin_lock_init(&nc->lock);
+ }
+ return nc;
+}
+
+/*
+ * Transfer objects in one arraycache to another.
+ * Locking must be handled by the caller.
+ *
+ * Return the number of entries transferred.
+ */
+static int transfer_objects(struct array_cache *to,
+ struct array_cache *from, unsigned int max)
+{
+ /* Figure out how many entries to transfer */
+ int nr = min3(from->avail, max, to->limit - to->avail);
+
+ if (!nr)
+ return 0;
+
+ memcpy(to->entry + to->avail, from->entry + from->avail -nr,
+ sizeof(void *) *nr);
+
+ from->avail -= nr;
+ to->avail += nr;
+ return nr;
+}
+
+#ifndef CONFIG_NUMA
+
+#define drain_alien_cache(cachep, alien) do { } while (0)
+#define reap_alien(cachep, l3) do { } while (0)
+
+static inline struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
+{
+ return (struct array_cache **)BAD_ALIEN_MAGIC;
+}
+
+static inline void free_alien_cache(struct array_cache **ac_ptr)
+{
+}
+
+static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
+{
+ return 0;
+}
+
+static inline void *alternate_node_alloc(struct kmem_cache *cachep,
+ gfp_t flags)
+{
+ return NULL;
+}
+
+static inline void *____cache_alloc_node(struct kmem_cache *cachep,
+ gfp_t flags, int nodeid)
+{
+ return NULL;
+}
+
+#else /* CONFIG_NUMA */
+
+static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
+static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
+
+static struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
+{
+ struct array_cache **ac_ptr;
+ int memsize = sizeof(void *) * nr_node_ids;
+ int i;
+
+ if (limit > 1)
+ limit = 12;
+ ac_ptr = kzalloc_node(memsize, gfp, node);
+ if (ac_ptr) {
+ for_each_node(i) {
+ if (i == node || !node_online(i))
+ continue;
+ ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d, gfp);
+ if (!ac_ptr[i]) {
+ for (i--; i >= 0; i--)
+ kfree(ac_ptr[i]);
+ kfree(ac_ptr);
+ return NULL;
+ }
+ }
+ }
+ return ac_ptr;
+}
+
+static void free_alien_cache(struct array_cache **ac_ptr)
+{
+ int i;
+
+ if (!ac_ptr)
+ return;
+ for_each_node(i)
+ kfree(ac_ptr[i]);
+ kfree(ac_ptr);
+}
+
+static void __drain_alien_cache(struct kmem_cache *cachep,
+ struct array_cache *ac, int node)
+{
+ struct kmem_list3 *rl3 = cachep->nodelists[node];
+
+ if (ac->avail) {
+ spin_lock(&rl3->list_lock);
+ /*
+ * Stuff objects into the remote nodes shared array first.
+ * That way we could avoid the overhead of putting the objects
+ * into the free lists and getting them back later.
+ */
+ if (rl3->shared)
+ transfer_objects(rl3->shared, ac, ac->limit);
+
+ free_block(cachep, ac->entry, ac->avail, node);
+ ac->avail = 0;
+ spin_unlock(&rl3->list_lock);
+ }
+}
+
+/*
+ * Called from cache_reap() to regularly drain alien caches round robin.
+ */
+static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3)
+{
+ int node = __this_cpu_read(slab_reap_node);
+
+ if (l3->alien) {
+ struct array_cache *ac = l3->alien[node];
+
+ if (ac && ac->avail &&
+ local_spin_trylock_irq(slab_lock, &ac->lock)) {
+ __drain_alien_cache(cachep, ac, node);
+ local_spin_unlock_irq(slab_lock, &ac->lock);
+ }
+ }
+}
+
+static void drain_alien_cache(struct kmem_cache *cachep,
+ struct array_cache **alien)
+{
+ int i = 0;
+ struct array_cache *ac;
+ unsigned long flags;
+
+ for_each_online_node(i) {
+ ac = alien[i];
+ if (ac) {
+ local_spin_lock_irqsave(slab_lock, &ac->lock, flags);
+ __drain_alien_cache(cachep, ac, i);
+ local_spin_unlock_irqrestore(slab_lock, &ac->lock, flags);
+ }
+ }
+}
+
+static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
+{
+ struct slab *slabp = virt_to_slab(objp);
+ int nodeid = slabp->nodeid;
+ struct kmem_list3 *l3;
+ struct array_cache *alien = NULL;
+ int node;
+
+ node = numa_mem_id();
+
+ /*
+ * Make sure we are not freeing a object from another node to the array
+ * cache on this cpu.
+ */
+ if (likely(slabp->nodeid == node))
+ return 0;
+
+ l3 = cachep->nodelists[node];
+ STATS_INC_NODEFREES(cachep);
+ if (l3->alien && l3->alien[nodeid]) {
+ alien = l3->alien[nodeid];
+ spin_lock(&alien->lock);
+ if (unlikely(alien->avail == alien->limit)) {
+ STATS_INC_ACOVERFLOW(cachep);
+ __drain_alien_cache(cachep, alien, nodeid);
+ }
+ alien->entry[alien->avail++] = objp;
+ spin_unlock(&alien->lock);
+ } else {
+ spin_lock(&(cachep->nodelists[nodeid])->list_lock);
+ free_block(cachep, &objp, 1, nodeid);
+ spin_unlock(&(cachep->nodelists[nodeid])->list_lock);
+ }
+ return 1;
+}
+#endif
+
+/*
+ * Allocates and initializes nodelists for a node on each slab cache, used for
+ * either memory or cpu hotplug. If memory is being hot-added, the kmem_list3
+ * will be allocated off-node since memory is not yet online for the new node.
+ * When hotplugging memory or a cpu, existing nodelists are not replaced if
+ * already in use.
+ *
+ * Must hold cache_chain_mutex.
+ */
+static int init_cache_nodelists_node(int node)
+{
+ struct kmem_cache *cachep;
+ struct kmem_list3 *l3;
+ const int memsize = sizeof(struct kmem_list3);
+
+ list_for_each_entry(cachep, &cache_chain, next) {
+ /*
+ * Set up the size64 kmemlist for cpu before we can
+ * begin anything. Make sure some other cpu on this
+ * node has not already allocated this
+ */
+ if (!cachep->nodelists[node]) {
+ l3 = kmalloc_node(memsize, GFP_KERNEL, node);
+ if (!l3)
+ return -ENOMEM;
+ kmem_list3_init(l3);
+ l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
+ ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
+
+ /*
+ * The l3s don't come and go as CPUs come and
+ * go. cache_chain_mutex is sufficient
+ * protection here.
+ */
+ cachep->nodelists[node] = l3;
+ }
+
+ local_spin_lock_irq(slab_lock, &cachep->nodelists[node]->list_lock);
+ cachep->nodelists[node]->free_limit =
+ (1 + nr_cpus_node(node)) *
+ cachep->batchcount + cachep->num;
+ local_spin_unlock_irq(slab_lock, &cachep->nodelists[node]->list_lock);
+ }
+ return 0;
+}
+
+static void __cpuinit cpuup_canceled(long cpu)
+{
+ struct kmem_cache *cachep;
+ struct kmem_list3 *l3 = NULL;
+ int node = cpu_to_mem(cpu);
+ const struct cpumask *mask = cpumask_of_node(node);
+
+ list_for_each_entry(cachep, &cache_chain, next) {
+ struct array_cache *nc;
+ struct array_cache *shared;
+ struct array_cache **alien;
+
+ /* cpu is dead; no one can alloc from it. */
+ nc = cachep->array[cpu];
+ cachep->array[cpu] = NULL;
+ l3 = cachep->nodelists[node];
+
+ if (!l3)
+ goto free_array_cache;
+
+ local_spin_lock_irq(slab_lock, &l3->list_lock);
+
+ /* Free limit for this kmem_list3 */
+ l3->free_limit -= cachep->batchcount;
+ if (nc)
+ free_block(cachep, nc->entry, nc->avail, node);
+
+ if (!cpumask_empty(mask)) {
+ unlock_l3_and_free_delayed(&l3->list_lock);
+ goto free_array_cache;
+ }
+
+ shared = l3->shared;
+ if (shared) {
+ free_block(cachep, shared->entry,
+ shared->avail, node);
+ l3->shared = NULL;
+ }
+
+ alien = l3->alien;
+ l3->alien = NULL;
+
+ unlock_l3_and_free_delayed(&l3->list_lock);
+
+ kfree(shared);
+ if (alien) {
+ drain_alien_cache(cachep, alien);
+ free_alien_cache(alien);
+ }
+free_array_cache:
+ kfree(nc);
+ }
+ /*
+ * In the previous loop, all the objects were freed to
+ * the respective cache's slabs, now we can go ahead and
+ * shrink each nodelist to its limit.
+ */
+ list_for_each_entry(cachep, &cache_chain, next) {
+ l3 = cachep->nodelists[node];
+ if (!l3)
+ continue;
+ drain_freelist(cachep, l3, l3->free_objects);
+ }
+}
+
+static int __cpuinit cpuup_prepare(long cpu)
+{
+ struct kmem_cache *cachep;
+ struct kmem_list3 *l3 = NULL;
+ int node = cpu_to_mem(cpu);
+ int err;
+
+ /*
+ * We need to do this right in the beginning since
+ * alloc_arraycache's are going to use this list.
+ * kmalloc_node allows us to add the slab to the right
+ * kmem_list3 and not this cpu's kmem_list3
+ */
+ err = init_cache_nodelists_node(node);
+ if (err < 0)
+ goto bad;
+
+ /*
+ * Now we can go ahead with allocating the shared arrays and
+ * array caches
+ */
+ list_for_each_entry(cachep, &cache_chain, next) {
+ struct array_cache *nc;
+ struct array_cache *shared = NULL;
+ struct array_cache **alien = NULL;
+
+ nc = alloc_arraycache(node, cachep->limit,
+ cachep->batchcount, GFP_KERNEL);
+ if (!nc)
+ goto bad;
+ if (cachep->shared) {
+ shared = alloc_arraycache(node,
+ cachep->shared * cachep->batchcount,
+ 0xbaadf00d, GFP_KERNEL);
+ if (!shared) {
+ kfree(nc);
+ goto bad;
+ }
+ }
+ if (use_alien_caches) {
+ alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL);
+ if (!alien) {
+ kfree(shared);
+ kfree(nc);
+ goto bad;
+ }
+ }
+ cachep->array[cpu] = nc;
+ l3 = cachep->nodelists[node];
+ BUG_ON(!l3);
+
+ local_spin_lock_irq(slab_lock, &l3->list_lock);
+ if (!l3->shared) {
+ /*
+ * We are serialised from CPU_DEAD or
+ * CPU_UP_CANCELLED by the cpucontrol lock
+ */
+ l3->shared = shared;
+ shared = NULL;
+ }
+#ifdef CONFIG_NUMA
+ if (!l3->alien) {
+ l3->alien = alien;
+ alien = NULL;
+ }
+#endif
+ local_spin_unlock_irq(slab_lock, &l3->list_lock);
+ kfree(shared);
+ free_alien_cache(alien);
+ if (cachep->flags & SLAB_DEBUG_OBJECTS)
+ slab_set_debugobj_lock_classes_node(cachep, node);
+ }
+ init_node_lock_keys(node);
+
+ return 0;
+bad:
+ cpuup_canceled(cpu);
+ return -ENOMEM;
+}
+
+static int __cpuinit cpuup_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ long cpu = (long)hcpu;
+ int err = 0;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
+ mutex_lock(&cache_chain_mutex);
+ err = cpuup_prepare(cpu);
+ mutex_unlock(&cache_chain_mutex);
+ break;
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ start_cpu_timer(cpu);
+ break;
+#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
+ /*
+ * Shutdown cache reaper. Note that the cache_chain_mutex is
+ * held so that if cache_reap() is invoked it cannot do
+ * anything expensive but will only modify reap_work
+ * and reschedule the timer.
+ */
+ cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu));
+ /* Now the cache_reaper is guaranteed to be not running. */
+ per_cpu(slab_reap_work, cpu).work.func = NULL;
+ break;
+ case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
+ start_cpu_timer(cpu);
+ break;
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ /*
+ * Even if all the cpus of a node are down, we don't free the
+ * kmem_list3 of any cache. This to avoid a race between
+ * cpu_down, and a kmalloc allocation from another cpu for
+ * memory from the node of the cpu going down. The list3
+ * structure is usually allocated from kmem_cache_create() and
+ * gets destroyed at kmem_cache_destroy().
+ */
+ /* fall through */
+#endif
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
+ mutex_lock(&cache_chain_mutex);
+ cpuup_canceled(cpu);
+ mutex_unlock(&cache_chain_mutex);
+ break;
+ }
+ return notifier_from_errno(err);
+}
+
+static struct notifier_block __cpuinitdata cpucache_notifier = {
+ &cpuup_callback, NULL, 0
+};
+
+#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
+/*
+ * Drains freelist for a node on each slab cache, used for memory hot-remove.
+ * Returns -EBUSY if all objects cannot be drained so that the node is not
+ * removed.
+ *
+ * Must hold cache_chain_mutex.
+ */
+static int __meminit drain_cache_nodelists_node(int node)
+{
+ struct kmem_cache *cachep;
+ int ret = 0;
+
+ list_for_each_entry(cachep, &cache_chain, next) {
+ struct kmem_list3 *l3;
+
+ l3 = cachep->nodelists[node];
+ if (!l3)
+ continue;
+
+ drain_freelist(cachep, l3, l3->free_objects);
+
+ if (!list_empty(&l3->slabs_full) ||
+ !list_empty(&l3->slabs_partial)) {
+ ret = -EBUSY;
+ break;
+ }
+ }
+ return ret;
+}
+
+static int __meminit slab_memory_callback(struct notifier_block *self,
+ unsigned long action, void *arg)
+{
+ struct memory_notify *mnb = arg;
+ int ret = 0;
+ int nid;
+
+ nid = mnb->status_change_nid;
+ if (nid < 0)
+ goto out;
+
+ switch (action) {
+ case MEM_GOING_ONLINE:
+ mutex_lock(&cache_chain_mutex);
+ ret = init_cache_nodelists_node(nid);
+ mutex_unlock(&cache_chain_mutex);
+ break;
+ case MEM_GOING_OFFLINE:
+ mutex_lock(&cache_chain_mutex);
+ ret = drain_cache_nodelists_node(nid);
+ mutex_unlock(&cache_chain_mutex);
+ break;
+ case MEM_ONLINE:
+ case MEM_OFFLINE:
+ case MEM_CANCEL_ONLINE:
+ case MEM_CANCEL_OFFLINE:
+ break;
+ }
+out:
+ return notifier_from_errno(ret);
+}
+#endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */
+
+/*
+ * swap the static kmem_list3 with kmalloced memory
+ */
+static void __init init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
+ int nodeid)
+{
+ struct kmem_list3 *ptr;
+
+ ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_NOWAIT, nodeid);
+ BUG_ON(!ptr);
+
+ memcpy(ptr, list, sizeof(struct kmem_list3));
+ /*
+ * Do not assume that spinlocks can be initialized via memcpy:
+ */
+ spin_lock_init(&ptr->list_lock);
+
+ MAKE_ALL_LISTS(cachep, ptr, nodeid);
+ cachep->nodelists[nodeid] = ptr;
+}
+
+/*
+ * For setting up all the kmem_list3s for cache whose buffer_size is same as
+ * size of kmem_list3.
+ */
+static void __init set_up_list3s(struct kmem_cache *cachep, int index)
+{
+ int node;
+
+ for_each_online_node(node) {
+ cachep->nodelists[node] = &initkmem_list3[index + node];
+ cachep->nodelists[node]->next_reap = jiffies +
+ REAPTIMEOUT_LIST3 +
+ ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
+ }
+}
+
+/*
+ * Initialisation. Called after the page allocator have been initialised and
+ * before smp_init().
+ */
+void __init kmem_cache_init(void)
+{
+ size_t left_over;
+ struct cache_sizes *sizes;
+ struct cache_names *names;
+ int i;
+ int order;
+ int node;
+
+ if (num_possible_nodes() == 1)
+ use_alien_caches = 0;
+
+ local_irq_lock_init(slab_lock);
+ for_each_possible_cpu(i)
+ INIT_LIST_HEAD(&per_cpu(slab_free_list, i));
+
+ for (i = 0; i < NUM_INIT_LISTS; i++) {
+ kmem_list3_init(&initkmem_list3[i]);
+ if (i < MAX_NUMNODES)
+ cache_cache.nodelists[i] = NULL;
+ }
+ set_up_list3s(&cache_cache, CACHE_CACHE);
+
+ /*
+ * Fragmentation resistance on low memory - only use bigger
+ * page orders on machines with more than 32MB of memory if
+ * not overridden on the command line.
+ */
+ if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT)
+ slab_max_order = SLAB_MAX_ORDER_HI;
+
+ /* Bootstrap is tricky, because several objects are allocated
+ * from caches that do not exist yet:
+ * 1) initialize the cache_cache cache: it contains the struct
+ * kmem_cache structures of all caches, except cache_cache itself:
+ * cache_cache is statically allocated.
+ * Initially an __init data area is used for the head array and the
+ * kmem_list3 structures, it's replaced with a kmalloc allocated
+ * array at the end of the bootstrap.
+ * 2) Create the first kmalloc cache.
+ * The struct kmem_cache for the new cache is allocated normally.
+ * An __init data area is used for the head array.
+ * 3) Create the remaining kmalloc caches, with minimally sized
+ * head arrays.
+ * 4) Replace the __init data head arrays for cache_cache and the first
+ * kmalloc cache with kmalloc allocated arrays.
+ * 5) Replace the __init data for kmem_list3 for cache_cache and
+ * the other cache's with kmalloc allocated memory.
+ * 6) Resize the head arrays of the kmalloc caches to their final sizes.
+ */
+
+ node = numa_mem_id();
+
+ /* 1) create the cache_cache */
+ INIT_LIST_HEAD(&cache_chain);
+ list_add(&cache_cache.next, &cache_chain);
+ cache_cache.colour_off = cache_line_size();
+ cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
+ cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE + node];
+
+ /*
+ * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids
+ */
+ cache_cache.buffer_size = offsetof(struct kmem_cache, array[nr_cpu_ids]) +
+ nr_node_ids * sizeof(struct kmem_list3 *);
+#if DEBUG
+ cache_cache.obj_size = cache_cache.buffer_size;
+#endif
+ cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
+ cache_line_size());
+ cache_cache.reciprocal_buffer_size =
+ reciprocal_value(cache_cache.buffer_size);
+
+ for (order = 0; order < MAX_ORDER; order++) {
+ cache_estimate(order, cache_cache.buffer_size,
+ cache_line_size(), 0, &left_over, &cache_cache.num);
+ if (cache_cache.num)
+ break;
+ }
+ BUG_ON(!cache_cache.num);
+ cache_cache.gfporder = order;
+ cache_cache.colour = left_over / cache_cache.colour_off;
+ cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) +
+ sizeof(struct slab), cache_line_size());
+
+ /* 2+3) create the kmalloc caches */
+ sizes = malloc_sizes;
+ names = cache_names;
+
+ /*
+ * Initialize the caches that provide memory for the array cache and the
+ * kmem_list3 structures first. Without this, further allocations will
+ * bug.
+ */
+
+ sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
+ sizes[INDEX_AC].cs_size,
+ ARCH_KMALLOC_MINALIGN,
+ ARCH_KMALLOC_FLAGS|SLAB_PANIC,
+ NULL);
+
+ if (INDEX_AC != INDEX_L3) {
+ sizes[INDEX_L3].cs_cachep =
+ kmem_cache_create(names[INDEX_L3].name,
+ sizes[INDEX_L3].cs_size,
+ ARCH_KMALLOC_MINALIGN,
+ ARCH_KMALLOC_FLAGS|SLAB_PANIC,
+ NULL);
+ }
+
+ slab_early_init = 0;
+
+ while (sizes->cs_size != ULONG_MAX) {
+ /*
+ * For performance, all the general caches are L1 aligned.
+ * This should be particularly beneficial on SMP boxes, as it
+ * eliminates "false sharing".
+ * Note for systems short on memory removing the alignment will
+ * allow tighter packing of the smaller caches.
+ */
+ if (!sizes->cs_cachep) {
+ sizes->cs_cachep = kmem_cache_create(names->name,
+ sizes->cs_size,
+ ARCH_KMALLOC_MINALIGN,
+ ARCH_KMALLOC_FLAGS|SLAB_PANIC,
+ NULL);
+ }
+#ifdef CONFIG_ZONE_DMA
+ sizes->cs_dmacachep = kmem_cache_create(
+ names->name_dma,
+ sizes->cs_size,
+ ARCH_KMALLOC_MINALIGN,
+ ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
+ SLAB_PANIC,
+ NULL);
+#endif
+ sizes++;
+ names++;
+ }
+ /* 4) Replace the bootstrap head arrays */
+ {
+ struct array_cache *ptr;
+
+ ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT);
+
+ BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
+ memcpy(ptr, cpu_cache_get(&cache_cache),
+ sizeof(struct arraycache_init));
+ /*
+ * Do not assume that spinlocks can be initialized via memcpy:
+ */
+ spin_lock_init(&ptr->lock);
+
+ cache_cache.array[smp_processor_id()] = ptr;
+
+ ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT);
+
+ BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
+ != &initarray_generic.cache);
+ memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
+ sizeof(struct arraycache_init));
+ /*
+ * Do not assume that spinlocks can be initialized via memcpy:
+ */
+ spin_lock_init(&ptr->lock);
+
+ malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
+ ptr;
+ }
+ /* 5) Replace the bootstrap kmem_list3's */
+ {
+ int nid;
+
+ for_each_online_node(nid) {
+ init_list(&cache_cache, &initkmem_list3[CACHE_CACHE + nid], nid);
+
+ init_list(malloc_sizes[INDEX_AC].cs_cachep,
+ &initkmem_list3[SIZE_AC + nid], nid);
+
+ if (INDEX_AC != INDEX_L3) {
+ init_list(malloc_sizes[INDEX_L3].cs_cachep,
+ &initkmem_list3[SIZE_L3 + nid], nid);
+ }
+ }
+ }
+
+ g_cpucache_up = EARLY;
+}
+
+void __init kmem_cache_init_late(void)
+{
+ struct kmem_cache *cachep;
+
+ g_cpucache_up = LATE;
+
+ /* 6) resize the head arrays to their final sizes */
+ mutex_lock(&cache_chain_mutex);
+ list_for_each_entry(cachep, &cache_chain, next) {
+ if (enable_cpucache(cachep, GFP_NOWAIT))
+ BUG();
+ init_cachep_lock_keys(cachep);
+ }
+ mutex_unlock(&cache_chain_mutex);
+
+ /* Done! */
+ g_cpucache_up = FULL;
+
+ /*
+ * Register a cpu startup notifier callback that initializes
+ * cpu_cache_get for all new cpus
+ */
+ register_cpu_notifier(&cpucache_notifier);
+
+#ifdef CONFIG_NUMA
+ /*
+ * Register a memory hotplug callback that initializes and frees
+ * nodelists.
+ */
+ hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
+#endif
+
+ /*
+ * The reap timers are started later, with a module init call: That part
+ * of the kernel is not yet operational.
+ */
+}
+
+static int __init cpucache_init(void)
+{
+ int cpu;
+
+ /*
+ * Register the timers that return unneeded pages to the page allocator
+ */
+ for_each_online_cpu(cpu)
+ start_cpu_timer(cpu);
+ return 0;
+}
+__initcall(cpucache_init);
+
+static noinline void
+slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
+{
+ struct kmem_list3 *l3;
+ struct slab *slabp;
+ unsigned long flags;
+ int node;
+
+ printk(KERN_WARNING
+ "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n",
+ nodeid, gfpflags);
+ printk(KERN_WARNING " cache: %s, object size: %d, order: %d\n",
+ cachep->name, cachep->buffer_size, cachep->gfporder);
+
+ for_each_online_node(node) {
+ unsigned long active_objs = 0, num_objs = 0, free_objects = 0;
+ unsigned long active_slabs = 0, num_slabs = 0;
+
+ l3 = cachep->nodelists[node];
+ if (!l3)
+ continue;
+
+ spin_lock_irqsave(&l3->list_lock, flags);
+ list_for_each_entry(slabp, &l3->slabs_full, list) {
+ active_objs += cachep->num;
+ active_slabs++;
+ }
+ list_for_each_entry(slabp, &l3->slabs_partial, list) {
+ active_objs += slabp->inuse;
+ active_slabs++;
+ }
+ list_for_each_entry(slabp, &l3->slabs_free, list)
+ num_slabs++;
+
+ free_objects += l3->free_objects;
+ spin_unlock_irqrestore(&l3->list_lock, flags);
+
+ num_slabs += active_slabs;
+ num_objs = num_slabs * cachep->num;
+ printk(KERN_WARNING
+ " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n",
+ node, active_slabs, num_slabs, active_objs, num_objs,
+ free_objects);
+ }
+}
+
+/*
+ * Interface to system's page allocator. No need to hold the cache-lock.
+ *
+ * If we requested dmaable memory, we will get it. Even if we
+ * did not request dmaable memory, we might get it, but that
+ * would be relatively rare and ignorable.
+ */
+static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
+{
+ struct page *page;
+ int nr_pages;
+ int i;
+
+#ifndef CONFIG_MMU
+ /*
+ * Nommu uses slab's for process anonymous memory allocations, and thus
+ * requires __GFP_COMP to properly refcount higher order allocations
+ */
+ flags |= __GFP_COMP;
+#endif
+
+ flags |= cachep->gfpflags;
+ if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
+ flags |= __GFP_RECLAIMABLE;
+
+ page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder);
+ if (!page) {
+ if (!(flags & __GFP_NOWARN) && printk_ratelimit())
+ slab_out_of_memory(cachep, flags, nodeid);
+ return NULL;
+ }
+
+ nr_pages = (1 << cachep->gfporder);
+ if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
+ add_zone_page_state(page_zone(page),
+ NR_SLAB_RECLAIMABLE, nr_pages);
+ else
+ add_zone_page_state(page_zone(page),
+ NR_SLAB_UNRECLAIMABLE, nr_pages);
+ for (i = 0; i < nr_pages; i++)
+ __SetPageSlab(page + i);
+
+ if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) {
+ kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid);
+
+ if (cachep->ctor)
+ kmemcheck_mark_uninitialized_pages(page, nr_pages);
+ else
+ kmemcheck_mark_unallocated_pages(page, nr_pages);
+ }
+
+ return page_address(page);
+}
+
+/*
+ * Interface to system's page release.
+ */
+static void kmem_freepages(struct kmem_cache *cachep, void *addr, bool delayed)
+{
+ unsigned long i = (1 << cachep->gfporder);
+ struct page *page, *basepage = virt_to_page(addr);
+ const unsigned long nr_freed = i;
+
+ page = basepage;
+
+ kmemcheck_free_shadow(page, cachep->gfporder);
+
+ if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
+ sub_zone_page_state(page_zone(page),
+ NR_SLAB_RECLAIMABLE, nr_freed);
+ else
+ sub_zone_page_state(page_zone(page),
+ NR_SLAB_UNRECLAIMABLE, nr_freed);
+ while (i--) {
+ BUG_ON(!PageSlab(page));
+ __ClearPageSlab(page);
+ page++;
+ }
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed_slab += nr_freed;
+
+ if (!delayed) {
+ free_pages((unsigned long)addr, cachep->gfporder);
+ } else {
+ basepage->index = cachep->gfporder;
+ list_add(&basepage->lru, &__get_cpu_var(slab_free_list));
+ }
+}
+
+static void kmem_rcu_free(struct rcu_head *head)
+{
+ struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
+ struct kmem_cache *cachep = slab_rcu->cachep;
+
+ kmem_freepages(cachep, slab_rcu->addr, false);
+ if (OFF_SLAB(cachep))
+ kmem_cache_free(cachep->slabp_cache, slab_rcu);
+}
+
+#if DEBUG
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
+ unsigned long caller)
+{
+ int size = obj_size(cachep);
+
+ addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
+
+ if (size < 5 * sizeof(unsigned long))
+ return;
+
+ *addr++ = 0x12345678;
+ *addr++ = caller;
+ *addr++ = smp_processor_id();
+ size -= 3 * sizeof(unsigned long);
+ {
+ unsigned long *sptr = &caller;
+ unsigned long svalue;
+
+ while (!kstack_end(sptr)) {
+ svalue = *sptr++;
+ if (kernel_text_address(svalue)) {
+ *addr++ = svalue;
+ size -= sizeof(unsigned long);
+ if (size <= sizeof(unsigned long))
+ break;
+ }
+ }
+
+ }
+ *addr++ = 0x87654321;
+}
+#endif
+
+static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
+{
+ int size = obj_size(cachep);
+ addr = &((char *)addr)[obj_offset(cachep)];
+
+ memset(addr, val, size);
+ *(unsigned char *)(addr + size - 1) = POISON_END;
+}
+
+static void dump_line(char *data, int offset, int limit)
+{
+ int i;
+ unsigned char error = 0;
+ int bad_count = 0;
+
+ printk(KERN_ERR "%03x: ", offset);
+ for (i = 0; i < limit; i++) {
+ if (data[offset + i] != POISON_FREE) {
+ error = data[offset + i];
+ bad_count++;
+ }
+ }
+ print_hex_dump(KERN_CONT, "", 0, 16, 1,
+ &data[offset], limit, 1);
+
+ if (bad_count == 1) {
+ error ^= POISON_FREE;
+ if (!(error & (error - 1))) {
+ printk(KERN_ERR "Single bit error detected. Probably "
+ "bad RAM.\n");
+#ifdef CONFIG_X86
+ printk(KERN_ERR "Run memtest86+ or a similar memory "
+ "test tool.\n");
+#else
+ printk(KERN_ERR "Run a memory test tool.\n");
+#endif
+ }
+ }
+}
+#endif
+
+#if DEBUG
+
+static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
+{
+ int i, size;
+ char *realobj;
+
+ if (cachep->flags & SLAB_RED_ZONE) {
+ printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n",
+ *dbg_redzone1(cachep, objp),
+ *dbg_redzone2(cachep, objp));
+ }
+
+ if (cachep->flags & SLAB_STORE_USER) {
+ printk(KERN_ERR "Last user: [<%p>]",
+ *dbg_userword(cachep, objp));
+ print_symbol("(%s)",
+ (unsigned long)*dbg_userword(cachep, objp));
+ printk("\n");
+ }
+ realobj = (char *)objp + obj_offset(cachep);
+ size = obj_size(cachep);
+ for (i = 0; i < size && lines; i += 16, lines--) {
+ int limit;
+ limit = 16;
+ if (i + limit > size)
+ limit = size - i;
+ dump_line(realobj, i, limit);
+ }
+}
+
+static void check_poison_obj(struct kmem_cache *cachep, void *objp)
+{
+ char *realobj;
+ int size, i;
+ int lines = 0;
+
+ realobj = (char *)objp + obj_offset(cachep);
+ size = obj_size(cachep);
+
+ for (i = 0; i < size; i++) {
+ char exp = POISON_FREE;
+ if (i == size - 1)
+ exp = POISON_END;
+ if (realobj[i] != exp) {
+ int limit;
+ /* Mismatch ! */
+ /* Print header */
+ if (lines == 0) {
+ printk(KERN_ERR
+ "Slab corruption (%s): %s start=%p, len=%d\n",
+ print_tainted(), cachep->name, realobj, size);
+ print_objinfo(cachep, objp, 0);
+ }
+ /* Hexdump the affected line */
+ i = (i / 16) * 16;
+ limit = 16;
+ if (i + limit > size)
+ limit = size - i;
+ dump_line(realobj, i, limit);
+ i += 16;
+ lines++;
+ /* Limit to 5 lines */
+ if (lines > 5)
+ break;
+ }
+ }
+ if (lines != 0) {
+ /* Print some data about the neighboring objects, if they
+ * exist:
+ */
+ struct slab *slabp = virt_to_slab(objp);
+ unsigned int objnr;
+
+ objnr = obj_to_index(cachep, slabp, objp);
+ if (objnr) {
+ objp = index_to_obj(cachep, slabp, objnr - 1);
+ realobj = (char *)objp + obj_offset(cachep);
+ printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
+ realobj, size);
+ print_objinfo(cachep, objp, 2);
+ }
+ if (objnr + 1 < cachep->num) {
+ objp = index_to_obj(cachep, slabp, objnr + 1);
+ realobj = (char *)objp + obj_offset(cachep);
+ printk(KERN_ERR "Next obj: start=%p, len=%d\n",
+ realobj, size);
+ print_objinfo(cachep, objp, 2);
+ }
+ }
+}
+#endif
+
+#if DEBUG
+static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
+{
+ int i;
+ for (i = 0; i < cachep->num; i++) {
+ void *objp = index_to_obj(cachep, slabp, i);
+
+ if (cachep->flags & SLAB_POISON) {
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ if (cachep->buffer_size % PAGE_SIZE == 0 &&
+ OFF_SLAB(cachep))
+ kernel_map_pages(virt_to_page(objp),
+ cachep->buffer_size / PAGE_SIZE, 1);
+ else
+ check_poison_obj(cachep, objp);
+#else
+ check_poison_obj(cachep, objp);
+#endif
+ }
+ if (cachep->flags & SLAB_RED_ZONE) {
+ if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
+ slab_error(cachep, "start of a freed object "
+ "was overwritten");
+ if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
+ slab_error(cachep, "end of a freed object "
+ "was overwritten");
+ }
+ }
+}
+#else
+static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
+{
+}
+#endif
+
+/**
+ * slab_destroy - destroy and release all objects in a slab
+ * @cachep: cache pointer being destroyed
+ * @slabp: slab pointer being destroyed
+ *
+ * Destroy all the objs in a slab, and release the mem back to the system.
+ * Before calling the slab must have been unlinked from the cache. The
+ * cache-lock is not held/needed.
+ */
+static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp,
+ bool delayed)
+{
+ void *addr = slabp->s_mem - slabp->colouroff;
+
+ slab_destroy_debugcheck(cachep, slabp);
+ if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
+ struct slab_rcu *slab_rcu;
+
+ slab_rcu = (struct slab_rcu *)slabp;
+ slab_rcu->cachep = cachep;
+ slab_rcu->addr = addr;
+ call_rcu(&slab_rcu->head, kmem_rcu_free);
+ } else {
+ kmem_freepages(cachep, addr, delayed);
+ if (OFF_SLAB(cachep))
+ kmem_cache_free(cachep->slabp_cache, slabp);
+ }
+}
+
+static void __kmem_cache_destroy(struct kmem_cache *cachep)
+{
+ int i;
+ struct kmem_list3 *l3;
+
+ for_each_online_cpu(i)
+ kfree(cachep->array[i]);
+
+ /* NUMA: free the list3 structures */
+ for_each_online_node(i) {
+ l3 = cachep->nodelists[i];
+ if (l3) {
+ kfree(l3->shared);
+ free_alien_cache(l3->alien);
+ kfree(l3);
+ }
+ }
+ kmem_cache_free(&cache_cache, cachep);
+}
+
+
+/**
+ * calculate_slab_order - calculate size (page order) of slabs
+ * @cachep: pointer to the cache that is being created
+ * @size: size of objects to be created in this cache.
+ * @align: required alignment for the objects.
+ * @flags: slab allocation flags
+ *
+ * Also calculates the number of objects per slab.
+ *
+ * This could be made much more intelligent. For now, try to avoid using
+ * high order pages for slabs. When the gfp() functions are more friendly
+ * towards high-order requests, this should be changed.
+ */
+static size_t calculate_slab_order(struct kmem_cache *cachep,
+ size_t size, size_t align, unsigned long flags)
+{
+ unsigned long offslab_limit;
+ size_t left_over = 0;
+ int gfporder;
+
+ for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) {
+ unsigned int num;
+ size_t remainder;
+
+ cache_estimate(gfporder, size, align, flags, &remainder, &num);
+ if (!num)
+ continue;
+
+ if (flags & CFLGS_OFF_SLAB) {
+ /*
+ * Max number of objs-per-slab for caches which
+ * use off-slab slabs. Needed to avoid a possible
+ * looping condition in cache_grow().
+ */
+ offslab_limit = size - sizeof(struct slab);
+ offslab_limit /= sizeof(kmem_bufctl_t);
+
+ if (num > offslab_limit)
+ break;
+ }
+
+ /* Found something acceptable - save it away */
+ cachep->num = num;
+ cachep->gfporder = gfporder;
+ left_over = remainder;
+
+ /*
+ * A VFS-reclaimable slab tends to have most allocations
+ * as GFP_NOFS and we really don't want to have to be allocating
+ * higher-order pages when we are unable to shrink dcache.
+ */
+ if (flags & SLAB_RECLAIM_ACCOUNT)
+ break;
+
+ /*
+ * Large number of objects is good, but very large slabs are
+ * currently bad for the gfp()s.
+ */
+ if (gfporder >= slab_max_order)
+ break;
+
+ /*
+ * Acceptable internal fragmentation?
+ */
+ if (left_over * 8 <= (PAGE_SIZE << gfporder))
+ break;
+ }
+ return left_over;
+}
+
+static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
+{
+ if (g_cpucache_up == FULL)
+ return enable_cpucache(cachep, gfp);
+
+ if (g_cpucache_up == NONE) {
+ /*
+ * Note: the first kmem_cache_create must create the cache
+ * that's used by kmalloc(24), otherwise the creation of
+ * further caches will BUG().
+ */
+ cachep->array[smp_processor_id()] = &initarray_generic.cache;
+
+ /*
+ * If the cache that's used by kmalloc(sizeof(kmem_list3)) is
+ * the first cache, then we need to set up all its list3s,
+ * otherwise the creation of further caches will BUG().
+ */
+ set_up_list3s(cachep, SIZE_AC);
+ if (INDEX_AC == INDEX_L3)
+ g_cpucache_up = PARTIAL_L3;
+ else
+ g_cpucache_up = PARTIAL_AC;
+ } else {
+ cachep->array[smp_processor_id()] =
+ kmalloc(sizeof(struct arraycache_init), gfp);
+
+ if (g_cpucache_up == PARTIAL_AC) {
+ set_up_list3s(cachep, SIZE_L3);
+ g_cpucache_up = PARTIAL_L3;
+ } else {
+ int node;
+ for_each_online_node(node) {
+ cachep->nodelists[node] =
+ kmalloc_node(sizeof(struct kmem_list3),
+ gfp, node);
+ BUG_ON(!cachep->nodelists[node]);
+ kmem_list3_init(cachep->nodelists[node]);
+ }
+ }
+ }
+ cachep->nodelists[numa_mem_id()]->next_reap =
+ jiffies + REAPTIMEOUT_LIST3 +
+ ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
+
+ cpu_cache_get(cachep)->avail = 0;
+ cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
+ cpu_cache_get(cachep)->batchcount = 1;
+ cpu_cache_get(cachep)->touched = 0;
+ cachep->batchcount = 1;
+ cachep->limit = BOOT_CPUCACHE_ENTRIES;
+ return 0;
+}
+
+/**
+ * kmem_cache_create - Create a cache.
+ * @name: A string which is used in /proc/slabinfo to identify this cache.
+ * @size: The size of objects to be created in this cache.
+ * @align: The required alignment for the objects.
+ * @flags: SLAB flags
+ * @ctor: A constructor for the objects.
+ *
+ * Returns a ptr to the cache on success, NULL on failure.
+ * Cannot be called within a int, but can be interrupted.
+ * The @ctor is run when new pages are allocated by the cache.
+ *
+ * @name must be valid until the cache is destroyed. This implies that
+ * the module calling this has to destroy the cache before getting unloaded.
+ *
+ * The flags are
+ *
+ * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
+ * to catch references to uninitialised memory.
+ *
+ * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
+ * for buffer overruns.
+ *
+ * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
+ * cacheline. This can be beneficial if you're counting cycles as closely
+ * as davem.
+ */
+struct kmem_cache *
+kmem_cache_create (const char *name, size_t size, size_t align,
+ unsigned long flags, void (*ctor)(void *))
+{
+ size_t left_over, slab_size, ralign;
+ struct kmem_cache *cachep = NULL, *pc;
+ gfp_t gfp;
+
+ /*
+ * Sanity checks... these are all serious usage bugs.
+ */
+ if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
+ size > KMALLOC_MAX_SIZE) {
+ printk(KERN_ERR "%s: Early error in slab %s\n", __func__,
+ name);
+ BUG();
+ }
+
+ /*
+ * We use cache_chain_mutex to ensure a consistent view of
+ * cpu_online_mask as well. Please see cpuup_callback
+ */
+ if (slab_is_available()) {
+ get_online_cpus();
+ mutex_lock(&cache_chain_mutex);
+ }
+
+ list_for_each_entry(pc, &cache_chain, next) {
+ char tmp;
+ int res;
+
+ /*
+ * This happens when the module gets unloaded and doesn't
+ * destroy its slab cache and no-one else reuses the vmalloc
+ * area of the module. Print a warning.
+ */
+ res = probe_kernel_address(pc->name, tmp);
+ if (res) {
+ printk(KERN_ERR
+ "SLAB: cache with size %d has lost its name\n",
+ pc->buffer_size);
+ continue;
+ }
+
+ if (!strcmp(pc->name, name)) {
+ printk(KERN_ERR
+ "kmem_cache_create: duplicate cache %s\n", name);
+ dump_stack();
+ goto oops;
+ }
+ }
+
+#if DEBUG
+ WARN_ON(strchr(name, ' ')); /* It confuses parsers */
+#if FORCED_DEBUG
+ /*
+ * Enable redzoning and last user accounting, except for caches with
+ * large objects, if the increased size would increase the object size
+ * above the next power of two: caches with object sizes just above a
+ * power of two have a significant amount of internal fragmentation.
+ */
+ if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN +
+ 2 * sizeof(unsigned long long)))
+ flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
+ if (!(flags & SLAB_DESTROY_BY_RCU))
+ flags |= SLAB_POISON;
+#endif
+ if (flags & SLAB_DESTROY_BY_RCU)
+ BUG_ON(flags & SLAB_POISON);
+#endif
+ /*
+ * Always checks flags, a caller might be expecting debug support which
+ * isn't available.
+ */
+ BUG_ON(flags & ~CREATE_MASK);
+
+ /*
+ * Check that size is in terms of words. This is needed to avoid
+ * unaligned accesses for some archs when redzoning is used, and makes
+ * sure any on-slab bufctl's are also correctly aligned.
+ */
+ if (size & (BYTES_PER_WORD - 1)) {
+ size += (BYTES_PER_WORD - 1);
+ size &= ~(BYTES_PER_WORD - 1);
+ }
+
+ /* calculate the final buffer alignment: */
+
+ /* 1) arch recommendation: can be overridden for debug */
+ if (flags & SLAB_HWCACHE_ALIGN) {
+ /*
+ * Default alignment: as specified by the arch code. Except if
+ * an object is really small, then squeeze multiple objects into
+ * one cacheline.
+ */
+ ralign = cache_line_size();
+ while (size <= ralign / 2)
+ ralign /= 2;
+ } else {
+ ralign = BYTES_PER_WORD;
+ }
+
+ /*
+ * Redzoning and user store require word alignment or possibly larger.
+ * Note this will be overridden by architecture or caller mandated
+ * alignment if either is greater than BYTES_PER_WORD.
+ */
+ if (flags & SLAB_STORE_USER)
+ ralign = BYTES_PER_WORD;
+
+ if (flags & SLAB_RED_ZONE) {
+ ralign = REDZONE_ALIGN;
+ /* If redzoning, ensure that the second redzone is suitably
+ * aligned, by adjusting the object size accordingly. */
+ size += REDZONE_ALIGN - 1;
+ size &= ~(REDZONE_ALIGN - 1);
+ }
+
+ /* 2) arch mandated alignment */
+ if (ralign < ARCH_SLAB_MINALIGN) {
+ ralign = ARCH_SLAB_MINALIGN;
+ }
+ /* 3) caller mandated alignment */
+ if (ralign < align) {
+ ralign = align;
+ }
+ /* disable debug if necessary */
+ if (ralign > __alignof__(unsigned long long))
+ flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
+ /*
+ * 4) Store it.
+ */
+ align = ralign;
+
+ if (slab_is_available())
+ gfp = GFP_KERNEL;
+ else
+ gfp = GFP_NOWAIT;
+
+ /* Get cache's description obj. */
+ cachep = kmem_cache_zalloc(&cache_cache, gfp);
+ if (!cachep)
+ goto oops;
+
+ cachep->nodelists = (struct kmem_list3 **)&cachep->array[nr_cpu_ids];
+#if DEBUG
+ cachep->obj_size = size;
+
+ /*
+ * Both debugging options require word-alignment which is calculated
+ * into align above.
+ */
+ if (flags & SLAB_RED_ZONE) {
+ /* add space for red zone words */
+ cachep->obj_offset += sizeof(unsigned long long);
+ size += 2 * sizeof(unsigned long long);
+ }
+ if (flags & SLAB_STORE_USER) {
+ /* user store requires one word storage behind the end of
+ * the real object. But if the second red zone needs to be
+ * aligned to 64 bits, we must allow that much space.
+ */
+ if (flags & SLAB_RED_ZONE)
+ size += REDZONE_ALIGN;
+ else
+ size += BYTES_PER_WORD;
+ }
+#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
+ if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
+ && cachep->obj_size > cache_line_size() && ALIGN(size, align) < PAGE_SIZE) {
+ cachep->obj_offset += PAGE_SIZE - ALIGN(size, align);
+ size = PAGE_SIZE;
+ }
+#endif
+#endif
+
+ /*
+ * Determine if the slab management is 'on' or 'off' slab.
+ * (bootstrapping cannot cope with offslab caches so don't do
+ * it too early on. Always use on-slab management when
+ * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak)
+ */
+ if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init &&
+ !(flags & SLAB_NOLEAKTRACE))
+ /*
+ * Size is large, assume best to place the slab management obj
+ * off-slab (should allow better packing of objs).
+ */
+ flags |= CFLGS_OFF_SLAB;
+
+ size = ALIGN(size, align);
+
+ left_over = calculate_slab_order(cachep, size, align, flags);
+
+ if (!cachep->num) {
+ printk(KERN_ERR
+ "kmem_cache_create: couldn't create cache %s.\n", name);
+ kmem_cache_free(&cache_cache, cachep);
+ cachep = NULL;
+ goto oops;
+ }
+ slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
+ + sizeof(struct slab), align);
+
+ /*
+ * If the slab has been placed off-slab, and we have enough space then
+ * move it on-slab. This is at the expense of any extra colouring.
+ */
+ if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) {
+ flags &= ~CFLGS_OFF_SLAB;
+ left_over -= slab_size;
+ }
+
+ if (flags & CFLGS_OFF_SLAB) {
+ /* really off slab. No need for manual alignment */
+ slab_size =
+ cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
+
+#ifdef CONFIG_PAGE_POISONING
+ /* If we're going to use the generic kernel_map_pages()
+ * poisoning, then it's going to smash the contents of
+ * the redzone and userword anyhow, so switch them off.
+ */
+ if (size % PAGE_SIZE == 0 && flags & SLAB_POISON)
+ flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
+#endif
+ }
+
+ cachep->colour_off = cache_line_size();
+ /* Offset must be a multiple of the alignment. */
+ if (cachep->colour_off < align)
+ cachep->colour_off = align;
+ cachep->colour = left_over / cachep->colour_off;
+ cachep->slab_size = slab_size;
+ cachep->flags = flags;
+ cachep->gfpflags = 0;
+ if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
+ cachep->gfpflags |= GFP_DMA;
+ cachep->buffer_size = size;
+ cachep->reciprocal_buffer_size = reciprocal_value(size);
+
+ if (flags & CFLGS_OFF_SLAB) {
+ cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
+ /*
+ * This is a possibility for one of the malloc_sizes caches.
+ * But since we go off slab only for object size greater than
+ * PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
+ * this should not happen at all.
+ * But leave a BUG_ON for some lucky dude.
+ */
+ BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));
+ }
+ cachep->ctor = ctor;
+ cachep->name = name;
+
+ if (setup_cpu_cache(cachep, gfp)) {
+ __kmem_cache_destroy(cachep);
+ cachep = NULL;
+ goto oops;
+ }
+
+ if (flags & SLAB_DEBUG_OBJECTS) {
+ /*
+ * Would deadlock through slab_destroy()->call_rcu()->
+ * debug_object_activate()->kmem_cache_alloc().
+ */
+ WARN_ON_ONCE(flags & SLAB_DESTROY_BY_RCU);
+
+ slab_set_debugobj_lock_classes(cachep);
+ }
+
+ init_cachep_lock_keys(cachep);
+
+ /* cache setup completed, link it into the list */
+ list_add(&cachep->next, &cache_chain);
+oops:
+ if (!cachep && (flags & SLAB_PANIC))
+ panic("kmem_cache_create(): failed to create slab `%s'\n",
+ name);
+ if (slab_is_available()) {
+ mutex_unlock(&cache_chain_mutex);
+ put_online_cpus();
+ }
+ return cachep;
+}
+EXPORT_SYMBOL(kmem_cache_create);
+
+#if DEBUG
+static void check_irq_off(void)
+{
+ BUG_ON_NONRT(!irqs_disabled());
+}
+
+static void check_irq_on(void)
+{
+ BUG_ON(irqs_disabled());
+}
+
+static void check_spinlock_acquired(struct kmem_cache *cachep)
+{
+#ifdef CONFIG_SMP
+ check_irq_off();
+ assert_spin_locked(&cachep->nodelists[numa_mem_id()]->list_lock);
+#endif
+}
+
+static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
+{
+#ifdef CONFIG_SMP
+ check_irq_off();
+ assert_spin_locked(&cachep->nodelists[node]->list_lock);
+#endif
+}
+
+#else
+#define check_irq_off() do { } while(0)
+#define check_irq_on() do { } while(0)
+#define check_spinlock_acquired(x) do { } while(0)
+#define check_spinlock_acquired_node(x, y) do { } while(0)
+#endif
+
+static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
+ struct array_cache *ac,
+ int force, int node);
+
+static void __do_drain(void *arg, unsigned int cpu)
+{
+ struct kmem_cache *cachep = arg;
+ struct array_cache *ac;
+ int node = cpu_to_mem(cpu);
+
+ ac = cpu_cache_get_on_cpu(cachep, cpu);
+ spin_lock(&cachep->nodelists[node]->list_lock);
+ free_block(cachep, ac->entry, ac->avail, node);
+ spin_unlock(&cachep->nodelists[node]->list_lock);
+ ac->avail = 0;
+}
+
+#ifndef CONFIG_PREEMPT_RT_BASE
+static void do_drain(void *arg)
+{
+ __do_drain(arg, smp_processor_id());
+}
+#else
+static void do_drain(void *arg, int cpu)
+{
+ LIST_HEAD(tmp);
+
+ lock_slab_on(cpu);
+ __do_drain(arg, cpu);
+ list_splice_init(&per_cpu(slab_free_list, cpu), &tmp);
+ unlock_slab_on(cpu);
+ free_delayed(&tmp);
+}
+#endif
+
+static void drain_cpu_caches(struct kmem_cache *cachep)
+{
+ struct kmem_list3 *l3;
+ int node;
+
+ slab_on_each_cpu(do_drain, cachep);
+ check_irq_on();
+ for_each_online_node(node) {
+ l3 = cachep->nodelists[node];
+ if (l3 && l3->alien)
+ drain_alien_cache(cachep, l3->alien);
+ }
+
+ for_each_online_node(node) {
+ l3 = cachep->nodelists[node];
+ if (l3)
+ drain_array(cachep, l3, l3->shared, 1, node);
+ }
+}
+
+/*
+ * Remove slabs from the list of free slabs.
+ * Specify the number of slabs to drain in tofree.
+ *
+ * Returns the actual number of slabs released.
+ */
+static int drain_freelist(struct kmem_cache *cache,
+ struct kmem_list3 *l3, int tofree)
+{
+ struct list_head *p;
+ int nr_freed;
+ struct slab *slabp;
+
+ nr_freed = 0;
+ while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
+
+ local_spin_lock_irq(slab_lock, &l3->list_lock);
+ p = l3->slabs_free.prev;
+ if (p == &l3->slabs_free) {
+ local_spin_unlock_irq(slab_lock, &l3->list_lock);
+ goto out;
+ }
+
+ slabp = list_entry(p, struct slab, list);
+#if DEBUG
+ BUG_ON(slabp->inuse);
+#endif
+ list_del(&slabp->list);
+ /*
+ * Safe to drop the lock. The slab is no longer linked
+ * to the cache.
+ */
+ l3->free_objects -= cache->num;
+ local_spin_unlock_irq(slab_lock, &l3->list_lock);
+ slab_destroy(cache, slabp, false);
+ nr_freed++;
+ }
+out:
+ return nr_freed;
+}
+
+/* Called with cache_chain_mutex held to protect against cpu hotplug */
+static int __cache_shrink(struct kmem_cache *cachep)
+{
+ int ret = 0, i = 0;
+ struct kmem_list3 *l3;
+
+ drain_cpu_caches(cachep);
+
+ check_irq_on();
+ for_each_online_node(i) {
+ l3 = cachep->nodelists[i];
+ if (!l3)
+ continue;
+
+ drain_freelist(cachep, l3, l3->free_objects);
+
+ ret += !list_empty(&l3->slabs_full) ||
+ !list_empty(&l3->slabs_partial);
+ }
+ return (ret ? 1 : 0);
+}
+
+/**
+ * kmem_cache_shrink - Shrink a cache.
+ * @cachep: The cache to shrink.
+ *
+ * Releases as many slabs as possible for a cache.
+ * To help debugging, a zero exit status indicates all slabs were released.
+ */
+int kmem_cache_shrink(struct kmem_cache *cachep)
+{
+ int ret;
+ BUG_ON(!cachep || in_interrupt());
+
+ get_online_cpus();
+ mutex_lock(&cache_chain_mutex);
+ ret = __cache_shrink(cachep);
+ mutex_unlock(&cache_chain_mutex);
+ put_online_cpus();
+ return ret;
+}
+EXPORT_SYMBOL(kmem_cache_shrink);
+
+/**
+ * kmem_cache_destroy - delete a cache
+ * @cachep: the cache to destroy
+ *
+ * Remove a &struct kmem_cache object from the slab cache.
+ *
+ * It is expected this function will be called by a module when it is
+ * unloaded. This will remove the cache completely, and avoid a duplicate
+ * cache being allocated each time a module is loaded and unloaded, if the
+ * module doesn't have persistent in-kernel storage across loads and unloads.
+ *
+ * The cache must be empty before calling this function.
+ *
+ * The caller must guarantee that no one will allocate memory from the cache
+ * during the kmem_cache_destroy().
+ */
+void kmem_cache_destroy(struct kmem_cache *cachep)
+{
+ BUG_ON(!cachep || in_interrupt());
+
+ /* Find the cache in the chain of caches. */
+ get_online_cpus();
+ mutex_lock(&cache_chain_mutex);
+ /*
+ * the chain is never empty, cache_cache is never destroyed
+ */
+ list_del(&cachep->next);
+ if (__cache_shrink(cachep)) {
+ slab_error(cachep, "Can't free all objects");
+ list_add(&cachep->next, &cache_chain);
+ mutex_unlock(&cache_chain_mutex);
+ put_online_cpus();
+ return;
+ }
+
+ if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
+ rcu_barrier();
+
+ __kmem_cache_destroy(cachep);
+ mutex_unlock(&cache_chain_mutex);
+ put_online_cpus();
+}
+EXPORT_SYMBOL(kmem_cache_destroy);
+
+/*
+ * Get the memory for a slab management obj.
+ * For a slab cache when the slab descriptor is off-slab, slab descriptors
+ * always come from malloc_sizes caches. The slab descriptor cannot
+ * come from the same cache which is getting created because,
+ * when we are searching for an appropriate cache for these
+ * descriptors in kmem_cache_create, we search through the malloc_sizes array.
+ * If we are creating a malloc_sizes cache here it would not be visible to
+ * kmem_find_general_cachep till the initialization is complete.
+ * Hence we cannot have slabp_cache same as the original cache.
+ */
+static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
+ int colour_off, gfp_t local_flags,
+ int nodeid)
+{
+ struct slab *slabp;
+
+ if (OFF_SLAB(cachep)) {
+ /* Slab management obj is off-slab. */
+ slabp = kmem_cache_alloc_node(cachep->slabp_cache,
+ local_flags, nodeid);
+ /*
+ * If the first object in the slab is leaked (it's allocated
+ * but no one has a reference to it), we want to make sure
+ * kmemleak does not treat the ->s_mem pointer as a reference
+ * to the object. Otherwise we will not report the leak.
+ */
+ kmemleak_scan_area(&slabp->list, sizeof(struct list_head),
+ local_flags);
+ if (!slabp)
+ return NULL;
+ } else {
+ slabp = objp + colour_off;
+ colour_off += cachep->slab_size;
+ }
+ slabp->inuse = 0;
+ slabp->colouroff = colour_off;
+ slabp->s_mem = objp + colour_off;
+ slabp->nodeid = nodeid;
+ slabp->free = 0;
+ return slabp;
+}
+
+static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
+{
+ return (kmem_bufctl_t *) (slabp + 1);
+}
+
+static void cache_init_objs(struct kmem_cache *cachep,
+ struct slab *slabp)
+{
+ int i;
+
+ for (i = 0; i < cachep->num; i++) {
+ void *objp = index_to_obj(cachep, slabp, i);
+#if DEBUG
+ /* need to poison the objs? */
+ if (cachep->flags & SLAB_POISON)
+ poison_obj(cachep, objp, POISON_FREE);
+ if (cachep->flags & SLAB_STORE_USER)
+ *dbg_userword(cachep, objp) = NULL;
+
+ if (cachep->flags & SLAB_RED_ZONE) {
+ *dbg_redzone1(cachep, objp) = RED_INACTIVE;
+ *dbg_redzone2(cachep, objp) = RED_INACTIVE;
+ }
+ /*
+ * Constructors are not allowed to allocate memory from the same
+ * cache which they are a constructor for. Otherwise, deadlock.
+ * They must also be threaded.
+ */
+ if (cachep->ctor && !(cachep->flags & SLAB_POISON))
+ cachep->ctor(objp + obj_offset(cachep));
+
+ if (cachep->flags & SLAB_RED_ZONE) {
+ if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
+ slab_error(cachep, "constructor overwrote the"
+ " end of an object");
+ if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
+ slab_error(cachep, "constructor overwrote the"
+ " start of an object");
+ }
+ if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
+ OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
+ kernel_map_pages(virt_to_page(objp),
+ cachep->buffer_size / PAGE_SIZE, 0);
+#else
+ if (cachep->ctor)
+ cachep->ctor(objp);
+#endif
+ slab_bufctl(slabp)[i] = i + 1;
+ }
+ slab_bufctl(slabp)[i - 1] = BUFCTL_END;
+}
+
+static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
+{
+ if (CONFIG_ZONE_DMA_FLAG) {
+ if (flags & GFP_DMA)
+ BUG_ON(!(cachep->gfpflags & GFP_DMA));
+ else
+ BUG_ON(cachep->gfpflags & GFP_DMA);
+ }
+}
+
+static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
+ int nodeid)
+{
+ void *objp = index_to_obj(cachep, slabp, slabp->free);
+ kmem_bufctl_t next;
+
+ slabp->inuse++;
+ next = slab_bufctl(slabp)[slabp->free];
+#if DEBUG
+ slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
+ WARN_ON(slabp->nodeid != nodeid);
+#endif
+ slabp->free = next;
+
+ return objp;
+}
+
+static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
+ void *objp, int nodeid)
+{
+ unsigned int objnr = obj_to_index(cachep, slabp, objp);
+
+#if DEBUG
+ /* Verify that the slab belongs to the intended node */
+ WARN_ON(slabp->nodeid != nodeid);
+
+ if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
+ printk(KERN_ERR "slab: double free detected in cache "
+ "'%s', objp %p\n", cachep->name, objp);
+ BUG();
+ }
+#endif
+ slab_bufctl(slabp)[objnr] = slabp->free;
+ slabp->free = objnr;
+ slabp->inuse--;
+}
+
+/*
+ * Map pages beginning at addr to the given cache and slab. This is required
+ * for the slab allocator to be able to lookup the cache and slab of a
+ * virtual address for kfree, ksize, and slab debugging.
+ */
+static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
+ void *addr)
+{
+ int nr_pages;
+ struct page *page;
+
+ page = virt_to_page(addr);
+
+ nr_pages = 1;
+ if (likely(!PageCompound(page)))
+ nr_pages <<= cache->gfporder;
+
+ do {
+ page_set_cache(page, cache);
+ page_set_slab(page, slab);
+ page++;
+ } while (--nr_pages);
+}
+
+/*
+ * Grow (by 1) the number of slabs within a cache. This is called by
+ * kmem_cache_alloc() when there are no active objs left in a cache.
+ */
+static int cache_grow(struct kmem_cache *cachep,
+ gfp_t flags, int nodeid, void *objp)
+{
+ struct slab *slabp;
+ size_t offset;
+ gfp_t local_flags;
+ struct kmem_list3 *l3;
+
+ /*
+ * Be lazy and only check for valid flags here, keeping it out of the
+ * critical path in kmem_cache_alloc().
+ */
+ BUG_ON(flags & GFP_SLAB_BUG_MASK);
+ local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
+
+ /* Take the l3 list lock to change the colour_next on this node */
+ check_irq_off();
+ l3 = cachep->nodelists[nodeid];
+ spin_lock(&l3->list_lock);
+
+ /* Get colour for the slab, and cal the next value. */
+ offset = l3->colour_next;
+ l3->colour_next++;
+ if (l3->colour_next >= cachep->colour)
+ l3->colour_next = 0;
+ spin_unlock(&l3->list_lock);
+
+ offset *= cachep->colour_off;
+
+ if (local_flags & __GFP_WAIT)
+ local_unlock_irq(slab_lock);
+
+ /*
+ * The test for missing atomic flag is performed here, rather than
+ * the more obvious place, simply to reduce the critical path length
+ * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
+ * will eventually be caught here (where it matters).
+ */
+ kmem_flagcheck(cachep, flags);
+
+ /*
+ * Get mem for the objs. Attempt to allocate a physical page from
+ * 'nodeid'.
+ */
+ if (!objp)
+ objp = kmem_getpages(cachep, local_flags, nodeid);
+ if (!objp)
+ goto failed;
+
+ /* Get slab management. */
+ slabp = alloc_slabmgmt(cachep, objp, offset,
+ local_flags & ~GFP_CONSTRAINT_MASK, nodeid);
+ if (!slabp)
+ goto opps1;
+
+ slab_map_pages(cachep, slabp, objp);
+
+ cache_init_objs(cachep, slabp);
+
+ if (local_flags & __GFP_WAIT)
+ local_lock_irq(slab_lock);
+ check_irq_off();
+ spin_lock(&l3->list_lock);
+
+ /* Make slab active. */
+ list_add_tail(&slabp->list, &(l3->slabs_free));
+ STATS_INC_GROWN(cachep);
+ l3->free_objects += cachep->num;
+ spin_unlock(&l3->list_lock);
+ return 1;
+opps1:
+ kmem_freepages(cachep, objp, false);
+failed:
+ if (local_flags & __GFP_WAIT)
+ local_lock_irq(slab_lock);
+ return 0;
+}
+
+#if DEBUG
+
+/*
+ * Perform extra freeing checks:
+ * - detect bad pointers.
+ * - POISON/RED_ZONE checking
+ */
+static void kfree_debugcheck(const void *objp)
+{
+ if (!virt_addr_valid(objp)) {
+ printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
+ (unsigned long)objp);
+ BUG();
+ }
+}
+
+static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
+{
+ unsigned long long redzone1, redzone2;
+
+ redzone1 = *dbg_redzone1(cache, obj);
+ redzone2 = *dbg_redzone2(cache, obj);
+
+ /*
+ * Redzone is ok.
+ */
+ if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
+ return;
+
+ if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
+ slab_error(cache, "double free detected");
+ else
+ slab_error(cache, "memory outside object was overwritten");
+
+ printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n",
+ obj, redzone1, redzone2);
+}
+
+static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
+ void *caller)
+{
+ struct page *page;
+ unsigned int objnr;
+ struct slab *slabp;
+
+ BUG_ON(virt_to_cache(objp) != cachep);
+
+ objp -= obj_offset(cachep);
+ kfree_debugcheck(objp);
+ page = virt_to_head_page(objp);
+
+ slabp = page_get_slab(page);
+
+ if (cachep->flags & SLAB_RED_ZONE) {
+ verify_redzone_free(cachep, objp);
+ *dbg_redzone1(cachep, objp) = RED_INACTIVE;
+ *dbg_redzone2(cachep, objp) = RED_INACTIVE;
+ }
+ if (cachep->flags & SLAB_STORE_USER)
+ *dbg_userword(cachep, objp) = caller;
+
+ objnr = obj_to_index(cachep, slabp, objp);
+
+ BUG_ON(objnr >= cachep->num);
+ BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
+
+#ifdef CONFIG_DEBUG_SLAB_LEAK
+ slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
+#endif
+ if (cachep->flags & SLAB_POISON) {
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
+ store_stackinfo(cachep, objp, (unsigned long)caller);
+ kernel_map_pages(virt_to_page(objp),
+ cachep->buffer_size / PAGE_SIZE, 0);
+ } else {
+ poison_obj(cachep, objp, POISON_FREE);
+ }
+#else
+ poison_obj(cachep, objp, POISON_FREE);
+#endif
+ }
+ return objp;
+}
+
+static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
+{
+ kmem_bufctl_t i;
+ int entries = 0;
+
+ /* Check slab's freelist to see if this obj is there. */
+ for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) {
+ entries++;
+ if (entries > cachep->num || i >= cachep->num)
+ goto bad;
+ }
+ if (entries != cachep->num - slabp->inuse) {
+bad:
+ printk(KERN_ERR "slab: Internal list corruption detected in "
+ "cache '%s'(%d), slabp %p(%d). Tainted(%s). Hexdump:\n",
+ cachep->name, cachep->num, slabp, slabp->inuse,
+ print_tainted());
+ print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, slabp,
+ sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t),
+ 1);
+ BUG();
+ }
+}
+#else
+#define kfree_debugcheck(x) do { } while(0)
+#define cache_free_debugcheck(x,objp,z) (objp)
+#define check_slabp(x,y) do { } while(0)
+#endif
+
+static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
+{
+ int batchcount;
+ struct kmem_list3 *l3;
+ struct array_cache *ac;
+ int node;
+
+retry:
+ check_irq_off();
+ node = numa_mem_id();
+ ac = cpu_cache_get(cachep);
+ batchcount = ac->batchcount;
+ if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
+ /*
+ * If there was little recent activity on this cache, then
+ * perform only a partial refill. Otherwise we could generate
+ * refill bouncing.
+ */
+ batchcount = BATCHREFILL_LIMIT;
+ }
+ l3 = cachep->nodelists[node];
+
+ BUG_ON(ac->avail > 0 || !l3);
+ spin_lock(&l3->list_lock);
+
+ /* See if we can refill from the shared array */
+ if (l3->shared && transfer_objects(ac, l3->shared, batchcount)) {
+ l3->shared->touched = 1;
+ goto alloc_done;
+ }
+
+ while (batchcount > 0) {
+ struct list_head *entry;
+ struct slab *slabp;
+ /* Get slab alloc is to come from. */
+ entry = l3->slabs_partial.next;
+ if (entry == &l3->slabs_partial) {
+ l3->free_touched = 1;
+ entry = l3->slabs_free.next;
+ if (entry == &l3->slabs_free)
+ goto must_grow;
+ }
+
+ slabp = list_entry(entry, struct slab, list);
+ check_slabp(cachep, slabp);
+ check_spinlock_acquired(cachep);
+
+ /*
+ * The slab was either on partial or free list so
+ * there must be at least one object available for
+ * allocation.
+ */
+ BUG_ON(slabp->inuse >= cachep->num);
+
+ while (slabp->inuse < cachep->num && batchcount--) {
+ STATS_INC_ALLOCED(cachep);
+ STATS_INC_ACTIVE(cachep);
+ STATS_SET_HIGH(cachep);
+
+ ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
+ node);
+ }
+ check_slabp(cachep, slabp);
+
+ /* move slabp to correct slabp list: */
+ list_del(&slabp->list);
+ if (slabp->free == BUFCTL_END)
+ list_add(&slabp->list, &l3->slabs_full);
+ else
+ list_add(&slabp->list, &l3->slabs_partial);
+ }
+
+must_grow:
+ l3->free_objects -= ac->avail;
+alloc_done:
+ spin_unlock(&l3->list_lock);
+
+ if (unlikely(!ac->avail)) {
+ int x;
+ x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
+
+ /* cache_grow can reenable interrupts, then ac could change. */
+ ac = cpu_cache_get(cachep);
+ if (!x && ac->avail == 0) /* no objects in sight? abort */
+ return NULL;
+
+ if (!ac->avail) /* objects refilled by interrupt? */
+ goto retry;
+ }
+ ac->touched = 1;
+ return ac->entry[--ac->avail];
+}
+
+static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
+ gfp_t flags)
+{
+ might_sleep_if(flags & __GFP_WAIT);
+#if DEBUG
+ kmem_flagcheck(cachep, flags);
+#endif
+}
+
+#if DEBUG
+static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
+ gfp_t flags, void *objp, void *caller)
+{
+ if (!objp)
+ return objp;
+ if (cachep->flags & SLAB_POISON) {
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
+ kernel_map_pages(virt_to_page(objp),
+ cachep->buffer_size / PAGE_SIZE, 1);
+ else
+ check_poison_obj(cachep, objp);
+#else
+ check_poison_obj(cachep, objp);
+#endif
+ poison_obj(cachep, objp, POISON_INUSE);
+ }
+ if (cachep->flags & SLAB_STORE_USER)
+ *dbg_userword(cachep, objp) = caller;
+
+ if (cachep->flags & SLAB_RED_ZONE) {
+ if (*dbg_redzone1(cachep, objp) != RED_INACTIVE ||
+ *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
+ slab_error(cachep, "double free, or memory outside"
+ " object was overwritten");
+ printk(KERN_ERR
+ "%p: redzone 1:0x%llx, redzone 2:0x%llx\n",
+ objp, *dbg_redzone1(cachep, objp),
+ *dbg_redzone2(cachep, objp));
+ }
+ *dbg_redzone1(cachep, objp) = RED_ACTIVE;
+ *dbg_redzone2(cachep, objp) = RED_ACTIVE;
+ }
+#ifdef CONFIG_DEBUG_SLAB_LEAK
+ {
+ struct slab *slabp;
+ unsigned objnr;
+
+ slabp = page_get_slab(virt_to_head_page(objp));
+ objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
+ slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
+ }
+#endif
+ objp += obj_offset(cachep);
+ if (cachep->ctor && cachep->flags & SLAB_POISON)
+ cachep->ctor(objp);
+ if (ARCH_SLAB_MINALIGN &&
+ ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) {
+ printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
+ objp, (int)ARCH_SLAB_MINALIGN);
+ }
+ return objp;
+}
+#else
+#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
+#endif
+
+static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags)
+{
+ if (cachep == &cache_cache)
+ return false;
+
+ return should_failslab(obj_size(cachep), flags, cachep->flags);
+}
+
+static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
+{
+ void *objp;
+ struct array_cache *ac;
+
+ check_irq_off();
+
+ ac = cpu_cache_get(cachep);
+ if (likely(ac->avail)) {
+ STATS_INC_ALLOCHIT(cachep);
+ ac->touched = 1;
+ objp = ac->entry[--ac->avail];
+ } else {
+ STATS_INC_ALLOCMISS(cachep);
+ objp = cache_alloc_refill(cachep, flags);
+ /*
+ * the 'ac' may be updated by cache_alloc_refill(),
+ * and kmemleak_erase() requires its correct value.
+ */
+ ac = cpu_cache_get(cachep);
+ }
+ /*
+ * To avoid a false negative, if an object that is in one of the
+ * per-CPU caches is leaked, we need to make sure kmemleak doesn't
+ * treat the array pointers as a reference to the object.
+ */
+ if (objp)
+ kmemleak_erase(&ac->entry[ac->avail]);
+ return objp;
+}
+
+#ifdef CONFIG_NUMA
+/*
+ * Try allocating on another node if PFA_SPREAD_SLAB|PF_MEMPOLICY.
+ *
+ * If we are in_interrupt, then process context, including cpusets and
+ * mempolicy, may not apply and should not be used for allocation policy.
+ */
+static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
+{
+ int nid_alloc, nid_here;
+
+ if (in_interrupt() || (flags & __GFP_THISNODE))
+ return NULL;
+ nid_alloc = nid_here = numa_mem_id();
+ if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
+ nid_alloc = cpuset_slab_spread_node();
+ else if (current->mempolicy)
+ nid_alloc = slab_node();
+ if (nid_alloc != nid_here)
+ return ____cache_alloc_node(cachep, flags, nid_alloc);
+ return NULL;
+}
+
+/*
+ * Fallback function if there was no memory available and no objects on a
+ * certain node and fall back is permitted. First we scan all the
+ * available nodelists for available objects. If that fails then we
+ * perform an allocation without specifying a node. This allows the page
+ * allocator to do its reclaim / fallback magic. We then insert the
+ * slab into the proper nodelist and then allocate from it.
+ */
+static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
+{
+ struct zonelist *zonelist;
+ gfp_t local_flags;
+ struct zoneref *z;
+ struct zone *zone;
+ enum zone_type high_zoneidx = gfp_zone(flags);
+ void *obj = NULL;
+ int nid;
+ unsigned int cpuset_mems_cookie;
+
+ if (flags & __GFP_THISNODE)
+ return NULL;
+
+ local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
+
+retry_cpuset:
+ cpuset_mems_cookie = get_mems_allowed();
+ zonelist = node_zonelist(slab_node(), flags);
+
+retry:
+ /*
+ * Look through allowed nodes for objects available
+ * from existing per node queues.
+ */
+ for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
+ nid = zone_to_nid(zone);
+
+ if (cpuset_zone_allowed_hardwall(zone, flags) &&
+ cache->nodelists[nid] &&
+ cache->nodelists[nid]->free_objects) {
+ obj = ____cache_alloc_node(cache,
+ flags | GFP_THISNODE, nid);
+ if (obj)
+ break;
+ }
+ }
+
+ if (!obj) {
+ /*
+ * This allocation will be performed within the constraints
+ * of the current cpuset / memory policy requirements.
+ * We may trigger various forms of reclaim on the allowed
+ * set and go into memory reserves if necessary.
+ */
+ if (local_flags & __GFP_WAIT)
+ local_unlock_irq(slab_lock);
+ kmem_flagcheck(cache, flags);
+ obj = kmem_getpages(cache, local_flags, numa_mem_id());
+ if (local_flags & __GFP_WAIT)
+ local_lock_irq(slab_lock);
+ if (obj) {
+ /*
+ * Insert into the appropriate per node queues
+ */
+ nid = page_to_nid(virt_to_page(obj));
+ if (cache_grow(cache, flags, nid, obj)) {
+ obj = ____cache_alloc_node(cache,
+ flags | GFP_THISNODE, nid);
+ if (!obj)
+ /*
+ * Another processor may allocate the
+ * objects in the slab since we are
+ * not holding any locks.
+ */
+ goto retry;
+ } else {
+ /* cache_grow already freed obj */
+ obj = NULL;
+ }
+ }
+ }
+
+ if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !obj))
+ goto retry_cpuset;
+ return obj;
+}
+
+/*
+ * A interface to enable slab creation on nodeid
+ */
+static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
+ int nodeid)
+{
+ struct list_head *entry;
+ struct slab *slabp;
+ struct kmem_list3 *l3;
+ void *obj;
+ int x;
+
+ l3 = cachep->nodelists[nodeid];
+ BUG_ON(!l3);
+
+retry:
+ check_irq_off();
+ spin_lock(&l3->list_lock);
+ entry = l3->slabs_partial.next;
+ if (entry == &l3->slabs_partial) {
+ l3->free_touched = 1;
+ entry = l3->slabs_free.next;
+ if (entry == &l3->slabs_free)
+ goto must_grow;
+ }
+
+ slabp = list_entry(entry, struct slab, list);
+ check_spinlock_acquired_node(cachep, nodeid);
+ check_slabp(cachep, slabp);
+
+ STATS_INC_NODEALLOCS(cachep);
+ STATS_INC_ACTIVE(cachep);
+ STATS_SET_HIGH(cachep);
+
+ BUG_ON(slabp->inuse == cachep->num);
+
+ obj = slab_get_obj(cachep, slabp, nodeid);
+ check_slabp(cachep, slabp);
+ l3->free_objects--;
+ /* move slabp to correct slabp list: */
+ list_del(&slabp->list);
+
+ if (slabp->free == BUFCTL_END)
+ list_add(&slabp->list, &l3->slabs_full);
+ else
+ list_add(&slabp->list, &l3->slabs_partial);
+
+ spin_unlock(&l3->list_lock);
+ goto done;
+
+must_grow:
+ spin_unlock(&l3->list_lock);
+ x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
+ if (x)
+ goto retry;
+
+ return fallback_alloc(cachep, flags);
+
+done:
+ return obj;
+}
+
+/**
+ * kmem_cache_alloc_node - Allocate an object on the specified node
+ * @cachep: The cache to allocate from.
+ * @flags: See kmalloc().
+ * @nodeid: node number of the target node.
+ * @caller: return address of caller, used for debug information
+ *
+ * Identical to kmem_cache_alloc but it will allocate memory on the given
+ * node, which can improve the performance for cpu bound structures.
+ *
+ * Fallback to other node is possible if __GFP_THISNODE is not set.
+ */
+static __always_inline void *
+__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
+ void *caller)
+{
+ unsigned long save_flags;
+ void *ptr;
+ int slab_node = numa_mem_id();
+
+ flags &= gfp_allowed_mask;
+
+ lockdep_trace_alloc(flags);
+
+ if (slab_should_failslab(cachep, flags))
+ return NULL;
+
+ cache_alloc_debugcheck_before(cachep, flags);
+ local_lock_irqsave(slab_lock, save_flags);
+
+ if (nodeid == NUMA_NO_NODE)
+ nodeid = slab_node;
+
+ if (unlikely(!cachep->nodelists[nodeid])) {
+ /* Node not bootstrapped yet */
+ ptr = fallback_alloc(cachep, flags);
+ goto out;
+ }
+
+ if (nodeid == slab_node) {
+ /*
+ * Use the locally cached objects if possible.
+ * However ____cache_alloc does not allow fallback
+ * to other nodes. It may fail while we still have
+ * objects on other nodes available.
+ */
+ ptr = ____cache_alloc(cachep, flags);
+ if (ptr)
+ goto out;
+ }
+ /* ___cache_alloc_node can fall back to other nodes */
+ ptr = ____cache_alloc_node(cachep, flags, nodeid);
+ out:
+ local_unlock_irqrestore(slab_lock, save_flags);
+ ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
+ kmemleak_alloc_recursive(ptr, obj_size(cachep), 1, cachep->flags,
+ flags);
+
+ if (likely(ptr))
+ kmemcheck_slab_alloc(cachep, flags, ptr, obj_size(cachep));
+
+ if (unlikely((flags & __GFP_ZERO) && ptr))
+ memset(ptr, 0, obj_size(cachep));
+
+ return ptr;
+}
+
+static __always_inline void *
+__do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
+{
+ void *objp;
+
+ if (unlikely((current->flags & PF_MEMPOLICY) || cpuset_do_slab_mem_spread())) {
+ objp = alternate_node_alloc(cache, flags);
+ if (objp)
+ goto out;
+ }
+ objp = ____cache_alloc(cache, flags);
+
+ /*
+ * We may just have run out of memory on the local node.
+ * ____cache_alloc_node() knows how to locate memory on other nodes
+ */
+ if (!objp)
+ objp = ____cache_alloc_node(cache, flags, numa_mem_id());
+
+ out:
+ return objp;
+}
+#else
+
+static __always_inline void *
+__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
+{
+ return ____cache_alloc(cachep, flags);
+}
+
+#endif /* CONFIG_NUMA */
+
+static __always_inline void *
+__cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
+{
+ unsigned long save_flags;
+ void *objp;
+
+ flags &= gfp_allowed_mask;
+
+ lockdep_trace_alloc(flags);
+
+ if (slab_should_failslab(cachep, flags))
+ return NULL;
+
+#ifdef CONFIG_MEM_CHECK
+ if (cachep->buffer_size > CONFIG_MEM_CHECK_SIZE) {
+ printk(KERN_ALERT"memcheck_slab %d %s (%pS)\n", cachep->buffer_size, current->comm, __builtin_return_address(0));
+ if (strcmp(current->comm,MEM_CHECK_THREAD_NAME)==0)
+ dump_stack();
+ }
+#endif
+
+ cache_alloc_debugcheck_before(cachep, flags);
+ local_lock_irqsave(slab_lock, save_flags);
+ objp = __do_cache_alloc(cachep, flags);
+ local_unlock_irqrestore(slab_lock, save_flags);
+ objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
+ kmemleak_alloc_recursive(objp, obj_size(cachep), 1, cachep->flags,
+ flags);
+ prefetchw(objp);
+
+ if (likely(objp))
+ kmemcheck_slab_alloc(cachep, flags, objp, obj_size(cachep));
+
+ if (unlikely((flags & __GFP_ZERO) && objp))
+ memset(objp, 0, obj_size(cachep));
+
+ return objp;
+}
+
+/*
+ * Caller needs to acquire correct kmem_list's list_lock
+ */
+static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
+ int node)
+{
+ int i;
+ struct kmem_list3 *l3;
+
+ for (i = 0; i < nr_objects; i++) {
+ void *objp = objpp[i];
+ struct slab *slabp;
+
+ slabp = virt_to_slab(objp);
+ l3 = cachep->nodelists[node];
+ list_del(&slabp->list);
+ check_spinlock_acquired_node(cachep, node);
+ check_slabp(cachep, slabp);
+ slab_put_obj(cachep, slabp, objp, node);
+ STATS_DEC_ACTIVE(cachep);
+ l3->free_objects++;
+ check_slabp(cachep, slabp);
+
+ /* fixup slab chains */
+ if (slabp->inuse == 0) {
+ if (l3->free_objects > l3->free_limit) {
+ l3->free_objects -= cachep->num;
+ /* No need to drop any previously held
+ * lock here, even if we have a off-slab slab
+ * descriptor it is guaranteed to come from
+ * a different cache, refer to comments before
+ * alloc_slabmgmt.
+ */
+ slab_destroy(cachep, slabp, true);
+ } else {
+ list_add(&slabp->list, &l3->slabs_free);
+ }
+ } else {
+ /* Unconditionally move a slab to the end of the
+ * partial list on free - maximum time for the
+ * other objects to be freed, too.
+ */
+ list_add_tail(&slabp->list, &l3->slabs_partial);
+ }
+ }
+}
+
+static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
+{
+ int batchcount;
+ struct kmem_list3 *l3;
+ int node = numa_mem_id();
+
+ batchcount = ac->batchcount;
+#if DEBUG
+ BUG_ON(!batchcount || batchcount > ac->avail);
+#endif
+ check_irq_off();
+ l3 = cachep->nodelists[node];
+ spin_lock(&l3->list_lock);
+ if (l3->shared) {
+ struct array_cache *shared_array = l3->shared;
+ int max = shared_array->limit - shared_array->avail;
+ if (max) {
+ if (batchcount > max)
+ batchcount = max;
+ memcpy(&(shared_array->entry[shared_array->avail]),
+ ac->entry, sizeof(void *) * batchcount);
+ shared_array->avail += batchcount;
+ goto free_done;
+ }
+ }
+
+ free_block(cachep, ac->entry, batchcount, node);
+free_done:
+#if STATS
+ {
+ int i = 0;
+ struct list_head *p;
+
+ p = l3->slabs_free.next;
+ while (p != &(l3->slabs_free)) {
+ struct slab *slabp;
+
+ slabp = list_entry(p, struct slab, list);
+ BUG_ON(slabp->inuse);
+
+ i++;
+ p = p->next;
+ }
+ STATS_SET_FREEABLE(cachep, i);
+ }
+#endif
+ spin_unlock(&l3->list_lock);
+ ac->avail -= batchcount;
+ memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
+}
+
+/*
+ * Release an obj back to its cache. If the obj has a constructed state, it must
+ * be in this state _before_ it is released. Called with disabled ints.
+ */
+static inline void __cache_free(struct kmem_cache *cachep, void *objp,
+ void *caller)
+{
+ struct array_cache *ac = cpu_cache_get(cachep);
+
+ check_irq_off();
+ kmemleak_free_recursive(objp, cachep->flags);
+ objp = cache_free_debugcheck(cachep, objp, caller);
+
+ kmemcheck_slab_free(cachep, objp, obj_size(cachep));
+
+ /*
+ * Skip calling cache_free_alien() when the platform is not numa.
+ * This will avoid cache misses that happen while accessing slabp (which
+ * is per page memory reference) to get nodeid. Instead use a global
+ * variable to skip the call, which is mostly likely to be present in
+ * the cache.
+ */
+ if (nr_online_nodes > 1 && cache_free_alien(cachep, objp))
+ return;
+
+ if (likely(ac->avail < ac->limit)) {
+ STATS_INC_FREEHIT(cachep);
+ } else {
+ STATS_INC_FREEMISS(cachep);
+ cache_flusharray(cachep, ac);
+ }
+
+ ac->entry[ac->avail++] = objp;
+}
+
+/**
+ * kmem_cache_alloc - Allocate an object
+ * @cachep: The cache to allocate from.
+ * @flags: See kmalloc().
+ *
+ * Allocate an object from this cache. The flags are only relevant
+ * if the cache has no available objects.
+ */
+void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
+{
+ void *ret = __cache_alloc(cachep, flags, __builtin_return_address(0));
+
+ trace_kmem_cache_alloc(_RET_IP_, ret,
+ obj_size(cachep), cachep->buffer_size, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(kmem_cache_alloc);
+
+#ifdef CONFIG_TRACING
+void *
+kmem_cache_alloc_trace(size_t size, struct kmem_cache *cachep, gfp_t flags)
+{
+ void *ret;
+
+ ret = __cache_alloc(cachep, flags, __builtin_return_address(0));
+
+ trace_kmalloc(_RET_IP_, ret,
+ size, slab_buffer_size(cachep), flags);
+ return ret;
+}
+EXPORT_SYMBOL(kmem_cache_alloc_trace);
+#endif
+
+#ifdef CONFIG_NUMA
+void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
+{
+ void *ret = __cache_alloc_node(cachep, flags, nodeid,
+ __builtin_return_address(0));
+
+ trace_kmem_cache_alloc_node(_RET_IP_, ret,
+ obj_size(cachep), cachep->buffer_size,
+ flags, nodeid);
+
+ return ret;
+}
+EXPORT_SYMBOL(kmem_cache_alloc_node);
+
+#ifdef CONFIG_TRACING
+void *kmem_cache_alloc_node_trace(size_t size,
+ struct kmem_cache *cachep,
+ gfp_t flags,
+ int nodeid)
+{
+ void *ret;
+
+ ret = __cache_alloc_node(cachep, flags, nodeid,
+ __builtin_return_address(0));
+ trace_kmalloc_node(_RET_IP_, ret,
+ size, slab_buffer_size(cachep),
+ flags, nodeid);
+ return ret;
+}
+EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
+#endif
+
+static __always_inline void *
+__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
+{
+ struct kmem_cache *cachep;
+
+ cachep = kmem_find_general_cachep(size, flags);
+ if (unlikely(ZERO_OR_NULL_PTR(cachep)))
+ return cachep;
+ return kmem_cache_alloc_node_trace(size, cachep, flags, node);
+}
+
+#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING)
+void *__kmalloc_node(size_t size, gfp_t flags, int node)
+{
+ return __do_kmalloc_node(size, flags, node,
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL(__kmalloc_node);
+
+void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
+ int node, unsigned long caller)
+{
+ return __do_kmalloc_node(size, flags, node, (void *)caller);
+}
+EXPORT_SYMBOL(__kmalloc_node_track_caller);
+#else
+void *__kmalloc_node(size_t size, gfp_t flags, int node)
+{
+ return __do_kmalloc_node(size, flags, node, NULL);
+}
+EXPORT_SYMBOL(__kmalloc_node);
+#endif /* CONFIG_DEBUG_SLAB || CONFIG_TRACING */
+#endif /* CONFIG_NUMA */
+
+ void *__kmalloc_node(size_t size, gfp_t flags, int node)
+{
+ return __kmalloc(size, flags);
+}
+EXPORT_SYMBOL(__kmalloc_node);
+/**
+ * __do_kmalloc - allocate memory
+ * @size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate (see kmalloc).
+ * @caller: function caller for debug tracking of the caller
+ */
+static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
+ void *caller)
+{
+ struct kmem_cache *cachep;
+ void *ret;
+
+#ifdef CONFIG_DEBUG_SLAB_MARK
+ int mark_flag = 0;
+ if(!size)
+ return ZERO_SIZE_PTR;
+ if(size <= 248){
+ size += 2 * sizeof(size_t);
+ mark_flag = 1;
+ }
+
+#endif
+
+#ifdef CONFIG_DEBUG_SLAB_MARK_HEAD
+ if (size <= PAGE_SIZE)
+ size += RECORD_COUNT * BYTES_PER_RECORD;
+#endif
+
+#ifdef CONFIG_KMALLOC_TRACKER
+ size_t len = 0;
+
+ if (!size)
+ return ZERO_SIZE_PTR;
+
+ size += HEAP_SUFFIX_SIZE;
+#endif
+
+ /* If you want to save a few bytes .text space: replace
+ * __ with kmem_.
+ * Then kmalloc uses the uninlined functions instead of the inline
+ * functions.
+ */
+ cachep = __find_general_cachep(size, flags);
+ if (unlikely(ZERO_OR_NULL_PTR(cachep)))
+ return cachep;
+ ret = __cache_alloc(cachep, flags, caller);
+
+ trace_kmalloc((unsigned long) caller, ret,
+ size, cachep->buffer_size, flags);
+
+#ifdef CONFIG_KMALLOC_TRACKER
+ if (ret) {
+ kmalloc_alloc_tracker(ret, KMALLOC_ORIGINAL_SIZE(size));
+ return KMALLOC_SETUP(ret);
+ }
+#endif
+
+#ifdef CONFIG_DEBUG_SLAB_MARK
+ if(ret && mark_flag){
+ *dbg_recordtask(cachep, ret) = current;
+ *dbg_recordcaller(cachep, ret) = caller;
+ mark_flag = 0;
+ }
+ else if (unlikely(!(flags & __GFP_ZERO) && ret)){
+ *dbg_recordtask(cachep, ret) = current;
+ *dbg_recordcaller(cachep, ret) = caller;
+ }
+#else
+ if (unlikely(!(flags & __GFP_ZERO) && ret)){
+ *dbg_recordtask(cachep, ret) = current;
+ *dbg_recordcaller(cachep, ret) = caller;
+ }
+#endif
+
+#ifdef CONFIG_DEBUG_SLAB_MARK_HEAD
+ if (ret && (obj_size(cachep) <= PAGE_SIZE)) {
+ *dbg_userrecord(ret,0) = (void *)RECORD_MAGIC;
+ *dbg_userrecord(ret,1) = caller;
+ *dbg_userrecord(ret,2) = current;
+ ret = (void *)dbg_userrecord(ret,RECORD_COUNT);
+ }
+#endif
+
+ return ret;
+}
+
+
+#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) || defined(CONFIG_DEBUG_SLAB_MARK) || defined(CONFIG_DEBUG_SLAB_MARK_HEAD)
+void *__kmalloc(size_t size, gfp_t flags)
+{
+ return __do_kmalloc(size, flags, __builtin_return_address(0));
+}
+EXPORT_SYMBOL(__kmalloc);
+
+void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller)
+{
+ return __do_kmalloc(size, flags, (void *)caller);
+}
+EXPORT_SYMBOL(__kmalloc_track_caller);
+
+#else
+void *__kmalloc(size_t size, gfp_t flags)
+{
+ return __do_kmalloc(size, flags, NULL);
+}
+EXPORT_SYMBOL(__kmalloc);
+#endif
+
+/**
+ * kmem_cache_free - Deallocate an object
+ * @cachep: The cache the allocation was from.
+ * @objp: The previously allocated object.
+ *
+ * Free an object which was previously allocated from this
+ * cache.
+ */
+void kmem_cache_free(struct kmem_cache *cachep, void *objp)
+{
+ unsigned long flags;
+
+ debug_check_no_locks_freed(objp, obj_size(cachep));
+ if (!(cachep->flags & SLAB_DEBUG_OBJECTS))
+ debug_check_no_obj_freed(objp, obj_size(cachep));
+ local_lock_irqsave(slab_lock, flags);
+ __cache_free(cachep, objp, __builtin_return_address(0));
+ unlock_slab_and_free_delayed(flags);
+
+ trace_kmem_cache_free(_RET_IP_, objp);
+}
+EXPORT_SYMBOL(kmem_cache_free);
+
+/**
+ * kfree - free previously allocated memory
+ * @objp: pointer returned by kmalloc.
+ *
+ * If @objp is NULL, no operation is performed.
+ *
+ * Don't free memory not originally allocated by kmalloc()
+ * or you will run into trouble.
+ */
+void kfree(const void *objp)
+{
+ struct kmem_cache *c;
+ unsigned long flags;
+
+ trace_kfree(_RET_IP_, objp);
+
+ if (unlikely(ZERO_OR_NULL_PTR(objp)))
+ return;
+
+#ifdef CONFIG_KMALLOC_TRACKER
+ int entry = 0;
+ void *mem = NULL;
+
+ mem = KMALLOC_BASE(objp);
+ entry = *(size_t *)(mem);
+
+ if ((entry != 0)&& (MEM_TRUE == check_node_entry(entry)))
+ {
+ mem_free_tracker((void *)entry, MEM_TRACKER_TYPE_KMALLOC);
+ }
+ else
+ {
+ panic("error\n");
+ }
+
+ kfree_debugcheck(mem);
+ c = virt_to_cache(mem);
+ debug_check_no_locks_freed(mem, obj_size(c));
+ debug_check_no_obj_freed(mem, obj_size(c));
+
+#else
+ kfree_debugcheck(objp);
+ c = virt_to_cache(objp);
+
+#ifdef CONFIG_DEBUG_SLAB_MARK_HEAD
+ if (obj_size(c) <= PAGE_SIZE) {
+ if (*dbg_userhead(objp) == (void *)RECORD_MAGIC) {
+ objp = (void *)dbg_userhead(objp);
+ } else {
+ panic("memmory corruption!!");
+ }
+ }
+#endif
+
+ debug_check_no_locks_freed(objp, obj_size(c));
+ debug_check_no_obj_freed(objp, obj_size(c));
+#endif
+
+ local_lock_irqsave(slab_lock, flags);
+
+#ifdef CONFIG_KMALLOC_TRACKER
+ __cache_free(c, (void *)mem, __builtin_return_address(0));
+#else
+ __cache_free(c, (void *)objp, __builtin_return_address(0));
+#endif
+ unlock_slab_and_free_delayed(flags);
+}
+EXPORT_SYMBOL(kfree);
+
+unsigned int kmem_cache_size(struct kmem_cache *cachep)
+{
+ return obj_size(cachep);
+}
+EXPORT_SYMBOL(kmem_cache_size);
+
+/*
+ * This initializes kmem_list3 or resizes various caches for all nodes.
+ */
+static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp)
+{
+ int node;
+ struct kmem_list3 *l3;
+ struct array_cache *new_shared;
+ struct array_cache **new_alien = NULL;
+
+ for_each_online_node(node) {
+
+ if (use_alien_caches) {
+ new_alien = alloc_alien_cache(node, cachep->limit, gfp);
+ if (!new_alien)
+ goto fail;
+ }
+
+ new_shared = NULL;
+ if (cachep->shared) {
+ new_shared = alloc_arraycache(node,
+ cachep->shared*cachep->batchcount,
+ 0xbaadf00d, gfp);
+ if (!new_shared) {
+ free_alien_cache(new_alien);
+ goto fail;
+ }
+ }
+
+ l3 = cachep->nodelists[node];
+ if (l3) {
+ struct array_cache *shared = l3->shared;
+
+ local_spin_lock_irq(slab_lock, &l3->list_lock);
+
+ if (shared)
+ free_block(cachep, shared->entry,
+ shared->avail, node);
+
+ l3->shared = new_shared;
+ if (!l3->alien) {
+ l3->alien = new_alien;
+ new_alien = NULL;
+ }
+ l3->free_limit = (1 + nr_cpus_node(node)) *
+ cachep->batchcount + cachep->num;
+ unlock_l3_and_free_delayed(&l3->list_lock);
+
+ kfree(shared);
+ free_alien_cache(new_alien);
+ continue;
+ }
+ l3 = kmalloc_node(sizeof(struct kmem_list3), gfp, node);
+ if (!l3) {
+ free_alien_cache(new_alien);
+ kfree(new_shared);
+ goto fail;
+ }
+
+ kmem_list3_init(l3);
+ l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
+ ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
+ l3->shared = new_shared;
+ l3->alien = new_alien;
+ l3->free_limit = (1 + nr_cpus_node(node)) *
+ cachep->batchcount + cachep->num;
+ cachep->nodelists[node] = l3;
+ }
+ return 0;
+
+fail:
+ if (!cachep->next.next) {
+ /* Cache is not active yet. Roll back what we did */
+ node--;
+ while (node >= 0) {
+ if (cachep->nodelists[node]) {
+ l3 = cachep->nodelists[node];
+
+ kfree(l3->shared);
+ free_alien_cache(l3->alien);
+ kfree(l3);
+ cachep->nodelists[node] = NULL;
+ }
+ node--;
+ }
+ }
+ return -ENOMEM;
+}
+
+struct ccupdate_struct {
+ struct kmem_cache *cachep;
+ struct array_cache *new[0];
+};
+
+static void __do_ccupdate_local(void *info, int cpu)
+{
+ struct ccupdate_struct *new = info;
+ struct array_cache *old;
+
+ old = cpu_cache_get_on_cpu(new->cachep, cpu);
+
+ new->cachep->array[cpu] = new->new[cpu];
+ new->new[cpu] = old;
+}
+
+#ifndef CONFIG_PREEMPT_RT_BASE
+static void do_ccupdate_local(void *info)
+{
+ __do_ccupdate_local(info, smp_processor_id());
+}
+#else
+static void do_ccupdate_local(void *info, int cpu)
+{
+ lock_slab_on(cpu);
+ __do_ccupdate_local(info, cpu);
+ unlock_slab_on(cpu);
+}
+#endif
+
+/* Always called with the cache_chain_mutex held */
+static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
+ int batchcount, int shared, gfp_t gfp)
+{
+ struct ccupdate_struct *new;
+ int i;
+
+ new = kzalloc(sizeof(*new) + nr_cpu_ids * sizeof(struct array_cache *),
+ gfp);
+ if (!new)
+ return -ENOMEM;
+
+ for_each_online_cpu(i) {
+ new->new[i] = alloc_arraycache(cpu_to_mem(i), limit,
+ batchcount, gfp);
+ if (!new->new[i]) {
+ for (i--; i >= 0; i--)
+ kfree(new->new[i]);
+ kfree(new);
+ return -ENOMEM;
+ }
+ }
+ new->cachep = cachep;
+
+ slab_on_each_cpu(do_ccupdate_local, (void *)new);
+
+ check_irq_on();
+ cachep->batchcount = batchcount;
+ cachep->limit = limit;
+ cachep->shared = shared;
+
+ for_each_online_cpu(i) {
+ struct array_cache *ccold = new->new[i];
+ if (!ccold)
+ continue;
+ local_spin_lock_irq(slab_lock,
+ &cachep->nodelists[cpu_to_mem(i)]->list_lock);
+ free_block(cachep, ccold->entry, ccold->avail, cpu_to_mem(i));
+
+ unlock_l3_and_free_delayed(&cachep->nodelists[cpu_to_mem(i)]->list_lock);
+ kfree(ccold);
+ }
+ kfree(new);
+ return alloc_kmemlist(cachep, gfp);
+}
+
+/* Called with cache_chain_mutex held always */
+static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp)
+{
+ int err;
+ int limit, shared;
+
+ /*
+ * The head array serves three purposes:
+ * - create a LIFO ordering, i.e. return objects that are cache-warm
+ * - reduce the number of spinlock operations.
+ * - reduce the number of linked list operations on the slab and
+ * bufctl chains: array operations are cheaper.
+ * The numbers are guessed, we should auto-tune as described by
+ * Bonwick.
+ */
+ if (cachep->buffer_size > 131072)
+ limit = 1;
+ else if (cachep->buffer_size > PAGE_SIZE)
+ limit = 8;
+ else if (cachep->buffer_size > 1024)
+ limit = 24;
+ else if (cachep->buffer_size > 256)
+ limit = 54;
+ else
+ limit = 120;
+
+ /*
+ * CPU bound tasks (e.g. network routing) can exhibit cpu bound
+ * allocation behaviour: Most allocs on one cpu, most free operations
+ * on another cpu. For these cases, an efficient object passing between
+ * cpus is necessary. This is provided by a shared array. The array
+ * replaces Bonwick's magazine layer.
+ * On uniprocessor, it's functionally equivalent (but less efficient)
+ * to a larger limit. Thus disabled by default.
+ */
+ shared = 0;
+ if (cachep->buffer_size <= PAGE_SIZE && num_possible_cpus() > 1)
+ shared = 8;
+
+#if DEBUG
+ /*
+ * With debugging enabled, large batchcount lead to excessively long
+ * periods with disabled local interrupts. Limit the batchcount
+ */
+ if (limit > 32)
+ limit = 32;
+#endif
+ err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared, gfp);
+ if (err)
+ printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
+ cachep->name, -err);
+ return err;
+}
+
+/*
+ * Drain an array if it contains any elements taking the l3 lock only if
+ * necessary. Note that the l3 listlock also protects the array_cache
+ * if drain_array() is used on the shared array.
+ */
+static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
+ struct array_cache *ac, int force, int node)
+{
+ int tofree;
+
+ if (!ac || !ac->avail)
+ return;
+ if (ac->touched && !force) {
+ ac->touched = 0;
+ } else {
+ local_spin_lock_irq(slab_lock, &l3->list_lock);
+ if (ac->avail) {
+ tofree = force ? ac->avail : (ac->limit + 4) / 5;
+ if (tofree > ac->avail)
+ tofree = (ac->avail + 1) / 2;
+ free_block(cachep, ac->entry, tofree, node);
+ ac->avail -= tofree;
+ memmove(ac->entry, &(ac->entry[tofree]),
+ sizeof(void *) * ac->avail);
+ }
+ local_spin_unlock_irq(slab_lock, &l3->list_lock);
+ }
+}
+
+/**
+ * cache_reap - Reclaim memory from caches.
+ * @w: work descriptor
+ *
+ * Called from workqueue/eventd every few seconds.
+ * Purpose:
+ * - clear the per-cpu caches for this CPU.
+ * - return freeable pages to the main free memory pool.
+ *
+ * If we cannot acquire the cache chain mutex then just give up - we'll try
+ * again on the next iteration.
+ */
+static void cache_reap(struct work_struct *w)
+{
+ struct kmem_cache *searchp;
+ struct kmem_list3 *l3;
+ int node = numa_mem_id();
+ struct delayed_work *work = to_delayed_work(w);
+
+ if (!mutex_trylock(&cache_chain_mutex))
+ /* Give up. Setup the next iteration. */
+ goto out;
+
+ list_for_each_entry(searchp, &cache_chain, next) {
+ check_irq_on();
+
+ /*
+ * We only take the l3 lock if absolutely necessary and we
+ * have established with reasonable certainty that
+ * we can do some work if the lock was obtained.
+ */
+ l3 = searchp->nodelists[node];
+
+ reap_alien(searchp, l3);
+
+ drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
+
+ /*
+ * These are racy checks but it does not matter
+ * if we skip one check or scan twice.
+ */
+ if (time_after(l3->next_reap, jiffies))
+ goto next;
+
+ l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
+
+ drain_array(searchp, l3, l3->shared, 0, node);
+
+ if (l3->free_touched)
+ l3->free_touched = 0;
+ else {
+ int freed;
+
+ freed = drain_freelist(searchp, l3, (l3->free_limit +
+ 5 * searchp->num - 1) / (5 * searchp->num));
+ STATS_ADD_REAPED(searchp, freed);
+ }
+next:
+ cond_resched();
+ }
+ check_irq_on();
+ mutex_unlock(&cache_chain_mutex);
+ next_reap_node();
+out:
+ /* Set up the next iteration */
+ schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
+}
+
+#ifdef CONFIG_SLABINFO
+
+static void print_slabinfo_header(struct seq_file *m)
+{
+ /*
+ * Output format version, so at least we can change it
+ * without _too_ many complaints.
+ */
+#if STATS
+ seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
+#else
+ seq_puts(m, "slabinfo - version: 2.1\n");
+#endif
+ seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
+ "<objperslab> <pagesperslab>");
+ seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
+ seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
+#if STATS
+ seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
+ "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
+ seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
+#endif
+ seq_putc(m, '\n');
+}
+
+static void *s_start(struct seq_file *m, loff_t *pos)
+{
+ loff_t n = *pos;
+
+ mutex_lock(&cache_chain_mutex);
+ if (!n)
+ print_slabinfo_header(m);
+
+ return seq_list_start(&cache_chain, *pos);
+}
+
+static void *s_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ return seq_list_next(p, &cache_chain, pos);
+}
+
+static void s_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&cache_chain_mutex);
+}
+
+static int s_show(struct seq_file *m, void *p)
+{
+ struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
+ struct slab *slabp;
+ unsigned long active_objs;
+ unsigned long num_objs;
+ unsigned long active_slabs = 0;
+ unsigned long num_slabs, free_objects = 0, shared_avail = 0;
+ const char *name;
+ char *error = NULL;
+ int node;
+ struct kmem_list3 *l3;
+
+ active_objs = 0;
+ num_slabs = 0;
+ for_each_online_node(node) {
+ l3 = cachep->nodelists[node];
+ if (!l3)
+ continue;
+
+ check_irq_on();
+ local_spin_lock_irq(slab_lock, &l3->list_lock);
+
+ list_for_each_entry(slabp, &l3->slabs_full, list) {
+ if (slabp->inuse != cachep->num && !error)
+ error = "slabs_full accounting error";
+ active_objs += cachep->num;
+ active_slabs++;
+ }
+ list_for_each_entry(slabp, &l3->slabs_partial, list) {
+ if (slabp->inuse == cachep->num && !error)
+ error = "slabs_partial inuse accounting error";
+ if (!slabp->inuse && !error)
+ error = "slabs_partial/inuse accounting error";
+ active_objs += slabp->inuse;
+ active_slabs++;
+ }
+ list_for_each_entry(slabp, &l3->slabs_free, list) {
+ if (slabp->inuse && !error)
+ error = "slabs_free/inuse accounting error";
+ num_slabs++;
+ }
+ free_objects += l3->free_objects;
+ if (l3->shared)
+ shared_avail += l3->shared->avail;
+
+ local_spin_unlock_irq(slab_lock, &l3->list_lock);
+ }
+ num_slabs += active_slabs;
+ num_objs = num_slabs * cachep->num;
+ if (num_objs - active_objs != free_objects && !error)
+ error = "free_objects accounting error";
+
+ name = cachep->name;
+ if (error)
+ printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
+
+ seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
+ name, active_objs, num_objs, cachep->buffer_size,
+ cachep->num, (1 << cachep->gfporder));
+ seq_printf(m, " : tunables %4u %4u %4u",
+ cachep->limit, cachep->batchcount, cachep->shared);
+ seq_printf(m, " : slabdata %6lu %6lu %6lu",
+ active_slabs, num_slabs, shared_avail);
+#if STATS
+ { /* list3 stats */
+ unsigned long high = cachep->high_mark;
+ unsigned long allocs = cachep->num_allocations;
+ unsigned long grown = cachep->grown;
+ unsigned long reaped = cachep->reaped;
+ unsigned long errors = cachep->errors;
+ unsigned long max_freeable = cachep->max_freeable;
+ unsigned long node_allocs = cachep->node_allocs;
+ unsigned long node_frees = cachep->node_frees;
+ unsigned long overflows = cachep->node_overflow;
+
+ seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu "
+ "%4lu %4lu %4lu %4lu %4lu",
+ allocs, high, grown,
+ reaped, errors, max_freeable, node_allocs,
+ node_frees, overflows);
+ }
+ /* cpu stats */
+ {
+ unsigned long allochit = atomic_read(&cachep->allochit);
+ unsigned long allocmiss = atomic_read(&cachep->allocmiss);
+ unsigned long freehit = atomic_read(&cachep->freehit);
+ unsigned long freemiss = atomic_read(&cachep->freemiss);
+
+ seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
+ allochit, allocmiss, freehit, freemiss);
+ }
+#endif
+ seq_putc(m, '\n');
+ return 0;
+}
+
+/*
+ * slabinfo_op - iterator that generates /proc/slabinfo
+ *
+ * Output layout:
+ * cache-name
+ * num-active-objs
+ * total-objs
+ * object size
+ * num-active-slabs
+ * total-slabs
+ * num-pages-per-slab
+ * + further values on SMP and with statistics enabled
+ */
+
+static const struct seq_operations slabinfo_op = {
+ .start = s_start,
+ .next = s_next,
+ .stop = s_stop,
+ .show = s_show,
+};
+
+#define MAX_SLABINFO_WRITE 128
+/**
+ * slabinfo_write - Tuning for the slab allocator
+ * @file: unused
+ * @buffer: user buffer
+ * @count: data length
+ * @ppos: unused
+ */
+static ssize_t slabinfo_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
+ int limit, batchcount, shared, res;
+ struct kmem_cache *cachep;
+
+ if (count > MAX_SLABINFO_WRITE)
+ return -EINVAL;
+ if (copy_from_user(&kbuf, buffer, count))
+ return -EFAULT;
+ kbuf[MAX_SLABINFO_WRITE] = '\0';
+
+ tmp = strchr(kbuf, ' ');
+ if (!tmp)
+ return -EINVAL;
+ *tmp = '\0';
+ tmp++;
+ if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
+ return -EINVAL;
+
+ /* Find the cache in the chain of caches. */
+ mutex_lock(&cache_chain_mutex);
+ res = -EINVAL;
+ list_for_each_entry(cachep, &cache_chain, next) {
+ if (!strcmp(cachep->name, kbuf)) {
+ if (limit < 1 || batchcount < 1 ||
+ batchcount > limit || shared < 0) {
+ res = 0;
+ } else {
+ res = do_tune_cpucache(cachep, limit,
+ batchcount, shared,
+ GFP_KERNEL);
+ }
+ break;
+ }
+ }
+ mutex_unlock(&cache_chain_mutex);
+ if (res >= 0)
+ res = count;
+ return res;
+}
+
+static int slabinfo_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &slabinfo_op);
+}
+
+static const struct file_operations proc_slabinfo_operations = {
+ .open = slabinfo_open,
+ .read = seq_read,
+ .write = slabinfo_write,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+#ifdef CONFIG_DEBUG_SLAB_LEAK
+
+static void *leaks_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&cache_chain_mutex);
+ return seq_list_start(&cache_chain, *pos);
+}
+
+static inline int add_caller(unsigned long *n, unsigned long v)
+{
+ unsigned long *p;
+ int l;
+ if (!v)
+ return 1;
+ l = n[1];
+ p = n + 2;
+ while (l) {
+ int i = l/2;
+ unsigned long *q = p + 2 * i;
+ if (*q == v) {
+ q[1]++;
+ return 1;
+ }
+ if (*q > v) {
+ l = i;
+ } else {
+ p = q + 2;
+ l -= i + 1;
+ }
+ }
+ if (++n[1] == n[0])
+ return 0;
+ memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n));
+ p[0] = v;
+ p[1] = 1;
+ return 1;
+}
+
+static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
+{
+ void *p;
+ int i;
+ if (n[0] == n[1])
+ return;
+ for (i = 0, p = s->s_mem; i < c->num; i++, p += c->buffer_size) {
+ if (slab_bufctl(s)[i] != BUFCTL_ACTIVE)
+ continue;
+ if (!add_caller(n, (unsigned long)*dbg_userword(c, p)))
+ return;
+ }
+}
+
+static void show_symbol(struct seq_file *m, unsigned long address)
+{
+#ifdef CONFIG_KALLSYMS
+ unsigned long offset, size;
+ char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN];
+
+ if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) {
+ seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
+ if (modname[0])
+ seq_printf(m, " [%s]", modname);
+ return;
+ }
+#endif
+ seq_printf(m, "%p", (void *)address);
+}
+
+static int leaks_show(struct seq_file *m, void *p)
+{
+ struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
+ struct slab *slabp;
+ struct kmem_list3 *l3;
+ const char *name;
+ unsigned long *n = m->private;
+ int node;
+ int i;
+
+ if (!(cachep->flags & SLAB_STORE_USER))
+ return 0;
+ if (!(cachep->flags & SLAB_RED_ZONE))
+ return 0;
+
+ /* OK, we can do it */
+
+ n[1] = 0;
+
+ for_each_online_node(node) {
+ l3 = cachep->nodelists[node];
+ if (!l3)
+ continue;
+
+ check_irq_on();
+ local_spin_lock_irq(slab_lock, &l3->list_lock);
+
+ list_for_each_entry(slabp, &l3->slabs_full, list)
+ handle_slab(n, cachep, slabp);
+ list_for_each_entry(slabp, &l3->slabs_partial, list)
+ handle_slab(n, cachep, slabp);
+ local_spin_unlock_irq(slab_lock, &l3->list_lock);
+ }
+ name = cachep->name;
+ if (n[0] == n[1]) {
+ /* Increase the buffer size */
+ mutex_unlock(&cache_chain_mutex);
+ m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL);
+ if (!m->private) {
+ /* Too bad, we are really out */
+ m->private = n;
+ mutex_lock(&cache_chain_mutex);
+ return -ENOMEM;
+ }
+ *(unsigned long *)m->private = n[0] * 2;
+ kfree(n);
+ mutex_lock(&cache_chain_mutex);
+ /* Now make sure this entry will be retried */
+ m->count = m->size;
+ return 0;
+ }
+ for (i = 0; i < n[1]; i++) {
+ seq_printf(m, "%s: %lu ", name, n[2*i+3]);
+ show_symbol(m, n[2*i+2]);
+ seq_putc(m, '\n');
+ }
+
+ return 0;
+}
+
+static const struct seq_operations slabstats_op = {
+ .start = leaks_start,
+ .next = s_next,
+ .stop = s_stop,
+ .show = leaks_show,
+};
+
+static int slabstats_open(struct inode *inode, struct file *file)
+{
+ unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL);
+ int ret = -ENOMEM;
+ if (n) {
+ ret = seq_open(file, &slabstats_op);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ *n = PAGE_SIZE / (2 * sizeof(unsigned long));
+ m->private = n;
+ n = NULL;
+ }
+ kfree(n);
+ }
+ return ret;
+}
+
+static const struct file_operations proc_slabstats_operations = {
+ .open = slabstats_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+#endif
+
+static int __init slab_proc_init(void)
+{
+ proc_create("slabinfo",S_IWUSR|S_IRUSR,NULL,&proc_slabinfo_operations);
+#ifdef CONFIG_DEBUG_SLAB_LEAK
+ proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations);
+#endif
+ return 0;
+}
+module_init(slab_proc_init);
+#endif
+
+/**
+ * ksize - get the actual amount of memory allocated for a given object
+ * @objp: Pointer to the object
+ *
+ * kmalloc may internally round up allocations and return more memory
+ * than requested. ksize() can be used to determine the actual amount of
+ * memory allocated. The caller may use this additional memory, even though
+ * a smaller amount of memory was initially specified with the kmalloc call.
+ * The caller must guarantee that objp points to a valid object previously
+ * allocated with either kmalloc() or kmem_cache_alloc(). The object
+ * must not be freed during the duration of the call.
+ */
+size_t ksize(const void *objp)
+{
+ BUG_ON(!objp);
+ if (unlikely(objp == ZERO_SIZE_PTR))
+ return 0;
+
+#ifdef CONFIG_DEBUG_SLAB_MARK_HEAD
+ if (obj_size(virt_to_cache(objp)) <= PAGE_SIZE)
+ return (obj_size(virt_to_cache(objp)) - RECORD_COUNT * BYTES_PER_RECORD);
+ else
+ return obj_size(virt_to_cache(objp));
+#else
+ return obj_size(virt_to_cache(objp));
+#endif
+}
+EXPORT_SYMBOL(ksize);
diff --git a/ap/os/linux/linux-3.4.x/mm/slob.c b/ap/os/linux/linux-3.4.x/mm/slob.c
new file mode 100755
index 0000000..5e6b4d7
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/slob.c
@@ -0,0 +1,1138 @@
+/*
+ * SLOB Allocator: Simple List Of Blocks
+ *
+ * Matt Mackall <mpm@selenic.com> 12/30/03
+ *
+ * NUMA support by Paul Mundt, 2007.
+ *
+ * How SLOB works:
+ *
+ * The core of SLOB is a traditional K&R style heap allocator, with
+ * support for returning aligned objects. The granularity of this
+ * allocator is as little as 2 bytes, however typically most architectures
+ * will require 4 bytes on 32-bit and 8 bytes on 64-bit.
+ *
+ * The slob heap is a set of linked list of pages from alloc_pages(),
+ * and within each page, there is a singly-linked list of free blocks
+ * (slob_t). The heap is grown on demand. To reduce fragmentation,
+ * heap pages are segregated into three lists, with objects less than
+ * 256 bytes, objects less than 1024 bytes, and all other objects.
+ *
+ * Allocation from heap involves first searching for a page with
+ * sufficient free blocks (using a next-fit-like approach) followed by
+ * a first-fit scan of the page. Deallocation inserts objects back
+ * into the free list in address order, so this is effectively an
+ * address-ordered first fit.
+ *
+ * Above this is an implementation of kmalloc/kfree. Blocks returned
+ * from kmalloc are prepended with a 4-byte header with the kmalloc size.
+ * If kmalloc is asked for objects of PAGE_SIZE or larger, it calls
+ * alloc_pages() directly, allocating compound pages so the page order
+ * does not have to be separately tracked, and also stores the exact
+ * allocation size in page->private so that it can be used to accurately
+ * provide ksize(). These objects are detected in kfree() because slob_page()
+ * is false for them.
+ *
+ * SLAB is emulated on top of SLOB by simply calling constructors and
+ * destructors for every SLAB allocation. Objects are returned with the
+ * 4-byte alignment unless the SLAB_HWCACHE_ALIGN flag is set, in which
+ * case the low-level allocator will fragment blocks to create the proper
+ * alignment. Again, objects of page-size or greater are allocated by
+ * calling alloc_pages(). As SLAB objects know their size, no separate
+ * size bookkeeping is necessary and there is essentially no allocation
+ * space overhead, and compound pages aren't needed for multi-page
+ * allocations.
+ *
+ * NUMA support in SLOB is fairly simplistic, pushing most of the real
+ * logic down to the page allocator, and simply doing the node accounting
+ * on the upper levels. In the event that a node id is explicitly
+ * provided, alloc_pages_exact_node() with the specified node id is used
+ * instead. The common case (or when the node id isn't explicitly provided)
+ * will default to the current node, as per numa_node_id().
+ *
+ * Node aware pages are still inserted in to the global freelist, and
+ * these are scanned for by matching against the node id encoded in the
+ * page flags. As a result, block allocations that can be satisfied from
+ * the freelist will only be done so on pages residing on the same node,
+ * in order to prevent random node placement.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/swap.h> /* struct reclaim_state */
+#include <linux/cache.h>
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/rcupdate.h>
+#include <linux/list.h>
+#include <linux/kmemleak.h>
+
+#include <trace/events/kmem.h>
+
+#include <linux/atomic.h>
+
+#ifdef CONFIG_KMALLOC_TRACKER
+#include <linux/mem_tracker_def.h>
+#endif
+
+#ifdef CONFIG_DEBUG_SLOB_MARK_HEAD
+
+#define BYTES_PER_RECORD (sizeof(void *))
+#define RECORD_MAGIC 0xdeaddead
+#define RECORD_COUNT 4
+
+static void **dbg_userrecord(void *mem,int index)
+{
+ return (void **)(mem + index * BYTES_PER_RECORD);
+}
+
+static void **dbg_userhead(void *mem)
+{
+ return (void **)(mem - RECORD_COUNT * BYTES_PER_RECORD);
+}
+#endif
+
+/*
+ * slob_block has a field 'units', which indicates size of block if +ve,
+ * or offset of next block if -ve (in SLOB_UNITs).
+ *
+ * Free blocks of size 1 unit simply contain the offset of the next block.
+ * Those with larger size contain their size in the first SLOB_UNIT of
+ * memory, and the offset of the next free block in the second SLOB_UNIT.
+ */
+#if PAGE_SIZE <= (32767 * 2)
+typedef s16 slobidx_t;
+#else
+typedef s32 slobidx_t;
+#endif
+
+struct slob_block {
+ slobidx_t units;
+};
+typedef struct slob_block slob_t;
+
+/*
+ * We use struct page fields to manage some slob allocation aspects,
+ * however to avoid the horrible mess in include/linux/mm_types.h, we'll
+ * just define our own struct page type variant here.
+ */
+struct slob_page {
+ union {
+ struct {
+ unsigned long flags; /* mandatory */
+ unsigned long index; /* mandatory */
+ slobidx_t units; /* free units left in page */
+ unsigned long pad[2];
+ slob_t *free; /* first free slob_t in page */
+ struct list_head list; /* linked list of free pages */
+ };
+ struct page page;
+ };
+};
+
+unsigned int g_slob_kmalloc_pages;
+unsigned int g_slob_kmem_cache_pages;
+raw_spinlock_t g_slob_kmalloc_spin_lock = (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER (g_slob_kmalloc_spin_lock);
+raw_spinlock_t g_slob_kmem_cache_spin_lock = (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER (g_slob_kmem_cache_spin_lock);
+
+static inline void struct_slob_page_wrong_size(void)
+{ BUILD_BUG_ON(sizeof(struct slob_page) != sizeof(struct page)); }
+
+/*
+ * free_slob_page: call before a slob_page is returned to the page allocator.
+ */
+static inline void free_slob_page(struct slob_page *sp)
+{
+ reset_page_mapcount(&sp->page);
+ sp->page.mapping = NULL;
+}
+
+/*
+ * All partially free slob pages go on these lists.
+ */
+#define SLOB_BREAK1 256
+#define SLOB_BREAK2 1024
+static LIST_HEAD(free_slob_small);
+static LIST_HEAD(free_slob_medium);
+static LIST_HEAD(free_slob_large);
+
+/*
+ * is_slob_page: True for all slob pages (false for bigblock pages)
+ */
+static inline int is_slob_page(struct slob_page *sp)
+{
+ return PageSlab((struct page *)sp);
+}
+
+static inline void set_slob_page(struct slob_page *sp)
+{
+ __SetPageSlab((struct page *)sp);
+}
+
+static inline void clear_slob_page(struct slob_page *sp)
+{
+ __ClearPageSlab((struct page *)sp);
+}
+
+static inline struct slob_page *slob_page(const void *addr)
+{
+ return (struct slob_page *)virt_to_page(addr);
+}
+
+/*
+ * slob_page_free: true for pages on free_slob_pages list.
+ */
+static inline int slob_page_free(struct slob_page *sp)
+{
+ return PageSlobFree((struct page *)sp);
+}
+
+static void set_slob_page_free(struct slob_page *sp, struct list_head *list)
+{
+ list_add(&sp->list, list);
+ __SetPageSlobFree((struct page *)sp);
+}
+
+static inline void clear_slob_page_free(struct slob_page *sp)
+{
+ list_del(&sp->list);
+ __ClearPageSlobFree((struct page *)sp);
+}
+
+#ifdef CONFIG_SLOB_OPT
+#define SLOB_CHUNK_SHIFT (L1_CACHE_SHIFT)
+#define SLOB_CHUNK_SIZE (1 << (SLOB_CHUNK_SHIFT))
+#define SLOB_LIST_NUM (PAGE_SIZE >> (SLOB_CHUNK_SHIFT))
+#define SLOB_LIST_LIMIT (0)
+
+
+struct slob_item_info
+{
+ struct list_head slob_list;
+ int count;
+};
+struct slob_item_info slob_sizes[SLOB_LIST_NUM];
+#else
+#define SLOB_CHUNK_SHIFT (L1_CACHE_SHIFT)
+#define SLOB_CHUNK_SIZE (1 << (SLOB_CHUNK_SHIFT))
+#define SLOB_LIST_NUM ((PAGE_SIZE >> (SLOB_CHUNK_SHIFT)))
+struct list_head slob_sizes[SLOB_LIST_NUM];
+#endif
+static inline void set_slob_page_list_index(struct slob_page *sp, unsigned long index)
+{
+ sp->index = index;
+}
+#ifdef CONFIG_SLOB_OPT
+static inline struct slob_item_info *get_slob_page_list_head(struct slob_page *sp)
+{
+ return &slob_sizes[sp->index];
+}
+#else
+static inline struct list_head *get_slob_page_list_head(struct slob_page *sp)
+{
+ return &slob_sizes[sp->index];
+}
+#endif
+static inline void clear_slob_page_list_index(struct slob_page *sp)
+{
+ sp->index = 0;
+}
+
+#define SLOB_UNIT sizeof(slob_t)
+#define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT)
+#define SLOB_ALIGN L1_CACHE_BYTES
+
+/*
+ * struct slob_rcu is inserted at the tail of allocated slob blocks, which
+ * were created with a SLAB_DESTROY_BY_RCU slab. slob_rcu is used to free
+ * the block using call_rcu.
+ */
+struct slob_rcu {
+ struct rcu_head head;
+ int size;
+};
+
+/*
+ * slob_lock protects all slob allocator structures.
+ */
+static DEFINE_SPINLOCK(slob_lock);
+
+/*
+ * Encode the given size and next info into a free slob block s.
+ */
+static void set_slob(slob_t *s, slobidx_t size, slob_t *next)
+{
+ slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK);
+ slobidx_t offset = next - base;
+
+ if (size > 1) {
+ s[0].units = size;
+ s[1].units = offset;
+ } else
+ s[0].units = -offset;
+}
+
+/*
+ * Return the size of a slob block.
+ */
+static slobidx_t slob_units(slob_t *s)
+{
+ if (s->units > 0)
+ return s->units;
+ return 1;
+}
+
+/*
+ * Return the next free slob block pointer after this one.
+ */
+static slob_t *slob_next(slob_t *s)
+{
+ slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK);
+ slobidx_t next;
+
+ if (s[0].units < 0)
+ next = -s[0].units;
+ else
+ next = s[1].units;
+ return base+next;
+}
+
+/*
+ * Returns true if s is the last free block in its page.
+ */
+static int slob_last(slob_t *s)
+{
+ return !((unsigned long)slob_next(s) & ~PAGE_MASK);
+}
+
+static void *slob_new_pages(gfp_t gfp, int order, int node)
+{
+ void *page;
+
+#ifdef CONFIG_NUMA
+ if (node != -1)
+ page = alloc_pages_exact_node(node, gfp, order);
+ else
+#endif
+ page = alloc_pages(gfp, order);
+
+ if (!page)
+ return NULL;
+
+ return page_address(page);
+}
+
+static void slob_free_pages(void *b, int order)
+{
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed_slab += 1 << order;
+ free_pages((unsigned long)b, order);
+}
+
+/*
+ * Allocate a slob block within a given slob_page sp.
+ */
+static void *slob_page_alloc(struct slob_page *sp, size_t size, int align)
+{
+ slob_t *prev, *cur, *aligned = NULL;
+ int delta = 0, units = SLOB_UNITS(size);
+
+ for (prev = NULL, cur = sp->free; ; prev = cur, cur = slob_next(cur)) {
+ slobidx_t avail = slob_units(cur);
+
+ if (align) {
+ aligned = (slob_t *)ALIGN((unsigned long)cur, align);
+ delta = aligned - cur;
+ }
+ if (avail >= units + delta) { /* room enough? */
+ slob_t *next;
+
+ if (delta) { /* need to fragment head to align? */
+ next = slob_next(cur);
+ set_slob(aligned, avail - delta, next);
+ set_slob(cur, delta, aligned);
+ prev = cur;
+ cur = aligned;
+ avail = slob_units(cur);
+ }
+
+ next = slob_next(cur);
+ if (avail == units) { /* exact fit? unlink. */
+ if (prev)
+ set_slob(prev, slob_units(prev), next);
+ else
+ sp->free = next;
+ } else { /* fragment */
+ if (prev)
+ set_slob(prev, slob_units(prev), cur + units);
+ else
+ sp->free = cur + units;
+ set_slob(cur + units, avail - units, next);
+ }
+
+ sp->units -= units;
+ if (!sp->units
+#ifdef CONFIG_SLOB_OPT
+ && size != PAGE_SIZE
+#endif
+ )
+ clear_slob_page_free(sp);
+ return cur;
+ }
+ if (slob_last(cur))
+ return NULL;
+ }
+}
+
+void slob_sizes_init(void)
+{
+ int i;
+
+ for (i = 0; i < SLOB_LIST_NUM; i++)
+ {
+#ifdef CONFIG_SLOB_OPT
+ INIT_LIST_HEAD(&slob_sizes[i].slob_list);
+#else
+ INIT_LIST_HEAD(&slob_sizes[i]);
+#endif
+ }
+
+}
+
+static struct list_head *find_general_slob_list(size_t size, size_t *general_size, unsigned long *index)
+{
+ int slob_index = 0;
+
+ if (size & (SLOB_CHUNK_SIZE - 1))
+ slob_index = size >> SLOB_CHUNK_SHIFT;
+ else
+ slob_index = (size >> SLOB_CHUNK_SHIFT) - 1;
+
+ *general_size = (slob_index + 1) << SLOB_CHUNK_SHIFT;
+ *index = slob_index;
+ return &(slob_sizes[slob_index]);
+}
+
+/*
+ * slob_alloc: entry point into the slob allocator.
+ */
+static void *slob_alloc_general(size_t size, gfp_t gfp, int align, int node)
+{
+ unsigned long index;
+ size_t general_size;
+ struct slob_page *sp;
+ struct list_head *prev;
+#ifdef CONFIG_SLOB_OPT
+ struct slob_item_info *slob_list;
+#else
+ struct list_head *slob_list;
+#endif
+ slob_t *b = NULL;
+ unsigned long flags;
+
+ if (size < PAGE_SIZE)
+ slob_list = find_general_slob_list(size, &general_size, &index);
+ else
+ panic("slob alloc error");
+
+ size = general_size;
+ spin_lock_irqsave(&slob_lock, flags);
+ /* Iterate through each partially free page, try to find room */
+#ifdef CONFIG_SLOB_OPT
+ if (size ==PAGE_SIZE && slob_list->count ==0 )
+ goto alloc_out;
+
+ list_for_each_entry(sp, &(slob_list->slob_list), list) {
+#else
+ list_for_each_entry(sp, slob_list, list) {
+#endif
+#ifdef CONFIG_NUMA
+ /*
+ * If there's a node specification, search for a partial
+ * page with a matching node id in the freelist.
+ */
+ if (node != -1 && page_to_nid(&sp->page) != node)
+ continue;
+#endif
+ /* Enough room on this page? */
+ if (sp->units < SLOB_UNITS(size))
+ continue;
+
+#ifdef CONFIG_SLOB_OPT
+ /*if it is a free block,count--*/
+ if (sp->units == SLOB_UNITS(PAGE_SIZE))
+ slob_list->count--;
+#endif
+ /* Attempt to alloc */
+ prev = sp->list.prev;
+ b = slob_page_alloc(sp, size, align);
+ if (!b)
+ continue;
+
+ /* Improve fragment distribution and reduce our average
+ * search time by starting our next search here. (see
+ * Knuth vol 1, sec 2.5, pg 449) */
+#ifdef CONFIG_SLOB_OPT
+ if (prev != slob_list->slob_list.prev &&
+ slob_list->slob_list.next != prev->next)
+ list_move_tail(&(slob_list->slob_list), prev->next);
+#else
+ if (prev != slob_list->prev &&
+ slob_list->next != prev->next)
+ list_move_tail(slob_list, prev->next);
+#endif
+ break;
+ }
+alloc_out:
+ spin_unlock_irqrestore(&slob_lock, flags);
+
+ /* Not enough space: must allocate a new page */
+ if (!b) {
+ b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node);
+ if (!b)
+ return NULL;
+ raw_spin_lock_irqsave(&g_slob_kmalloc_spin_lock, flags);
+ g_slob_kmalloc_pages++;
+ raw_spin_unlock_irqrestore(&g_slob_kmalloc_spin_lock, flags);
+ sp = slob_page(b);
+ set_slob_page(sp);
+
+ spin_lock_irqsave(&slob_lock, flags);
+ sp->units = SLOB_UNITS(PAGE_SIZE);
+ sp->free = b;
+ INIT_LIST_HEAD(&sp->list);
+ set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE));
+#ifdef CONFIG_SLOB_OPT
+ set_slob_page_free(sp, &(slob_list->slob_list));
+#else
+ set_slob_page_free(sp, slob_list);
+#endif
+ b = slob_page_alloc(sp, size, align);
+ BUG_ON(!b);
+ set_slob_page_list_index(sp, index);
+ spin_unlock_irqrestore(&slob_lock, flags);
+ }
+ if (unlikely((gfp & __GFP_ZERO) && b))
+ memset(b, 0, size);
+ return b;
+}
+
+static size_t slob_find_general_size(struct slob_page *sp)
+{
+ return (sp->index + 1) << SLOB_CHUNK_SHIFT;
+}
+
+/*
+ * slob_free: entry point into the slob allocator.
+ */
+static void slob_free_general(const void *block, struct slob_page *sp)
+{
+ size_t size;
+ slob_t *prev, *next, *b = (slob_t *)block;
+ slobidx_t units;
+ unsigned long flags;
+#ifdef CONFIG_SLOB_OPT
+ struct slob_item_info *slob_list;
+#else
+ struct list_head *slob_list;
+#endif
+ if (unlikely(ZERO_OR_NULL_PTR(block)))
+ return;
+
+ slob_list = get_slob_page_list_head(sp);
+ size = slob_find_general_size(sp);
+
+ units = SLOB_UNITS(size);
+
+ spin_lock_irqsave(&slob_lock, flags);
+
+ if (sp->units + units == SLOB_UNITS(PAGE_SIZE)) {
+#ifdef CONFIG_SLOB_OPT
+ if (slob_list->count < SLOB_LIST_LIMIT && slob_page_free(sp)){
+ sp->units += units;
+ sp->free = page_address((struct page *)sp);
+ set_slob(sp->free, SLOB_UNITS(PAGE_SIZE), sp->free + SLOB_UNITS(PAGE_SIZE));
+ slob_list->count++;
+ // if (slob_list->slob_list.next != &sp->list)
+ // list_move(&sp->list, &(slob_list->slob_list));
+
+ spin_unlock_irqrestore(&slob_lock, flags);
+ return;
+ }
+#endif
+ /* Go directly to page allocator. Do not pass slob allocator */
+ if (slob_page_free(sp))
+ clear_slob_page_free(sp);
+ spin_unlock_irqrestore(&slob_lock, flags);
+ clear_slob_page(sp);
+ clear_slob_page_list_index(sp);
+ free_slob_page(sp);
+ slob_free_pages(b, 0);
+ raw_spin_lock_irqsave(&g_slob_kmalloc_spin_lock, flags);
+ g_slob_kmalloc_pages--;
+ raw_spin_unlock_irqrestore(&g_slob_kmalloc_spin_lock, flags);
+ return;
+ }
+
+ if (!slob_page_free(sp)) {
+ /* This slob page is about to become partially free. Easy! */
+ sp->units = units;
+ sp->free = b;
+ set_slob(b, units,
+ (void *)((unsigned long)(b +
+ SLOB_UNITS(PAGE_SIZE)) & PAGE_MASK));
+#ifdef CONFIG_SLOB_OPT
+ set_slob_page_free(sp, &(slob_list->slob_list));
+#else
+ set_slob_page_free(sp, slob_list);
+#endif
+ goto out;
+ }
+
+ /*
+ * Otherwise the page is already partially free, so find reinsertion
+ * point.
+ */
+ sp->units += units;
+
+ if (b < sp->free) {
+ if (b + units == sp->free) {
+ units += slob_units(sp->free);
+ sp->free = slob_next(sp->free);
+ }
+ set_slob(b, units, sp->free);
+ sp->free = b;
+ } else {
+ prev = sp->free;
+ next = slob_next(prev);
+ while (b > next) {
+ prev = next;
+ next = slob_next(prev);
+ }
+
+ if (unlikely((b == prev) || (b == next)))
+ panic("slob: double free error!\n");
+
+ if (!slob_last(prev) && b + units == next) {
+ units += slob_units(next);
+ set_slob(b, units, slob_next(next));
+ } else
+ set_slob(b, units, next);
+
+ if (prev + slob_units(prev) == b) {
+ units = slob_units(b) + slob_units(prev);
+ set_slob(prev, units, slob_next(b));
+ } else
+ set_slob(prev, slob_units(prev), b);
+ }
+#ifdef CONFIG_SLOB_OPT
+ if (slob_list->slob_list.next != &sp->list)
+ list_move(&sp->list, &(slob_list->slob_list));
+#else
+ if (slob_list->next != &sp->list)
+ list_move(&sp->list, slob_list);
+#endif
+out:
+ spin_unlock_irqrestore(&slob_lock, flags);
+}
+
+static void *slob_alloc(size_t size, gfp_t gfp, int align, int node)
+{
+ struct slob_page *sp;
+ struct list_head *prev;
+ struct list_head *slob_list;
+ slob_t *b = NULL;
+ unsigned long flags;
+
+ if (size < SLOB_BREAK1)
+ slob_list = &free_slob_small;
+ else if (size < SLOB_BREAK2)
+ slob_list = &free_slob_medium;
+ else
+ slob_list = &free_slob_large;
+
+ spin_lock_irqsave(&slob_lock, flags);
+ /* Iterate through each partially free page, try to find room */
+ list_for_each_entry(sp, slob_list, list) {
+#ifdef CONFIG_NUMA
+ /*
+ * If there's a node specification, search for a partial
+ * page with a matching node id in the freelist.
+ */
+ if (node != -1 && page_to_nid(&sp->page) != node)
+ continue;
+#endif
+ /* Enough room on this page? */
+ if (sp->units < SLOB_UNITS(size))
+ continue;
+
+ /* Attempt to alloc */
+ prev = sp->list.prev;
+ b = slob_page_alloc(sp, size, align);
+ if (!b)
+ continue;
+
+ /* Improve fragment distribution and reduce our average
+ * search time by starting our next search here. (see
+ * Knuth vol 1, sec 2.5, pg 449) */
+ if (prev != slob_list->prev &&
+ slob_list->next != prev->next)
+ list_move_tail(slob_list, prev->next);
+ break;
+ }
+ spin_unlock_irqrestore(&slob_lock, flags);
+
+ /* Not enough space: must allocate a new page */
+ if (!b) {
+ b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node);
+ if (!b)
+ return NULL;
+ raw_spin_lock_irqsave(&g_slob_kmem_cache_spin_lock, flags);
+ g_slob_kmem_cache_pages++;
+ raw_spin_unlock_irqrestore(&g_slob_kmem_cache_spin_lock, flags);
+ sp = slob_page(b);
+ set_slob_page(sp);
+
+ spin_lock_irqsave(&slob_lock, flags);
+ sp->units = SLOB_UNITS(PAGE_SIZE);
+ sp->free = b;
+ INIT_LIST_HEAD(&sp->list);
+ set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE));
+ set_slob_page_free(sp, slob_list);
+ b = slob_page_alloc(sp, size, align);
+ BUG_ON(!b);
+ spin_unlock_irqrestore(&slob_lock, flags);
+ }
+ if (unlikely((gfp & __GFP_ZERO) && b))
+ memset(b, 0, size);
+ return b;
+}
+
+/*
+ * slob_free: entry point into the slob allocator.
+ */
+static void slob_free(void *block, int size)
+{
+ struct slob_page *sp;
+ slob_t *prev, *next, *b = (slob_t *)block;
+ slobidx_t units;
+ unsigned long flags;
+ struct list_head *slob_list;
+
+ if (unlikely(ZERO_OR_NULL_PTR(block)))
+ return;
+ BUG_ON(!size);
+
+ sp = slob_page(block);
+ units = SLOB_UNITS(size);
+
+ spin_lock_irqsave(&slob_lock, flags);
+
+ if (sp->units + units == SLOB_UNITS(PAGE_SIZE)) {
+ /* Go directly to page allocator. Do not pass slob allocator */
+ if (slob_page_free(sp))
+ clear_slob_page_free(sp);
+ spin_unlock_irqrestore(&slob_lock, flags);
+ clear_slob_page(sp);
+ free_slob_page(sp);
+ slob_free_pages(b, 0);
+ raw_spin_lock_irqsave(&g_slob_kmem_cache_spin_lock, flags);
+ g_slob_kmem_cache_pages--;
+ raw_spin_unlock_irqrestore(&g_slob_kmem_cache_spin_lock, flags);
+ return;
+ }
+
+ if (!slob_page_free(sp)) {
+ /* This slob page is about to become partially free. Easy! */
+ sp->units = units;
+ sp->free = b;
+ set_slob(b, units,
+ (void *)((unsigned long)(b +
+ SLOB_UNITS(PAGE_SIZE)) & PAGE_MASK));
+ if (size < SLOB_BREAK1)
+ slob_list = &free_slob_small;
+ else if (size < SLOB_BREAK2)
+ slob_list = &free_slob_medium;
+ else
+ slob_list = &free_slob_large;
+ set_slob_page_free(sp, slob_list);
+ goto out;
+ }
+
+ /*
+ * Otherwise the page is already partially free, so find reinsertion
+ * point.
+ */
+ sp->units += units;
+
+ if (b < sp->free) {
+ if (b + units == sp->free) {
+ units += slob_units(sp->free);
+ sp->free = slob_next(sp->free);
+ }
+ set_slob(b, units, sp->free);
+ sp->free = b;
+ } else {
+ prev = sp->free;
+ next = slob_next(prev);
+ while (b > next) {
+ prev = next;
+ next = slob_next(prev);
+ }
+
+ if (!slob_last(prev) && b + units == next) {
+ units += slob_units(next);
+ set_slob(b, units, slob_next(next));
+ } else
+ set_slob(b, units, next);
+
+ if (prev + slob_units(prev) == b) {
+ units = slob_units(b) + slob_units(prev);
+ set_slob(prev, units, slob_next(b));
+ } else
+ set_slob(prev, slob_units(prev), b);
+ }
+out:
+ spin_unlock_irqrestore(&slob_lock, flags);
+}
+
+/*
+ * End of slob allocator proper. Begin kmem_cache_alloc and kmalloc frontend.
+ */
+
+void *__kmalloc_node(size_t size, gfp_t gfp, int node)
+{
+ int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
+ void *ret;
+ unsigned long flags;
+
+ if (!size)
+ return ZERO_SIZE_PTR;
+
+ gfp &= gfp_allowed_mask;
+
+ lockdep_trace_alloc(gfp);
+
+#ifdef CONFIG_DEBUG_SLOB_MARK_HEAD
+ if (size < PAGE_SIZE)
+ size += RECORD_COUNT * BYTES_PER_RECORD;
+#endif
+
+#ifdef CONFIG_KMALLOC_TRACKER
+ size += HEAP_SUFFIX_SIZE;
+#endif
+
+ if (size < PAGE_SIZE) {
+ if (!size)
+ return ZERO_SIZE_PTR;
+
+ ret = slob_alloc_general(size, gfp, align, node);
+
+ trace_kmalloc_node(_RET_IP_, ret,
+ size, size, gfp, node);
+
+#ifdef CONFIG_DEBUG_SLOB_MARK_HEAD
+ if (ret) {
+ *dbg_userrecord(ret,0) = (void *)RECORD_MAGIC;
+ *dbg_userrecord(ret,1) = __builtin_return_address(0);
+ *dbg_userrecord(ret,2) = current;
+ ret = (void *)dbg_userrecord(ret,RECORD_COUNT);
+ }
+
+#endif
+
+#ifdef CONFIG_KMALLOC_TRACKER
+ if (ret) {
+ kmalloc_alloc_tracker(ret, KMALLOC_ORIGINAL_SIZE(size));
+ return KMALLOC_SETUP(ret);
+ }
+#endif
+ } else {
+ unsigned int order = get_order(size);
+
+ if (likely(order))
+ gfp |= __GFP_COMP;
+ ret = slob_new_pages(gfp, order, node);
+ if (ret) {
+ struct page *page;
+ page = virt_to_page(ret);
+ page->private = size;
+ raw_spin_lock_irqsave(&g_slob_kmalloc_spin_lock, flags);
+ g_slob_kmalloc_pages += (1 << order);
+ raw_spin_unlock_irqrestore(&g_slob_kmalloc_spin_lock, flags);
+ }
+
+ trace_kmalloc_node(_RET_IP_, ret,
+ size, PAGE_SIZE << order, gfp, node);
+ }
+
+ kmemleak_alloc(ret, size, 1, gfp);
+ return ret;
+}
+EXPORT_SYMBOL(__kmalloc_node);
+
+void kfree(const void *block)
+{
+ struct slob_page *sp;
+ unsigned long flags;
+
+ trace_kfree(_RET_IP_, block);
+
+ if (unlikely(ZERO_OR_NULL_PTR(block)))
+ return;
+ kmemleak_free(block);
+
+#ifdef CONFIG_KMALLOC_TRACKER
+ int entry = 0;
+ void *mem = NULL;
+
+ sp = slob_page(block);
+ if (is_slob_page(sp)) {
+
+ mem = KMALLOC_BASE(block);
+ entry = *(size_t *)(mem);
+
+ if ((entry != 0) && (MEM_TRUE == check_node_entry(entry))) {
+ mem_free_tracker((void *)entry, MEM_TRACKER_TYPE_KMALLOC);
+ }else
+ panic("mem out!!");
+ slob_free_general(mem, sp);
+ } else
+ put_page(&sp->page);
+#else
+ sp = slob_page(block);
+ if (is_slob_page(sp)) {
+#ifdef CONFIG_DEBUG_SLOB_MARK_HEAD
+ if (*dbg_userhead(block) == (void *)RECORD_MAGIC) {
+ block = (void *)dbg_userhead(block);
+ } else
+ panic("memmory corruption!!");
+#endif
+ slob_free_general(block, sp);
+ } else {
+ struct page *page;
+ unsigned int order;
+ page = &sp->page;
+ order = get_order(page->private);
+ raw_spin_lock_irqsave(&g_slob_kmalloc_spin_lock, flags);
+ g_slob_kmalloc_pages -= (1 << order);
+ raw_spin_unlock_irqrestore(&g_slob_kmalloc_spin_lock, flags);
+ put_page(&sp->page);
+ }
+#endif
+
+}
+EXPORT_SYMBOL(kfree);
+
+/* can't use ksize for kmem_cache_alloc memory, only kmalloc */
+size_t ksize(const void *block)
+{
+ struct slob_page *sp;
+
+ BUG_ON(!block);
+ if (unlikely(block == ZERO_SIZE_PTR))
+ return 0;
+
+ sp = slob_page(block);
+ if (is_slob_page(sp)) {
+#ifdef CONFIG_SLOB_OPT
+ struct slob_item_info *slob_list;
+#else
+ struct list_head *slob_list;
+#endif
+ slob_list = get_slob_page_list_head(sp);
+
+#ifdef CONFIG_KMALLOC_TRACKER
+ return (slob_find_general_size(sp) - 2 * sizeof(size_t));
+#endif
+
+#ifdef CONFIG_DEBUG_SLOB_MARK_HEAD
+ return (slob_find_general_size(sp) - RECORD_COUNT * BYTES_PER_RECORD);
+#else
+ return slob_find_general_size(sp);
+#endif
+
+ } else
+ return sp->page.private;
+}
+EXPORT_SYMBOL(ksize);
+
+struct kmem_cache {
+ unsigned int size, align;
+ unsigned long flags;
+ const char *name;
+ void (*ctor)(void *);
+};
+
+struct kmem_cache *kmem_cache_create(const char *name, size_t size,
+ size_t align, unsigned long flags, void (*ctor)(void *))
+{
+ struct kmem_cache *c;
+
+ c = slob_alloc(sizeof(struct kmem_cache),
+ GFP_KERNEL, ARCH_KMALLOC_MINALIGN, -1);
+
+ if (c) {
+ c->name = name;
+ c->size = size;
+ if (flags & SLAB_DESTROY_BY_RCU) {
+ /* leave room for rcu footer at the end of object */
+ c->size += sizeof(struct slob_rcu);
+ }
+ c->flags = flags;
+ c->ctor = ctor;
+ /* ignore alignment unless it's forced */
+ c->align = (flags & SLAB_HWCACHE_ALIGN) ? SLOB_ALIGN : 0;
+ if (c->align < ARCH_SLAB_MINALIGN)
+ c->align = ARCH_SLAB_MINALIGN;
+ if (c->align < align)
+ c->align = align;
+ } else if (flags & SLAB_PANIC)
+ panic("Cannot create slab cache %s\n", name);
+
+ kmemleak_alloc(c, sizeof(struct kmem_cache), 1, GFP_KERNEL);
+ return c;
+}
+EXPORT_SYMBOL(kmem_cache_create);
+
+void kmem_cache_destroy(struct kmem_cache *c)
+{
+ kmemleak_free(c);
+ if (c->flags & SLAB_DESTROY_BY_RCU)
+ rcu_barrier();
+ slob_free(c, sizeof(struct kmem_cache));
+}
+EXPORT_SYMBOL(kmem_cache_destroy);
+
+static unsigned int align(unsigned int i)
+{
+ return (i + 7) & ~7u;
+}
+void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node)
+{
+ void *b;
+
+ flags &= gfp_allowed_mask;
+ unsigned long spin_flags;
+
+ lockdep_trace_alloc(flags);
+
+ if (c->size < PAGE_SIZE) {
+ //b = slob_alloc(c->size, flags, c->align, node);
+ c->size = align(c->size);/*align 8*/
+ c->align = 0;
+ b = slob_alloc(c->size, flags, 0, node);/*already align 8*/
+ trace_kmem_cache_alloc_node(_RET_IP_, b, c->size,
+ SLOB_UNITS(c->size) * SLOB_UNIT,
+ flags, node);
+ } else {
+ b = slob_new_pages(flags, get_order(c->size), node);
+ if(b) {
+ raw_spin_lock_irqsave(&g_slob_kmem_cache_spin_lock, spin_flags);
+ g_slob_kmem_cache_pages += (1 << get_order(c->size));
+ raw_spin_unlock_irqrestore(&g_slob_kmem_cache_spin_lock, spin_flags);
+ }
+ trace_kmem_cache_alloc_node(_RET_IP_, b, c->size,
+ PAGE_SIZE << get_order(c->size),
+ flags, node);
+ }
+ if (c->ctor)
+ c->ctor(b);
+
+ kmemleak_alloc_recursive(b, c->size, 1, c->flags, flags);
+ return b;
+}
+
+EXPORT_SYMBOL(kmem_cache_alloc_node);
+static void __kmem_cache_free(void *b, int size)
+{
+ unsigned long flags;
+ if (size < PAGE_SIZE)
+ slob_free(b, size);
+ else {
+ slob_free_pages(b, get_order(size));
+ raw_spin_lock_irqsave(&g_slob_kmem_cache_spin_lock, flags);
+ g_slob_kmem_cache_pages -= (1 << get_order(size));
+ raw_spin_unlock_irqrestore(&g_slob_kmem_cache_spin_lock, flags);
+ }
+}
+
+static void kmem_rcu_free(struct rcu_head *head)
+{
+ struct slob_rcu *slob_rcu = (struct slob_rcu *)head;
+ void *b = (void *)slob_rcu - (slob_rcu->size - sizeof(struct slob_rcu));
+
+ __kmem_cache_free(b, slob_rcu->size);
+}
+
+void kmem_cache_free(struct kmem_cache *c, void *b)
+{
+ kmemleak_free_recursive(b, c->flags);
+
+ if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) {
+ struct slob_rcu *slob_rcu;
+ slob_rcu = b + (c->size - sizeof(struct slob_rcu));
+ slob_rcu->size = c->size;
+ call_rcu(&slob_rcu->head, kmem_rcu_free);
+ } else {
+ __kmem_cache_free(b, c->size);
+ }
+
+ trace_kmem_cache_free(_RET_IP_, b);
+}
+EXPORT_SYMBOL(kmem_cache_free);
+
+unsigned int kmem_cache_size(struct kmem_cache *c)
+{
+ return c->size;
+}
+EXPORT_SYMBOL(kmem_cache_size);
+
+int kmem_cache_shrink(struct kmem_cache *d)
+{
+#ifdef CONFIG_SLOB_OPT
+ int i;
+ unsigned long flags;
+ struct slob_page *sp,*n;
+
+ for (i = 0; i < SLOB_LIST_NUM; i++){
+ if (slob_sizes[i].count == 0)
+ continue;
+ spin_lock_irqsave(&slob_lock, flags);
+
+ list_for_each_entry_safe(sp, n, &(slob_sizes[i].slob_list), list) {
+ if (sp->units == SLOB_UNITS(PAGE_SIZE)){
+ if (slob_page_free(sp))
+ clear_slob_page_free(sp);
+ clear_slob_page(sp);
+ clear_slob_page_list_index(sp);
+ free_slob_page(sp);
+ slob_free_pages(page_address((struct page*)sp), 0);
+ }
+ }
+ slob_sizes[i].count = 0;
+ spin_unlock_irqrestore(&slob_lock, flags);
+
+ }
+#endif
+ return 0;
+}
+EXPORT_SYMBOL(kmem_cache_shrink);
+
+static unsigned int slob_ready __read_mostly;
+
+int slab_is_available(void)
+{
+ return slob_ready;
+}
+
+void __init kmem_cache_init(void)
+{
+ slob_ready = 1;
+}
+
+void __init kmem_cache_init_late(void)
+{
+ /* Nothing to do */
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/slub.c b/ap/os/linux/linux-3.4.x/mm/slub.c
new file mode 100644
index 0000000..9308c8a
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/slub.c
@@ -0,0 +1,5502 @@
+/*
+ * SLUB: A slab allocator that limits cache line use instead of queuing
+ * objects in per cpu and per node lists.
+ *
+ * The allocator synchronizes using per slab locks or atomic operatios
+ * and only uses a centralized lock to manage a pool of partial slabs.
+ *
+ * (C) 2007 SGI, Christoph Lameter
+ * (C) 2011 Linux Foundation, Christoph Lameter
+ */
+
+#include <linux/mm.h>
+#include <linux/swap.h> /* struct reclaim_state */
+#include <linux/module.h>
+#include <linux/bit_spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/bitops.h>
+#include <linux/slab.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/kmemcheck.h>
+#include <linux/cpu.h>
+#include <linux/cpuset.h>
+#include <linux/mempolicy.h>
+#include <linux/ctype.h>
+#include <linux/debugobjects.h>
+#include <linux/kallsyms.h>
+#include <linux/memory.h>
+#include <linux/math64.h>
+#include <linux/fault-inject.h>
+#include <linux/stacktrace.h>
+#include <linux/prefetch.h>
+
+#include <trace/events/kmem.h>
+
+/*
+ * Lock order:
+ * 1. slub_lock (Global Semaphore)
+ * 2. node->list_lock
+ * 3. slab_lock(page) (Only on some arches and for debugging)
+ *
+ * slub_lock
+ *
+ * The role of the slub_lock is to protect the list of all the slabs
+ * and to synchronize major metadata changes to slab cache structures.
+ *
+ * The slab_lock is only used for debugging and on arches that do not
+ * have the ability to do a cmpxchg_double. It only protects the second
+ * double word in the page struct. Meaning
+ * A. page->freelist -> List of object free in a page
+ * B. page->counters -> Counters of objects
+ * C. page->frozen -> frozen state
+ *
+ * If a slab is frozen then it is exempt from list management. It is not
+ * on any list. The processor that froze the slab is the one who can
+ * perform list operations on the page. Other processors may put objects
+ * onto the freelist but the processor that froze the slab is the only
+ * one that can retrieve the objects from the page's freelist.
+ *
+ * The list_lock protects the partial and full list on each node and
+ * the partial slab counter. If taken then no new slabs may be added or
+ * removed from the lists nor make the number of partial slabs be modified.
+ * (Note that the total number of slabs is an atomic value that may be
+ * modified without taking the list lock).
+ *
+ * The list_lock is a centralized lock and thus we avoid taking it as
+ * much as possible. As long as SLUB does not have to handle partial
+ * slabs, operations can continue without any centralized lock. F.e.
+ * allocating a long series of objects that fill up slabs does not require
+ * the list lock.
+ * Interrupts are disabled during allocation and deallocation in order to
+ * make the slab allocator safe to use in the context of an irq. In addition
+ * interrupts are disabled to ensure that the processor does not change
+ * while handling per_cpu slabs, due to kernel preemption.
+ *
+ * SLUB assigns one slab for allocation to each processor.
+ * Allocations only occur from these slabs called cpu slabs.
+ *
+ * Slabs with free elements are kept on a partial list and during regular
+ * operations no list for full slabs is used. If an object in a full slab is
+ * freed then the slab will show up again on the partial lists.
+ * We track full slabs for debugging purposes though because otherwise we
+ * cannot scan all objects.
+ *
+ * Slabs are freed when they become empty. Teardown and setup is
+ * minimal so we rely on the page allocators per cpu caches for
+ * fast frees and allocs.
+ *
+ * Overloading of page flags that are otherwise used for LRU management.
+ *
+ * PageActive The slab is frozen and exempt from list processing.
+ * This means that the slab is dedicated to a purpose
+ * such as satisfying allocations for a specific
+ * processor. Objects may be freed in the slab while
+ * it is frozen but slab_free will then skip the usual
+ * list operations. It is up to the processor holding
+ * the slab to integrate the slab into the slab lists
+ * when the slab is no longer needed.
+ *
+ * One use of this flag is to mark slabs that are
+ * used for allocations. Then such a slab becomes a cpu
+ * slab. The cpu slab may be equipped with an additional
+ * freelist that allows lockless access to
+ * free objects in addition to the regular freelist
+ * that requires the slab lock.
+ *
+ * PageError Slab requires special handling due to debug
+ * options set. This moves slab handling out of
+ * the fast path and disables lockless freelists.
+ */
+
+#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
+ SLAB_TRACE | SLAB_DEBUG_FREE)
+
+static inline int kmem_cache_debug(struct kmem_cache *s)
+{
+#ifdef CONFIG_SLUB_DEBUG
+ return unlikely(s->flags & SLAB_DEBUG_FLAGS);
+#else
+ return 0;
+#endif
+}
+
+/*
+ * Issues still to be resolved:
+ *
+ * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
+ *
+ * - Variable sizing of the per node arrays
+ */
+
+/* Enable to test recovery from slab corruption on boot */
+#undef SLUB_RESILIENCY_TEST
+
+/* Enable to log cmpxchg failures */
+#undef SLUB_DEBUG_CMPXCHG
+
+/*
+ * Mininum number of partial slabs. These will be left on the partial
+ * lists even if they are empty. kmem_cache_shrink may reclaim them.
+ */
+#define MIN_PARTIAL 5
+
+/*
+ * Maximum number of desirable partial slabs.
+ * The existence of more partial slabs makes kmem_cache_shrink
+ * sort the partial list by the number of objects in the.
+ */
+#define MAX_PARTIAL 10
+
+#define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
+ SLAB_POISON | SLAB_STORE_USER)
+
+/*
+ * Debugging flags that require metadata to be stored in the slab. These get
+ * disabled when slub_debug=O is used and a cache's min order increases with
+ * metadata.
+ */
+#define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
+
+/*
+ * Set of flags that will prevent slab merging
+ */
+#define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
+ SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
+ SLAB_FAILSLAB)
+
+#define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
+ SLAB_CACHE_DMA | SLAB_NOTRACK)
+
+#define OO_SHIFT 16
+#define OO_MASK ((1 << OO_SHIFT) - 1)
+#define MAX_OBJS_PER_PAGE 32767 /* since page.objects is u15 */
+
+/* Internal SLUB flags */
+#define __OBJECT_POISON 0x80000000UL /* Poison object */
+#define __CMPXCHG_DOUBLE 0x40000000UL /* Use cmpxchg_double */
+
+static int kmem_size = sizeof(struct kmem_cache);
+
+#ifdef CONFIG_SMP
+static struct notifier_block slab_notifier;
+#endif
+
+static enum {
+ DOWN, /* No slab functionality available */
+ PARTIAL, /* Kmem_cache_node works */
+ UP, /* Everything works but does not show up in sysfs */
+ SYSFS /* Sysfs up */
+} slab_state = DOWN;
+
+/* A list of all slab caches on the system */
+static DECLARE_RWSEM(slub_lock);
+static LIST_HEAD(slab_caches);
+
+/*
+ * Tracking user of a slab.
+ */
+#define TRACK_ADDRS_COUNT 16
+struct track {
+ unsigned long addr; /* Called from address */
+#ifdef CONFIG_STACKTRACE
+ unsigned long addrs[TRACK_ADDRS_COUNT]; /* Called from address */
+#endif
+ int cpu; /* Was running on cpu */
+ int pid; /* Pid context */
+ unsigned long when; /* When did the operation occur */
+};
+
+enum track_item { TRACK_ALLOC, TRACK_FREE };
+
+#ifdef CONFIG_SYSFS
+static int sysfs_slab_add(struct kmem_cache *);
+static int sysfs_slab_alias(struct kmem_cache *, const char *);
+static void sysfs_slab_remove(struct kmem_cache *);
+
+#else
+static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
+static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
+ { return 0; }
+static inline void sysfs_slab_remove(struct kmem_cache *s)
+{
+ kfree(s->name);
+ kfree(s);
+}
+
+#endif
+
+static inline void stat(const struct kmem_cache *s, enum stat_item si)
+{
+#ifdef CONFIG_SLUB_STATS
+ __this_cpu_inc(s->cpu_slab->stat[si]);
+#endif
+}
+
+/********************************************************************
+ * Core slab cache functions
+ *******************************************************************/
+
+int slab_is_available(void)
+{
+ return slab_state >= UP;
+}
+
+static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
+{
+ return s->node[node];
+}
+
+/* Verify that a pointer has an address that is valid within a slab page */
+static inline int check_valid_pointer(struct kmem_cache *s,
+ struct page *page, const void *object)
+{
+ void *base;
+
+ if (!object)
+ return 1;
+
+ base = page_address(page);
+ if (object < base || object >= base + page->objects * s->size ||
+ (object - base) % s->size) {
+ return 0;
+ }
+
+ return 1;
+}
+
+static inline void *get_freepointer(struct kmem_cache *s, void *object)
+{
+ return *(void **)(object + s->offset);
+}
+
+static void prefetch_freepointer(const struct kmem_cache *s, void *object)
+{
+ prefetch(object + s->offset);
+}
+
+static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
+{
+ void *p;
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p));
+#else
+ p = get_freepointer(s, object);
+#endif
+ return p;
+}
+
+static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
+{
+ *(void **)(object + s->offset) = fp;
+}
+
+/* Loop over all objects in a slab */
+#define for_each_object(__p, __s, __addr, __objects) \
+ for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
+ __p += (__s)->size)
+
+/* Determine object index from a given position */
+static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
+{
+ return (p - addr) / s->size;
+}
+
+static inline size_t slab_ksize(const struct kmem_cache *s)
+{
+#ifdef CONFIG_SLUB_DEBUG
+ /*
+ * Debugging requires use of the padding between object
+ * and whatever may come after it.
+ */
+ if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
+ return s->objsize;
+
+#endif
+ /*
+ * If we have the need to store the freelist pointer
+ * back there or track user information then we can
+ * only use the space before that information.
+ */
+ if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
+ return s->inuse;
+ /*
+ * Else we can use all the padding etc for the allocation
+ */
+ return s->size;
+}
+
+static inline int order_objects(int order, unsigned long size, int reserved)
+{
+ return ((PAGE_SIZE << order) - reserved) / size;
+}
+
+static inline struct kmem_cache_order_objects oo_make(int order,
+ unsigned long size, int reserved)
+{
+ struct kmem_cache_order_objects x = {
+ (order << OO_SHIFT) + order_objects(order, size, reserved)
+ };
+
+ return x;
+}
+
+static inline int oo_order(struct kmem_cache_order_objects x)
+{
+ return x.x >> OO_SHIFT;
+}
+
+static inline int oo_objects(struct kmem_cache_order_objects x)
+{
+ return x.x & OO_MASK;
+}
+
+/*
+ * Per slab locking using the pagelock
+ */
+static __always_inline void slab_lock(struct page *page)
+{
+ bit_spin_lock(PG_locked, &page->flags);
+}
+
+static __always_inline void slab_unlock(struct page *page)
+{
+ __bit_spin_unlock(PG_locked, &page->flags);
+}
+
+/* Interrupts must be disabled (for the fallback code to work right) */
+static inline bool __cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
+ void *freelist_old, unsigned long counters_old,
+ void *freelist_new, unsigned long counters_new,
+ const char *n)
+{
+ VM_BUG_ON(!irqs_disabled());
+#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
+ defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
+ if (s->flags & __CMPXCHG_DOUBLE) {
+ if (cmpxchg_double(&page->freelist, &page->counters,
+ freelist_old, counters_old,
+ freelist_new, counters_new))
+ return 1;
+ } else
+#endif
+ {
+ slab_lock(page);
+ if (page->freelist == freelist_old && page->counters == counters_old) {
+ page->freelist = freelist_new;
+ page->counters = counters_new;
+ slab_unlock(page);
+ return 1;
+ }
+ slab_unlock(page);
+ }
+
+ cpu_relax();
+ stat(s, CMPXCHG_DOUBLE_FAIL);
+
+#ifdef SLUB_DEBUG_CMPXCHG
+ printk(KERN_INFO "%s %s: cmpxchg double redo ", n, s->name);
+#endif
+
+ return 0;
+}
+
+static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
+ void *freelist_old, unsigned long counters_old,
+ void *freelist_new, unsigned long counters_new,
+ const char *n)
+{
+#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
+ defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
+ if (s->flags & __CMPXCHG_DOUBLE) {
+ if (cmpxchg_double(&page->freelist, &page->counters,
+ freelist_old, counters_old,
+ freelist_new, counters_new))
+ return 1;
+ } else
+#endif
+ {
+ unsigned long flags;
+
+ local_irq_save(flags);
+ slab_lock(page);
+ if (page->freelist == freelist_old && page->counters == counters_old) {
+ page->freelist = freelist_new;
+ page->counters = counters_new;
+ slab_unlock(page);
+ local_irq_restore(flags);
+ return 1;
+ }
+ slab_unlock(page);
+ local_irq_restore(flags);
+ }
+
+ cpu_relax();
+ stat(s, CMPXCHG_DOUBLE_FAIL);
+
+#ifdef SLUB_DEBUG_CMPXCHG
+ printk(KERN_INFO "%s %s: cmpxchg double redo ", n, s->name);
+#endif
+
+ return 0;
+}
+
+#ifdef CONFIG_SLUB_DEBUG
+/*
+ * Determine a map of object in use on a page.
+ *
+ * Node listlock must be held to guarantee that the page does
+ * not vanish from under us.
+ */
+static void get_map(struct kmem_cache *s, struct page *page, unsigned long *map)
+{
+ void *p;
+ void *addr = page_address(page);
+
+ for (p = page->freelist; p; p = get_freepointer(s, p))
+ set_bit(slab_index(p, s, addr), map);
+}
+
+/*
+ * Debug settings:
+ */
+#ifdef CONFIG_SLUB_DEBUG_ON
+static int slub_debug = DEBUG_DEFAULT_FLAGS;
+#else
+static int slub_debug;
+#endif
+
+static char *slub_debug_slabs;
+static int disable_higher_order_debug;
+
+/*
+ * Object debugging
+ */
+static void print_section(char *text, u8 *addr, unsigned int length)
+{
+ print_hex_dump(KERN_ERR, text, DUMP_PREFIX_ADDRESS, 16, 1, addr,
+ length, 1);
+}
+
+static struct track *get_track(struct kmem_cache *s, void *object,
+ enum track_item alloc)
+{
+ struct track *p;
+
+ if (s->offset)
+ p = object + s->offset + sizeof(void *);
+ else
+ p = object + s->inuse;
+
+ return p + alloc;
+}
+
+static void set_track(struct kmem_cache *s, void *object,
+ enum track_item alloc, unsigned long addr)
+{
+ struct track *p = get_track(s, object, alloc);
+
+ if (addr) {
+#ifdef CONFIG_STACKTRACE
+ struct stack_trace trace;
+ int i;
+
+ trace.nr_entries = 0;
+ trace.max_entries = TRACK_ADDRS_COUNT;
+ trace.entries = p->addrs;
+ trace.skip = 3;
+ save_stack_trace(&trace);
+
+ /* See rant in lockdep.c */
+ if (trace.nr_entries != 0 &&
+ trace.entries[trace.nr_entries - 1] == ULONG_MAX)
+ trace.nr_entries--;
+
+ for (i = trace.nr_entries; i < TRACK_ADDRS_COUNT; i++)
+ p->addrs[i] = 0;
+#endif
+ p->addr = addr;
+ p->cpu = smp_processor_id();
+ p->pid = current->pid;
+ p->when = jiffies;
+ } else
+ memset(p, 0, sizeof(struct track));
+}
+
+static void init_tracking(struct kmem_cache *s, void *object)
+{
+ if (!(s->flags & SLAB_STORE_USER))
+ return;
+
+ set_track(s, object, TRACK_FREE, 0UL);
+ set_track(s, object, TRACK_ALLOC, 0UL);
+}
+
+static void print_track(const char *s, struct track *t)
+{
+ if (!t->addr)
+ return;
+
+ printk(KERN_ERR "INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
+ s, (void *)t->addr, jiffies - t->when, t->cpu, t->pid);
+#ifdef CONFIG_STACKTRACE
+ {
+ int i;
+ for (i = 0; i < TRACK_ADDRS_COUNT; i++)
+ if (t->addrs[i])
+ printk(KERN_ERR "\t%pS\n", (void *)t->addrs[i]);
+ else
+ break;
+ }
+#endif
+}
+
+static void print_tracking(struct kmem_cache *s, void *object)
+{
+ if (!(s->flags & SLAB_STORE_USER))
+ return;
+
+ print_track("Allocated", get_track(s, object, TRACK_ALLOC));
+ print_track("Freed", get_track(s, object, TRACK_FREE));
+}
+
+static void print_page_info(struct page *page)
+{
+ printk(KERN_ERR "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
+ page, page->objects, page->inuse, page->freelist, page->flags);
+
+}
+
+static void slab_bug(struct kmem_cache *s, char *fmt, ...)
+{
+ va_list args;
+ char buf[100];
+
+ va_start(args, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, args);
+ va_end(args);
+ printk(KERN_ERR "========================================"
+ "=====================================\n");
+ printk(KERN_ERR "BUG %s (%s): %s\n", s->name, print_tainted(), buf);
+ printk(KERN_ERR "----------------------------------------"
+ "-------------------------------------\n\n");
+}
+
+static void slab_fix(struct kmem_cache *s, char *fmt, ...)
+{
+ va_list args;
+ char buf[100];
+
+ va_start(args, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, args);
+ va_end(args);
+ printk(KERN_ERR "FIX %s: %s\n", s->name, buf);
+}
+
+static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
+{
+ unsigned int off; /* Offset of last byte */
+ u8 *addr = page_address(page);
+
+ print_tracking(s, p);
+
+ print_page_info(page);
+
+ printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
+ p, p - addr, get_freepointer(s, p));
+
+ if (p > addr + 16)
+ print_section("Bytes b4 ", p - 16, 16);
+
+ print_section("Object ", p, min_t(unsigned long, s->objsize,
+ PAGE_SIZE));
+ if (s->flags & SLAB_RED_ZONE)
+ print_section("Redzone ", p + s->objsize,
+ s->inuse - s->objsize);
+
+ if (s->offset)
+ off = s->offset + sizeof(void *);
+ else
+ off = s->inuse;
+
+ if (s->flags & SLAB_STORE_USER)
+ off += 2 * sizeof(struct track);
+
+ if (off != s->size)
+ /* Beginning of the filler is the free pointer */
+ print_section("Padding ", p + off, s->size - off);
+
+ dump_stack();
+}
+
+static void object_err(struct kmem_cache *s, struct page *page,
+ u8 *object, char *reason)
+{
+ slab_bug(s, "%s", reason);
+ print_trailer(s, page, object);
+}
+
+static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...)
+{
+ va_list args;
+ char buf[100];
+
+ va_start(args, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, args);
+ va_end(args);
+ slab_bug(s, "%s", buf);
+ print_page_info(page);
+ dump_stack();
+}
+
+static void init_object(struct kmem_cache *s, void *object, u8 val)
+{
+ u8 *p = object;
+
+ if (s->flags & __OBJECT_POISON) {
+ memset(p, POISON_FREE, s->objsize - 1);
+ p[s->objsize - 1] = POISON_END;
+ }
+
+ if (s->flags & SLAB_RED_ZONE)
+ memset(p + s->objsize, val, s->inuse - s->objsize);
+}
+
+static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
+ void *from, void *to)
+{
+ slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data);
+ memset(from, data, to - from);
+}
+
+static int check_bytes_and_report(struct kmem_cache *s, struct page *page,
+ u8 *object, char *what,
+ u8 *start, unsigned int value, unsigned int bytes)
+{
+ u8 *fault;
+ u8 *end;
+
+ fault = memchr_inv(start, value, bytes);
+ if (!fault)
+ return 1;
+
+ end = start + bytes;
+ while (end > fault && end[-1] == value)
+ end--;
+
+ slab_bug(s, "%s overwritten", what);
+ printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
+ fault, end - 1, fault[0], value);
+ print_trailer(s, page, object);
+
+ restore_bytes(s, what, value, fault, end);
+ return 0;
+}
+
+/*
+ * Object layout:
+ *
+ * object address
+ * Bytes of the object to be managed.
+ * If the freepointer may overlay the object then the free
+ * pointer is the first word of the object.
+ *
+ * Poisoning uses 0x6b (POISON_FREE) and the last byte is
+ * 0xa5 (POISON_END)
+ *
+ * object + s->objsize
+ * Padding to reach word boundary. This is also used for Redzoning.
+ * Padding is extended by another word if Redzoning is enabled and
+ * objsize == inuse.
+ *
+ * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
+ * 0xcc (RED_ACTIVE) for objects in use.
+ *
+ * object + s->inuse
+ * Meta data starts here.
+ *
+ * A. Free pointer (if we cannot overwrite object on free)
+ * B. Tracking data for SLAB_STORE_USER
+ * C. Padding to reach required alignment boundary or at mininum
+ * one word if debugging is on to be able to detect writes
+ * before the word boundary.
+ *
+ * Padding is done using 0x5a (POISON_INUSE)
+ *
+ * object + s->size
+ * Nothing is used beyond s->size.
+ *
+ * If slabcaches are merged then the objsize and inuse boundaries are mostly
+ * ignored. And therefore no slab options that rely on these boundaries
+ * may be used with merged slabcaches.
+ */
+
+static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p)
+{
+ unsigned long off = s->inuse; /* The end of info */
+
+ if (s->offset)
+ /* Freepointer is placed after the object. */
+ off += sizeof(void *);
+
+ if (s->flags & SLAB_STORE_USER)
+ /* We also have user information there */
+ off += 2 * sizeof(struct track);
+
+ if (s->size == off)
+ return 1;
+
+ return check_bytes_and_report(s, page, p, "Object padding",
+ p + off, POISON_INUSE, s->size - off);
+}
+
+/* Check the pad bytes at the end of a slab page */
+static int slab_pad_check(struct kmem_cache *s, struct page *page)
+{
+ u8 *start;
+ u8 *fault;
+ u8 *end;
+ int length;
+ int remainder;
+
+ if (!(s->flags & SLAB_POISON))
+ return 1;
+
+ start = page_address(page);
+ length = (PAGE_SIZE << compound_order(page)) - s->reserved;
+ end = start + length;
+ remainder = length % s->size;
+ if (!remainder)
+ return 1;
+
+ fault = memchr_inv(end - remainder, POISON_INUSE, remainder);
+ if (!fault)
+ return 1;
+ while (end > fault && end[-1] == POISON_INUSE)
+ end--;
+
+ slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
+ print_section("Padding ", end - remainder, remainder);
+
+ restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end);
+ return 0;
+}
+
+static int check_object(struct kmem_cache *s, struct page *page,
+ void *object, u8 val)
+{
+ u8 *p = object;
+ u8 *endobject = object + s->objsize;
+
+ if (s->flags & SLAB_RED_ZONE) {
+ if (!check_bytes_and_report(s, page, object, "Redzone",
+ endobject, val, s->inuse - s->objsize))
+ return 0;
+ } else {
+ if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) {
+ check_bytes_and_report(s, page, p, "Alignment padding",
+ endobject, POISON_INUSE, s->inuse - s->objsize);
+ }
+ }
+
+ if (s->flags & SLAB_POISON) {
+ if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON) &&
+ (!check_bytes_and_report(s, page, p, "Poison", p,
+ POISON_FREE, s->objsize - 1) ||
+ !check_bytes_and_report(s, page, p, "Poison",
+ p + s->objsize - 1, POISON_END, 1)))
+ return 0;
+ /*
+ * check_pad_bytes cleans up on its own.
+ */
+ check_pad_bytes(s, page, p);
+ }
+
+ if (!s->offset && val == SLUB_RED_ACTIVE)
+ /*
+ * Object and freepointer overlap. Cannot check
+ * freepointer while object is allocated.
+ */
+ return 1;
+
+ /* Check free pointer validity */
+ if (!check_valid_pointer(s, page, get_freepointer(s, p))) {
+ object_err(s, page, p, "Freepointer corrupt");
+ /*
+ * No choice but to zap it and thus lose the remainder
+ * of the free objects in this slab. May cause
+ * another error because the object count is now wrong.
+ */
+ set_freepointer(s, p, NULL);
+ return 0;
+ }
+ return 1;
+}
+
+static int check_slab(struct kmem_cache *s, struct page *page)
+{
+ int maxobj;
+
+ VM_BUG_ON(!irqs_disabled());
+
+ if (!PageSlab(page)) {
+ slab_err(s, page, "Not a valid slab page");
+ return 0;
+ }
+
+ maxobj = order_objects(compound_order(page), s->size, s->reserved);
+ if (page->objects > maxobj) {
+ slab_err(s, page, "objects %u > max %u",
+ s->name, page->objects, maxobj);
+ return 0;
+ }
+ if (page->inuse > page->objects) {
+ slab_err(s, page, "inuse %u > max %u",
+ s->name, page->inuse, page->objects);
+ return 0;
+ }
+ /* Slab_pad_check fixes things up after itself */
+ slab_pad_check(s, page);
+ return 1;
+}
+
+/*
+ * Determine if a certain object on a page is on the freelist. Must hold the
+ * slab lock to guarantee that the chains are in a consistent state.
+ */
+static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
+{
+ int nr = 0;
+ void *fp;
+ void *object = NULL;
+ unsigned long max_objects;
+
+ fp = page->freelist;
+ while (fp && nr <= page->objects) {
+ if (fp == search)
+ return 1;
+ if (!check_valid_pointer(s, page, fp)) {
+ if (object) {
+ object_err(s, page, object,
+ "Freechain corrupt");
+ set_freepointer(s, object, NULL);
+ break;
+ } else {
+ slab_err(s, page, "Freepointer corrupt");
+ page->freelist = NULL;
+ page->inuse = page->objects;
+ slab_fix(s, "Freelist cleared");
+ return 0;
+ }
+ break;
+ }
+ object = fp;
+ fp = get_freepointer(s, object);
+ nr++;
+ }
+
+ max_objects = order_objects(compound_order(page), s->size, s->reserved);
+ if (max_objects > MAX_OBJS_PER_PAGE)
+ max_objects = MAX_OBJS_PER_PAGE;
+
+ if (page->objects != max_objects) {
+ slab_err(s, page, "Wrong number of objects. Found %d but "
+ "should be %d", page->objects, max_objects);
+ page->objects = max_objects;
+ slab_fix(s, "Number of objects adjusted.");
+ }
+ if (page->inuse != page->objects - nr) {
+ slab_err(s, page, "Wrong object count. Counter is %d but "
+ "counted were %d", page->inuse, page->objects - nr);
+ page->inuse = page->objects - nr;
+ slab_fix(s, "Object count adjusted.");
+ }
+ return search == NULL;
+}
+
+static void trace(struct kmem_cache *s, struct page *page, void *object,
+ int alloc)
+{
+ if (s->flags & SLAB_TRACE) {
+ printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
+ s->name,
+ alloc ? "alloc" : "free",
+ object, page->inuse,
+ page->freelist);
+
+ if (!alloc)
+ print_section("Object ", (void *)object, s->objsize);
+
+ dump_stack();
+ }
+}
+
+/*
+ * Hooks for other subsystems that check memory allocations. In a typical
+ * production configuration these hooks all should produce no code at all.
+ */
+static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
+{
+ flags &= gfp_allowed_mask;
+ lockdep_trace_alloc(flags);
+ might_sleep_if(flags & __GFP_WAIT);
+
+ return should_failslab(s->objsize, flags, s->flags);
+}
+
+static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, void *object)
+{
+ flags &= gfp_allowed_mask;
+ kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
+ kmemleak_alloc_recursive(object, s->objsize, 1, s->flags, flags);
+}
+
+static inline void slab_free_hook(struct kmem_cache *s, void *x)
+{
+ kmemleak_free_recursive(x, s->flags);
+
+ /*
+ * Trouble is that we may no longer disable interupts in the fast path
+ * So in order to make the debug calls that expect irqs to be
+ * disabled we need to disable interrupts temporarily.
+ */
+#if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
+ {
+ unsigned long flags;
+
+ local_irq_save(flags);
+ kmemcheck_slab_free(s, x, s->objsize);
+ debug_check_no_locks_freed(x, s->objsize);
+ local_irq_restore(flags);
+ }
+#endif
+ if (!(s->flags & SLAB_DEBUG_OBJECTS))
+ debug_check_no_obj_freed(x, s->objsize);
+}
+
+/*
+ * Tracking of fully allocated slabs for debugging purposes.
+ *
+ * list_lock must be held.
+ */
+static void add_full(struct kmem_cache *s,
+ struct kmem_cache_node *n, struct page *page)
+{
+ if (!(s->flags & SLAB_STORE_USER))
+ return;
+
+ list_add(&page->lru, &n->full);
+}
+
+/*
+ * list_lock must be held.
+ */
+static void remove_full(struct kmem_cache *s, struct page *page)
+{
+ if (!(s->flags & SLAB_STORE_USER))
+ return;
+
+ list_del(&page->lru);
+}
+
+/* Tracking of the number of slabs for debugging purposes */
+static inline unsigned long slabs_node(struct kmem_cache *s, int node)
+{
+ struct kmem_cache_node *n = get_node(s, node);
+
+ return atomic_long_read(&n->nr_slabs);
+}
+
+static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
+{
+ return atomic_long_read(&n->nr_slabs);
+}
+
+static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
+{
+ struct kmem_cache_node *n = get_node(s, node);
+
+ /*
+ * May be called early in order to allocate a slab for the
+ * kmem_cache_node structure. Solve the chicken-egg
+ * dilemma by deferring the increment of the count during
+ * bootstrap (see early_kmem_cache_node_alloc).
+ */
+ if (n) {
+ atomic_long_inc(&n->nr_slabs);
+ atomic_long_add(objects, &n->total_objects);
+ }
+}
+static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
+{
+ struct kmem_cache_node *n = get_node(s, node);
+
+ atomic_long_dec(&n->nr_slabs);
+ atomic_long_sub(objects, &n->total_objects);
+}
+
+/* Object debug checks for alloc/free paths */
+static void setup_object_debug(struct kmem_cache *s, struct page *page,
+ void *object)
+{
+ if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
+ return;
+
+ init_object(s, object, SLUB_RED_INACTIVE);
+ init_tracking(s, object);
+}
+
+static noinline int alloc_debug_processing(struct kmem_cache *s, struct page *page,
+ void *object, unsigned long addr)
+{
+ if (!check_slab(s, page))
+ goto bad;
+
+ if (!check_valid_pointer(s, page, object)) {
+ object_err(s, page, object, "Freelist Pointer check fails");
+ goto bad;
+ }
+
+ if (!check_object(s, page, object, SLUB_RED_INACTIVE))
+ goto bad;
+
+ /* Success perform special debug activities for allocs */
+ if (s->flags & SLAB_STORE_USER)
+ set_track(s, object, TRACK_ALLOC, addr);
+ trace(s, page, object, 1);
+ init_object(s, object, SLUB_RED_ACTIVE);
+ return 1;
+
+bad:
+ if (PageSlab(page)) {
+ /*
+ * If this is a slab page then lets do the best we can
+ * to avoid issues in the future. Marking all objects
+ * as used avoids touching the remaining objects.
+ */
+ slab_fix(s, "Marking all objects used");
+ page->inuse = page->objects;
+ page->freelist = NULL;
+ }
+ return 0;
+}
+
+static noinline int free_debug_processing(struct kmem_cache *s,
+ struct page *page, void *object, unsigned long addr)
+{
+ unsigned long flags;
+ int rc = 0;
+
+ local_irq_save(flags);
+ slab_lock(page);
+
+ if (!check_slab(s, page))
+ goto fail;
+
+ if (!check_valid_pointer(s, page, object)) {
+ slab_err(s, page, "Invalid object pointer 0x%p", object);
+ goto fail;
+ }
+
+ if (on_freelist(s, page, object)) {
+ object_err(s, page, object, "Object already free");
+ goto fail;
+ }
+
+ if (!check_object(s, page, object, SLUB_RED_ACTIVE))
+ goto out;
+
+ if (unlikely(s != page->slab)) {
+ if (!PageSlab(page)) {
+ slab_err(s, page, "Attempt to free object(0x%p) "
+ "outside of slab", object);
+ } else if (!page->slab) {
+ printk(KERN_ERR
+ "SLUB <none>: no slab for object 0x%p.\n",
+ object);
+ dump_stack();
+ } else
+ object_err(s, page, object,
+ "page slab pointer corrupt.");
+ goto fail;
+ }
+
+ if (s->flags & SLAB_STORE_USER)
+ set_track(s, object, TRACK_FREE, addr);
+ trace(s, page, object, 0);
+ init_object(s, object, SLUB_RED_INACTIVE);
+ rc = 1;
+out:
+ slab_unlock(page);
+ local_irq_restore(flags);
+ return rc;
+
+fail:
+ slab_fix(s, "Object at 0x%p not freed", object);
+ goto out;
+}
+
+static int __init setup_slub_debug(char *str)
+{
+ slub_debug = DEBUG_DEFAULT_FLAGS;
+ if (*str++ != '=' || !*str)
+ /*
+ * No options specified. Switch on full debugging.
+ */
+ goto out;
+
+ if (*str == ',')
+ /*
+ * No options but restriction on slabs. This means full
+ * debugging for slabs matching a pattern.
+ */
+ goto check_slabs;
+
+ if (tolower(*str) == 'o') {
+ /*
+ * Avoid enabling debugging on caches if its minimum order
+ * would increase as a result.
+ */
+ disable_higher_order_debug = 1;
+ goto out;
+ }
+
+ slub_debug = 0;
+ if (*str == '-')
+ /*
+ * Switch off all debugging measures.
+ */
+ goto out;
+
+ /*
+ * Determine which debug features should be switched on
+ */
+ for (; *str && *str != ','; str++) {
+ switch (tolower(*str)) {
+ case 'f':
+ slub_debug |= SLAB_DEBUG_FREE;
+ break;
+ case 'z':
+ slub_debug |= SLAB_RED_ZONE;
+ break;
+ case 'p':
+ slub_debug |= SLAB_POISON;
+ break;
+ case 'u':
+ slub_debug |= SLAB_STORE_USER;
+ break;
+ case 't':
+ slub_debug |= SLAB_TRACE;
+ break;
+ case 'a':
+ slub_debug |= SLAB_FAILSLAB;
+ break;
+ default:
+ printk(KERN_ERR "slub_debug option '%c' "
+ "unknown. skipped\n", *str);
+ }
+ }
+
+check_slabs:
+ if (*str == ',')
+ slub_debug_slabs = str + 1;
+out:
+ return 1;
+}
+
+__setup("slub_debug", setup_slub_debug);
+
+static unsigned long kmem_cache_flags(unsigned long objsize,
+ unsigned long flags, const char *name,
+ void (*ctor)(void *))
+{
+ /*
+ * Enable debugging if selected on the kernel commandline.
+ */
+ if (slub_debug && (!slub_debug_slabs ||
+ !strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs))))
+ flags |= slub_debug;
+
+ return flags;
+}
+#else
+static inline void setup_object_debug(struct kmem_cache *s,
+ struct page *page, void *object) {}
+
+static inline int alloc_debug_processing(struct kmem_cache *s,
+ struct page *page, void *object, unsigned long addr) { return 0; }
+
+static inline int free_debug_processing(struct kmem_cache *s,
+ struct page *page, void *object, unsigned long addr) { return 0; }
+
+static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
+ { return 1; }
+static inline int check_object(struct kmem_cache *s, struct page *page,
+ void *object, u8 val) { return 1; }
+static inline void add_full(struct kmem_cache *s, struct kmem_cache_node *n,
+ struct page *page) {}
+static inline void remove_full(struct kmem_cache *s, struct page *page) {}
+static inline unsigned long kmem_cache_flags(unsigned long objsize,
+ unsigned long flags, const char *name,
+ void (*ctor)(void *))
+{
+ return flags;
+}
+#define slub_debug 0
+
+#define disable_higher_order_debug 0
+
+static inline unsigned long slabs_node(struct kmem_cache *s, int node)
+ { return 0; }
+static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
+ { return 0; }
+static inline void inc_slabs_node(struct kmem_cache *s, int node,
+ int objects) {}
+static inline void dec_slabs_node(struct kmem_cache *s, int node,
+ int objects) {}
+
+static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
+ { return 0; }
+
+static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
+ void *object) {}
+
+static inline void slab_free_hook(struct kmem_cache *s, void *x) {}
+
+#endif /* CONFIG_SLUB_DEBUG */
+
+static void setup_object(struct kmem_cache *s, struct page *page,
+ void *object)
+{
+ setup_object_debug(s, page, object);
+ if (unlikely(s->ctor))
+ s->ctor(object);
+}
+
+/*
+ * Slab allocation and freeing
+ */
+static inline struct page *alloc_slab_page(gfp_t flags, int node,
+ struct kmem_cache_order_objects oo)
+{
+ int order = oo_order(oo);
+
+ flags |= __GFP_NOTRACK;
+
+ if (node == NUMA_NO_NODE)
+ return alloc_pages(flags, order);
+ else
+ return alloc_pages_exact_node(node, flags, order);
+}
+
+static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
+{
+ struct page *page;
+ struct kmem_cache_order_objects oo = s->oo;
+ gfp_t alloc_gfp;
+ void *start, *last, *p;
+ int idx, order;
+
+ flags &= gfp_allowed_mask;
+
+ if (flags & __GFP_WAIT)
+ local_irq_enable();
+
+ flags |= s->allocflags;
+
+ /*
+ * Let the initial higher-order allocation fail under memory pressure
+ * so we fall-back to the minimum order allocation.
+ */
+ alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL;
+
+ page = alloc_slab_page(alloc_gfp, node, oo);
+ if (unlikely(!page)) {
+ oo = s->min;
+ /*
+ * Allocation may have failed due to fragmentation.
+ * Try a lower order alloc if possible
+ */
+ page = alloc_slab_page(flags, node, oo);
+ if (unlikely(!page))
+ goto out;
+ stat(s, ORDER_FALLBACK);
+ }
+
+ if (kmemcheck_enabled
+ && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
+ int pages = 1 << oo_order(oo);
+
+ kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
+
+ /*
+ * Objects from caches that have a constructor don't get
+ * cleared when they're allocated, so we need to do it here.
+ */
+ if (s->ctor)
+ kmemcheck_mark_uninitialized_pages(page, pages);
+ else
+ kmemcheck_mark_unallocated_pages(page, pages);
+ }
+
+ page->objects = oo_objects(oo);
+ page->slab = s;
+ page->flags |= 1 << PG_slab;
+
+ start = page_address(page);
+
+ if (unlikely(s->flags & SLAB_POISON))
+ memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page));
+
+ last = start;
+ for_each_object(p, s, start, page->objects) {
+ setup_object(s, page, last);
+ set_freepointer(s, last, p);
+ last = p;
+ }
+ setup_object(s, page, last);
+ set_freepointer(s, last, NULL);
+
+ page->freelist = start;
+ page->inuse = page->objects;
+ page->frozen = 1;
+
+out:
+ if (flags & __GFP_WAIT)
+ local_irq_disable();
+ if (!page)
+ return NULL;
+
+ mod_zone_page_state(page_zone(page),
+ (s->flags & SLAB_RECLAIM_ACCOUNT) ?
+ NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
+ 1 << oo_order(oo));
+
+ inc_slabs_node(s, page_to_nid(page), page->objects);
+
+ return page;
+}
+
+static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
+{
+ if (unlikely(flags & GFP_SLAB_BUG_MASK)) {
+ pr_emerg("gfp: %u\n", flags & GFP_SLAB_BUG_MASK);
+ BUG();
+ }
+
+ return allocate_slab(s,
+ flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
+}
+
+static void __free_slab(struct kmem_cache *s, struct page *page)
+{
+ int order = compound_order(page);
+ int pages = 1 << order;
+
+ if (kmem_cache_debug(s)) {
+ void *p;
+
+ slab_pad_check(s, page);
+ for_each_object(p, s, page_address(page),
+ page->objects)
+ check_object(s, page, p, SLUB_RED_INACTIVE);
+ }
+
+ kmemcheck_free_shadow(page, compound_order(page));
+
+ mod_zone_page_state(page_zone(page),
+ (s->flags & SLAB_RECLAIM_ACCOUNT) ?
+ NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
+ -pages);
+
+ __ClearPageSlab(page);
+ reset_page_mapcount(page);
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed_slab += pages;
+ __free_pages(page, order);
+}
+
+#define need_reserve_slab_rcu \
+ (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
+
+static void rcu_free_slab(struct rcu_head *h)
+{
+ struct page *page;
+
+ if (need_reserve_slab_rcu)
+ page = virt_to_head_page(h);
+ else
+ page = container_of((struct list_head *)h, struct page, lru);
+
+ __free_slab(page->slab, page);
+}
+
+static void free_slab(struct kmem_cache *s, struct page *page)
+{
+ if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
+ struct rcu_head *head;
+
+ if (need_reserve_slab_rcu) {
+ int order = compound_order(page);
+ int offset = (PAGE_SIZE << order) - s->reserved;
+
+ VM_BUG_ON(s->reserved != sizeof(*head));
+ head = page_address(page) + offset;
+ } else {
+ /*
+ * RCU free overloads the RCU head over the LRU
+ */
+ head = (void *)&page->lru;
+ }
+
+ call_rcu(head, rcu_free_slab);
+ } else
+ __free_slab(s, page);
+}
+
+static void discard_slab(struct kmem_cache *s, struct page *page)
+{
+ dec_slabs_node(s, page_to_nid(page), page->objects);
+ free_slab(s, page);
+}
+
+/*
+ * Management of partially allocated slabs.
+ *
+ * list_lock must be held.
+ */
+static inline void add_partial(struct kmem_cache_node *n,
+ struct page *page, int tail)
+{
+ n->nr_partial++;
+ if (tail == DEACTIVATE_TO_TAIL)
+ list_add_tail(&page->lru, &n->partial);
+ else
+ list_add(&page->lru, &n->partial);
+}
+
+/*
+ * list_lock must be held.
+ */
+static inline void remove_partial(struct kmem_cache_node *n,
+ struct page *page)
+{
+ list_del(&page->lru);
+ n->nr_partial--;
+}
+
+/*
+ * Lock slab, remove from the partial list and put the object into the
+ * per cpu freelist.
+ *
+ * Returns a list of objects or NULL if it fails.
+ *
+ * Must hold list_lock.
+ */
+static inline void *acquire_slab(struct kmem_cache *s,
+ struct kmem_cache_node *n, struct page *page,
+ int mode)
+{
+ void *freelist;
+ unsigned long counters;
+ struct page new;
+
+ /*
+ * Zap the freelist and set the frozen bit.
+ * The old freelist is the list of objects for the
+ * per cpu allocation list.
+ */
+ do {
+ freelist = page->freelist;
+ counters = page->counters;
+ new.counters = counters;
+ if (mode) {
+ new.inuse = page->objects;
+ new.freelist = NULL;
+ } else {
+ new.freelist = freelist;
+ }
+
+ VM_BUG_ON(new.frozen);
+ new.frozen = 1;
+
+ } while (!__cmpxchg_double_slab(s, page,
+ freelist, counters,
+ new.freelist, new.counters,
+ "lock and freeze"));
+
+ remove_partial(n, page);
+ return freelist;
+}
+
+static int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain);
+
+/*
+ * Try to allocate a partial slab from a specific node.
+ */
+static void *get_partial_node(struct kmem_cache *s,
+ struct kmem_cache_node *n, struct kmem_cache_cpu *c)
+{
+ struct page *page, *page2;
+ void *object = NULL;
+
+ /*
+ * Racy check. If we mistakenly see no partial slabs then we
+ * just allocate an empty slab. If we mistakenly try to get a
+ * partial slab and there is none available then get_partials()
+ * will return NULL.
+ */
+ if (!n || !n->nr_partial)
+ return NULL;
+
+ spin_lock(&n->list_lock);
+ list_for_each_entry_safe(page, page2, &n->partial, lru) {
+ void *t = acquire_slab(s, n, page, object == NULL);
+ int available;
+
+ if (!t)
+ break;
+
+ if (!object) {
+ c->page = page;
+ c->node = page_to_nid(page);
+ stat(s, ALLOC_FROM_PARTIAL);
+ object = t;
+ available = page->objects - page->inuse;
+ } else {
+ available = put_cpu_partial(s, page, 0);
+ stat(s, CPU_PARTIAL_NODE);
+ }
+ if (kmem_cache_debug(s) || available > s->cpu_partial / 2)
+ break;
+
+ }
+ spin_unlock(&n->list_lock);
+ return object;
+}
+
+/*
+ * Get a page from somewhere. Search in increasing NUMA distances.
+ */
+static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags,
+ struct kmem_cache_cpu *c)
+{
+#ifdef CONFIG_NUMA
+ struct zonelist *zonelist;
+ struct zoneref *z;
+ struct zone *zone;
+ enum zone_type high_zoneidx = gfp_zone(flags);
+ void *object;
+ unsigned int cpuset_mems_cookie;
+
+ /*
+ * The defrag ratio allows a configuration of the tradeoffs between
+ * inter node defragmentation and node local allocations. A lower
+ * defrag_ratio increases the tendency to do local allocations
+ * instead of attempting to obtain partial slabs from other nodes.
+ *
+ * If the defrag_ratio is set to 0 then kmalloc() always
+ * returns node local objects. If the ratio is higher then kmalloc()
+ * may return off node objects because partial slabs are obtained
+ * from other nodes and filled up.
+ *
+ * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
+ * defrag_ratio = 1000) then every (well almost) allocation will
+ * first attempt to defrag slab caches on other nodes. This means
+ * scanning over all nodes to look for partial slabs which may be
+ * expensive if we do it every time we are trying to find a slab
+ * with available objects.
+ */
+ if (!s->remote_node_defrag_ratio ||
+ get_cycles() % 1024 > s->remote_node_defrag_ratio)
+ return NULL;
+
+ do {
+ cpuset_mems_cookie = get_mems_allowed();
+ zonelist = node_zonelist(slab_node(), flags);
+ for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
+ struct kmem_cache_node *n;
+
+ n = get_node(s, zone_to_nid(zone));
+
+ if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
+ n->nr_partial > s->min_partial) {
+ object = get_partial_node(s, n, c);
+ if (object) {
+ /*
+ * Return the object even if
+ * put_mems_allowed indicated that
+ * the cpuset mems_allowed was
+ * updated in parallel. It's a
+ * harmless race between the alloc
+ * and the cpuset update.
+ */
+ put_mems_allowed(cpuset_mems_cookie);
+ return object;
+ }
+ }
+ }
+ } while (!put_mems_allowed(cpuset_mems_cookie));
+#endif
+ return NULL;
+}
+
+/*
+ * Get a partial page, lock it and return it.
+ */
+static void *get_partial(struct kmem_cache *s, gfp_t flags, int node,
+ struct kmem_cache_cpu *c)
+{
+ void *object;
+ int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node;
+
+ object = get_partial_node(s, get_node(s, searchnode), c);
+ if (object || node != NUMA_NO_NODE)
+ return object;
+
+ return get_any_partial(s, flags, c);
+}
+
+#ifdef CONFIG_PREEMPT
+/*
+ * Calculate the next globally unique transaction for disambiguiation
+ * during cmpxchg. The transactions start with the cpu number and are then
+ * incremented by CONFIG_NR_CPUS.
+ */
+#define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS)
+#else
+/*
+ * No preemption supported therefore also no need to check for
+ * different cpus.
+ */
+#define TID_STEP 1
+#endif
+
+static inline unsigned long next_tid(unsigned long tid)
+{
+ return tid + TID_STEP;
+}
+
+static inline unsigned int tid_to_cpu(unsigned long tid)
+{
+ return tid % TID_STEP;
+}
+
+static inline unsigned long tid_to_event(unsigned long tid)
+{
+ return tid / TID_STEP;
+}
+
+static inline unsigned int init_tid(int cpu)
+{
+ return cpu;
+}
+
+static inline void note_cmpxchg_failure(const char *n,
+ const struct kmem_cache *s, unsigned long tid)
+{
+#ifdef SLUB_DEBUG_CMPXCHG
+ unsigned long actual_tid = __this_cpu_read(s->cpu_slab->tid);
+
+ printk(KERN_INFO "%s %s: cmpxchg redo ", n, s->name);
+
+#ifdef CONFIG_PREEMPT
+ if (tid_to_cpu(tid) != tid_to_cpu(actual_tid))
+ printk("due to cpu change %d -> %d\n",
+ tid_to_cpu(tid), tid_to_cpu(actual_tid));
+ else
+#endif
+ if (tid_to_event(tid) != tid_to_event(actual_tid))
+ printk("due to cpu running other code. Event %ld->%ld\n",
+ tid_to_event(tid), tid_to_event(actual_tid));
+ else
+ printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
+ actual_tid, tid, next_tid(tid));
+#endif
+ stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
+}
+
+void init_kmem_cache_cpus(struct kmem_cache *s)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu);
+}
+
+/*
+ * Remove the cpu slab
+ */
+static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
+{
+ enum slab_modes { M_NONE, M_PARTIAL, M_FULL, M_FREE };
+ struct page *page = c->page;
+ struct kmem_cache_node *n = get_node(s, page_to_nid(page));
+ int lock = 0;
+ enum slab_modes l = M_NONE, m = M_NONE;
+ void *freelist;
+ void *nextfree;
+ int tail = DEACTIVATE_TO_HEAD;
+ struct page new;
+ struct page old;
+
+ if (page->freelist) {
+ stat(s, DEACTIVATE_REMOTE_FREES);
+ tail = DEACTIVATE_TO_TAIL;
+ }
+
+ c->tid = next_tid(c->tid);
+ c->page = NULL;
+ freelist = c->freelist;
+ c->freelist = NULL;
+
+ /*
+ * Stage one: Free all available per cpu objects back
+ * to the page freelist while it is still frozen. Leave the
+ * last one.
+ *
+ * There is no need to take the list->lock because the page
+ * is still frozen.
+ */
+ while (freelist && (nextfree = get_freepointer(s, freelist))) {
+ void *prior;
+ unsigned long counters;
+
+ do {
+ prior = page->freelist;
+ counters = page->counters;
+ set_freepointer(s, freelist, prior);
+ new.counters = counters;
+ new.inuse--;
+ VM_BUG_ON(!new.frozen);
+
+ } while (!__cmpxchg_double_slab(s, page,
+ prior, counters,
+ freelist, new.counters,
+ "drain percpu freelist"));
+
+ freelist = nextfree;
+ }
+
+ /*
+ * Stage two: Ensure that the page is unfrozen while the
+ * list presence reflects the actual number of objects
+ * during unfreeze.
+ *
+ * We setup the list membership and then perform a cmpxchg
+ * with the count. If there is a mismatch then the page
+ * is not unfrozen but the page is on the wrong list.
+ *
+ * Then we restart the process which may have to remove
+ * the page from the list that we just put it on again
+ * because the number of objects in the slab may have
+ * changed.
+ */
+redo:
+
+ old.freelist = page->freelist;
+ old.counters = page->counters;
+ VM_BUG_ON(!old.frozen);
+
+ /* Determine target state of the slab */
+ new.counters = old.counters;
+ if (freelist) {
+ new.inuse--;
+ set_freepointer(s, freelist, old.freelist);
+ new.freelist = freelist;
+ } else
+ new.freelist = old.freelist;
+
+ new.frozen = 0;
+
+ if (!new.inuse && n->nr_partial > s->min_partial)
+ m = M_FREE;
+ else if (new.freelist) {
+ m = M_PARTIAL;
+ if (!lock) {
+ lock = 1;
+ /*
+ * Taking the spinlock removes the possiblity
+ * that acquire_slab() will see a slab page that
+ * is frozen
+ */
+ spin_lock(&n->list_lock);
+ }
+ } else {
+ m = M_FULL;
+ if (kmem_cache_debug(s) && !lock) {
+ lock = 1;
+ /*
+ * This also ensures that the scanning of full
+ * slabs from diagnostic functions will not see
+ * any frozen slabs.
+ */
+ spin_lock(&n->list_lock);
+ }
+ }
+
+ if (l != m) {
+
+ if (l == M_PARTIAL)
+
+ remove_partial(n, page);
+
+ else if (l == M_FULL)
+
+ remove_full(s, page);
+
+ if (m == M_PARTIAL) {
+
+ add_partial(n, page, tail);
+ stat(s, tail);
+
+ } else if (m == M_FULL) {
+
+ stat(s, DEACTIVATE_FULL);
+ add_full(s, n, page);
+
+ }
+ }
+
+ l = m;
+ if (!__cmpxchg_double_slab(s, page,
+ old.freelist, old.counters,
+ new.freelist, new.counters,
+ "unfreezing slab"))
+ goto redo;
+
+ if (lock)
+ spin_unlock(&n->list_lock);
+
+ if (m == M_FREE) {
+ stat(s, DEACTIVATE_EMPTY);
+ discard_slab(s, page);
+ stat(s, FREE_SLAB);
+ }
+}
+
+/* Unfreeze all the cpu partial slabs */
+static void unfreeze_partials(struct kmem_cache *s)
+{
+ struct kmem_cache_node *n = NULL, *n2 = NULL;
+ struct kmem_cache_cpu *c = this_cpu_ptr(s->cpu_slab);
+ struct page *page, *discard_page = NULL;
+
+ while ((page = c->partial)) {
+ struct page new;
+ struct page old;
+
+ c->partial = page->next;
+
+ n2 = get_node(s, page_to_nid(page));
+ if (n != n2) {
+ if (n)
+ spin_unlock(&n->list_lock);
+
+ n = n2;
+ spin_lock(&n->list_lock);
+ }
+
+ do {
+
+ old.freelist = page->freelist;
+ old.counters = page->counters;
+ VM_BUG_ON(!old.frozen);
+
+ new.counters = old.counters;
+ new.freelist = old.freelist;
+
+ new.frozen = 0;
+
+ } while (!cmpxchg_double_slab(s, page,
+ old.freelist, old.counters,
+ new.freelist, new.counters,
+ "unfreezing slab"));
+
+ if (unlikely(!new.inuse && n->nr_partial > s->min_partial)) {
+ page->next = discard_page;
+ discard_page = page;
+ } else {
+ add_partial(n, page, DEACTIVATE_TO_TAIL);
+ stat(s, FREE_ADD_PARTIAL);
+ }
+ }
+
+ if (n)
+ spin_unlock(&n->list_lock);
+
+ while (discard_page) {
+ page = discard_page;
+ discard_page = discard_page->next;
+
+ stat(s, DEACTIVATE_EMPTY);
+ discard_slab(s, page);
+ stat(s, FREE_SLAB);
+ }
+}
+
+/*
+ * Put a page that was just frozen (in __slab_free) into a partial page
+ * slot if available. This is done without interrupts disabled and without
+ * preemption disabled. The cmpxchg is racy and may put the partial page
+ * onto a random cpus partial slot.
+ *
+ * If we did not find a slot then simply move all the partials to the
+ * per node partial list.
+ */
+int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
+{
+ struct page *oldpage;
+ int pages;
+ int pobjects;
+
+ do {
+ pages = 0;
+ pobjects = 0;
+ oldpage = this_cpu_read(s->cpu_slab->partial);
+
+ if (oldpage) {
+ pobjects = oldpage->pobjects;
+ pages = oldpage->pages;
+ if (drain && pobjects > s->cpu_partial) {
+ unsigned long flags;
+ /*
+ * partial array is full. Move the existing
+ * set to the per node partial list.
+ */
+ local_irq_save(flags);
+ unfreeze_partials(s);
+ local_irq_restore(flags);
+ pobjects = 0;
+ pages = 0;
+ stat(s, CPU_PARTIAL_DRAIN);
+ }
+ }
+
+ pages++;
+ pobjects += page->objects - page->inuse;
+
+ page->pages = pages;
+ page->pobjects = pobjects;
+ page->next = oldpage;
+
+ } while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) != oldpage);
+ return pobjects;
+}
+
+static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
+{
+ stat(s, CPUSLAB_FLUSH);
+ deactivate_slab(s, c);
+}
+
+/*
+ * Flush cpu slab.
+ *
+ * Called from IPI handler with interrupts disabled.
+ */
+static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
+{
+ struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
+
+ if (likely(c)) {
+ if (c->page)
+ flush_slab(s, c);
+
+ unfreeze_partials(s);
+ }
+}
+
+static void flush_cpu_slab(void *d)
+{
+ struct kmem_cache *s = d;
+
+ __flush_cpu_slab(s, smp_processor_id());
+}
+
+static bool has_cpu_slab(int cpu, void *info)
+{
+ struct kmem_cache *s = info;
+ struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
+
+ return c->page || c->partial;
+}
+
+static void flush_all(struct kmem_cache *s)
+{
+ on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1, GFP_ATOMIC);
+}
+
+/*
+ * Check if the objects in a per cpu structure fit numa
+ * locality expectations.
+ */
+static inline int node_match(struct kmem_cache_cpu *c, int node)
+{
+#ifdef CONFIG_NUMA
+ if (node != NUMA_NO_NODE && c->node != node)
+ return 0;
+#endif
+ return 1;
+}
+
+static int count_free(struct page *page)
+{
+ return page->objects - page->inuse;
+}
+
+static unsigned long count_partial(struct kmem_cache_node *n,
+ int (*get_count)(struct page *))
+{
+ unsigned long flags;
+ unsigned long x = 0;
+ struct page *page;
+
+ spin_lock_irqsave(&n->list_lock, flags);
+ list_for_each_entry(page, &n->partial, lru)
+ x += get_count(page);
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ return x;
+}
+
+static inline unsigned long node_nr_objs(struct kmem_cache_node *n)
+{
+#ifdef CONFIG_SLUB_DEBUG
+ return atomic_long_read(&n->total_objects);
+#else
+ return 0;
+#endif
+}
+
+static noinline void
+slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
+{
+ int node;
+
+ printk(KERN_WARNING
+ "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n",
+ nid, gfpflags);
+ printk(KERN_WARNING " cache: %s, object size: %d, buffer size: %d, "
+ "default order: %d, min order: %d\n", s->name, s->objsize,
+ s->size, oo_order(s->oo), oo_order(s->min));
+
+ if (oo_order(s->min) > get_order(s->objsize))
+ printk(KERN_WARNING " %s debugging increased min order, use "
+ "slub_debug=O to disable.\n", s->name);
+
+ for_each_online_node(node) {
+ struct kmem_cache_node *n = get_node(s, node);
+ unsigned long nr_slabs;
+ unsigned long nr_objs;
+ unsigned long nr_free;
+
+ if (!n)
+ continue;
+
+ nr_free = count_partial(n, count_free);
+ nr_slabs = node_nr_slabs(n);
+ nr_objs = node_nr_objs(n);
+
+ printk(KERN_WARNING
+ " node %d: slabs: %ld, objs: %ld, free: %ld\n",
+ node, nr_slabs, nr_objs, nr_free);
+ }
+}
+
+static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags,
+ int node, struct kmem_cache_cpu **pc)
+{
+ void *object;
+ struct kmem_cache_cpu *c;
+ struct page *page = new_slab(s, flags, node);
+
+ if (page) {
+ c = __this_cpu_ptr(s->cpu_slab);
+ if (c->page)
+ flush_slab(s, c);
+
+ /*
+ * No other reference to the page yet so we can
+ * muck around with it freely without cmpxchg
+ */
+ object = page->freelist;
+ page->freelist = NULL;
+
+ stat(s, ALLOC_SLAB);
+ c->node = page_to_nid(page);
+ c->page = page;
+ *pc = c;
+ } else
+ object = NULL;
+
+ return object;
+}
+
+/*
+ * Check the page->freelist of a page and either transfer the freelist to the per cpu freelist
+ * or deactivate the page.
+ *
+ * The page is still frozen if the return value is not NULL.
+ *
+ * If this function returns NULL then the page has been unfrozen.
+ */
+static inline void *get_freelist(struct kmem_cache *s, struct page *page)
+{
+ struct page new;
+ unsigned long counters;
+ void *freelist;
+
+ do {
+ freelist = page->freelist;
+ counters = page->counters;
+ new.counters = counters;
+ VM_BUG_ON(!new.frozen);
+
+ new.inuse = page->objects;
+ new.frozen = freelist != NULL;
+
+ } while (!cmpxchg_double_slab(s, page,
+ freelist, counters,
+ NULL, new.counters,
+ "get_freelist"));
+
+ return freelist;
+}
+
+/*
+ * Slow path. The lockless freelist is empty or we need to perform
+ * debugging duties.
+ *
+ * Processing is still very fast if new objects have been freed to the
+ * regular freelist. In that case we simply take over the regular freelist
+ * as the lockless freelist and zap the regular freelist.
+ *
+ * If that is not working then we fall back to the partial lists. We take the
+ * first element of the freelist as the object to allocate now and move the
+ * rest of the freelist to the lockless freelist.
+ *
+ * And if we were unable to get a new slab from the partial slab lists then
+ * we need to allocate a new slab. This is the slowest path since it involves
+ * a call to the page allocator and the setup of a new slab.
+ */
+static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
+ unsigned long addr, struct kmem_cache_cpu *c)
+{
+ void **object;
+ unsigned long flags;
+
+ local_irq_save(flags);
+#ifdef CONFIG_PREEMPT
+ /*
+ * We may have been preempted and rescheduled on a different
+ * cpu before disabling interrupts. Need to reload cpu area
+ * pointer.
+ */
+ c = this_cpu_ptr(s->cpu_slab);
+#endif
+
+ if (!c->page)
+ goto new_slab;
+redo:
+ if (unlikely(!node_match(c, node))) {
+ stat(s, ALLOC_NODE_MISMATCH);
+ deactivate_slab(s, c);
+ goto new_slab;
+ }
+
+ /* must check again c->freelist in case of cpu migration or IRQ */
+ object = c->freelist;
+ if (object)
+ goto load_freelist;
+
+ stat(s, ALLOC_SLOWPATH);
+
+ object = get_freelist(s, c->page);
+
+ if (!object) {
+ c->page = NULL;
+ stat(s, DEACTIVATE_BYPASS);
+ goto new_slab;
+ }
+
+ stat(s, ALLOC_REFILL);
+
+load_freelist:
+ c->freelist = get_freepointer(s, object);
+ c->tid = next_tid(c->tid);
+ local_irq_restore(flags);
+ return object;
+
+new_slab:
+
+ if (c->partial) {
+ c->page = c->partial;
+ c->partial = c->page->next;
+ c->node = page_to_nid(c->page);
+ stat(s, CPU_PARTIAL_ALLOC);
+ c->freelist = NULL;
+ goto redo;
+ }
+
+ /* Then do expensive stuff like retrieving pages from the partial lists */
+ object = get_partial(s, gfpflags, node, c);
+
+ if (unlikely(!object)) {
+
+ object = new_slab_objects(s, gfpflags, node, &c);
+
+ if (unlikely(!object)) {
+ if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
+ slab_out_of_memory(s, gfpflags, node);
+
+ local_irq_restore(flags);
+ return NULL;
+ }
+ }
+
+ if (likely(!kmem_cache_debug(s)))
+ goto load_freelist;
+
+ /* Only entered in the debug case */
+ if (!alloc_debug_processing(s, c->page, object, addr))
+ goto new_slab; /* Slab failed checks. Next slab needed */
+
+ c->freelist = get_freepointer(s, object);
+ deactivate_slab(s, c);
+ c->node = NUMA_NO_NODE;
+ local_irq_restore(flags);
+ return object;
+}
+
+/*
+ * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
+ * have the fastpath folded into their functions. So no function call
+ * overhead for requests that can be satisfied on the fastpath.
+ *
+ * The fastpath works by first checking if the lockless freelist can be used.
+ * If not then __slab_alloc is called for slow processing.
+ *
+ * Otherwise we can simply pick the next object from the lockless free list.
+ */
+static __always_inline void *slab_alloc(struct kmem_cache *s,
+ gfp_t gfpflags, int node, unsigned long addr)
+{
+ void **object;
+ struct kmem_cache_cpu *c;
+ unsigned long tid;
+
+ if (slab_pre_alloc_hook(s, gfpflags))
+ return NULL;
+
+redo:
+
+ /*
+ * Must read kmem_cache cpu data via this cpu ptr. Preemption is
+ * enabled. We may switch back and forth between cpus while
+ * reading from one cpu area. That does not matter as long
+ * as we end up on the original cpu again when doing the cmpxchg.
+ */
+ c = __this_cpu_ptr(s->cpu_slab);
+
+ /*
+ * The transaction ids are globally unique per cpu and per operation on
+ * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
+ * occurs on the right processor and that there was no operation on the
+ * linked list in between.
+ */
+ tid = c->tid;
+ barrier();
+
+ object = c->freelist;
+ if (unlikely(!object || !node_match(c, node)))
+
+ object = __slab_alloc(s, gfpflags, node, addr, c);
+
+ else {
+ void *next_object = get_freepointer_safe(s, object);
+
+ /*
+ * The cmpxchg will only match if there was no additional
+ * operation and if we are on the right processor.
+ *
+ * The cmpxchg does the following atomically (without lock semantics!)
+ * 1. Relocate first pointer to the current per cpu area.
+ * 2. Verify that tid and freelist have not been changed
+ * 3. If they were not changed replace tid and freelist
+ *
+ * Since this is without lock semantics the protection is only against
+ * code executing on this cpu *not* from access by other cpus.
+ */
+ if (unlikely(!this_cpu_cmpxchg_double(
+ s->cpu_slab->freelist, s->cpu_slab->tid,
+ object, tid,
+ next_object, next_tid(tid)))) {
+
+ note_cmpxchg_failure("slab_alloc", s, tid);
+ goto redo;
+ }
+ prefetch_freepointer(s, next_object);
+ stat(s, ALLOC_FASTPATH);
+ }
+
+ if (unlikely(gfpflags & __GFP_ZERO) && object)
+ memset(object, 0, s->objsize);
+
+ slab_post_alloc_hook(s, gfpflags, object);
+
+ return object;
+}
+
+void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
+{
+ void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_);
+
+ trace_kmem_cache_alloc(_RET_IP_, ret, s->objsize, s->size, gfpflags);
+
+ return ret;
+}
+EXPORT_SYMBOL(kmem_cache_alloc);
+
+#ifdef CONFIG_TRACING
+void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
+{
+ void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_);
+ trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags);
+ return ret;
+}
+EXPORT_SYMBOL(kmem_cache_alloc_trace);
+
+void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
+{
+ void *ret = kmalloc_order(size, flags, order);
+ trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
+ return ret;
+}
+EXPORT_SYMBOL(kmalloc_order_trace);
+#endif
+
+#ifdef CONFIG_NUMA
+void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
+{
+ void *ret = slab_alloc(s, gfpflags, node, _RET_IP_);
+
+ trace_kmem_cache_alloc_node(_RET_IP_, ret,
+ s->objsize, s->size, gfpflags, node);
+
+ return ret;
+}
+EXPORT_SYMBOL(kmem_cache_alloc_node);
+
+#ifdef CONFIG_TRACING
+void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
+ gfp_t gfpflags,
+ int node, size_t size)
+{
+ void *ret = slab_alloc(s, gfpflags, node, _RET_IP_);
+
+ trace_kmalloc_node(_RET_IP_, ret,
+ size, s->size, gfpflags, node);
+ return ret;
+}
+EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
+#endif
+#endif
+
+/*
+ * Slow patch handling. This may still be called frequently since objects
+ * have a longer lifetime than the cpu slabs in most processing loads.
+ *
+ * So we still attempt to reduce cache line usage. Just take the slab
+ * lock and free the item. If there is no additional partial page
+ * handling required then we can return immediately.
+ */
+static void __slab_free(struct kmem_cache *s, struct page *page,
+ void *x, unsigned long addr)
+{
+ void *prior;
+ void **object = (void *)x;
+ int was_frozen;
+ int inuse;
+ struct page new;
+ unsigned long counters;
+ struct kmem_cache_node *n = NULL;
+ unsigned long uninitialized_var(flags);
+
+ stat(s, FREE_SLOWPATH);
+
+ if (kmem_cache_debug(s) && !free_debug_processing(s, page, x, addr))
+ return;
+
+ do {
+ prior = page->freelist;
+ counters = page->counters;
+ set_freepointer(s, object, prior);
+ new.counters = counters;
+ was_frozen = new.frozen;
+ new.inuse--;
+ if ((!new.inuse || !prior) && !was_frozen && !n) {
+
+ if (!kmem_cache_debug(s) && !prior)
+
+ /*
+ * Slab was on no list before and will be partially empty
+ * We can defer the list move and instead freeze it.
+ */
+ new.frozen = 1;
+
+ else { /* Needs to be taken off a list */
+
+ n = get_node(s, page_to_nid(page));
+ /*
+ * Speculatively acquire the list_lock.
+ * If the cmpxchg does not succeed then we may
+ * drop the list_lock without any processing.
+ *
+ * Otherwise the list_lock will synchronize with
+ * other processors updating the list of slabs.
+ */
+ spin_lock_irqsave(&n->list_lock, flags);
+
+ }
+ }
+ inuse = new.inuse;
+
+ } while (!cmpxchg_double_slab(s, page,
+ prior, counters,
+ object, new.counters,
+ "__slab_free"));
+
+ if (likely(!n)) {
+
+ /*
+ * If we just froze the page then put it onto the
+ * per cpu partial list.
+ */
+ if (new.frozen && !was_frozen) {
+ put_cpu_partial(s, page, 1);
+ stat(s, CPU_PARTIAL_FREE);
+ }
+ /*
+ * The list lock was not taken therefore no list
+ * activity can be necessary.
+ */
+ if (was_frozen)
+ stat(s, FREE_FROZEN);
+ return;
+ }
+
+ /*
+ * was_frozen may have been set after we acquired the list_lock in
+ * an earlier loop. So we need to check it here again.
+ */
+ if (was_frozen)
+ stat(s, FREE_FROZEN);
+ else {
+ if (unlikely(!inuse && n->nr_partial > s->min_partial))
+ goto slab_empty;
+
+ /*
+ * Objects left in the slab. If it was not on the partial list before
+ * then add it.
+ */
+ if (unlikely(!prior)) {
+ remove_full(s, page);
+ add_partial(n, page, DEACTIVATE_TO_TAIL);
+ stat(s, FREE_ADD_PARTIAL);
+ }
+ }
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ return;
+
+slab_empty:
+ if (prior) {
+ /*
+ * Slab on the partial list.
+ */
+ remove_partial(n, page);
+ stat(s, FREE_REMOVE_PARTIAL);
+ } else
+ /* Slab must be on the full list */
+ remove_full(s, page);
+
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ stat(s, FREE_SLAB);
+ discard_slab(s, page);
+}
+
+/*
+ * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
+ * can perform fastpath freeing without additional function calls.
+ *
+ * The fastpath is only possible if we are freeing to the current cpu slab
+ * of this processor. This typically the case if we have just allocated
+ * the item before.
+ *
+ * If fastpath is not possible then fall back to __slab_free where we deal
+ * with all sorts of special processing.
+ */
+static __always_inline void slab_free(struct kmem_cache *s,
+ struct page *page, void *x, unsigned long addr)
+{
+ void **object = (void *)x;
+ struct kmem_cache_cpu *c;
+ unsigned long tid;
+
+ slab_free_hook(s, x);
+
+redo:
+ /*
+ * Determine the currently cpus per cpu slab.
+ * The cpu may change afterward. However that does not matter since
+ * data is retrieved via this pointer. If we are on the same cpu
+ * during the cmpxchg then the free will succedd.
+ */
+ c = __this_cpu_ptr(s->cpu_slab);
+
+ tid = c->tid;
+ barrier();
+
+ if (likely(page == c->page)) {
+ set_freepointer(s, object, c->freelist);
+
+ if (unlikely(!this_cpu_cmpxchg_double(
+ s->cpu_slab->freelist, s->cpu_slab->tid,
+ c->freelist, tid,
+ object, next_tid(tid)))) {
+
+ note_cmpxchg_failure("slab_free", s, tid);
+ goto redo;
+ }
+ stat(s, FREE_FASTPATH);
+ } else
+ __slab_free(s, page, x, addr);
+
+}
+
+void kmem_cache_free(struct kmem_cache *s, void *x)
+{
+ struct page *page;
+
+ page = virt_to_head_page(x);
+
+ slab_free(s, page, x, _RET_IP_);
+
+ trace_kmem_cache_free(_RET_IP_, x);
+}
+EXPORT_SYMBOL(kmem_cache_free);
+
+/*
+ * Object placement in a slab is made very easy because we always start at
+ * offset 0. If we tune the size of the object to the alignment then we can
+ * get the required alignment by putting one properly sized object after
+ * another.
+ *
+ * Notice that the allocation order determines the sizes of the per cpu
+ * caches. Each processor has always one slab available for allocations.
+ * Increasing the allocation order reduces the number of times that slabs
+ * must be moved on and off the partial lists and is therefore a factor in
+ * locking overhead.
+ */
+
+/*
+ * Mininum / Maximum order of slab pages. This influences locking overhead
+ * and slab fragmentation. A higher order reduces the number of partial slabs
+ * and increases the number of allocations possible without having to
+ * take the list_lock.
+ */
+static int slub_min_order;
+static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER;
+static int slub_min_objects;
+
+/*
+ * Merge control. If this is set then no merging of slab caches will occur.
+ * (Could be removed. This was introduced to pacify the merge skeptics.)
+ */
+static int slub_nomerge;
+
+/*
+ * Calculate the order of allocation given an slab object size.
+ *
+ * The order of allocation has significant impact on performance and other
+ * system components. Generally order 0 allocations should be preferred since
+ * order 0 does not cause fragmentation in the page allocator. Larger objects
+ * be problematic to put into order 0 slabs because there may be too much
+ * unused space left. We go to a higher order if more than 1/16th of the slab
+ * would be wasted.
+ *
+ * In order to reach satisfactory performance we must ensure that a minimum
+ * number of objects is in one slab. Otherwise we may generate too much
+ * activity on the partial lists which requires taking the list_lock. This is
+ * less a concern for large slabs though which are rarely used.
+ *
+ * slub_max_order specifies the order where we begin to stop considering the
+ * number of objects in a slab as critical. If we reach slub_max_order then
+ * we try to keep the page order as low as possible. So we accept more waste
+ * of space in favor of a small page order.
+ *
+ * Higher order allocations also allow the placement of more objects in a
+ * slab and thereby reduce object handling overhead. If the user has
+ * requested a higher mininum order then we start with that one instead of
+ * the smallest order which will fit the object.
+ */
+static inline int slab_order(int size, int min_objects,
+ int max_order, int fract_leftover, int reserved)
+{
+ int order;
+ int rem;
+ int min_order = slub_min_order;
+
+ if (order_objects(min_order, size, reserved) > MAX_OBJS_PER_PAGE)
+ return get_order(size * MAX_OBJS_PER_PAGE) - 1;
+
+ for (order = max(min_order,
+ fls(min_objects * size - 1) - PAGE_SHIFT);
+ order <= max_order; order++) {
+
+ unsigned long slab_size = PAGE_SIZE << order;
+
+ if (slab_size < min_objects * size + reserved)
+ continue;
+
+ rem = (slab_size - reserved) % size;
+
+ if (rem <= slab_size / fract_leftover)
+ break;
+
+ }
+
+ return order;
+}
+
+static inline int calculate_order(int size, int reserved)
+{
+ int order;
+ int min_objects;
+ int fraction;
+ int max_objects;
+
+ /*
+ * Attempt to find best configuration for a slab. This
+ * works by first attempting to generate a layout with
+ * the best configuration and backing off gradually.
+ *
+ * First we reduce the acceptable waste in a slab. Then
+ * we reduce the minimum objects required in a slab.
+ */
+ min_objects = slub_min_objects;
+ if (!min_objects)
+ min_objects = 4 * (fls(nr_cpu_ids) + 1);
+ max_objects = order_objects(slub_max_order, size, reserved);
+ min_objects = min(min_objects, max_objects);
+
+ while (min_objects > 1) {
+ fraction = 16;
+ while (fraction >= 4) {
+ order = slab_order(size, min_objects,
+ slub_max_order, fraction, reserved);
+ if (order <= slub_max_order)
+ return order;
+ fraction /= 2;
+ }
+ min_objects--;
+ }
+
+ /*
+ * We were unable to place multiple objects in a slab. Now
+ * lets see if we can place a single object there.
+ */
+ order = slab_order(size, 1, slub_max_order, 1, reserved);
+ if (order <= slub_max_order)
+ return order;
+
+ /*
+ * Doh this slab cannot be placed using slub_max_order.
+ */
+ order = slab_order(size, 1, MAX_ORDER, 1, reserved);
+ if (order < MAX_ORDER)
+ return order;
+ return -ENOSYS;
+}
+
+/*
+ * Figure out what the alignment of the objects will be.
+ */
+static unsigned long calculate_alignment(unsigned long flags,
+ unsigned long align, unsigned long size)
+{
+ /*
+ * If the user wants hardware cache aligned objects then follow that
+ * suggestion if the object is sufficiently large.
+ *
+ * The hardware cache alignment cannot override the specified
+ * alignment though. If that is greater then use it.
+ */
+ if (flags & SLAB_HWCACHE_ALIGN) {
+ unsigned long ralign = cache_line_size();
+ while (size <= ralign / 2)
+ ralign /= 2;
+ align = max(align, ralign);
+ }
+
+ if (align < ARCH_SLAB_MINALIGN)
+ align = ARCH_SLAB_MINALIGN;
+
+ return ALIGN(align, sizeof(void *));
+}
+
+static void
+init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s)
+{
+ n->nr_partial = 0;
+ spin_lock_init(&n->list_lock);
+ INIT_LIST_HEAD(&n->partial);
+#ifdef CONFIG_SLUB_DEBUG
+ atomic_long_set(&n->nr_slabs, 0);
+ atomic_long_set(&n->total_objects, 0);
+ INIT_LIST_HEAD(&n->full);
+#endif
+}
+
+static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
+{
+ BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
+ SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu));
+
+ /*
+ * Must align to double word boundary for the double cmpxchg
+ * instructions to work; see __pcpu_double_call_return_bool().
+ */
+ s->cpu_slab = __alloc_percpu(sizeof(struct kmem_cache_cpu),
+ 2 * sizeof(void *));
+
+ if (!s->cpu_slab)
+ return 0;
+
+ init_kmem_cache_cpus(s);
+
+ return 1;
+}
+
+static struct kmem_cache *kmem_cache_node;
+
+/*
+ * No kmalloc_node yet so do it by hand. We know that this is the first
+ * slab on the node for this slabcache. There are no concurrent accesses
+ * possible.
+ *
+ * Note that this function only works on the kmalloc_node_cache
+ * when allocating for the kmalloc_node_cache. This is used for bootstrapping
+ * memory on a fresh node that has no slab structures yet.
+ */
+static void early_kmem_cache_node_alloc(int node)
+{
+ struct page *page;
+ struct kmem_cache_node *n;
+
+ BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node));
+
+ page = new_slab(kmem_cache_node, GFP_NOWAIT, node);
+
+ BUG_ON(!page);
+ if (page_to_nid(page) != node) {
+ printk(KERN_ERR "SLUB: Unable to allocate memory from "
+ "node %d\n", node);
+ printk(KERN_ERR "SLUB: Allocating a useless per node structure "
+ "in order to be able to continue\n");
+ }
+
+ n = page->freelist;
+ BUG_ON(!n);
+ page->freelist = get_freepointer(kmem_cache_node, n);
+ page->inuse = 1;
+ page->frozen = 0;
+ kmem_cache_node->node[node] = n;
+#ifdef CONFIG_SLUB_DEBUG
+ init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);
+ init_tracking(kmem_cache_node, n);
+#endif
+ init_kmem_cache_node(n, kmem_cache_node);
+ inc_slabs_node(kmem_cache_node, node, page->objects);
+
+ add_partial(n, page, DEACTIVATE_TO_HEAD);
+}
+
+static void free_kmem_cache_nodes(struct kmem_cache *s)
+{
+ int node;
+
+ for_each_node_state(node, N_NORMAL_MEMORY) {
+ struct kmem_cache_node *n = s->node[node];
+
+ if (n)
+ kmem_cache_free(kmem_cache_node, n);
+
+ s->node[node] = NULL;
+ }
+}
+
+static int init_kmem_cache_nodes(struct kmem_cache *s)
+{
+ int node;
+
+ for_each_node_state(node, N_NORMAL_MEMORY) {
+ struct kmem_cache_node *n;
+
+ if (slab_state == DOWN) {
+ early_kmem_cache_node_alloc(node);
+ continue;
+ }
+ n = kmem_cache_alloc_node(kmem_cache_node,
+ GFP_KERNEL, node);
+
+ if (!n) {
+ free_kmem_cache_nodes(s);
+ return 0;
+ }
+
+ s->node[node] = n;
+ init_kmem_cache_node(n, s);
+ }
+ return 1;
+}
+
+static void set_min_partial(struct kmem_cache *s, unsigned long min)
+{
+ if (min < MIN_PARTIAL)
+ min = MIN_PARTIAL;
+ else if (min > MAX_PARTIAL)
+ min = MAX_PARTIAL;
+ s->min_partial = min;
+}
+
+/*
+ * calculate_sizes() determines the order and the distribution of data within
+ * a slab object.
+ */
+static int calculate_sizes(struct kmem_cache *s, int forced_order)
+{
+ unsigned long flags = s->flags;
+ unsigned long size = s->objsize;
+ unsigned long align = s->align;
+ int order;
+
+ /*
+ * Round up object size to the next word boundary. We can only
+ * place the free pointer at word boundaries and this determines
+ * the possible location of the free pointer.
+ */
+ size = ALIGN(size, sizeof(void *));
+
+#ifdef CONFIG_SLUB_DEBUG
+ /*
+ * Determine if we can poison the object itself. If the user of
+ * the slab may touch the object after free or before allocation
+ * then we should never poison the object itself.
+ */
+ if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
+ !s->ctor)
+ s->flags |= __OBJECT_POISON;
+ else
+ s->flags &= ~__OBJECT_POISON;
+
+
+ /*
+ * If we are Redzoning then check if there is some space between the
+ * end of the object and the free pointer. If not then add an
+ * additional word to have some bytes to store Redzone information.
+ */
+ if ((flags & SLAB_RED_ZONE) && size == s->objsize)
+ size += sizeof(void *);
+#endif
+
+ /*
+ * With that we have determined the number of bytes in actual use
+ * by the object. This is the potential offset to the free pointer.
+ */
+ s->inuse = size;
+
+ if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
+ s->ctor)) {
+ /*
+ * Relocate free pointer after the object if it is not
+ * permitted to overwrite the first word of the object on
+ * kmem_cache_free.
+ *
+ * This is the case if we do RCU, have a constructor or
+ * destructor or are poisoning the objects.
+ */
+ s->offset = size;
+ size += sizeof(void *);
+ }
+
+#ifdef CONFIG_SLUB_DEBUG
+ if (flags & SLAB_STORE_USER)
+ /*
+ * Need to store information about allocs and frees after
+ * the object.
+ */
+ size += 2 * sizeof(struct track);
+
+ if (flags & SLAB_RED_ZONE)
+ /*
+ * Add some empty padding so that we can catch
+ * overwrites from earlier objects rather than let
+ * tracking information or the free pointer be
+ * corrupted if a user writes before the start
+ * of the object.
+ */
+ size += sizeof(void *);
+#endif
+
+ /*
+ * Determine the alignment based on various parameters that the
+ * user specified and the dynamic determination of cache line size
+ * on bootup.
+ */
+ align = calculate_alignment(flags, align, s->objsize);
+ s->align = align;
+
+ /*
+ * SLUB stores one object immediately after another beginning from
+ * offset 0. In order to align the objects we have to simply size
+ * each object to conform to the alignment.
+ */
+ size = ALIGN(size, align);
+ s->size = size;
+ if (forced_order >= 0)
+ order = forced_order;
+ else
+ order = calculate_order(size, s->reserved);
+
+ if (order < 0)
+ return 0;
+
+ s->allocflags = 0;
+ if (order)
+ s->allocflags |= __GFP_COMP;
+
+ if (s->flags & SLAB_CACHE_DMA)
+ s->allocflags |= SLUB_DMA;
+
+ if (s->flags & SLAB_RECLAIM_ACCOUNT)
+ s->allocflags |= __GFP_RECLAIMABLE;
+
+ /*
+ * Determine the number of objects per slab
+ */
+ s->oo = oo_make(order, size, s->reserved);
+ s->min = oo_make(get_order(size), size, s->reserved);
+ if (oo_objects(s->oo) > oo_objects(s->max))
+ s->max = s->oo;
+
+ return !!oo_objects(s->oo);
+
+}
+
+static int kmem_cache_open(struct kmem_cache *s,
+ const char *name, size_t size,
+ size_t align, unsigned long flags,
+ void (*ctor)(void *))
+{
+ memset(s, 0, kmem_size);
+ s->name = name;
+ s->ctor = ctor;
+ s->objsize = size;
+ s->align = align;
+ s->flags = kmem_cache_flags(size, flags, name, ctor);
+ s->reserved = 0;
+
+ if (need_reserve_slab_rcu && (s->flags & SLAB_DESTROY_BY_RCU))
+ s->reserved = sizeof(struct rcu_head);
+
+ if (!calculate_sizes(s, -1))
+ goto error;
+ if (disable_higher_order_debug) {
+ /*
+ * Disable debugging flags that store metadata if the min slab
+ * order increased.
+ */
+ if (get_order(s->size) > get_order(s->objsize)) {
+ s->flags &= ~DEBUG_METADATA_FLAGS;
+ s->offset = 0;
+ if (!calculate_sizes(s, -1))
+ goto error;
+ }
+ }
+
+#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
+ defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
+ if (system_has_cmpxchg_double() && (s->flags & SLAB_DEBUG_FLAGS) == 0)
+ /* Enable fast mode */
+ s->flags |= __CMPXCHG_DOUBLE;
+#endif
+
+ /*
+ * The larger the object size is, the more pages we want on the partial
+ * list to avoid pounding the page allocator excessively.
+ */
+ set_min_partial(s, ilog2(s->size) / 2);
+
+ /*
+ * cpu_partial determined the maximum number of objects kept in the
+ * per cpu partial lists of a processor.
+ *
+ * Per cpu partial lists mainly contain slabs that just have one
+ * object freed. If they are used for allocation then they can be
+ * filled up again with minimal effort. The slab will never hit the
+ * per node partial lists and therefore no locking will be required.
+ *
+ * This setting also determines
+ *
+ * A) The number of objects from per cpu partial slabs dumped to the
+ * per node list when we reach the limit.
+ * B) The number of objects in cpu partial slabs to extract from the
+ * per node list when we run out of per cpu objects. We only fetch 50%
+ * to keep some capacity around for frees.
+ */
+ if (kmem_cache_debug(s))
+ s->cpu_partial = 0;
+ else if (s->size >= PAGE_SIZE)
+ s->cpu_partial = 2;
+ else if (s->size >= 1024)
+ s->cpu_partial = 6;
+ else if (s->size >= 256)
+ s->cpu_partial = 13;
+ else
+ s->cpu_partial = 30;
+
+ s->refcount = 1;
+#ifdef CONFIG_NUMA
+ s->remote_node_defrag_ratio = 1000;
+#endif
+ if (!init_kmem_cache_nodes(s))
+ goto error;
+
+ if (alloc_kmem_cache_cpus(s))
+ return 1;
+
+ free_kmem_cache_nodes(s);
+error:
+ if (flags & SLAB_PANIC)
+ panic("Cannot create slab %s size=%lu realsize=%u "
+ "order=%u offset=%u flags=%lx\n",
+ s->name, (unsigned long)size, s->size, oo_order(s->oo),
+ s->offset, flags);
+ return 0;
+}
+
+/*
+ * Determine the size of a slab object
+ */
+unsigned int kmem_cache_size(struct kmem_cache *s)
+{
+ return s->objsize;
+}
+EXPORT_SYMBOL(kmem_cache_size);
+
+static void list_slab_objects(struct kmem_cache *s, struct page *page,
+ const char *text)
+{
+#ifdef CONFIG_SLUB_DEBUG
+ void *addr = page_address(page);
+ void *p;
+ unsigned long *map = kzalloc(BITS_TO_LONGS(page->objects) *
+ sizeof(long), GFP_ATOMIC);
+ if (!map)
+ return;
+ slab_err(s, page, "%s", text);
+ slab_lock(page);
+
+ get_map(s, page, map);
+ for_each_object(p, s, addr, page->objects) {
+
+ if (!test_bit(slab_index(p, s, addr), map)) {
+ printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n",
+ p, p - addr);
+ print_tracking(s, p);
+ }
+ }
+ slab_unlock(page);
+ kfree(map);
+#endif
+}
+
+/*
+ * Attempt to free all partial slabs on a node.
+ * This is called from kmem_cache_close(). We must be the last thread
+ * using the cache and therefore we do not need to lock anymore.
+ */
+static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
+{
+ struct page *page, *h;
+
+ list_for_each_entry_safe(page, h, &n->partial, lru) {
+ if (!page->inuse) {
+ remove_partial(n, page);
+ discard_slab(s, page);
+ } else {
+ list_slab_objects(s, page,
+ "Objects remaining on kmem_cache_close()");
+ }
+ }
+}
+
+/*
+ * Release all resources used by a slab cache.
+ */
+static inline int kmem_cache_close(struct kmem_cache *s)
+{
+ int node;
+
+ flush_all(s);
+ free_percpu(s->cpu_slab);
+ /* Attempt to free all objects */
+ for_each_node_state(node, N_NORMAL_MEMORY) {
+ struct kmem_cache_node *n = get_node(s, node);
+
+ free_partial(s, n);
+ if (n->nr_partial || slabs_node(s, node))
+ return 1;
+ }
+ free_kmem_cache_nodes(s);
+ return 0;
+}
+
+/*
+ * Close a cache and release the kmem_cache structure
+ * (must be used for caches created using kmem_cache_create)
+ */
+void kmem_cache_destroy(struct kmem_cache *s)
+{
+ down_write(&slub_lock);
+ s->refcount--;
+ if (!s->refcount) {
+ list_del(&s->list);
+ up_write(&slub_lock);
+ if (kmem_cache_close(s)) {
+ printk(KERN_ERR "SLUB %s: %s called for cache that "
+ "still has objects.\n", s->name, __func__);
+ dump_stack();
+ }
+ if (s->flags & SLAB_DESTROY_BY_RCU)
+ rcu_barrier();
+ sysfs_slab_remove(s);
+ } else
+ up_write(&slub_lock);
+}
+EXPORT_SYMBOL(kmem_cache_destroy);
+
+/********************************************************************
+ * Kmalloc subsystem
+ *******************************************************************/
+
+struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];
+EXPORT_SYMBOL(kmalloc_caches);
+
+static struct kmem_cache *kmem_cache;
+
+#ifdef CONFIG_ZONE_DMA
+static struct kmem_cache *kmalloc_dma_caches[SLUB_PAGE_SHIFT];
+#endif
+
+static int __init setup_slub_min_order(char *str)
+{
+ get_option(&str, &slub_min_order);
+
+ return 1;
+}
+
+__setup("slub_min_order=", setup_slub_min_order);
+
+static int __init setup_slub_max_order(char *str)
+{
+ get_option(&str, &slub_max_order);
+ slub_max_order = min(slub_max_order, MAX_ORDER - 1);
+
+ return 1;
+}
+
+__setup("slub_max_order=", setup_slub_max_order);
+
+static int __init setup_slub_min_objects(char *str)
+{
+ get_option(&str, &slub_min_objects);
+
+ return 1;
+}
+
+__setup("slub_min_objects=", setup_slub_min_objects);
+
+static int __init setup_slub_nomerge(char *str)
+{
+ slub_nomerge = 1;
+ return 1;
+}
+
+__setup("slub_nomerge", setup_slub_nomerge);
+
+static struct kmem_cache *__init create_kmalloc_cache(const char *name,
+ int size, unsigned int flags)
+{
+ struct kmem_cache *s;
+
+ s = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
+
+ /*
+ * This function is called with IRQs disabled during early-boot on
+ * single CPU so there's no need to take slub_lock here.
+ */
+ if (!kmem_cache_open(s, name, size, ARCH_KMALLOC_MINALIGN,
+ flags, NULL))
+ goto panic;
+
+ list_add(&s->list, &slab_caches);
+ return s;
+
+panic:
+ panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
+ return NULL;
+}
+
+/*
+ * Conversion table for small slabs sizes / 8 to the index in the
+ * kmalloc array. This is necessary for slabs < 192 since we have non power
+ * of two cache sizes there. The size of larger slabs can be determined using
+ * fls.
+ */
+static s8 size_index[24] = {
+ 3, /* 8 */
+ 4, /* 16 */
+ 5, /* 24 */
+ 5, /* 32 */
+ 6, /* 40 */
+ 6, /* 48 */
+ 6, /* 56 */
+ 6, /* 64 */
+ 1, /* 72 */
+ 1, /* 80 */
+ 1, /* 88 */
+ 1, /* 96 */
+ 7, /* 104 */
+ 7, /* 112 */
+ 7, /* 120 */
+ 7, /* 128 */
+ 2, /* 136 */
+ 2, /* 144 */
+ 2, /* 152 */
+ 2, /* 160 */
+ 2, /* 168 */
+ 2, /* 176 */
+ 2, /* 184 */
+ 2 /* 192 */
+};
+
+static inline int size_index_elem(size_t bytes)
+{
+ return (bytes - 1) / 8;
+}
+
+static struct kmem_cache *get_slab(size_t size, gfp_t flags)
+{
+ int index;
+
+ if (size <= 192) {
+ if (!size)
+ return ZERO_SIZE_PTR;
+
+ index = size_index[size_index_elem(size)];
+ } else
+ index = fls(size - 1);
+
+#ifdef CONFIG_ZONE_DMA
+ if (unlikely((flags & SLUB_DMA)))
+ return kmalloc_dma_caches[index];
+
+#endif
+ return kmalloc_caches[index];
+}
+
+void *__kmalloc(size_t size, gfp_t flags)
+{
+ struct kmem_cache *s;
+ void *ret;
+
+ if (unlikely(size > SLUB_MAX_SIZE))
+ return kmalloc_large(size, flags);
+
+ s = get_slab(size, flags);
+
+ if (unlikely(ZERO_OR_NULL_PTR(s)))
+ return s;
+
+ ret = slab_alloc(s, flags, NUMA_NO_NODE, _RET_IP_);
+
+ trace_kmalloc(_RET_IP_, ret, size, s->size, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(__kmalloc);
+
+#ifdef CONFIG_NUMA
+static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
+{
+ struct page *page;
+ void *ptr = NULL;
+
+ flags |= __GFP_COMP | __GFP_NOTRACK;
+ page = alloc_pages_node(node, flags, get_order(size));
+ if (page)
+ ptr = page_address(page);
+
+ kmemleak_alloc(ptr, size, 1, flags);
+ return ptr;
+}
+
+void *__kmalloc_node(size_t size, gfp_t flags, int node)
+{
+ struct kmem_cache *s;
+ void *ret;
+
+ if (unlikely(size > SLUB_MAX_SIZE)) {
+ ret = kmalloc_large_node(size, flags, node);
+
+ trace_kmalloc_node(_RET_IP_, ret,
+ size, PAGE_SIZE << get_order(size),
+ flags, node);
+
+ return ret;
+ }
+
+ s = get_slab(size, flags);
+
+ if (unlikely(ZERO_OR_NULL_PTR(s)))
+ return s;
+
+ ret = slab_alloc(s, flags, node, _RET_IP_);
+
+ trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node);
+
+ return ret;
+}
+EXPORT_SYMBOL(__kmalloc_node);
+#endif
+
+size_t ksize(const void *object)
+{
+ struct page *page;
+
+ if (unlikely(object == ZERO_SIZE_PTR))
+ return 0;
+
+ page = virt_to_head_page(object);
+
+ if (unlikely(!PageSlab(page))) {
+ WARN_ON(!PageCompound(page));
+ return PAGE_SIZE << compound_order(page);
+ }
+
+ return slab_ksize(page->slab);
+}
+EXPORT_SYMBOL(ksize);
+
+#ifdef CONFIG_SLUB_DEBUG
+bool verify_mem_not_deleted(const void *x)
+{
+ struct page *page;
+ void *object = (void *)x;
+ unsigned long flags;
+ bool rv;
+
+ if (unlikely(ZERO_OR_NULL_PTR(x)))
+ return false;
+
+ local_irq_save(flags);
+
+ page = virt_to_head_page(x);
+ if (unlikely(!PageSlab(page))) {
+ /* maybe it was from stack? */
+ rv = true;
+ goto out_unlock;
+ }
+
+ slab_lock(page);
+ if (on_freelist(page->slab, page, object)) {
+ object_err(page->slab, page, object, "Object is on free-list");
+ rv = false;
+ } else {
+ rv = true;
+ }
+ slab_unlock(page);
+
+out_unlock:
+ local_irq_restore(flags);
+ return rv;
+}
+EXPORT_SYMBOL(verify_mem_not_deleted);
+#endif
+
+void kfree(const void *x)
+{
+ struct page *page;
+ void *object = (void *)x;
+
+ trace_kfree(_RET_IP_, x);
+
+ if (unlikely(ZERO_OR_NULL_PTR(x)))
+ return;
+
+ page = virt_to_head_page(x);
+ if (unlikely(!PageSlab(page))) {
+ BUG_ON(!PageCompound(page));
+ kmemleak_free(x);
+ put_page(page);
+ return;
+ }
+ slab_free(page->slab, page, object, _RET_IP_);
+}
+EXPORT_SYMBOL(kfree);
+
+/*
+ * kmem_cache_shrink removes empty slabs from the partial lists and sorts
+ * the remaining slabs by the number of items in use. The slabs with the
+ * most items in use come first. New allocations will then fill those up
+ * and thus they can be removed from the partial lists.
+ *
+ * The slabs with the least items are placed last. This results in them
+ * being allocated from last increasing the chance that the last objects
+ * are freed in them.
+ */
+int kmem_cache_shrink(struct kmem_cache *s)
+{
+ int node;
+ int i;
+ struct kmem_cache_node *n;
+ struct page *page;
+ struct page *t;
+ int objects = oo_objects(s->max);
+ struct list_head *slabs_by_inuse =
+ kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL);
+ unsigned long flags;
+
+ if (!slabs_by_inuse)
+ return -ENOMEM;
+
+ flush_all(s);
+ for_each_node_state(node, N_NORMAL_MEMORY) {
+ n = get_node(s, node);
+
+ if (!n->nr_partial)
+ continue;
+
+ for (i = 0; i < objects; i++)
+ INIT_LIST_HEAD(slabs_by_inuse + i);
+
+ spin_lock_irqsave(&n->list_lock, flags);
+
+ /*
+ * Build lists indexed by the items in use in each slab.
+ *
+ * Note that concurrent frees may occur while we hold the
+ * list_lock. page->inuse here is the upper limit.
+ */
+ list_for_each_entry_safe(page, t, &n->partial, lru) {
+ list_move(&page->lru, slabs_by_inuse + page->inuse);
+ if (!page->inuse)
+ n->nr_partial--;
+ }
+
+ /*
+ * Rebuild the partial list with the slabs filled up most
+ * first and the least used slabs at the end.
+ */
+ for (i = objects - 1; i > 0; i--)
+ list_splice(slabs_by_inuse + i, n->partial.prev);
+
+ spin_unlock_irqrestore(&n->list_lock, flags);
+
+ /* Release empty slabs */
+ list_for_each_entry_safe(page, t, slabs_by_inuse, lru)
+ discard_slab(s, page);
+ }
+
+ kfree(slabs_by_inuse);
+ return 0;
+}
+EXPORT_SYMBOL(kmem_cache_shrink);
+
+#if defined(CONFIG_MEMORY_HOTPLUG)
+static int slab_mem_going_offline_callback(void *arg)
+{
+ struct kmem_cache *s;
+
+ down_read(&slub_lock);
+ list_for_each_entry(s, &slab_caches, list)
+ kmem_cache_shrink(s);
+ up_read(&slub_lock);
+
+ return 0;
+}
+
+static void slab_mem_offline_callback(void *arg)
+{
+ struct kmem_cache_node *n;
+ struct kmem_cache *s;
+ struct memory_notify *marg = arg;
+ int offline_node;
+
+ offline_node = marg->status_change_nid;
+
+ /*
+ * If the node still has available memory. we need kmem_cache_node
+ * for it yet.
+ */
+ if (offline_node < 0)
+ return;
+
+ down_read(&slub_lock);
+ list_for_each_entry(s, &slab_caches, list) {
+ n = get_node(s, offline_node);
+ if (n) {
+ /*
+ * if n->nr_slabs > 0, slabs still exist on the node
+ * that is going down. We were unable to free them,
+ * and offline_pages() function shouldn't call this
+ * callback. So, we must fail.
+ */
+ BUG_ON(slabs_node(s, offline_node));
+
+ s->node[offline_node] = NULL;
+ kmem_cache_free(kmem_cache_node, n);
+ }
+ }
+ up_read(&slub_lock);
+}
+
+static int slab_mem_going_online_callback(void *arg)
+{
+ struct kmem_cache_node *n;
+ struct kmem_cache *s;
+ struct memory_notify *marg = arg;
+ int nid = marg->status_change_nid;
+ int ret = 0;
+
+ /*
+ * If the node's memory is already available, then kmem_cache_node is
+ * already created. Nothing to do.
+ */
+ if (nid < 0)
+ return 0;
+
+ /*
+ * We are bringing a node online. No memory is available yet. We must
+ * allocate a kmem_cache_node structure in order to bring the node
+ * online.
+ */
+ down_read(&slub_lock);
+ list_for_each_entry(s, &slab_caches, list) {
+ /*
+ * XXX: kmem_cache_alloc_node will fallback to other nodes
+ * since memory is not yet available from the node that
+ * is brought up.
+ */
+ n = kmem_cache_alloc(kmem_cache_node, GFP_KERNEL);
+ if (!n) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ init_kmem_cache_node(n, s);
+ s->node[nid] = n;
+ }
+out:
+ up_read(&slub_lock);
+ return ret;
+}
+
+static int slab_memory_callback(struct notifier_block *self,
+ unsigned long action, void *arg)
+{
+ int ret = 0;
+
+ switch (action) {
+ case MEM_GOING_ONLINE:
+ ret = slab_mem_going_online_callback(arg);
+ break;
+ case MEM_GOING_OFFLINE:
+ ret = slab_mem_going_offline_callback(arg);
+ break;
+ case MEM_OFFLINE:
+ case MEM_CANCEL_ONLINE:
+ slab_mem_offline_callback(arg);
+ break;
+ case MEM_ONLINE:
+ case MEM_CANCEL_OFFLINE:
+ break;
+ }
+ if (ret)
+ ret = notifier_from_errno(ret);
+ else
+ ret = NOTIFY_OK;
+ return ret;
+}
+
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+/********************************************************************
+ * Basic setup of slabs
+ *******************************************************************/
+
+/*
+ * Used for early kmem_cache structures that were allocated using
+ * the page allocator
+ */
+
+static void __init kmem_cache_bootstrap_fixup(struct kmem_cache *s)
+{
+ int node;
+
+ list_add(&s->list, &slab_caches);
+ s->refcount = -1;
+
+ for_each_node_state(node, N_NORMAL_MEMORY) {
+ struct kmem_cache_node *n = get_node(s, node);
+ struct page *p;
+
+ if (n) {
+ list_for_each_entry(p, &n->partial, lru)
+ p->slab = s;
+
+#ifdef CONFIG_SLUB_DEBUG
+ list_for_each_entry(p, &n->full, lru)
+ p->slab = s;
+#endif
+ }
+ }
+}
+
+void __init kmem_cache_init(void)
+{
+ int i;
+ int caches = 0;
+ struct kmem_cache *temp_kmem_cache;
+ int order;
+ struct kmem_cache *temp_kmem_cache_node;
+ unsigned long kmalloc_size;
+
+ if (debug_guardpage_minorder())
+ slub_max_order = 0;
+
+ kmem_size = offsetof(struct kmem_cache, node) +
+ nr_node_ids * sizeof(struct kmem_cache_node *);
+
+ /* Allocate two kmem_caches from the page allocator */
+ kmalloc_size = ALIGN(kmem_size, cache_line_size());
+ order = get_order(2 * kmalloc_size);
+ kmem_cache = (void *)__get_free_pages(GFP_NOWAIT, order);
+
+ /*
+ * Must first have the slab cache available for the allocations of the
+ * struct kmem_cache_node's. There is special bootstrap code in
+ * kmem_cache_open for slab_state == DOWN.
+ */
+ kmem_cache_node = (void *)kmem_cache + kmalloc_size;
+
+ kmem_cache_open(kmem_cache_node, "kmem_cache_node",
+ sizeof(struct kmem_cache_node),
+ 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
+
+ hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
+
+ /* Able to allocate the per node structures */
+ slab_state = PARTIAL;
+
+ temp_kmem_cache = kmem_cache;
+ kmem_cache_open(kmem_cache, "kmem_cache", kmem_size,
+ 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
+ kmem_cache = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
+ memcpy(kmem_cache, temp_kmem_cache, kmem_size);
+
+ /*
+ * Allocate kmem_cache_node properly from the kmem_cache slab.
+ * kmem_cache_node is separately allocated so no need to
+ * update any list pointers.
+ */
+ temp_kmem_cache_node = kmem_cache_node;
+
+ kmem_cache_node = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
+ memcpy(kmem_cache_node, temp_kmem_cache_node, kmem_size);
+
+ kmem_cache_bootstrap_fixup(kmem_cache_node);
+
+ caches++;
+ kmem_cache_bootstrap_fixup(kmem_cache);
+ caches++;
+ /* Free temporary boot structure */
+ free_pages((unsigned long)temp_kmem_cache, order);
+
+ /* Now we can use the kmem_cache to allocate kmalloc slabs */
+
+ /*
+ * Patch up the size_index table if we have strange large alignment
+ * requirements for the kmalloc array. This is only the case for
+ * MIPS it seems. The standard arches will not generate any code here.
+ *
+ * Largest permitted alignment is 256 bytes due to the way we
+ * handle the index determination for the smaller caches.
+ *
+ * Make sure that nothing crazy happens if someone starts tinkering
+ * around with ARCH_KMALLOC_MINALIGN
+ */
+ BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
+ (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
+
+ for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
+ int elem = size_index_elem(i);
+ if (elem >= ARRAY_SIZE(size_index))
+ break;
+ size_index[elem] = KMALLOC_SHIFT_LOW;
+ }
+
+ if (KMALLOC_MIN_SIZE == 64) {
+ /*
+ * The 96 byte size cache is not used if the alignment
+ * is 64 byte.
+ */
+ for (i = 64 + 8; i <= 96; i += 8)
+ size_index[size_index_elem(i)] = 7;
+ } else if (KMALLOC_MIN_SIZE == 128) {
+ /*
+ * The 192 byte sized cache is not used if the alignment
+ * is 128 byte. Redirect kmalloc to use the 256 byte cache
+ * instead.
+ */
+ for (i = 128 + 8; i <= 192; i += 8)
+ size_index[size_index_elem(i)] = 8;
+ }
+
+ /* Caches that are not of the two-to-the-power-of size */
+ if (KMALLOC_MIN_SIZE <= 32) {
+ kmalloc_caches[1] = create_kmalloc_cache("kmalloc-96", 96, 0);
+ caches++;
+ }
+
+ if (KMALLOC_MIN_SIZE <= 64) {
+ kmalloc_caches[2] = create_kmalloc_cache("kmalloc-192", 192, 0);
+ caches++;
+ }
+
+ for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) {
+ kmalloc_caches[i] = create_kmalloc_cache("kmalloc", 1 << i, 0);
+ caches++;
+ }
+
+ slab_state = UP;
+
+ /* Provide the correct kmalloc names now that the caches are up */
+ if (KMALLOC_MIN_SIZE <= 32) {
+ kmalloc_caches[1]->name = kstrdup(kmalloc_caches[1]->name, GFP_NOWAIT);
+ BUG_ON(!kmalloc_caches[1]->name);
+ }
+
+ if (KMALLOC_MIN_SIZE <= 64) {
+ kmalloc_caches[2]->name = kstrdup(kmalloc_caches[2]->name, GFP_NOWAIT);
+ BUG_ON(!kmalloc_caches[2]->name);
+ }
+
+ for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) {
+ char *s = kasprintf(GFP_NOWAIT, "kmalloc-%d", 1 << i);
+
+ BUG_ON(!s);
+ kmalloc_caches[i]->name = s;
+ }
+
+#ifdef CONFIG_SMP
+ register_cpu_notifier(&slab_notifier);
+#endif
+
+#ifdef CONFIG_ZONE_DMA
+ for (i = 0; i < SLUB_PAGE_SHIFT; i++) {
+ struct kmem_cache *s = kmalloc_caches[i];
+
+ if (s && s->size) {
+ char *name = kasprintf(GFP_NOWAIT,
+ "dma-kmalloc-%d", s->objsize);
+
+ BUG_ON(!name);
+ kmalloc_dma_caches[i] = create_kmalloc_cache(name,
+ s->objsize, SLAB_CACHE_DMA);
+ }
+ }
+#endif
+ printk(KERN_INFO
+ "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
+ " CPUs=%d, Nodes=%d\n",
+ caches, cache_line_size(),
+ slub_min_order, slub_max_order, slub_min_objects,
+ nr_cpu_ids, nr_node_ids);
+}
+
+void __init kmem_cache_init_late(void)
+{
+}
+
+/*
+ * Find a mergeable slab cache
+ */
+static int slab_unmergeable(struct kmem_cache *s)
+{
+ if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
+ return 1;
+
+ if (s->ctor)
+ return 1;
+
+ /*
+ * We may have set a slab to be unmergeable during bootstrap.
+ */
+ if (s->refcount < 0)
+ return 1;
+
+ return 0;
+}
+
+static struct kmem_cache *find_mergeable(size_t size,
+ size_t align, unsigned long flags, const char *name,
+ void (*ctor)(void *))
+{
+ struct kmem_cache *s;
+
+ if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
+ return NULL;
+
+ if (ctor)
+ return NULL;
+
+ size = ALIGN(size, sizeof(void *));
+ align = calculate_alignment(flags, align, size);
+ size = ALIGN(size, align);
+ flags = kmem_cache_flags(size, flags, name, NULL);
+
+ list_for_each_entry(s, &slab_caches, list) {
+ if (slab_unmergeable(s))
+ continue;
+
+ if (size > s->size)
+ continue;
+
+ if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME))
+ continue;
+ /*
+ * Check if alignment is compatible.
+ * Courtesy of Adrian Drzewiecki
+ */
+ if ((s->size & ~(align - 1)) != s->size)
+ continue;
+
+ if (s->size - size >= sizeof(void *))
+ continue;
+
+ return s;
+ }
+ return NULL;
+}
+
+struct kmem_cache *kmem_cache_create(const char *name, size_t size,
+ size_t align, unsigned long flags, void (*ctor)(void *))
+{
+ struct kmem_cache *s;
+ char *n;
+
+ if (WARN_ON(!name))
+ return NULL;
+
+ down_write(&slub_lock);
+ s = find_mergeable(size, align, flags, name, ctor);
+ if (s) {
+ s->refcount++;
+ /*
+ * Adjust the object sizes so that we clear
+ * the complete object on kzalloc.
+ */
+ s->objsize = max(s->objsize, (int)size);
+ s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
+
+ if (sysfs_slab_alias(s, name)) {
+ s->refcount--;
+ goto err;
+ }
+ up_write(&slub_lock);
+ return s;
+ }
+
+ n = kstrdup(name, GFP_KERNEL);
+ if (!n)
+ goto err;
+
+ s = kmalloc(kmem_size, GFP_KERNEL);
+ if (s) {
+ if (kmem_cache_open(s, n,
+ size, align, flags, ctor)) {
+ list_add(&s->list, &slab_caches);
+ up_write(&slub_lock);
+ if (sysfs_slab_add(s)) {
+ down_write(&slub_lock);
+ list_del(&s->list);
+ kfree(n);
+ kfree(s);
+ goto err;
+ }
+ return s;
+ }
+ kfree(n);
+ kfree(s);
+ }
+err:
+ up_write(&slub_lock);
+
+ if (flags & SLAB_PANIC)
+ panic("Cannot create slabcache %s\n", name);
+ else
+ s = NULL;
+ return s;
+}
+EXPORT_SYMBOL(kmem_cache_create);
+
+#ifdef CONFIG_SMP
+/*
+ * Use the cpu notifier to insure that the cpu slabs are flushed when
+ * necessary.
+ */
+static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ long cpu = (long)hcpu;
+ struct kmem_cache *s;
+ unsigned long flags;
+
+ switch (action) {
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ down_read(&slub_lock);
+ list_for_each_entry(s, &slab_caches, list) {
+ local_irq_save(flags);
+ __flush_cpu_slab(s, cpu);
+ local_irq_restore(flags);
+ }
+ up_read(&slub_lock);
+ break;
+ default:
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata slab_notifier = {
+ .notifier_call = slab_cpuup_callback
+};
+
+#endif
+
+void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
+{
+ struct kmem_cache *s;
+ void *ret;
+
+ if (unlikely(size > SLUB_MAX_SIZE))
+ return kmalloc_large(size, gfpflags);
+
+ s = get_slab(size, gfpflags);
+
+ if (unlikely(ZERO_OR_NULL_PTR(s)))
+ return s;
+
+ ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, caller);
+
+ /* Honor the call site pointer we received. */
+ trace_kmalloc(caller, ret, size, s->size, gfpflags);
+
+ return ret;
+}
+
+#ifdef CONFIG_NUMA
+void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
+ int node, unsigned long caller)
+{
+ struct kmem_cache *s;
+ void *ret;
+
+ if (unlikely(size > SLUB_MAX_SIZE)) {
+ ret = kmalloc_large_node(size, gfpflags, node);
+
+ trace_kmalloc_node(caller, ret,
+ size, PAGE_SIZE << get_order(size),
+ gfpflags, node);
+
+ return ret;
+ }
+
+ s = get_slab(size, gfpflags);
+
+ if (unlikely(ZERO_OR_NULL_PTR(s)))
+ return s;
+
+ ret = slab_alloc(s, gfpflags, node, caller);
+
+ /* Honor the call site pointer we received. */
+ trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node);
+
+ return ret;
+}
+#endif
+
+#ifdef CONFIG_SYSFS
+static int count_inuse(struct page *page)
+{
+ return page->inuse;
+}
+
+static int count_total(struct page *page)
+{
+ return page->objects;
+}
+#endif
+
+#ifdef CONFIG_SLUB_DEBUG
+static int validate_slab(struct kmem_cache *s, struct page *page,
+ unsigned long *map)
+{
+ void *p;
+ void *addr = page_address(page);
+
+ if (!check_slab(s, page) ||
+ !on_freelist(s, page, NULL))
+ return 0;
+
+ /* Now we know that a valid freelist exists */
+ bitmap_zero(map, page->objects);
+
+ get_map(s, page, map);
+ for_each_object(p, s, addr, page->objects) {
+ if (test_bit(slab_index(p, s, addr), map))
+ if (!check_object(s, page, p, SLUB_RED_INACTIVE))
+ return 0;
+ }
+
+ for_each_object(p, s, addr, page->objects)
+ if (!test_bit(slab_index(p, s, addr), map))
+ if (!check_object(s, page, p, SLUB_RED_ACTIVE))
+ return 0;
+ return 1;
+}
+
+static void validate_slab_slab(struct kmem_cache *s, struct page *page,
+ unsigned long *map)
+{
+ slab_lock(page);
+ validate_slab(s, page, map);
+ slab_unlock(page);
+}
+
+static int validate_slab_node(struct kmem_cache *s,
+ struct kmem_cache_node *n, unsigned long *map)
+{
+ unsigned long count = 0;
+ struct page *page;
+ unsigned long flags;
+
+ spin_lock_irqsave(&n->list_lock, flags);
+
+ list_for_each_entry(page, &n->partial, lru) {
+ validate_slab_slab(s, page, map);
+ count++;
+ }
+ if (count != n->nr_partial)
+ printk(KERN_ERR "SLUB %s: %ld partial slabs counted but "
+ "counter=%ld\n", s->name, count, n->nr_partial);
+
+ if (!(s->flags & SLAB_STORE_USER))
+ goto out;
+
+ list_for_each_entry(page, &n->full, lru) {
+ validate_slab_slab(s, page, map);
+ count++;
+ }
+ if (count != atomic_long_read(&n->nr_slabs))
+ printk(KERN_ERR "SLUB: %s %ld slabs counted but "
+ "counter=%ld\n", s->name, count,
+ atomic_long_read(&n->nr_slabs));
+
+out:
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ return count;
+}
+
+static long validate_slab_cache(struct kmem_cache *s)
+{
+ int node;
+ unsigned long count = 0;
+ unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
+ sizeof(unsigned long), GFP_KERNEL);
+
+ if (!map)
+ return -ENOMEM;
+
+ flush_all(s);
+ for_each_node_state(node, N_NORMAL_MEMORY) {
+ struct kmem_cache_node *n = get_node(s, node);
+
+ count += validate_slab_node(s, n, map);
+ }
+ kfree(map);
+ return count;
+}
+/*
+ * Generate lists of code addresses where slabcache objects are allocated
+ * and freed.
+ */
+
+struct location {
+ unsigned long count;
+ unsigned long addr;
+ long long sum_time;
+ long min_time;
+ long max_time;
+ long min_pid;
+ long max_pid;
+ DECLARE_BITMAP(cpus, NR_CPUS);
+ nodemask_t nodes;
+};
+
+struct loc_track {
+ unsigned long max;
+ unsigned long count;
+ struct location *loc;
+};
+
+static void free_loc_track(struct loc_track *t)
+{
+ if (t->max)
+ free_pages((unsigned long)t->loc,
+ get_order(sizeof(struct location) * t->max));
+}
+
+static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
+{
+ struct location *l;
+ int order;
+
+ order = get_order(sizeof(struct location) * max);
+
+ l = (void *)__get_free_pages(flags, order);
+ if (!l)
+ return 0;
+
+ if (t->count) {
+ memcpy(l, t->loc, sizeof(struct location) * t->count);
+ free_loc_track(t);
+ }
+ t->max = max;
+ t->loc = l;
+ return 1;
+}
+
+static int add_location(struct loc_track *t, struct kmem_cache *s,
+ const struct track *track)
+{
+ long start, end, pos;
+ struct location *l;
+ unsigned long caddr;
+ unsigned long age = jiffies - track->when;
+
+ start = -1;
+ end = t->count;
+
+ for ( ; ; ) {
+ pos = start + (end - start + 1) / 2;
+
+ /*
+ * There is nothing at "end". If we end up there
+ * we need to add something to before end.
+ */
+ if (pos == end)
+ break;
+
+ caddr = t->loc[pos].addr;
+ if (track->addr == caddr) {
+
+ l = &t->loc[pos];
+ l->count++;
+ if (track->when) {
+ l->sum_time += age;
+ if (age < l->min_time)
+ l->min_time = age;
+ if (age > l->max_time)
+ l->max_time = age;
+
+ if (track->pid < l->min_pid)
+ l->min_pid = track->pid;
+ if (track->pid > l->max_pid)
+ l->max_pid = track->pid;
+
+ cpumask_set_cpu(track->cpu,
+ to_cpumask(l->cpus));
+ }
+ node_set(page_to_nid(virt_to_page(track)), l->nodes);
+ return 1;
+ }
+
+ if (track->addr < caddr)
+ end = pos;
+ else
+ start = pos;
+ }
+
+ /*
+ * Not found. Insert new tracking element.
+ */
+ if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
+ return 0;
+
+ l = t->loc + pos;
+ if (pos < t->count)
+ memmove(l + 1, l,
+ (t->count - pos) * sizeof(struct location));
+ t->count++;
+ l->count = 1;
+ l->addr = track->addr;
+ l->sum_time = age;
+ l->min_time = age;
+ l->max_time = age;
+ l->min_pid = track->pid;
+ l->max_pid = track->pid;
+ cpumask_clear(to_cpumask(l->cpus));
+ cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));
+ nodes_clear(l->nodes);
+ node_set(page_to_nid(virt_to_page(track)), l->nodes);
+ return 1;
+}
+
+static void process_slab(struct loc_track *t, struct kmem_cache *s,
+ struct page *page, enum track_item alloc,
+ unsigned long *map)
+{
+ void *addr = page_address(page);
+ void *p;
+
+ bitmap_zero(map, page->objects);
+ get_map(s, page, map);
+
+ for_each_object(p, s, addr, page->objects)
+ if (!test_bit(slab_index(p, s, addr), map))
+ add_location(t, s, get_track(s, p, alloc));
+}
+
+static int list_locations(struct kmem_cache *s, char *buf,
+ enum track_item alloc)
+{
+ int len = 0;
+ unsigned long i;
+ struct loc_track t = { 0, 0, NULL };
+ int node;
+ unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
+ sizeof(unsigned long), GFP_KERNEL);
+
+ if (!map || !alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
+ GFP_TEMPORARY)) {
+ kfree(map);
+ return sprintf(buf, "Out of memory\n");
+ }
+ /* Push back cpu slabs */
+ flush_all(s);
+
+ for_each_node_state(node, N_NORMAL_MEMORY) {
+ struct kmem_cache_node *n = get_node(s, node);
+ unsigned long flags;
+ struct page *page;
+
+ if (!atomic_long_read(&n->nr_slabs))
+ continue;
+
+ spin_lock_irqsave(&n->list_lock, flags);
+ list_for_each_entry(page, &n->partial, lru)
+ process_slab(&t, s, page, alloc, map);
+ list_for_each_entry(page, &n->full, lru)
+ process_slab(&t, s, page, alloc, map);
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ }
+
+ for (i = 0; i < t.count; i++) {
+ struct location *l = &t.loc[i];
+
+ if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100)
+ break;
+ len += sprintf(buf + len, "%7ld ", l->count);
+
+ if (l->addr)
+ len += sprintf(buf + len, "%pS", (void *)l->addr);
+ else
+ len += sprintf(buf + len, "<not-available>");
+
+ if (l->sum_time != l->min_time) {
+ len += sprintf(buf + len, " age=%ld/%ld/%ld",
+ l->min_time,
+ (long)div_u64(l->sum_time, l->count),
+ l->max_time);
+ } else
+ len += sprintf(buf + len, " age=%ld",
+ l->min_time);
+
+ if (l->min_pid != l->max_pid)
+ len += sprintf(buf + len, " pid=%ld-%ld",
+ l->min_pid, l->max_pid);
+ else
+ len += sprintf(buf + len, " pid=%ld",
+ l->min_pid);
+
+ if (num_online_cpus() > 1 &&
+ !cpumask_empty(to_cpumask(l->cpus)) &&
+ len < PAGE_SIZE - 60) {
+ len += sprintf(buf + len, " cpus=");
+ len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50,
+ to_cpumask(l->cpus));
+ }
+
+ if (nr_online_nodes > 1 && !nodes_empty(l->nodes) &&
+ len < PAGE_SIZE - 60) {
+ len += sprintf(buf + len, " nodes=");
+ len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50,
+ l->nodes);
+ }
+
+ len += sprintf(buf + len, "\n");
+ }
+
+ free_loc_track(&t);
+ kfree(map);
+ if (!t.count)
+ len += sprintf(buf, "No data\n");
+ return len;
+}
+#endif
+
+#ifdef SLUB_RESILIENCY_TEST
+static void resiliency_test(void)
+{
+ u8 *p;
+
+ BUILD_BUG_ON(KMALLOC_MIN_SIZE > 16 || SLUB_PAGE_SHIFT < 10);
+
+ printk(KERN_ERR "SLUB resiliency testing\n");
+ printk(KERN_ERR "-----------------------\n");
+ printk(KERN_ERR "A. Corruption after allocation\n");
+
+ p = kzalloc(16, GFP_KERNEL);
+ p[16] = 0x12;
+ printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer"
+ " 0x12->0x%p\n\n", p + 16);
+
+ validate_slab_cache(kmalloc_caches[4]);
+
+ /* Hmmm... The next two are dangerous */
+ p = kzalloc(32, GFP_KERNEL);
+ p[32 + sizeof(void *)] = 0x34;
+ printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
+ " 0x34 -> -0x%p\n", p);
+ printk(KERN_ERR
+ "If allocated object is overwritten then not detectable\n\n");
+
+ validate_slab_cache(kmalloc_caches[5]);
+ p = kzalloc(64, GFP_KERNEL);
+ p += 64 + (get_cycles() & 0xff) * sizeof(void *);
+ *p = 0x56;
+ printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
+ p);
+ printk(KERN_ERR
+ "If allocated object is overwritten then not detectable\n\n");
+ validate_slab_cache(kmalloc_caches[6]);
+
+ printk(KERN_ERR "\nB. Corruption after free\n");
+ p = kzalloc(128, GFP_KERNEL);
+ kfree(p);
+ *p = 0x78;
+ printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
+ validate_slab_cache(kmalloc_caches[7]);
+
+ p = kzalloc(256, GFP_KERNEL);
+ kfree(p);
+ p[50] = 0x9a;
+ printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
+ p);
+ validate_slab_cache(kmalloc_caches[8]);
+
+ p = kzalloc(512, GFP_KERNEL);
+ kfree(p);
+ p[512] = 0xab;
+ printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
+ validate_slab_cache(kmalloc_caches[9]);
+}
+#else
+#ifdef CONFIG_SYSFS
+static void resiliency_test(void) {};
+#endif
+#endif
+
+#ifdef CONFIG_SYSFS
+enum slab_stat_type {
+ SL_ALL, /* All slabs */
+ SL_PARTIAL, /* Only partially allocated slabs */
+ SL_CPU, /* Only slabs used for cpu caches */
+ SL_OBJECTS, /* Determine allocated objects not slabs */
+ SL_TOTAL /* Determine object capacity not slabs */
+};
+
+#define SO_ALL (1 << SL_ALL)
+#define SO_PARTIAL (1 << SL_PARTIAL)
+#define SO_CPU (1 << SL_CPU)
+#define SO_OBJECTS (1 << SL_OBJECTS)
+#define SO_TOTAL (1 << SL_TOTAL)
+
+static ssize_t show_slab_objects(struct kmem_cache *s,
+ char *buf, unsigned long flags)
+{
+ unsigned long total = 0;
+ int node;
+ int x;
+ unsigned long *nodes;
+ unsigned long *per_cpu;
+
+ nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
+ if (!nodes)
+ return -ENOMEM;
+ per_cpu = nodes + nr_node_ids;
+
+ if (flags & SO_CPU) {
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
+ int node = ACCESS_ONCE(c->node);
+ struct page *page;
+
+ if (node < 0)
+ continue;
+ page = ACCESS_ONCE(c->page);
+ if (page) {
+ if (flags & SO_TOTAL)
+ x = page->objects;
+ else if (flags & SO_OBJECTS)
+ x = page->inuse;
+ else
+ x = 1;
+
+ total += x;
+ nodes[node] += x;
+ }
+ page = c->partial;
+
+ if (page) {
+ node = page_to_nid(page);
+ if (flags & SO_TOTAL)
+ WARN_ON_ONCE(1);
+ else if (flags & SO_OBJECTS)
+ WARN_ON_ONCE(1);
+ else
+ x = page->pages;
+ total += x;
+ nodes[node] += x;
+ }
+ per_cpu[node]++;
+ }
+ }
+
+ lock_memory_hotplug();
+#ifdef CONFIG_SLUB_DEBUG
+ if (flags & SO_ALL) {
+ for_each_node_state(node, N_NORMAL_MEMORY) {
+ struct kmem_cache_node *n = get_node(s, node);
+
+ if (flags & SO_TOTAL)
+ x = atomic_long_read(&n->total_objects);
+ else if (flags & SO_OBJECTS)
+ x = atomic_long_read(&n->total_objects) -
+ count_partial(n, count_free);
+
+ else
+ x = atomic_long_read(&n->nr_slabs);
+ total += x;
+ nodes[node] += x;
+ }
+
+ } else
+#endif
+ if (flags & SO_PARTIAL) {
+ for_each_node_state(node, N_NORMAL_MEMORY) {
+ struct kmem_cache_node *n = get_node(s, node);
+
+ if (flags & SO_TOTAL)
+ x = count_partial(n, count_total);
+ else if (flags & SO_OBJECTS)
+ x = count_partial(n, count_inuse);
+ else
+ x = n->nr_partial;
+ total += x;
+ nodes[node] += x;
+ }
+ }
+ x = sprintf(buf, "%lu", total);
+#ifdef CONFIG_NUMA
+ for_each_node_state(node, N_NORMAL_MEMORY)
+ if (nodes[node])
+ x += sprintf(buf + x, " N%d=%lu",
+ node, nodes[node]);
+#endif
+ unlock_memory_hotplug();
+ kfree(nodes);
+ return x + sprintf(buf + x, "\n");
+}
+
+#ifdef CONFIG_SLUB_DEBUG
+static int any_slab_objects(struct kmem_cache *s)
+{
+ int node;
+
+ for_each_online_node(node) {
+ struct kmem_cache_node *n = get_node(s, node);
+
+ if (!n)
+ continue;
+
+ if (atomic_long_read(&n->total_objects))
+ return 1;
+ }
+ return 0;
+}
+#endif
+
+#define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
+#define to_slab(n) container_of(n, struct kmem_cache, kobj)
+
+struct slab_attribute {
+ struct attribute attr;
+ ssize_t (*show)(struct kmem_cache *s, char *buf);
+ ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
+};
+
+#define SLAB_ATTR_RO(_name) \
+ static struct slab_attribute _name##_attr = \
+ __ATTR(_name, 0400, _name##_show, NULL)
+
+#define SLAB_ATTR(_name) \
+ static struct slab_attribute _name##_attr = \
+ __ATTR(_name, 0600, _name##_show, _name##_store)
+
+static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", s->size);
+}
+SLAB_ATTR_RO(slab_size);
+
+static ssize_t align_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", s->align);
+}
+SLAB_ATTR_RO(align);
+
+static ssize_t object_size_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", s->objsize);
+}
+SLAB_ATTR_RO(object_size);
+
+static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", oo_objects(s->oo));
+}
+SLAB_ATTR_RO(objs_per_slab);
+
+static ssize_t order_store(struct kmem_cache *s,
+ const char *buf, size_t length)
+{
+ unsigned long order;
+ int err;
+
+ err = strict_strtoul(buf, 10, &order);
+ if (err)
+ return err;
+
+ if (order > slub_max_order || order < slub_min_order)
+ return -EINVAL;
+
+ calculate_sizes(s, order);
+ return length;
+}
+
+static ssize_t order_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", oo_order(s->oo));
+}
+SLAB_ATTR(order);
+
+static ssize_t min_partial_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%lu\n", s->min_partial);
+}
+
+static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
+ size_t length)
+{
+ unsigned long min;
+ int err;
+
+ err = strict_strtoul(buf, 10, &min);
+ if (err)
+ return err;
+
+ set_min_partial(s, min);
+ return length;
+}
+SLAB_ATTR(min_partial);
+
+static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%u\n", s->cpu_partial);
+}
+
+static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
+ size_t length)
+{
+ unsigned long objects;
+ int err;
+
+ err = strict_strtoul(buf, 10, &objects);
+ if (err)
+ return err;
+ if (objects && kmem_cache_debug(s))
+ return -EINVAL;
+
+ s->cpu_partial = objects;
+ flush_all(s);
+ return length;
+}
+SLAB_ATTR(cpu_partial);
+
+static ssize_t ctor_show(struct kmem_cache *s, char *buf)
+{
+ if (!s->ctor)
+ return 0;
+ return sprintf(buf, "%pS\n", s->ctor);
+}
+SLAB_ATTR_RO(ctor);
+
+static ssize_t aliases_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", s->refcount - 1);
+}
+SLAB_ATTR_RO(aliases);
+
+static ssize_t partial_show(struct kmem_cache *s, char *buf)
+{
+ return show_slab_objects(s, buf, SO_PARTIAL);
+}
+SLAB_ATTR_RO(partial);
+
+static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
+{
+ return show_slab_objects(s, buf, SO_CPU);
+}
+SLAB_ATTR_RO(cpu_slabs);
+
+static ssize_t objects_show(struct kmem_cache *s, char *buf)
+{
+ return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
+}
+SLAB_ATTR_RO(objects);
+
+static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
+{
+ return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
+}
+SLAB_ATTR_RO(objects_partial);
+
+static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf)
+{
+ int objects = 0;
+ int pages = 0;
+ int cpu;
+ int len;
+
+ for_each_online_cpu(cpu) {
+ struct page *page = per_cpu_ptr(s->cpu_slab, cpu)->partial;
+
+ if (page) {
+ pages += page->pages;
+ objects += page->pobjects;
+ }
+ }
+
+ len = sprintf(buf, "%d(%d)", objects, pages);
+
+#ifdef CONFIG_SMP
+ for_each_online_cpu(cpu) {
+ struct page *page = per_cpu_ptr(s->cpu_slab, cpu) ->partial;
+
+ if (page && len < PAGE_SIZE - 20)
+ len += sprintf(buf + len, " C%d=%d(%d)", cpu,
+ page->pobjects, page->pages);
+ }
+#endif
+ return len + sprintf(buf + len, "\n");
+}
+SLAB_ATTR_RO(slabs_cpu_partial);
+
+static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
+}
+
+static ssize_t reclaim_account_store(struct kmem_cache *s,
+ const char *buf, size_t length)
+{
+ s->flags &= ~SLAB_RECLAIM_ACCOUNT;
+ if (buf[0] == '1')
+ s->flags |= SLAB_RECLAIM_ACCOUNT;
+ return length;
+}
+SLAB_ATTR(reclaim_account);
+
+static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
+}
+SLAB_ATTR_RO(hwcache_align);
+
+#ifdef CONFIG_ZONE_DMA
+static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
+}
+SLAB_ATTR_RO(cache_dma);
+#endif
+
+static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
+}
+SLAB_ATTR_RO(destroy_by_rcu);
+
+static ssize_t reserved_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", s->reserved);
+}
+SLAB_ATTR_RO(reserved);
+
+#ifdef CONFIG_SLUB_DEBUG
+static ssize_t slabs_show(struct kmem_cache *s, char *buf)
+{
+ return show_slab_objects(s, buf, SO_ALL);
+}
+SLAB_ATTR_RO(slabs);
+
+static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
+{
+ return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
+}
+SLAB_ATTR_RO(total_objects);
+
+static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
+}
+
+static ssize_t sanity_checks_store(struct kmem_cache *s,
+ const char *buf, size_t length)
+{
+ s->flags &= ~SLAB_DEBUG_FREE;
+ if (buf[0] == '1') {
+ s->flags &= ~__CMPXCHG_DOUBLE;
+ s->flags |= SLAB_DEBUG_FREE;
+ }
+ return length;
+}
+SLAB_ATTR(sanity_checks);
+
+static ssize_t trace_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
+}
+
+static ssize_t trace_store(struct kmem_cache *s, const char *buf,
+ size_t length)
+{
+ s->flags &= ~SLAB_TRACE;
+ if (buf[0] == '1') {
+ s->flags &= ~__CMPXCHG_DOUBLE;
+ s->flags |= SLAB_TRACE;
+ }
+ return length;
+}
+SLAB_ATTR(trace);
+
+static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
+}
+
+static ssize_t red_zone_store(struct kmem_cache *s,
+ const char *buf, size_t length)
+{
+ if (any_slab_objects(s))
+ return -EBUSY;
+
+ s->flags &= ~SLAB_RED_ZONE;
+ if (buf[0] == '1') {
+ s->flags &= ~__CMPXCHG_DOUBLE;
+ s->flags |= SLAB_RED_ZONE;
+ }
+ calculate_sizes(s, -1);
+ return length;
+}
+SLAB_ATTR(red_zone);
+
+static ssize_t poison_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
+}
+
+static ssize_t poison_store(struct kmem_cache *s,
+ const char *buf, size_t length)
+{
+ if (any_slab_objects(s))
+ return -EBUSY;
+
+ s->flags &= ~SLAB_POISON;
+ if (buf[0] == '1') {
+ s->flags &= ~__CMPXCHG_DOUBLE;
+ s->flags |= SLAB_POISON;
+ }
+ calculate_sizes(s, -1);
+ return length;
+}
+SLAB_ATTR(poison);
+
+static ssize_t store_user_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
+}
+
+static ssize_t store_user_store(struct kmem_cache *s,
+ const char *buf, size_t length)
+{
+ if (any_slab_objects(s))
+ return -EBUSY;
+
+ s->flags &= ~SLAB_STORE_USER;
+ if (buf[0] == '1') {
+ s->flags &= ~__CMPXCHG_DOUBLE;
+ s->flags |= SLAB_STORE_USER;
+ }
+ calculate_sizes(s, -1);
+ return length;
+}
+SLAB_ATTR(store_user);
+
+static ssize_t validate_show(struct kmem_cache *s, char *buf)
+{
+ return 0;
+}
+
+static ssize_t validate_store(struct kmem_cache *s,
+ const char *buf, size_t length)
+{
+ int ret = -EINVAL;
+
+ if (buf[0] == '1') {
+ ret = validate_slab_cache(s);
+ if (ret >= 0)
+ ret = length;
+ }
+ return ret;
+}
+SLAB_ATTR(validate);
+
+static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
+{
+ if (!(s->flags & SLAB_STORE_USER))
+ return -ENOSYS;
+ return list_locations(s, buf, TRACK_ALLOC);
+}
+SLAB_ATTR_RO(alloc_calls);
+
+static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
+{
+ if (!(s->flags & SLAB_STORE_USER))
+ return -ENOSYS;
+ return list_locations(s, buf, TRACK_FREE);
+}
+SLAB_ATTR_RO(free_calls);
+#endif /* CONFIG_SLUB_DEBUG */
+
+#ifdef CONFIG_FAILSLAB
+static ssize_t failslab_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
+}
+
+static ssize_t failslab_store(struct kmem_cache *s, const char *buf,
+ size_t length)
+{
+ s->flags &= ~SLAB_FAILSLAB;
+ if (buf[0] == '1')
+ s->flags |= SLAB_FAILSLAB;
+ return length;
+}
+SLAB_ATTR(failslab);
+#endif
+
+static ssize_t shrink_show(struct kmem_cache *s, char *buf)
+{
+ return 0;
+}
+
+static ssize_t shrink_store(struct kmem_cache *s,
+ const char *buf, size_t length)
+{
+ if (buf[0] == '1') {
+ int rc = kmem_cache_shrink(s);
+
+ if (rc)
+ return rc;
+ } else
+ return -EINVAL;
+ return length;
+}
+SLAB_ATTR(shrink);
+
+#ifdef CONFIG_NUMA
+static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
+{
+ return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10);
+}
+
+static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
+ const char *buf, size_t length)
+{
+ unsigned long ratio;
+ int err;
+
+ err = strict_strtoul(buf, 10, &ratio);
+ if (err)
+ return err;
+
+ if (ratio <= 100)
+ s->remote_node_defrag_ratio = ratio * 10;
+
+ return length;
+}
+SLAB_ATTR(remote_node_defrag_ratio);
+#endif
+
+#ifdef CONFIG_SLUB_STATS
+static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
+{
+ unsigned long sum = 0;
+ int cpu;
+ int len;
+ int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
+
+ if (!data)
+ return -ENOMEM;
+
+ for_each_online_cpu(cpu) {
+ unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si];
+
+ data[cpu] = x;
+ sum += x;
+ }
+
+ len = sprintf(buf, "%lu", sum);
+
+#ifdef CONFIG_SMP
+ for_each_online_cpu(cpu) {
+ if (data[cpu] && len < PAGE_SIZE - 20)
+ len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]);
+ }
+#endif
+ kfree(data);
+ return len + sprintf(buf + len, "\n");
+}
+
+static void clear_stat(struct kmem_cache *s, enum stat_item si)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu)
+ per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0;
+}
+
+#define STAT_ATTR(si, text) \
+static ssize_t text##_show(struct kmem_cache *s, char *buf) \
+{ \
+ return show_stat(s, buf, si); \
+} \
+static ssize_t text##_store(struct kmem_cache *s, \
+ const char *buf, size_t length) \
+{ \
+ if (buf[0] != '0') \
+ return -EINVAL; \
+ clear_stat(s, si); \
+ return length; \
+} \
+SLAB_ATTR(text); \
+
+STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
+STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
+STAT_ATTR(FREE_FASTPATH, free_fastpath);
+STAT_ATTR(FREE_SLOWPATH, free_slowpath);
+STAT_ATTR(FREE_FROZEN, free_frozen);
+STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
+STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
+STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
+STAT_ATTR(ALLOC_SLAB, alloc_slab);
+STAT_ATTR(ALLOC_REFILL, alloc_refill);
+STAT_ATTR(ALLOC_NODE_MISMATCH, alloc_node_mismatch);
+STAT_ATTR(FREE_SLAB, free_slab);
+STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
+STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
+STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
+STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
+STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
+STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
+STAT_ATTR(DEACTIVATE_BYPASS, deactivate_bypass);
+STAT_ATTR(ORDER_FALLBACK, order_fallback);
+STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail);
+STAT_ATTR(CMPXCHG_DOUBLE_FAIL, cmpxchg_double_fail);
+STAT_ATTR(CPU_PARTIAL_ALLOC, cpu_partial_alloc);
+STAT_ATTR(CPU_PARTIAL_FREE, cpu_partial_free);
+STAT_ATTR(CPU_PARTIAL_NODE, cpu_partial_node);
+STAT_ATTR(CPU_PARTIAL_DRAIN, cpu_partial_drain);
+#endif
+
+static struct attribute *slab_attrs[] = {
+ &slab_size_attr.attr,
+ &object_size_attr.attr,
+ &objs_per_slab_attr.attr,
+ &order_attr.attr,
+ &min_partial_attr.attr,
+ &cpu_partial_attr.attr,
+ &objects_attr.attr,
+ &objects_partial_attr.attr,
+ &partial_attr.attr,
+ &cpu_slabs_attr.attr,
+ &ctor_attr.attr,
+ &aliases_attr.attr,
+ &align_attr.attr,
+ &hwcache_align_attr.attr,
+ &reclaim_account_attr.attr,
+ &destroy_by_rcu_attr.attr,
+ &shrink_attr.attr,
+ &reserved_attr.attr,
+ &slabs_cpu_partial_attr.attr,
+#ifdef CONFIG_SLUB_DEBUG
+ &total_objects_attr.attr,
+ &slabs_attr.attr,
+ &sanity_checks_attr.attr,
+ &trace_attr.attr,
+ &red_zone_attr.attr,
+ &poison_attr.attr,
+ &store_user_attr.attr,
+ &validate_attr.attr,
+ &alloc_calls_attr.attr,
+ &free_calls_attr.attr,
+#endif
+#ifdef CONFIG_ZONE_DMA
+ &cache_dma_attr.attr,
+#endif
+#ifdef CONFIG_NUMA
+ &remote_node_defrag_ratio_attr.attr,
+#endif
+#ifdef CONFIG_SLUB_STATS
+ &alloc_fastpath_attr.attr,
+ &alloc_slowpath_attr.attr,
+ &free_fastpath_attr.attr,
+ &free_slowpath_attr.attr,
+ &free_frozen_attr.attr,
+ &free_add_partial_attr.attr,
+ &free_remove_partial_attr.attr,
+ &alloc_from_partial_attr.attr,
+ &alloc_slab_attr.attr,
+ &alloc_refill_attr.attr,
+ &alloc_node_mismatch_attr.attr,
+ &free_slab_attr.attr,
+ &cpuslab_flush_attr.attr,
+ &deactivate_full_attr.attr,
+ &deactivate_empty_attr.attr,
+ &deactivate_to_head_attr.attr,
+ &deactivate_to_tail_attr.attr,
+ &deactivate_remote_frees_attr.attr,
+ &deactivate_bypass_attr.attr,
+ &order_fallback_attr.attr,
+ &cmpxchg_double_fail_attr.attr,
+ &cmpxchg_double_cpu_fail_attr.attr,
+ &cpu_partial_alloc_attr.attr,
+ &cpu_partial_free_attr.attr,
+ &cpu_partial_node_attr.attr,
+ &cpu_partial_drain_attr.attr,
+#endif
+#ifdef CONFIG_FAILSLAB
+ &failslab_attr.attr,
+#endif
+
+ NULL
+};
+
+static struct attribute_group slab_attr_group = {
+ .attrs = slab_attrs,
+};
+
+static ssize_t slab_attr_show(struct kobject *kobj,
+ struct attribute *attr,
+ char *buf)
+{
+ struct slab_attribute *attribute;
+ struct kmem_cache *s;
+ int err;
+
+ attribute = to_slab_attr(attr);
+ s = to_slab(kobj);
+
+ if (!attribute->show)
+ return -EIO;
+
+ err = attribute->show(s, buf);
+
+ return err;
+}
+
+static ssize_t slab_attr_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buf, size_t len)
+{
+ struct slab_attribute *attribute;
+ struct kmem_cache *s;
+ int err;
+
+ attribute = to_slab_attr(attr);
+ s = to_slab(kobj);
+
+ if (!attribute->store)
+ return -EIO;
+
+ err = attribute->store(s, buf, len);
+
+ return err;
+}
+
+static void kmem_cache_release(struct kobject *kobj)
+{
+ struct kmem_cache *s = to_slab(kobj);
+
+ kfree(s->name);
+ kfree(s);
+}
+
+static const struct sysfs_ops slab_sysfs_ops = {
+ .show = slab_attr_show,
+ .store = slab_attr_store,
+};
+
+static struct kobj_type slab_ktype = {
+ .sysfs_ops = &slab_sysfs_ops,
+ .release = kmem_cache_release
+};
+
+static int uevent_filter(struct kset *kset, struct kobject *kobj)
+{
+ struct kobj_type *ktype = get_ktype(kobj);
+
+ if (ktype == &slab_ktype)
+ return 1;
+ return 0;
+}
+
+static const struct kset_uevent_ops slab_uevent_ops = {
+ .filter = uevent_filter,
+};
+
+static struct kset *slab_kset;
+
+#define ID_STR_LENGTH 64
+
+/* Create a unique string id for a slab cache:
+ *
+ * Format :[flags-]size
+ */
+static char *create_unique_id(struct kmem_cache *s)
+{
+ char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
+ char *p = name;
+
+ BUG_ON(!name);
+
+ *p++ = ':';
+ /*
+ * First flags affecting slabcache operations. We will only
+ * get here for aliasable slabs so we do not need to support
+ * too many flags. The flags here must cover all flags that
+ * are matched during merging to guarantee that the id is
+ * unique.
+ */
+ if (s->flags & SLAB_CACHE_DMA)
+ *p++ = 'd';
+ if (s->flags & SLAB_RECLAIM_ACCOUNT)
+ *p++ = 'a';
+ if (s->flags & SLAB_DEBUG_FREE)
+ *p++ = 'F';
+ if (!(s->flags & SLAB_NOTRACK))
+ *p++ = 't';
+ if (p != name + 1)
+ *p++ = '-';
+ p += sprintf(p, "%07d", s->size);
+ BUG_ON(p > name + ID_STR_LENGTH - 1);
+ return name;
+}
+
+static int sysfs_slab_add(struct kmem_cache *s)
+{
+ int err;
+ const char *name;
+ int unmergeable;
+
+ if (slab_state < SYSFS)
+ /* Defer until later */
+ return 0;
+
+ unmergeable = slab_unmergeable(s);
+ if (unmergeable) {
+ /*
+ * Slabcache can never be merged so we can use the name proper.
+ * This is typically the case for debug situations. In that
+ * case we can catch duplicate names easily.
+ */
+ sysfs_remove_link(&slab_kset->kobj, s->name);
+ name = s->name;
+ } else {
+ /*
+ * Create a unique name for the slab as a target
+ * for the symlinks.
+ */
+ name = create_unique_id(s);
+ }
+
+ s->kobj.kset = slab_kset;
+ err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
+ if (err) {
+ kobject_put(&s->kobj);
+ return err;
+ }
+
+ err = sysfs_create_group(&s->kobj, &slab_attr_group);
+ if (err) {
+ kobject_del(&s->kobj);
+ kobject_put(&s->kobj);
+ return err;
+ }
+ kobject_uevent(&s->kobj, KOBJ_ADD);
+ if (!unmergeable) {
+ /* Setup first alias */
+ sysfs_slab_alias(s, s->name);
+ kfree(name);
+ }
+ return 0;
+}
+
+static void sysfs_slab_remove(struct kmem_cache *s)
+{
+ if (slab_state < SYSFS)
+ /*
+ * Sysfs has not been setup yet so no need to remove the
+ * cache from sysfs.
+ */
+ return;
+
+ kobject_uevent(&s->kobj, KOBJ_REMOVE);
+ kobject_del(&s->kobj);
+ kobject_put(&s->kobj);
+}
+
+/*
+ * Need to buffer aliases during bootup until sysfs becomes
+ * available lest we lose that information.
+ */
+struct saved_alias {
+ struct kmem_cache *s;
+ const char *name;
+ struct saved_alias *next;
+};
+
+static struct saved_alias *alias_list;
+
+static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
+{
+ struct saved_alias *al;
+
+ if (slab_state == SYSFS) {
+ /*
+ * If we have a leftover link then remove it.
+ */
+ sysfs_remove_link(&slab_kset->kobj, name);
+ return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
+ }
+
+ al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
+ if (!al)
+ return -ENOMEM;
+
+ al->s = s;
+ al->name = name;
+ al->next = alias_list;
+ alias_list = al;
+ return 0;
+}
+
+static int __init slab_sysfs_init(void)
+{
+ struct kmem_cache *s;
+ int err;
+
+ down_write(&slub_lock);
+
+ slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj);
+ if (!slab_kset) {
+ up_write(&slub_lock);
+ printk(KERN_ERR "Cannot register slab subsystem.\n");
+ return -ENOSYS;
+ }
+
+ slab_state = SYSFS;
+
+ list_for_each_entry(s, &slab_caches, list) {
+ err = sysfs_slab_add(s);
+ if (err)
+ printk(KERN_ERR "SLUB: Unable to add boot slab %s"
+ " to sysfs\n", s->name);
+ }
+
+ while (alias_list) {
+ struct saved_alias *al = alias_list;
+
+ alias_list = alias_list->next;
+ err = sysfs_slab_alias(al->s, al->name);
+ if (err)
+ printk(KERN_ERR "SLUB: Unable to add boot slab alias"
+ " %s to sysfs\n", s->name);
+ kfree(al);
+ }
+
+ up_write(&slub_lock);
+ resiliency_test();
+ return 0;
+}
+
+__initcall(slab_sysfs_init);
+#endif /* CONFIG_SYSFS */
+
+/*
+ * The /proc/slabinfo ABI
+ */
+#ifdef CONFIG_SLABINFO
+static void print_slabinfo_header(struct seq_file *m)
+{
+ seq_puts(m, "slabinfo - version: 2.1\n");
+ seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
+ "<objperslab> <pagesperslab>");
+ seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
+ seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
+ seq_putc(m, '\n');
+}
+
+static void *s_start(struct seq_file *m, loff_t *pos)
+{
+ loff_t n = *pos;
+
+ down_read(&slub_lock);
+ if (!n)
+ print_slabinfo_header(m);
+
+ return seq_list_start(&slab_caches, *pos);
+}
+
+static void *s_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ return seq_list_next(p, &slab_caches, pos);
+}
+
+static void s_stop(struct seq_file *m, void *p)
+{
+ up_read(&slub_lock);
+}
+
+static int s_show(struct seq_file *m, void *p)
+{
+ unsigned long nr_partials = 0;
+ unsigned long nr_slabs = 0;
+ unsigned long nr_inuse = 0;
+ unsigned long nr_objs = 0;
+ unsigned long nr_free = 0;
+ struct kmem_cache *s;
+ int node;
+
+ s = list_entry(p, struct kmem_cache, list);
+
+ for_each_online_node(node) {
+ struct kmem_cache_node *n = get_node(s, node);
+
+ if (!n)
+ continue;
+
+ nr_partials += n->nr_partial;
+ nr_slabs += atomic_long_read(&n->nr_slabs);
+ nr_objs += atomic_long_read(&n->total_objects);
+ nr_free += count_partial(n, count_free);
+ }
+
+ nr_inuse = nr_objs - nr_free;
+
+ seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
+ nr_objs, s->size, oo_objects(s->oo),
+ (1 << oo_order(s->oo)));
+ seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
+ seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
+ 0UL);
+ seq_putc(m, '\n');
+ return 0;
+}
+
+static const struct seq_operations slabinfo_op = {
+ .start = s_start,
+ .next = s_next,
+ .stop = s_stop,
+ .show = s_show,
+};
+
+static int slabinfo_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &slabinfo_op);
+}
+
+static const struct file_operations proc_slabinfo_operations = {
+ .open = slabinfo_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static int __init slab_proc_init(void)
+{
+ proc_create("slabinfo", S_IRUSR, NULL, &proc_slabinfo_operations);
+ return 0;
+}
+module_init(slab_proc_init);
+#endif /* CONFIG_SLABINFO */
diff --git a/ap/os/linux/linux-3.4.x/mm/sparse-vmemmap.c b/ap/os/linux/linux-3.4.x/mm/sparse-vmemmap.c
new file mode 100644
index 0000000..1b7e22a
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/sparse-vmemmap.c
@@ -0,0 +1,226 @@
+/*
+ * Virtual Memory Map support
+ *
+ * (C) 2007 sgi. Christoph Lameter.
+ *
+ * Virtual memory maps allow VM primitives pfn_to_page, page_to_pfn,
+ * virt_to_page, page_address() to be implemented as a base offset
+ * calculation without memory access.
+ *
+ * However, virtual mappings need a page table and TLBs. Many Linux
+ * architectures already map their physical space using 1-1 mappings
+ * via TLBs. For those arches the virtual memory map is essentially
+ * for free if we use the same page size as the 1-1 mappings. In that
+ * case the overhead consists of a few additional pages that are
+ * allocated to create a view of memory for vmemmap.
+ *
+ * The architecture is expected to provide a vmemmap_populate() function
+ * to instantiate the mapping.
+ */
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include <linux/sched.h>
+#include <asm/dma.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+/*
+ * Allocate a block of memory to be used to back the virtual memory map
+ * or to back the page tables that are used to create the mapping.
+ * Uses the main allocators if they are available, else bootmem.
+ */
+
+static void * __init_refok __earlyonly_bootmem_alloc(int node,
+ unsigned long size,
+ unsigned long align,
+ unsigned long goal)
+{
+ return __alloc_bootmem_node_high(NODE_DATA(node), size, align, goal);
+}
+
+static void *vmemmap_buf;
+static void *vmemmap_buf_end;
+
+void * __meminit vmemmap_alloc_block(unsigned long size, int node)
+{
+ /* If the main allocator is up use that, fallback to bootmem. */
+ if (slab_is_available()) {
+ struct page *page;
+
+ if (node_state(node, N_HIGH_MEMORY))
+ page = alloc_pages_node(node,
+ GFP_KERNEL | __GFP_ZERO, get_order(size));
+ else
+ page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
+ get_order(size));
+ if (page)
+ return page_address(page);
+ return NULL;
+ } else
+ return __earlyonly_bootmem_alloc(node, size, size,
+ __pa(MAX_DMA_ADDRESS));
+}
+
+/* need to make sure size is all the same during early stage */
+void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node)
+{
+ void *ptr;
+
+ if (!vmemmap_buf)
+ return vmemmap_alloc_block(size, node);
+
+ /* take the from buf */
+ ptr = (void *)ALIGN((unsigned long)vmemmap_buf, size);
+ if (ptr + size > vmemmap_buf_end)
+ return vmemmap_alloc_block(size, node);
+
+ vmemmap_buf = ptr + size;
+
+ return ptr;
+}
+
+void __meminit vmemmap_verify(pte_t *pte, int node,
+ unsigned long start, unsigned long end)
+{
+ unsigned long pfn = pte_pfn(*pte);
+ int actual_node = early_pfn_to_nid(pfn);
+
+ if (node_distance(actual_node, node) > LOCAL_DISTANCE)
+ printk(KERN_WARNING "[%lx-%lx] potential offnode "
+ "page_structs\n", start, end - 1);
+}
+
+pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
+{
+ pte_t *pte = pte_offset_kernel(pmd, addr);
+ if (pte_none(*pte)) {
+ pte_t entry;
+ void *p = vmemmap_alloc_block_buf(PAGE_SIZE, node);
+ if (!p)
+ return NULL;
+ entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
+ set_pte_at(&init_mm, addr, pte, entry);
+ }
+ return pte;
+}
+
+pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
+{
+ pmd_t *pmd = pmd_offset(pud, addr);
+ if (pmd_none(*pmd)) {
+ void *p = vmemmap_alloc_block(PAGE_SIZE, node);
+ if (!p)
+ return NULL;
+ pmd_populate_kernel(&init_mm, pmd, p);
+ }
+ return pmd;
+}
+
+pud_t * __meminit vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node)
+{
+ pud_t *pud = pud_offset(pgd, addr);
+ if (pud_none(*pud)) {
+ void *p = vmemmap_alloc_block(PAGE_SIZE, node);
+ if (!p)
+ return NULL;
+ pud_populate(&init_mm, pud, p);
+ }
+ return pud;
+}
+
+pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
+{
+ pgd_t *pgd = pgd_offset_k(addr);
+ if (pgd_none(*pgd)) {
+ void *p = vmemmap_alloc_block(PAGE_SIZE, node);
+ if (!p)
+ return NULL;
+ pgd_populate(&init_mm, pgd, p);
+ }
+ return pgd;
+}
+
+int __meminit vmemmap_populate_basepages(struct page *start_page,
+ unsigned long size, int node)
+{
+ unsigned long addr = (unsigned long)start_page;
+ unsigned long end = (unsigned long)(start_page + size);
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ for (; addr < end; addr += PAGE_SIZE) {
+ pgd = vmemmap_pgd_populate(addr, node);
+ if (!pgd)
+ return -ENOMEM;
+ pud = vmemmap_pud_populate(pgd, addr, node);
+ if (!pud)
+ return -ENOMEM;
+ pmd = vmemmap_pmd_populate(pud, addr, node);
+ if (!pmd)
+ return -ENOMEM;
+ pte = vmemmap_pte_populate(pmd, addr, node);
+ if (!pte)
+ return -ENOMEM;
+ vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
+ }
+
+ return 0;
+}
+
+struct page * __meminit sparse_mem_map_populate(unsigned long pnum, int nid)
+{
+ struct page *map = pfn_to_page(pnum * PAGES_PER_SECTION);
+ int error = vmemmap_populate(map, PAGES_PER_SECTION, nid);
+ if (error)
+ return NULL;
+
+ return map;
+}
+
+void __init sparse_mem_maps_populate_node(struct page **map_map,
+ unsigned long pnum_begin,
+ unsigned long pnum_end,
+ unsigned long map_count, int nodeid)
+{
+ unsigned long pnum;
+ unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
+ void *vmemmap_buf_start;
+
+ size = ALIGN(size, PMD_SIZE);
+ vmemmap_buf_start = __earlyonly_bootmem_alloc(nodeid, size * map_count,
+ PMD_SIZE, __pa(MAX_DMA_ADDRESS));
+
+ if (vmemmap_buf_start) {
+ vmemmap_buf = vmemmap_buf_start;
+ vmemmap_buf_end = vmemmap_buf_start + size * map_count;
+ }
+
+ for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
+ struct mem_section *ms;
+
+ if (!present_section_nr(pnum))
+ continue;
+
+ map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
+ if (map_map[pnum])
+ continue;
+ ms = __nr_to_section(pnum);
+ printk(KERN_ERR "%s: sparsemem memory map backing failed "
+ "some memory will not be available.\n", __func__);
+ ms->section_mem_map = 0;
+ }
+
+ if (vmemmap_buf_start) {
+ /* need to free left buf */
+ free_bootmem(__pa(vmemmap_buf), vmemmap_buf_end - vmemmap_buf);
+ vmemmap_buf = NULL;
+ vmemmap_buf_end = NULL;
+ }
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/sparse.c b/ap/os/linux/linux-3.4.x/mm/sparse.c
new file mode 100644
index 0000000..42935b5
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/sparse.c
@@ -0,0 +1,794 @@
+/*
+ * sparse memory mappings.
+ */
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/mmzone.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/export.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include "internal.h"
+#include <asm/dma.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+/*
+ * Permanent SPARSEMEM data:
+ *
+ * 1) mem_section - memory sections, mem_map's for valid memory
+ */
+#ifdef CONFIG_SPARSEMEM_EXTREME
+struct mem_section *mem_section[NR_SECTION_ROOTS]
+ ____cacheline_internodealigned_in_smp;
+#else
+struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
+ ____cacheline_internodealigned_in_smp;
+#endif
+EXPORT_SYMBOL(mem_section);
+
+#ifdef NODE_NOT_IN_PAGE_FLAGS
+/*
+ * If we did not store the node number in the page then we have to
+ * do a lookup in the section_to_node_table in order to find which
+ * node the page belongs to.
+ */
+#if MAX_NUMNODES <= 256
+static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
+#else
+static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
+#endif
+
+int page_to_nid(const struct page *page)
+{
+ return section_to_node_table[page_to_section(page)];
+}
+EXPORT_SYMBOL(page_to_nid);
+
+static void set_section_nid(unsigned long section_nr, int nid)
+{
+ section_to_node_table[section_nr] = nid;
+}
+#else /* !NODE_NOT_IN_PAGE_FLAGS */
+static inline void set_section_nid(unsigned long section_nr, int nid)
+{
+}
+#endif
+
+#ifdef CONFIG_SPARSEMEM_EXTREME
+static struct mem_section noinline __init_refok *sparse_index_alloc(int nid)
+{
+ struct mem_section *section = NULL;
+ unsigned long array_size = SECTIONS_PER_ROOT *
+ sizeof(struct mem_section);
+
+ if (slab_is_available()) {
+ if (node_state(nid, N_HIGH_MEMORY))
+ section = kmalloc_node(array_size, GFP_KERNEL, nid);
+ else
+ section = kmalloc(array_size, GFP_KERNEL);
+ } else
+ section = alloc_bootmem_node(NODE_DATA(nid), array_size);
+
+ if (section)
+ memset(section, 0, array_size);
+
+ return section;
+}
+
+static int __meminit sparse_index_init(unsigned long section_nr, int nid)
+{
+ static DEFINE_SPINLOCK(index_init_lock);
+ unsigned long root = SECTION_NR_TO_ROOT(section_nr);
+ struct mem_section *section;
+ int ret = 0;
+
+ if (mem_section[root])
+ return -EEXIST;
+
+ section = sparse_index_alloc(nid);
+ if (!section)
+ return -ENOMEM;
+ /*
+ * This lock keeps two different sections from
+ * reallocating for the same index
+ */
+ spin_lock(&index_init_lock);
+
+ if (mem_section[root]) {
+ ret = -EEXIST;
+ goto out;
+ }
+
+ mem_section[root] = section;
+out:
+ spin_unlock(&index_init_lock);
+ return ret;
+}
+#else /* !SPARSEMEM_EXTREME */
+static inline int sparse_index_init(unsigned long section_nr, int nid)
+{
+ return 0;
+}
+#endif
+
+/*
+ * Although written for the SPARSEMEM_EXTREME case, this happens
+ * to also work for the flat array case because
+ * NR_SECTION_ROOTS==NR_MEM_SECTIONS.
+ */
+int __section_nr(struct mem_section* ms)
+{
+ unsigned long root_nr;
+ struct mem_section* root;
+
+ for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
+ root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
+ if (!root)
+ continue;
+
+ if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
+ break;
+ }
+
+ return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
+}
+
+/*
+ * During early boot, before section_mem_map is used for an actual
+ * mem_map, we use section_mem_map to store the section's NUMA
+ * node. This keeps us from having to use another data structure. The
+ * node information is cleared just before we store the real mem_map.
+ */
+static inline unsigned long sparse_encode_early_nid(int nid)
+{
+ return (nid << SECTION_NID_SHIFT);
+}
+
+static inline int sparse_early_nid(struct mem_section *section)
+{
+ return (section->section_mem_map >> SECTION_NID_SHIFT);
+}
+
+/* Validate the physical addressing limitations of the model */
+void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn,
+ unsigned long *end_pfn)
+{
+ unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
+
+ /*
+ * Sanity checks - do not allow an architecture to pass
+ * in larger pfns than the maximum scope of sparsemem:
+ */
+ if (*start_pfn > max_sparsemem_pfn) {
+ mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
+ "Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
+ *start_pfn, *end_pfn, max_sparsemem_pfn);
+ WARN_ON_ONCE(1);
+ *start_pfn = max_sparsemem_pfn;
+ *end_pfn = max_sparsemem_pfn;
+ } else if (*end_pfn > max_sparsemem_pfn) {
+ mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
+ "End of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
+ *start_pfn, *end_pfn, max_sparsemem_pfn);
+ WARN_ON_ONCE(1);
+ *end_pfn = max_sparsemem_pfn;
+ }
+}
+
+/* Record a memory area against a node. */
+void __init memory_present(int nid, unsigned long start, unsigned long end)
+{
+ unsigned long pfn;
+
+ start &= PAGE_SECTION_MASK;
+ mminit_validate_memmodel_limits(&start, &end);
+ for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
+ unsigned long section = pfn_to_section_nr(pfn);
+ struct mem_section *ms;
+
+ sparse_index_init(section, nid);
+ set_section_nid(section, nid);
+
+ ms = __nr_to_section(section);
+ if (!ms->section_mem_map)
+ ms->section_mem_map = sparse_encode_early_nid(nid) |
+ SECTION_MARKED_PRESENT;
+ }
+}
+
+/*
+ * Only used by the i386 NUMA architecures, but relatively
+ * generic code.
+ */
+unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ unsigned long pfn;
+ unsigned long nr_pages = 0;
+
+ mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
+ for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ if (nid != early_pfn_to_nid(pfn))
+ continue;
+
+ if (pfn_present(pfn))
+ nr_pages += PAGES_PER_SECTION;
+ }
+
+ return nr_pages * sizeof(struct page);
+}
+
+/*
+ * Subtle, we encode the real pfn into the mem_map such that
+ * the identity pfn - section_mem_map will return the actual
+ * physical page frame number.
+ */
+static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
+{
+ return (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
+}
+
+/*
+ * Decode mem_map from the coded memmap
+ */
+struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
+{
+ /* mask off the extra low bits of information */
+ coded_mem_map &= SECTION_MAP_MASK;
+ return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
+}
+
+static int __meminit sparse_init_one_section(struct mem_section *ms,
+ unsigned long pnum, struct page *mem_map,
+ unsigned long *pageblock_bitmap)
+{
+ if (!present_section(ms))
+ return -EINVAL;
+
+ ms->section_mem_map &= ~SECTION_MAP_MASK;
+ ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
+ SECTION_HAS_MEM_MAP;
+ ms->pageblock_flags = pageblock_bitmap;
+
+ return 1;
+}
+
+unsigned long usemap_size(void)
+{
+ unsigned long size_bytes;
+ size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
+ size_bytes = roundup(size_bytes, sizeof(unsigned long));
+ return size_bytes;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+static unsigned long *__kmalloc_section_usemap(void)
+{
+ return kmalloc(usemap_size(), GFP_KERNEL);
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+static unsigned long * __init
+sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
+ unsigned long count)
+{
+ unsigned long section_nr;
+
+ /*
+ * A page may contain usemaps for other sections preventing the
+ * page being freed and making a section unremovable while
+ * other sections referencing the usemap retmain active. Similarly,
+ * a pgdat can prevent a section being removed. If section A
+ * contains a pgdat and section B contains the usemap, both
+ * sections become inter-dependent. This allocates usemaps
+ * from the same section as the pgdat where possible to avoid
+ * this problem.
+ */
+ section_nr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
+ return alloc_bootmem_section(usemap_size() * count, section_nr);
+}
+
+static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
+{
+ unsigned long usemap_snr, pgdat_snr;
+ static unsigned long old_usemap_snr = NR_MEM_SECTIONS;
+ static unsigned long old_pgdat_snr = NR_MEM_SECTIONS;
+ struct pglist_data *pgdat = NODE_DATA(nid);
+ int usemap_nid;
+
+ usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT);
+ pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
+ if (usemap_snr == pgdat_snr)
+ return;
+
+ if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
+ /* skip redundant message */
+ return;
+
+ old_usemap_snr = usemap_snr;
+ old_pgdat_snr = pgdat_snr;
+
+ usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
+ if (usemap_nid != nid) {
+ printk(KERN_INFO
+ "node %d must be removed before remove section %ld\n",
+ nid, usemap_snr);
+ return;
+ }
+ /*
+ * There is a circular dependency.
+ * Some platforms allow un-removable section because they will just
+ * gather other removable sections for dynamic partitioning.
+ * Just notify un-removable section's number here.
+ */
+ printk(KERN_INFO "Section %ld and %ld (node %d)", usemap_snr,
+ pgdat_snr, nid);
+ printk(KERN_CONT
+ " have a circular dependency on usemap and pgdat allocations\n");
+}
+#else
+static unsigned long * __init
+sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
+ unsigned long count)
+{
+ return NULL;
+}
+
+static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
+{
+}
+#endif /* CONFIG_MEMORY_HOTREMOVE */
+
+static void __init sparse_early_usemaps_alloc_node(unsigned long**usemap_map,
+ unsigned long pnum_begin,
+ unsigned long pnum_end,
+ unsigned long usemap_count, int nodeid)
+{
+ void *usemap;
+ unsigned long pnum;
+ int size = usemap_size();
+
+ usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nodeid),
+ usemap_count);
+ if (!usemap) {
+ usemap = alloc_bootmem_node(NODE_DATA(nodeid), size * usemap_count);
+ if (!usemap) {
+ printk(KERN_WARNING "%s: allocation failed\n", __func__);
+ return;
+ }
+ }
+
+ for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
+ if (!present_section_nr(pnum))
+ continue;
+ usemap_map[pnum] = usemap;
+ usemap += size;
+ check_usemap_section_nr(nodeid, usemap_map[pnum]);
+ }
+}
+
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid)
+{
+ struct page *map;
+ unsigned long size;
+
+ map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
+ if (map)
+ return map;
+
+ size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
+ map = __alloc_bootmem_node_high(NODE_DATA(nid), size,
+ PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
+ return map;
+}
+void __init sparse_mem_maps_populate_node(struct page **map_map,
+ unsigned long pnum_begin,
+ unsigned long pnum_end,
+ unsigned long map_count, int nodeid)
+{
+ void *map;
+ unsigned long pnum;
+ unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
+
+ map = alloc_remap(nodeid, size * map_count);
+ if (map) {
+ for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
+ if (!present_section_nr(pnum))
+ continue;
+ map_map[pnum] = map;
+ map += size;
+ }
+ return;
+ }
+
+ size = PAGE_ALIGN(size);
+ map = __alloc_bootmem_node_high(NODE_DATA(nodeid), size * map_count,
+ PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
+ if (map) {
+ for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
+ if (!present_section_nr(pnum))
+ continue;
+ map_map[pnum] = map;
+ map += size;
+ }
+ return;
+ }
+
+ /* fallback */
+ for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
+ struct mem_section *ms;
+
+ if (!present_section_nr(pnum))
+ continue;
+ map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
+ if (map_map[pnum])
+ continue;
+ ms = __nr_to_section(pnum);
+ printk(KERN_ERR "%s: sparsemem memory map backing failed "
+ "some memory will not be available.\n", __func__);
+ ms->section_mem_map = 0;
+ }
+}
+#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
+
+#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
+static void __init sparse_early_mem_maps_alloc_node(struct page **map_map,
+ unsigned long pnum_begin,
+ unsigned long pnum_end,
+ unsigned long map_count, int nodeid)
+{
+ sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
+ map_count, nodeid);
+}
+#else
+static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
+{
+ struct page *map;
+ struct mem_section *ms = __nr_to_section(pnum);
+ int nid = sparse_early_nid(ms);
+
+ map = sparse_mem_map_populate(pnum, nid);
+ if (map)
+ return map;
+
+ printk(KERN_ERR "%s: sparsemem memory map backing failed "
+ "some memory will not be available.\n", __func__);
+ ms->section_mem_map = 0;
+ return NULL;
+}
+#endif
+
+void __attribute__((weak)) __meminit vmemmap_populate_print_last(void)
+{
+}
+
+/*
+ * Allocate the accumulated non-linear sections, allocate a mem_map
+ * for each and record the physical to section mapping.
+ */
+void __init sparse_init(void)
+{
+ unsigned long pnum;
+ struct page *map;
+ unsigned long *usemap;
+ unsigned long **usemap_map;
+ int size;
+ int nodeid_begin = 0;
+ unsigned long pnum_begin = 0;
+ unsigned long usemap_count;
+#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
+ unsigned long map_count;
+ int size2;
+ struct page **map_map;
+#endif
+
+ /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
+ set_pageblock_order();
+
+ /*
+ * map is using big page (aka 2M in x86 64 bit)
+ * usemap is less one page (aka 24 bytes)
+ * so alloc 2M (with 2M align) and 24 bytes in turn will
+ * make next 2M slip to one more 2M later.
+ * then in big system, the memory will have a lot of holes...
+ * here try to allocate 2M pages continuously.
+ *
+ * powerpc need to call sparse_init_one_section right after each
+ * sparse_early_mem_map_alloc, so allocate usemap_map at first.
+ */
+ size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
+ usemap_map = alloc_bootmem(size);
+ if (!usemap_map)
+ panic("can not allocate usemap_map\n");
+
+ for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
+ struct mem_section *ms;
+
+ if (!present_section_nr(pnum))
+ continue;
+ ms = __nr_to_section(pnum);
+ nodeid_begin = sparse_early_nid(ms);
+ pnum_begin = pnum;
+ break;
+ }
+ usemap_count = 1;
+ for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
+ struct mem_section *ms;
+ int nodeid;
+
+ if (!present_section_nr(pnum))
+ continue;
+ ms = __nr_to_section(pnum);
+ nodeid = sparse_early_nid(ms);
+ if (nodeid == nodeid_begin) {
+ usemap_count++;
+ continue;
+ }
+ /* ok, we need to take cake of from pnum_begin to pnum - 1*/
+ sparse_early_usemaps_alloc_node(usemap_map, pnum_begin, pnum,
+ usemap_count, nodeid_begin);
+ /* new start, update count etc*/
+ nodeid_begin = nodeid;
+ pnum_begin = pnum;
+ usemap_count = 1;
+ }
+ /* ok, last chunk */
+ sparse_early_usemaps_alloc_node(usemap_map, pnum_begin, NR_MEM_SECTIONS,
+ usemap_count, nodeid_begin);
+
+#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
+ size2 = sizeof(struct page *) * NR_MEM_SECTIONS;
+ map_map = alloc_bootmem(size2);
+ if (!map_map)
+ panic("can not allocate map_map\n");
+
+ for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
+ struct mem_section *ms;
+
+ if (!present_section_nr(pnum))
+ continue;
+ ms = __nr_to_section(pnum);
+ nodeid_begin = sparse_early_nid(ms);
+ pnum_begin = pnum;
+ break;
+ }
+ map_count = 1;
+ for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
+ struct mem_section *ms;
+ int nodeid;
+
+ if (!present_section_nr(pnum))
+ continue;
+ ms = __nr_to_section(pnum);
+ nodeid = sparse_early_nid(ms);
+ if (nodeid == nodeid_begin) {
+ map_count++;
+ continue;
+ }
+ /* ok, we need to take cake of from pnum_begin to pnum - 1*/
+ sparse_early_mem_maps_alloc_node(map_map, pnum_begin, pnum,
+ map_count, nodeid_begin);
+ /* new start, update count etc*/
+ nodeid_begin = nodeid;
+ pnum_begin = pnum;
+ map_count = 1;
+ }
+ /* ok, last chunk */
+ sparse_early_mem_maps_alloc_node(map_map, pnum_begin, NR_MEM_SECTIONS,
+ map_count, nodeid_begin);
+#endif
+
+ for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
+ if (!present_section_nr(pnum))
+ continue;
+
+ usemap = usemap_map[pnum];
+ if (!usemap)
+ continue;
+
+#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
+ map = map_map[pnum];
+#else
+ map = sparse_early_mem_map_alloc(pnum);
+#endif
+ if (!map)
+ continue;
+
+ sparse_init_one_section(__nr_to_section(pnum), pnum, map,
+ usemap);
+ }
+
+ vmemmap_populate_print_last();
+
+#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
+ free_bootmem(__pa(map_map), size2);
+#endif
+ free_bootmem(__pa(usemap_map), size);
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
+ unsigned long nr_pages)
+{
+ /* This will make the necessary allocations eventually. */
+ return sparse_mem_map_populate(pnum, nid);
+}
+static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
+{
+ return; /* XXX: Not implemented yet */
+}
+static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
+{
+}
+#else
+static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
+{
+ struct page *page, *ret;
+ unsigned long memmap_size = sizeof(struct page) * nr_pages;
+
+ page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
+ if (page)
+ goto got_map_page;
+
+ ret = vmalloc(memmap_size);
+ if (ret)
+ goto got_map_ptr;
+
+ return NULL;
+got_map_page:
+ ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
+got_map_ptr:
+ memset(ret, 0, memmap_size);
+
+ return ret;
+}
+
+static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
+ unsigned long nr_pages)
+{
+ return __kmalloc_section_memmap(nr_pages);
+}
+
+static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
+{
+ if (is_vmalloc_addr(memmap))
+ vfree(memmap);
+ else
+ free_pages((unsigned long)memmap,
+ get_order(sizeof(struct page) * nr_pages));
+}
+
+static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
+{
+ unsigned long maps_section_nr, removing_section_nr, i;
+ unsigned long magic;
+ struct page *page = virt_to_page(memmap);
+
+ for (i = 0; i < nr_pages; i++, page++) {
+ magic = (unsigned long) page->lru.next;
+
+ BUG_ON(magic == NODE_INFO);
+
+ maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
+ removing_section_nr = page->private;
+
+ /*
+ * When this function is called, the removing section is
+ * logical offlined state. This means all pages are isolated
+ * from page allocator. If removing section's memmap is placed
+ * on the same section, it must not be freed.
+ * If it is freed, page allocator may allocate it which will
+ * be removed physically soon.
+ */
+ if (maps_section_nr != removing_section_nr)
+ put_page_bootmem(page);
+ }
+}
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+
+static void free_section_usemap(struct page *memmap, unsigned long *usemap)
+{
+ struct page *usemap_page;
+ unsigned long nr_pages;
+
+ if (!usemap)
+ return;
+
+ usemap_page = virt_to_page(usemap);
+ /*
+ * Check to see if allocation came from hot-plug-add
+ */
+ if (PageSlab(usemap_page)) {
+ kfree(usemap);
+ if (memmap)
+ __kfree_section_memmap(memmap, PAGES_PER_SECTION);
+ return;
+ }
+
+ /*
+ * The usemap came from bootmem. This is packed with other usemaps
+ * on the section which has pgdat at boot time. Just keep it as is now.
+ */
+
+ if (memmap) {
+ nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
+ >> PAGE_SHIFT;
+
+ free_map_bootmem(memmap, nr_pages);
+ }
+}
+
+/*
+ * returns the number of sections whose mem_maps were properly
+ * set. If this is <=0, then that means that the passed-in
+ * map was not consumed and must be freed.
+ */
+int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
+ int nr_pages)
+{
+ unsigned long section_nr = pfn_to_section_nr(start_pfn);
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ struct mem_section *ms;
+ struct page *memmap;
+ unsigned long *usemap;
+ unsigned long flags;
+ int ret;
+
+ /*
+ * no locking for this, because it does its own
+ * plus, it does a kmalloc
+ */
+ ret = sparse_index_init(section_nr, pgdat->node_id);
+ if (ret < 0 && ret != -EEXIST)
+ return ret;
+ memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, nr_pages);
+ if (!memmap)
+ return -ENOMEM;
+ usemap = __kmalloc_section_usemap();
+ if (!usemap) {
+ __kfree_section_memmap(memmap, nr_pages);
+ return -ENOMEM;
+ }
+
+ pgdat_resize_lock(pgdat, &flags);
+
+ ms = __pfn_to_section(start_pfn);
+ if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
+ ret = -EEXIST;
+ goto out;
+ }
+
+ ms->section_mem_map |= SECTION_MARKED_PRESENT;
+
+ ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
+
+out:
+ pgdat_resize_unlock(pgdat, &flags);
+ if (ret <= 0) {
+ kfree(usemap);
+ __kfree_section_memmap(memmap, nr_pages);
+ }
+ return ret;
+}
+
+void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
+{
+ struct page *memmap = NULL;
+ unsigned long *usemap = NULL;
+
+ if (ms->section_mem_map) {
+ usemap = ms->pageblock_flags;
+ memmap = sparse_decode_mem_map(ms->section_mem_map,
+ __section_nr(ms));
+ ms->section_mem_map = 0;
+ ms->pageblock_flags = NULL;
+ }
+
+ free_section_usemap(memmap, usemap);
+}
+#endif
diff --git a/ap/os/linux/linux-3.4.x/mm/swap.c b/ap/os/linux/linux-3.4.x/mm/swap.c
new file mode 100644
index 0000000..08b3011
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/swap.c
@@ -0,0 +1,875 @@
+/*
+ * linux/mm/swap.c
+ *
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ */
+
+/*
+ * This file contains the default values for the operation of the
+ * Linux VM subsystem. Fine-tuning documentation can be found in
+ * Documentation/sysctl/vm.txt.
+ * Started 18.12.91
+ * Swap aging added 23.2.95, Stephen Tweedie.
+ * Buffermem limits added 12.3.98, Rik van Riel.
+ */
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/kernel_stat.h>
+#include <linux/swap.h>
+#include <linux/mman.h>
+#include <linux/pagemap.h>
+#include <linux/pagevec.h>
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/mm_inline.h>
+#include <linux/percpu_counter.h>
+#include <linux/percpu.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+#include <linux/backing-dev.h>
+#include <linux/memcontrol.h>
+#include <linux/gfp.h>
+#include <linux/hugetlb.h>
+#include <linux/locallock.h>
+
+#include "internal.h"
+
+/* How many pages do we try to swap or page in/out together? */
+int page_cluster;
+
+static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs);
+static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs);
+static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs);
+
+static DEFINE_LOCAL_IRQ_LOCK(rotate_lock);
+static DEFINE_LOCAL_IRQ_LOCK(swapvec_lock);
+
+/*
+ * This path almost never happens for VM activity - pages are normally
+ * freed via pagevecs. But it gets used by networking.
+ */
+static void __page_cache_release(struct page *page)
+{
+ if (PageLRU(page)) {
+ unsigned long flags;
+ struct zone *zone = page_zone(page);
+
+ spin_lock_irqsave(&zone->lru_lock, flags);
+ VM_BUG_ON(!PageLRU(page));
+ __ClearPageLRU(page);
+ del_page_from_lru_list(zone, page, page_off_lru(page));
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
+ }
+}
+
+static void __put_single_page(struct page *page)
+{
+ __page_cache_release(page);
+ free_hot_cold_page(page, 0);
+}
+
+static void __put_compound_page(struct page *page)
+{
+ compound_page_dtor *dtor;
+
+ if (!PageHuge(page))
+ __page_cache_release(page);
+ dtor = get_compound_page_dtor(page);
+ (*dtor)(page);
+}
+
+static void put_compound_page(struct page *page)
+{
+ if (unlikely(PageTail(page))) {
+ /* __split_huge_page_refcount can run under us */
+ struct page *page_head = compound_trans_head(page);
+
+ if (likely(page != page_head &&
+ get_page_unless_zero(page_head))) {
+ unsigned long flags;
+
+ if (PageHeadHuge(page_head)) {
+ if (likely(PageTail(page))) {
+ /*
+ * __split_huge_page_refcount
+ * cannot race here.
+ */
+ VM_BUG_ON(!PageHead(page_head));
+ atomic_dec(&page->_mapcount);
+ if (put_page_testzero(page_head))
+ VM_BUG_ON(1);
+ if (put_page_testzero(page_head))
+ __put_compound_page(page_head);
+ return;
+ } else {
+ /*
+ * __split_huge_page_refcount
+ * run before us, "page" was a
+ * THP tail. The split
+ * page_head has been freed
+ * and reallocated as slab or
+ * hugetlbfs page of smaller
+ * order (only possible if
+ * reallocated as slab on
+ * x86).
+ */
+ goto skip_lock;
+ }
+ }
+ /*
+ * page_head wasn't a dangling pointer but it
+ * may not be a head page anymore by the time
+ * we obtain the lock. That is ok as long as it
+ * can't be freed from under us.
+ */
+ flags = compound_lock_irqsave(page_head);
+ if (unlikely(!PageTail(page))) {
+ /* __split_huge_page_refcount run before us */
+ compound_unlock_irqrestore(page_head, flags);
+ VM_BUG_ON(PageHead(page_head));
+skip_lock:
+ if (put_page_testzero(page_head)) {
+ /*
+ * The head page may have been
+ * freed and reallocated as a
+ * compound page of smaller
+ * order and then freed again.
+ * All we know is that it
+ * cannot have become: a THP
+ * page, a compound page of
+ * higher order, a tail page.
+ * That is because we still
+ * hold the refcount of the
+ * split THP tail and
+ * page_head was the THP head
+ * before the split.
+ */
+ if (PageHead(page_head))
+ __put_compound_page(page_head);
+ else
+ __put_single_page(page_head);
+ }
+out_put_single:
+ if (put_page_testzero(page))
+ __put_single_page(page);
+ return;
+ }
+ VM_BUG_ON(page_head != page->first_page);
+ /*
+ * We can release the refcount taken by
+ * get_page_unless_zero() now that
+ * __split_huge_page_refcount() is blocked on
+ * the compound_lock.
+ */
+ if (put_page_testzero(page_head))
+ VM_BUG_ON(1);
+ /* __split_huge_page_refcount will wait now */
+ VM_BUG_ON(page_mapcount(page) <= 0);
+ atomic_dec(&page->_mapcount);
+ VM_BUG_ON(atomic_read(&page_head->_count) <= 0);
+ VM_BUG_ON(atomic_read(&page->_count) != 0);
+ compound_unlock_irqrestore(page_head, flags);
+ if (put_page_testzero(page_head)) {
+ if (PageHead(page_head))
+ __put_compound_page(page_head);
+ else
+ __put_single_page(page_head);
+ }
+ } else {
+ /* page_head is a dangling pointer */
+ VM_BUG_ON(PageTail(page));
+ goto out_put_single;
+ }
+ } else if (put_page_testzero(page)) {
+ if (PageHead(page))
+ __put_compound_page(page);
+ else
+ __put_single_page(page);
+ }
+}
+
+void put_page(struct page *page)
+{
+ if (unlikely(PageCompound(page)))
+ put_compound_page(page);
+ else if (put_page_testzero(page))
+ __put_single_page(page);
+}
+EXPORT_SYMBOL(put_page);
+
+/*
+ * This function is exported but must not be called by anything other
+ * than get_page(). It implements the slow path of get_page().
+ */
+bool __get_page_tail(struct page *page)
+{
+ /*
+ * This takes care of get_page() if run on a tail page
+ * returned by one of the get_user_pages/follow_page variants.
+ * get_user_pages/follow_page itself doesn't need the compound
+ * lock because it runs __get_page_tail_foll() under the
+ * proper PT lock that already serializes against
+ * split_huge_page().
+ */
+ unsigned long flags;
+ bool got = false;
+ struct page *page_head = compound_trans_head(page);
+
+ if (likely(page != page_head && get_page_unless_zero(page_head))) {
+ /* Ref to put_compound_page() comment. */
+ if (PageHeadHuge(page_head)) {
+ if (likely(PageTail(page))) {
+ /*
+ * This is a hugetlbfs
+ * page. __split_huge_page_refcount
+ * cannot race here.
+ */
+ VM_BUG_ON(!PageHead(page_head));
+ __get_page_tail_foll(page, false);
+ return true;
+ } else {
+ /*
+ * __split_huge_page_refcount run
+ * before us, "page" was a THP
+ * tail. The split page_head has been
+ * freed and reallocated as slab or
+ * hugetlbfs page of smaller order
+ * (only possible if reallocated as
+ * slab on x86).
+ */
+ put_page(page_head);
+ return false;
+ }
+ }
+ /*
+ * page_head wasn't a dangling pointer but it
+ * may not be a head page anymore by the time
+ * we obtain the lock. That is ok as long as it
+ * can't be freed from under us.
+ */
+ flags = compound_lock_irqsave(page_head);
+ /* here __split_huge_page_refcount won't run anymore */
+ if (likely(PageTail(page))) {
+ __get_page_tail_foll(page, false);
+ got = true;
+ }
+ compound_unlock_irqrestore(page_head, flags);
+ if (unlikely(!got))
+ put_page(page_head);
+ }
+ return got;
+}
+EXPORT_SYMBOL(__get_page_tail);
+
+/**
+ * put_pages_list() - release a list of pages
+ * @pages: list of pages threaded on page->lru
+ *
+ * Release a list of pages which are strung together on page.lru. Currently
+ * used by read_cache_pages() and related error recovery code.
+ */
+void put_pages_list(struct list_head *pages)
+{
+ while (!list_empty(pages)) {
+ struct page *victim;
+
+ victim = list_entry(pages->prev, struct page, lru);
+ list_del(&victim->lru);
+ page_cache_release(victim);
+ }
+}
+EXPORT_SYMBOL(put_pages_list);
+
+static void pagevec_lru_move_fn(struct pagevec *pvec,
+ void (*move_fn)(struct page *page, void *arg),
+ void *arg)
+{
+ int i;
+ struct zone *zone = NULL;
+ unsigned long flags = 0;
+
+ for (i = 0; i < pagevec_count(pvec); i++) {
+ struct page *page = pvec->pages[i];
+ struct zone *pagezone = page_zone(page);
+
+ if (pagezone != zone) {
+ if (zone)
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
+ zone = pagezone;
+ spin_lock_irqsave(&zone->lru_lock, flags);
+ }
+
+ (*move_fn)(page, arg);
+ }
+ if (zone)
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
+ release_pages(pvec->pages, pvec->nr, pvec->cold);
+ pagevec_reinit(pvec);
+}
+
+static void pagevec_move_tail_fn(struct page *page, void *arg)
+{
+ int *pgmoved = arg;
+
+ if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+ enum lru_list lru = page_lru_base_type(page);
+ struct lruvec *lruvec;
+
+ lruvec = mem_cgroup_lru_move_lists(page_zone(page),
+ page, lru, lru);
+ list_move_tail(&page->lru, &lruvec->lists[lru]);
+ (*pgmoved)++;
+ }
+}
+
+/*
+ * pagevec_move_tail() must be called with IRQ disabled.
+ * Otherwise this may cause nasty races.
+ */
+static void pagevec_move_tail(struct pagevec *pvec)
+{
+ int pgmoved = 0;
+
+ pagevec_lru_move_fn(pvec, pagevec_move_tail_fn, &pgmoved);
+ __count_vm_events(PGROTATED, pgmoved);
+}
+
+/*
+ * Writeback is about to end against a page which has been marked for immediate
+ * reclaim. If it still appears to be reclaimable, move it to the tail of the
+ * inactive list.
+ */
+void rotate_reclaimable_page(struct page *page)
+{
+ if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) &&
+ !PageUnevictable(page) && PageLRU(page)) {
+ struct pagevec *pvec;
+ unsigned long flags;
+
+ page_cache_get(page);
+ local_lock_irqsave(rotate_lock, flags);
+ pvec = &__get_cpu_var(lru_rotate_pvecs);
+ if (!pagevec_add(pvec, page))
+ pagevec_move_tail(pvec);
+ local_unlock_irqrestore(rotate_lock, flags);
+ }
+}
+
+static void update_page_reclaim_stat(struct zone *zone, struct page *page,
+ int file, int rotated)
+{
+ struct zone_reclaim_stat *reclaim_stat = &zone->reclaim_stat;
+ struct zone_reclaim_stat *memcg_reclaim_stat;
+
+ memcg_reclaim_stat = mem_cgroup_get_reclaim_stat_from_page(page);
+
+ reclaim_stat->recent_scanned[file]++;
+ if (rotated)
+ reclaim_stat->recent_rotated[file]++;
+
+ if (!memcg_reclaim_stat)
+ return;
+
+ memcg_reclaim_stat->recent_scanned[file]++;
+ if (rotated)
+ memcg_reclaim_stat->recent_rotated[file]++;
+}
+
+static void __activate_page(struct page *page, void *arg)
+{
+ struct zone *zone = page_zone(page);
+
+ if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+ int file = page_is_file_cache(page);
+ int lru = page_lru_base_type(page);
+ del_page_from_lru_list(zone, page, lru);
+
+ SetPageActive(page);
+ lru += LRU_ACTIVE;
+ add_page_to_lru_list(zone, page, lru);
+ __count_vm_event(PGACTIVATE);
+
+ update_page_reclaim_stat(zone, page, file, 1);
+ }
+}
+
+#ifdef CONFIG_SMP
+static DEFINE_PER_CPU(struct pagevec, activate_page_pvecs);
+
+static void activate_page_drain(int cpu)
+{
+ struct pagevec *pvec = &per_cpu(activate_page_pvecs, cpu);
+
+ if (pagevec_count(pvec))
+ pagevec_lru_move_fn(pvec, __activate_page, NULL);
+}
+
+void activate_page(struct page *page)
+{
+ if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+ struct pagevec *pvec = &get_locked_var(swapvec_lock,
+ activate_page_pvecs);
+
+ page_cache_get(page);
+ if (!pagevec_add(pvec, page))
+ pagevec_lru_move_fn(pvec, __activate_page, NULL);
+ put_locked_var(swapvec_lock, activate_page_pvecs);
+ }
+}
+
+#else
+static inline void activate_page_drain(int cpu)
+{
+}
+
+void activate_page(struct page *page)
+{
+ struct zone *zone = page_zone(page);
+
+ spin_lock_irq(&zone->lru_lock);
+ __activate_page(page, NULL);
+ spin_unlock_irq(&zone->lru_lock);
+}
+#endif
+
+/*
+ * Mark a page as having seen activity.
+ *
+ * inactive,unreferenced -> inactive,referenced
+ * inactive,referenced -> active,unreferenced
+ * active,unreferenced -> active,referenced
+ */
+void mark_page_accessed(struct page *page)
+{
+ if (!PageActive(page) && !PageUnevictable(page) &&
+ PageReferenced(page) && PageLRU(page)) {
+ activate_page(page);
+ ClearPageReferenced(page);
+ } else if (!PageReferenced(page)) {
+ SetPageReferenced(page);
+ }
+}
+EXPORT_SYMBOL(mark_page_accessed);
+
+void __lru_cache_add(struct page *page, enum lru_list lru)
+{
+ struct pagevec *pvec = &get_locked_var(swapvec_lock, lru_add_pvecs)[lru];
+
+ page_cache_get(page);
+ if (!pagevec_add(pvec, page))
+ __pagevec_lru_add(pvec, lru);
+ put_locked_var(swapvec_lock, lru_add_pvecs);
+}
+EXPORT_SYMBOL(__lru_cache_add);
+
+/**
+ * lru_cache_add_lru - add a page to a page list
+ * @page: the page to be added to the LRU.
+ * @lru: the LRU list to which the page is added.
+ */
+void lru_cache_add_lru(struct page *page, enum lru_list lru)
+{
+ if (PageActive(page)) {
+ VM_BUG_ON(PageUnevictable(page));
+ ClearPageActive(page);
+ } else if (PageUnevictable(page)) {
+ VM_BUG_ON(PageActive(page));
+ ClearPageUnevictable(page);
+ }
+
+ VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page));
+ __lru_cache_add(page, lru);
+}
+
+/**
+ * add_page_to_unevictable_list - add a page to the unevictable list
+ * @page: the page to be added to the unevictable list
+ *
+ * Add page directly to its zone's unevictable list. To avoid races with
+ * tasks that might be making the page evictable, through eg. munlock,
+ * munmap or exit, while it's not on the lru, we want to add the page
+ * while it's locked or otherwise "invisible" to other tasks. This is
+ * difficult to do when using the pagevec cache, so bypass that.
+ */
+void add_page_to_unevictable_list(struct page *page)
+{
+ struct zone *zone = page_zone(page);
+
+ spin_lock_irq(&zone->lru_lock);
+ SetPageUnevictable(page);
+ SetPageLRU(page);
+ add_page_to_lru_list(zone, page, LRU_UNEVICTABLE);
+ spin_unlock_irq(&zone->lru_lock);
+}
+
+/*
+ * If the page can not be invalidated, it is moved to the
+ * inactive list to speed up its reclaim. It is moved to the
+ * head of the list, rather than the tail, to give the flusher
+ * threads some time to write it out, as this is much more
+ * effective than the single-page writeout from reclaim.
+ *
+ * If the page isn't page_mapped and dirty/writeback, the page
+ * could reclaim asap using PG_reclaim.
+ *
+ * 1. active, mapped page -> none
+ * 2. active, dirty/writeback page -> inactive, head, PG_reclaim
+ * 3. inactive, mapped page -> none
+ * 4. inactive, dirty/writeback page -> inactive, head, PG_reclaim
+ * 5. inactive, clean -> inactive, tail
+ * 6. Others -> none
+ *
+ * In 4, why it moves inactive's head, the VM expects the page would
+ * be write it out by flusher threads as this is much more effective
+ * than the single-page writeout from reclaim.
+ */
+static void lru_deactivate_fn(struct page *page, void *arg)
+{
+ int lru, file;
+ bool active;
+ struct zone *zone = page_zone(page);
+
+ if (!PageLRU(page))
+ return;
+
+ if (PageUnevictable(page))
+ return;
+
+ /* Some processes are using the page */
+ if (page_mapped(page))
+ return;
+
+ active = PageActive(page);
+
+ file = page_is_file_cache(page);
+ lru = page_lru_base_type(page);
+ del_page_from_lru_list(zone, page, lru + active);
+ ClearPageActive(page);
+ ClearPageReferenced(page);
+ add_page_to_lru_list(zone, page, lru);
+
+ if (PageWriteback(page) || PageDirty(page)) {
+ /*
+ * PG_reclaim could be raced with end_page_writeback
+ * It can make readahead confusing. But race window
+ * is _really_ small and it's non-critical problem.
+ */
+ SetPageReclaim(page);
+ } else {
+ struct lruvec *lruvec;
+ /*
+ * The page's writeback ends up during pagevec
+ * We moves tha page into tail of inactive.
+ */
+ lruvec = mem_cgroup_lru_move_lists(zone, page, lru, lru);
+ list_move_tail(&page->lru, &lruvec->lists[lru]);
+ __count_vm_event(PGROTATED);
+ }
+
+ if (active)
+ __count_vm_event(PGDEACTIVATE);
+ update_page_reclaim_stat(zone, page, file, 0);
+}
+
+/*
+ * Drain pages out of the cpu's pagevecs.
+ * Either "cpu" is the current CPU, and preemption has already been
+ * disabled; or "cpu" is being hot-unplugged, and is already dead.
+ */
+void lru_add_drain_cpu(int cpu)
+{
+ struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu);
+ struct pagevec *pvec;
+ int lru;
+
+ for_each_lru(lru) {
+ pvec = &pvecs[lru - LRU_BASE];
+ if (pagevec_count(pvec))
+ __pagevec_lru_add(pvec, lru);
+ }
+
+ pvec = &per_cpu(lru_rotate_pvecs, cpu);
+ if (pagevec_count(pvec)) {
+ unsigned long flags;
+
+ /* No harm done if a racing interrupt already did this */
+ local_lock_irqsave(rotate_lock, flags);
+ pagevec_move_tail(pvec);
+ local_unlock_irqrestore(rotate_lock, flags);
+ }
+
+ pvec = &per_cpu(lru_deactivate_pvecs, cpu);
+ if (pagevec_count(pvec))
+ pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL);
+
+ activate_page_drain(cpu);
+}
+
+/**
+ * deactivate_page - forcefully deactivate a page
+ * @page: page to deactivate
+ *
+ * This function hints the VM that @page is a good reclaim candidate,
+ * for example if its invalidation fails due to the page being dirty
+ * or under writeback.
+ */
+void deactivate_page(struct page *page)
+{
+ /*
+ * In a workload with many unevictable page such as mprotect, unevictable
+ * page deactivation for accelerating reclaim is pointless.
+ */
+ if (PageUnevictable(page))
+ return;
+
+ if (likely(get_page_unless_zero(page))) {
+ struct pagevec *pvec = &get_locked_var(swapvec_lock,
+ lru_deactivate_pvecs);
+
+ if (!pagevec_add(pvec, page))
+ pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL);
+ put_locked_var(swapvec_lock, lru_deactivate_pvecs);
+ }
+}
+
+void lru_add_drain(void)
+{
+ lru_add_drain_cpu(local_lock_cpu(swapvec_lock));
+ local_unlock_cpu(swapvec_lock);
+}
+
+static void lru_add_drain_per_cpu(struct work_struct *dummy)
+{
+ lru_add_drain();
+}
+
+/*
+ * Returns 0 for success
+ */
+int lru_add_drain_all(void)
+{
+ return schedule_on_each_cpu(lru_add_drain_per_cpu);
+}
+
+/*
+ * Batched page_cache_release(). Decrement the reference count on all the
+ * passed pages. If it fell to zero then remove the page from the LRU and
+ * free it.
+ *
+ * Avoid taking zone->lru_lock if possible, but if it is taken, retain it
+ * for the remainder of the operation.
+ *
+ * The locking in this function is against shrink_inactive_list(): we recheck
+ * the page count inside the lock to see whether shrink_inactive_list()
+ * grabbed the page via the LRU. If it did, give up: shrink_inactive_list()
+ * will free it.
+ */
+void release_pages(struct page **pages, int nr, int cold)
+{
+ int i;
+ LIST_HEAD(pages_to_free);
+ struct zone *zone = NULL;
+ unsigned long uninitialized_var(flags);
+
+ for (i = 0; i < nr; i++) {
+ struct page *page = pages[i];
+
+ if (unlikely(PageCompound(page))) {
+ if (zone) {
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
+ zone = NULL;
+ }
+ put_compound_page(page);
+ continue;
+ }
+
+ if (!put_page_testzero(page))
+ continue;
+
+ if (PageLRU(page)) {
+ struct zone *pagezone = page_zone(page);
+
+ if (pagezone != zone) {
+ if (zone)
+ spin_unlock_irqrestore(&zone->lru_lock,
+ flags);
+ zone = pagezone;
+ spin_lock_irqsave(&zone->lru_lock, flags);
+ }
+ VM_BUG_ON(!PageLRU(page));
+ __ClearPageLRU(page);
+ del_page_from_lru_list(zone, page, page_off_lru(page));
+ }
+
+ list_add(&page->lru, &pages_to_free);
+ }
+ if (zone)
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
+
+ free_hot_cold_page_list(&pages_to_free, cold);
+}
+EXPORT_SYMBOL(release_pages);
+
+/*
+ * The pages which we're about to release may be in the deferred lru-addition
+ * queues. That would prevent them from really being freed right now. That's
+ * OK from a correctness point of view but is inefficient - those pages may be
+ * cache-warm and we want to give them back to the page allocator ASAP.
+ *
+ * So __pagevec_release() will drain those queues here. __pagevec_lru_add()
+ * and __pagevec_lru_add_active() call release_pages() directly to avoid
+ * mutual recursion.
+ */
+void __pagevec_release(struct pagevec *pvec)
+{
+ lru_add_drain();
+ release_pages(pvec->pages, pagevec_count(pvec), pvec->cold);
+ pagevec_reinit(pvec);
+}
+EXPORT_SYMBOL(__pagevec_release);
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+/* used by __split_huge_page_refcount() */
+void lru_add_page_tail(struct zone* zone,
+ struct page *page, struct page *page_tail)
+{
+ int uninitialized_var(active);
+ enum lru_list lru;
+ const int file = 0;
+
+ VM_BUG_ON(!PageHead(page));
+ VM_BUG_ON(PageCompound(page_tail));
+ VM_BUG_ON(PageLRU(page_tail));
+ VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&zone->lru_lock));
+
+ SetPageLRU(page_tail);
+
+ if (page_evictable(page_tail, NULL)) {
+ if (PageActive(page)) {
+ SetPageActive(page_tail);
+ active = 1;
+ lru = LRU_ACTIVE_ANON;
+ } else {
+ active = 0;
+ lru = LRU_INACTIVE_ANON;
+ }
+ } else {
+ SetPageUnevictable(page_tail);
+ lru = LRU_UNEVICTABLE;
+ }
+
+ if (likely(PageLRU(page)))
+ list_add_tail(&page_tail->lru, &page->lru);
+ else {
+ struct list_head *list_head;
+ /*
+ * Head page has not yet been counted, as an hpage,
+ * so we must account for each subpage individually.
+ *
+ * Use the standard add function to put page_tail on the list,
+ * but then correct its position so they all end up in order.
+ */
+ add_page_to_lru_list(zone, page_tail, lru);
+ list_head = page_tail->lru.prev;
+ list_move_tail(&page_tail->lru, list_head);
+ }
+
+ if (!PageUnevictable(page))
+ update_page_reclaim_stat(zone, page_tail, file, active);
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+static void __pagevec_lru_add_fn(struct page *page, void *arg)
+{
+ enum lru_list lru = (enum lru_list)arg;
+ struct zone *zone = page_zone(page);
+ int file = is_file_lru(lru);
+ int active = is_active_lru(lru);
+
+ VM_BUG_ON(PageActive(page));
+ VM_BUG_ON(PageUnevictable(page));
+ VM_BUG_ON(PageLRU(page));
+
+ SetPageLRU(page);
+ if (active)
+ SetPageActive(page);
+ add_page_to_lru_list(zone, page, lru);
+ update_page_reclaim_stat(zone, page, file, active);
+}
+
+/*
+ * Add the passed pages to the LRU, then drop the caller's refcount
+ * on them. Reinitialises the caller's pagevec.
+ */
+void __pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
+{
+ VM_BUG_ON(is_unevictable_lru(lru));
+
+ pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, (void *)lru);
+}
+EXPORT_SYMBOL(__pagevec_lru_add);
+
+/**
+ * pagevec_lookup - gang pagecache lookup
+ * @pvec: Where the resulting pages are placed
+ * @mapping: The address_space to search
+ * @start: The starting page index
+ * @nr_pages: The maximum number of pages
+ *
+ * pagevec_lookup() will search for and return a group of up to @nr_pages pages
+ * in the mapping. The pages are placed in @pvec. pagevec_lookup() takes a
+ * reference against the pages in @pvec.
+ *
+ * The search returns a group of mapping-contiguous pages with ascending
+ * indexes. There may be holes in the indices due to not-present pages.
+ *
+ * pagevec_lookup() returns the number of pages which were found.
+ */
+unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
+ pgoff_t start, unsigned nr_pages)
+{
+ pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages);
+ return pagevec_count(pvec);
+}
+EXPORT_SYMBOL(pagevec_lookup);
+
+unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping,
+ pgoff_t *index, int tag, unsigned nr_pages)
+{
+ pvec->nr = find_get_pages_tag(mapping, index, tag,
+ nr_pages, pvec->pages);
+ return pagevec_count(pvec);
+}
+EXPORT_SYMBOL(pagevec_lookup_tag);
+
+/* Early setup for the local locks */
+static int __init swap_init_locks(void)
+{
+ local_irq_lock_init(rotate_lock);
+ local_irq_lock_init(swapvec_lock);
+ return 1;
+}
+early_initcall(swap_init_locks);
+
+/*
+ * Perform any setup for the swap system
+ */
+void __init swap_setup(void)
+{
+ unsigned long megs = totalram_pages >> (20 - PAGE_SHIFT);
+
+#ifdef CONFIG_SWAP
+ bdi_init(swapper_space.backing_dev_info);
+#endif
+
+ /* Use a smaller cluster for small-memory machines */
+ if (megs < 16)
+ page_cluster = 2;
+ else
+ page_cluster = 3;
+ /*
+ * Right now other parts of the system means that we
+ * _really_ don't want to cluster much more
+ */
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/swap_state.c b/ap/os/linux/linux-3.4.x/mm/swap_state.c
new file mode 100644
index 0000000..6c5cf85
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/swap_state.c
@@ -0,0 +1,416 @@
+/*
+ * linux/mm/swap_state.c
+ *
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ * Swap reorganised 29.12.95, Stephen Tweedie
+ *
+ * Rewritten to use page cache, (C) 1998 Stephen Tweedie
+ */
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <linux/kernel_stat.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/backing-dev.h>
+#include <linux/pagevec.h>
+#include <linux/migrate.h>
+#include <linux/page_cgroup.h>
+
+#include <asm/pgtable.h>
+
+/*
+ * swapper_space is a fiction, retained to simplify the path through
+ * vmscan's shrink_page_list.
+ */
+static const struct address_space_operations swap_aops = {
+ .writepage = swap_writepage,
+ .set_page_dirty = __set_page_dirty_no_writeback,
+ .migratepage = migrate_page,
+};
+
+static struct backing_dev_info swap_backing_dev_info = {
+ .name = "swap",
+ .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED,
+};
+
+struct address_space swapper_space = {
+ .page_tree = RADIX_TREE_INIT(GFP_ATOMIC|__GFP_NOWARN),
+ .tree_lock = __SPIN_LOCK_UNLOCKED(swapper_space.tree_lock),
+ .a_ops = &swap_aops,
+ .i_mmap_nonlinear = LIST_HEAD_INIT(swapper_space.i_mmap_nonlinear),
+ .backing_dev_info = &swap_backing_dev_info,
+};
+
+#define INC_CACHE_INFO(x) do { swap_cache_info.x++; } while (0)
+
+static struct {
+ unsigned long add_total;
+ unsigned long del_total;
+ unsigned long find_success;
+ unsigned long find_total;
+} swap_cache_info;
+
+void show_swap_cache_info(void)
+{
+ printk("%lu pages in swap cache\n", total_swapcache_pages);
+ printk("Swap cache stats: add %lu, delete %lu, find %lu/%lu\n",
+ swap_cache_info.add_total, swap_cache_info.del_total,
+ swap_cache_info.find_success, swap_cache_info.find_total);
+ printk("Free swap = %ldkB\n", nr_swap_pages << (PAGE_SHIFT - 10));
+ printk("Total swap = %lukB\n", total_swap_pages << (PAGE_SHIFT - 10));
+}
+
+/*
+ * __add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
+ * but sets SwapCache flag and private instead of mapping and index.
+ */
+static int __add_to_swap_cache(struct page *page, swp_entry_t entry)
+{
+ int error;
+
+ VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON(PageSwapCache(page));
+ VM_BUG_ON(!PageSwapBacked(page));
+
+ page_cache_get(page);
+ SetPageSwapCache(page);
+ set_page_private(page, entry.val);
+
+ spin_lock_irq(&swapper_space.tree_lock);
+ error = radix_tree_insert(&swapper_space.page_tree, entry.val, page);
+ if (likely(!error)) {
+ total_swapcache_pages++;
+#ifndef CONFIG_LIMIT_PAGE_CACHE
+ __inc_zone_page_state(page, NR_FILE_PAGES);
+#endif
+ INC_CACHE_INFO(add_total);
+ }
+ spin_unlock_irq(&swapper_space.tree_lock);
+
+ if (unlikely(error)) {
+ /*
+ * Only the context which have set SWAP_HAS_CACHE flag
+ * would call add_to_swap_cache().
+ * So add_to_swap_cache() doesn't returns -EEXIST.
+ */
+ VM_BUG_ON(error == -EEXIST);
+ set_page_private(page, 0UL);
+ ClearPageSwapCache(page);
+ page_cache_release(page);
+ }
+
+ return error;
+}
+
+
+int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
+{
+ int error;
+
+ error = radix_tree_preload(gfp_mask);
+ if (!error) {
+ error = __add_to_swap_cache(page, entry);
+ radix_tree_preload_end();
+ }
+ return error;
+}
+
+/*
+ * This must be called only on pages that have
+ * been verified to be in the swap cache.
+ */
+void __delete_from_swap_cache(struct page *page)
+{
+ VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON(!PageSwapCache(page));
+ VM_BUG_ON(PageWriteback(page));
+
+ radix_tree_delete(&swapper_space.page_tree, page_private(page));
+ set_page_private(page, 0);
+ ClearPageSwapCache(page);
+ total_swapcache_pages--;
+#ifndef CONFIG_LIMIT_PAGE_CACHE
+ __dec_zone_page_state(page, NR_FILE_PAGES);
+#endif
+ INC_CACHE_INFO(del_total);
+}
+
+/**
+ * add_to_swap - allocate swap space for a page
+ * @page: page we want to move to swap
+ *
+ * Allocate swap space for the page and add the page to the
+ * swap cache. Caller needs to hold the page lock.
+ */
+int add_to_swap(struct page *page)
+{
+ swp_entry_t entry;
+ int err;
+
+ VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON(!PageUptodate(page));
+
+ entry = get_swap_page();
+ if (!entry.val)
+ return 0;
+
+ if (unlikely(PageTransHuge(page)))
+ if (unlikely(split_huge_page(page))) {
+ swapcache_free(entry, NULL);
+ return 0;
+ }
+
+ /*
+ * Radix-tree node allocations from PF_MEMALLOC contexts could
+ * completely exhaust the page allocator. __GFP_NOMEMALLOC
+ * stops emergency reserves from being allocated.
+ *
+ * TODO: this could cause a theoretical memory reclaim
+ * deadlock in the swap out path.
+ */
+ /*
+ * Add it to the swap cache and mark it dirty
+ */
+ err = add_to_swap_cache(page, entry,
+ __GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
+
+ if (!err) { /* Success */
+ SetPageDirty(page);
+ return 1;
+ } else { /* -ENOMEM radix-tree allocation failure */
+ /*
+ * add_to_swap_cache() doesn't return -EEXIST, so we can safely
+ * clear SWAP_HAS_CACHE flag.
+ */
+ swapcache_free(entry, NULL);
+ return 0;
+ }
+}
+
+/*
+ * This must be called only on pages that have
+ * been verified to be in the swap cache and locked.
+ * It will never put the page into the free list,
+ * the caller has a reference on the page.
+ */
+void delete_from_swap_cache(struct page *page)
+{
+ swp_entry_t entry;
+
+ entry.val = page_private(page);
+
+ spin_lock_irq(&swapper_space.tree_lock);
+ __delete_from_swap_cache(page);
+ spin_unlock_irq(&swapper_space.tree_lock);
+
+ swapcache_free(entry, page);
+ page_cache_release(page);
+}
+
+/*
+ * If we are the only user, then try to free up the swap cache.
+ *
+ * Its ok to check for PageSwapCache without the page lock
+ * here because we are going to recheck again inside
+ * try_to_free_swap() _with_ the lock.
+ * - Marcelo
+ */
+static inline void free_swap_cache(struct page *page)
+{
+ if (PageSwapCache(page) && !page_mapped(page) && trylock_page(page)) {
+ try_to_free_swap(page);
+ unlock_page(page);
+ }
+}
+
+/*
+ * Perform a free_page(), also freeing any swap cache associated with
+ * this page if it is the last user of the page.
+ */
+void free_page_and_swap_cache(struct page *page)
+{
+ free_swap_cache(page);
+ page_cache_release(page);
+}
+
+/*
+ * Passed an array of pages, drop them all from swapcache and then release
+ * them. They are removed from the LRU and freed if this is their last use.
+ */
+void free_pages_and_swap_cache(struct page **pages, int nr)
+{
+ struct page **pagep = pages;
+
+ lru_add_drain();
+ while (nr) {
+ int todo = min(nr, PAGEVEC_SIZE);
+ int i;
+
+ for (i = 0; i < todo; i++)
+ free_swap_cache(pagep[i]);
+ release_pages(pagep, todo, 0);
+ pagep += todo;
+ nr -= todo;
+ }
+}
+
+/*
+ * Lookup a swap entry in the swap cache. A found page will be returned
+ * unlocked and with its refcount incremented - we rely on the kernel
+ * lock getting page table operations atomic even if we drop the page
+ * lock before returning.
+ */
+struct page * lookup_swap_cache(swp_entry_t entry)
+{
+ struct page *page;
+
+ page = find_get_page(&swapper_space, entry.val);
+
+ if (page)
+ INC_CACHE_INFO(find_success);
+
+ INC_CACHE_INFO(find_total);
+ return page;
+}
+
+/*
+ * Locate a page of swap in physical memory, reserving swap cache space
+ * and reading the disk if it is not already cached.
+ * A failure return means that either the page allocation failed or that
+ * the swap entry is no longer in use.
+ */
+struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
+ struct vm_area_struct *vma, unsigned long addr)
+{
+ struct page *found_page, *new_page = NULL;
+ int err;
+
+ do {
+ /*
+ * First check the swap cache. Since this is normally
+ * called after lookup_swap_cache() failed, re-calling
+ * that would confuse statistics.
+ */
+ found_page = find_get_page(&swapper_space, entry.val);
+ if (found_page)
+ break;
+
+ /*
+ * Get a new page to read into from swap.
+ */
+ if (!new_page) {
+ new_page = alloc_page_vma(gfp_mask, vma, addr);
+ if (!new_page)
+ break; /* Out of memory */
+ }
+
+ /*
+ * call radix_tree_preload() while we can wait.
+ */
+ err = radix_tree_preload(gfp_mask & GFP_KERNEL);
+ if (err)
+ break;
+
+ /*
+ * Swap entry may have been freed since our caller observed it.
+ */
+ err = swapcache_prepare(entry);
+ if (err == -EEXIST) {
+ radix_tree_preload_end();
+ /*
+ * We might race against get_swap_page() and stumble
+ * across a SWAP_HAS_CACHE swap_map entry whose page
+ * has not been brought into the swapcache yet, while
+ * the other end is scheduled away waiting on discard
+ * I/O completion at scan_swap_map().
+ *
+ * In order to avoid turning this transitory state
+ * into a permanent loop around this -EEXIST case
+ * if !CONFIG_PREEMPT and the I/O completion happens
+ * to be waiting on the CPU waitqueue where we are now
+ * busy looping, we just conditionally invoke the
+ * scheduler here, if there are some more important
+ * tasks to run.
+ */
+ cond_resched();
+ continue;
+ }
+ if (err) { /* swp entry is obsolete ? */
+ radix_tree_preload_end();
+ break;
+ }
+
+ /* May fail (-ENOMEM) if radix-tree node allocation failed. */
+ __set_page_locked(new_page);
+ SetPageSwapBacked(new_page);
+ err = __add_to_swap_cache(new_page, entry);
+ if (likely(!err)) {
+ radix_tree_preload_end();
+ /*
+ * Initiate read into locked page and return.
+ */
+ lru_cache_add_anon(new_page);
+ swap_readpage(new_page);
+ return new_page;
+ }
+ radix_tree_preload_end();
+ ClearPageSwapBacked(new_page);
+ __clear_page_locked(new_page);
+ /*
+ * add_to_swap_cache() doesn't return -EEXIST, so we can safely
+ * clear SWAP_HAS_CACHE flag.
+ */
+ swapcache_free(entry, NULL);
+ } while (err != -ENOMEM);
+
+ if (new_page)
+ page_cache_release(new_page);
+ return found_page;
+}
+
+/**
+ * swapin_readahead - swap in pages in hope we need them soon
+ * @entry: swap entry of this memory
+ * @gfp_mask: memory allocation flags
+ * @vma: user vma this address belongs to
+ * @addr: target address for mempolicy
+ *
+ * Returns the struct page for entry and addr, after queueing swapin.
+ *
+ * Primitive swap readahead code. We simply read an aligned block of
+ * (1 << page_cluster) entries in the swap area. This method is chosen
+ * because it doesn't cost us any seek time. We also make sure to queue
+ * the 'original' request together with the readahead ones...
+ *
+ * This has been extended to use the NUMA policies from the mm triggering
+ * the readahead.
+ *
+ * Caller must hold down_read on the vma->vm_mm if vma is not NULL.
+ */
+struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
+ struct vm_area_struct *vma, unsigned long addr)
+{
+ struct page *page;
+ unsigned long offset = swp_offset(entry);
+ unsigned long start_offset, end_offset;
+ unsigned long mask = (1UL << page_cluster) - 1;
+
+ /* Read a page_cluster sized and aligned cluster around offset. */
+ start_offset = offset & ~mask;
+ end_offset = offset | mask;
+ if (!start_offset) /* First page is swap header. */
+ start_offset++;
+
+ for (offset = start_offset; offset <= end_offset ; offset++) {
+ /* Ok, do the async read-ahead now */
+ page = read_swap_cache_async(swp_entry(swp_type(entry), offset),
+ gfp_mask, vma, addr);
+ if (!page)
+ continue;
+ page_cache_release(page);
+ }
+ lru_add_drain(); /* Push any new pages onto the LRU now */
+ return read_swap_cache_async(entry, gfp_mask, vma, addr);
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/swapfile.c b/ap/os/linux/linux-3.4.x/mm/swapfile.c
new file mode 100644
index 0000000..38186d9
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/swapfile.c
@@ -0,0 +1,2505 @@
+/*
+ * linux/mm/swapfile.c
+ *
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ * Swap reorganised 29.12.95, Stephen Tweedie
+ */
+
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/mman.h>
+#include <linux/slab.h>
+#include <linux/kernel_stat.h>
+#include <linux/swap.h>
+#include <linux/vmalloc.h>
+#include <linux/pagemap.h>
+#include <linux/namei.h>
+#include <linux/shmem_fs.h>
+#include <linux/blkdev.h>
+#include <linux/random.h>
+#include <linux/writeback.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/ksm.h>
+#include <linux/rmap.h>
+#include <linux/security.h>
+#include <linux/backing-dev.h>
+#include <linux/mutex.h>
+#include <linux/capability.h>
+#include <linux/syscalls.h>
+#include <linux/memcontrol.h>
+#include <linux/poll.h>
+#include <linux/oom.h>
+
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+#include <linux/swapops.h>
+#include <linux/page_cgroup.h>
+
+static bool swap_count_continued(struct swap_info_struct *, pgoff_t,
+ unsigned char);
+static void free_swap_count_continuations(struct swap_info_struct *);
+static sector_t map_swap_entry(swp_entry_t, struct block_device**);
+
+static DEFINE_SPINLOCK(swap_lock);
+static unsigned int nr_swapfiles;
+long nr_swap_pages;
+long total_swap_pages;
+static int least_priority;
+
+static const char Bad_file[] = "Bad swap file entry ";
+static const char Unused_file[] = "Unused swap file entry ";
+static const char Bad_offset[] = "Bad swap offset entry ";
+static const char Unused_offset[] = "Unused swap offset entry ";
+
+static struct swap_list_t swap_list = {-1, -1};
+
+static struct swap_info_struct *swap_info[MAX_SWAPFILES];
+
+static DEFINE_MUTEX(swapon_mutex);
+
+static DECLARE_WAIT_QUEUE_HEAD(proc_poll_wait);
+/* Activity counter to indicate that a swapon or swapoff has occurred */
+static atomic_t proc_poll_event = ATOMIC_INIT(0);
+
+static inline unsigned char swap_count(unsigned char ent)
+{
+ return ent & ~SWAP_HAS_CACHE; /* may include SWAP_HAS_CONT flag */
+}
+
+/* returns 1 if swap entry is freed */
+static int
+__try_to_reclaim_swap(struct swap_info_struct *si, unsigned long offset)
+{
+ swp_entry_t entry = swp_entry(si->type, offset);
+ struct page *page;
+ int ret = 0;
+
+ page = find_get_page(&swapper_space, entry.val);
+ if (!page)
+ return 0;
+ /*
+ * This function is called from scan_swap_map() and it's called
+ * by vmscan.c at reclaiming pages. So, we hold a lock on a page, here.
+ * We have to use trylock for avoiding deadlock. This is a special
+ * case and you should use try_to_free_swap() with explicit lock_page()
+ * in usual operations.
+ */
+ if (trylock_page(page)) {
+ ret = try_to_free_swap(page);
+ unlock_page(page);
+ }
+ page_cache_release(page);
+ return ret;
+}
+
+/*
+ * swapon tell device that all the old swap contents can be discarded,
+ * to allow the swap device to optimize its wear-levelling.
+ */
+static int discard_swap(struct swap_info_struct *si)
+{
+ struct swap_extent *se;
+ sector_t start_block;
+ sector_t nr_blocks;
+ int err = 0;
+
+ /* Do not discard the swap header page! */
+ se = &si->first_swap_extent;
+ start_block = (se->start_block + 1) << (PAGE_SHIFT - 9);
+ nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9);
+ if (nr_blocks) {
+ err = blkdev_issue_discard(si->bdev, start_block,
+ nr_blocks, GFP_KERNEL, 0);
+ if (err)
+ return err;
+ cond_resched();
+ }
+
+ list_for_each_entry(se, &si->first_swap_extent.list, list) {
+ start_block = se->start_block << (PAGE_SHIFT - 9);
+ nr_blocks = (sector_t)se->nr_pages << (PAGE_SHIFT - 9);
+
+ err = blkdev_issue_discard(si->bdev, start_block,
+ nr_blocks, GFP_KERNEL, 0);
+ if (err)
+ break;
+
+ cond_resched();
+ }
+ return err; /* That will often be -EOPNOTSUPP */
+}
+
+/*
+ * swap allocation tell device that a cluster of swap can now be discarded,
+ * to allow the swap device to optimize its wear-levelling.
+ */
+static void discard_swap_cluster(struct swap_info_struct *si,
+ pgoff_t start_page, pgoff_t nr_pages)
+{
+ struct swap_extent *se = si->curr_swap_extent;
+ int found_extent = 0;
+
+ while (nr_pages) {
+ struct list_head *lh;
+
+ if (se->start_page <= start_page &&
+ start_page < se->start_page + se->nr_pages) {
+ pgoff_t offset = start_page - se->start_page;
+ sector_t start_block = se->start_block + offset;
+ sector_t nr_blocks = se->nr_pages - offset;
+
+ if (nr_blocks > nr_pages)
+ nr_blocks = nr_pages;
+ start_page += nr_blocks;
+ nr_pages -= nr_blocks;
+
+ if (!found_extent++)
+ si->curr_swap_extent = se;
+
+ start_block <<= PAGE_SHIFT - 9;
+ nr_blocks <<= PAGE_SHIFT - 9;
+ if (blkdev_issue_discard(si->bdev, start_block,
+ nr_blocks, GFP_NOIO, 0))
+ break;
+ }
+
+ lh = se->list.next;
+ se = list_entry(lh, struct swap_extent, list);
+ }
+}
+
+static int wait_for_discard(void *word)
+{
+ schedule();
+ return 0;
+}
+
+#define SWAPFILE_CLUSTER 256
+#define LATENCY_LIMIT 256
+
+static unsigned long scan_swap_map(struct swap_info_struct *si,
+ unsigned char usage)
+{
+ unsigned long offset;
+ unsigned long scan_base;
+ unsigned long last_in_cluster = 0;
+ int latency_ration = LATENCY_LIMIT;
+ int found_free_cluster = 0;
+
+ /*
+ * We try to cluster swap pages by allocating them sequentially
+ * in swap. Once we've allocated SWAPFILE_CLUSTER pages this
+ * way, however, we resort to first-free allocation, starting
+ * a new cluster. This prevents us from scattering swap pages
+ * all over the entire swap partition, so that we reduce
+ * overall disk seek times between swap pages. -- sct
+ * But we do now try to find an empty cluster. -Andrea
+ * And we let swap pages go all over an SSD partition. Hugh
+ */
+
+ si->flags += SWP_SCANNING;
+ scan_base = offset = si->cluster_next;
+
+ if (unlikely(!si->cluster_nr--)) {
+ if (si->pages - si->inuse_pages < SWAPFILE_CLUSTER) {
+ si->cluster_nr = SWAPFILE_CLUSTER - 1;
+ goto checks;
+ }
+ if (si->flags & SWP_DISCARDABLE) {
+ /*
+ * Start range check on racing allocations, in case
+ * they overlap the cluster we eventually decide on
+ * (we scan without swap_lock to allow preemption).
+ * It's hardly conceivable that cluster_nr could be
+ * wrapped during our scan, but don't depend on it.
+ */
+ if (si->lowest_alloc)
+ goto checks;
+ si->lowest_alloc = si->max;
+ si->highest_alloc = 0;
+ }
+ spin_unlock(&swap_lock);
+
+ /*
+ * If seek is expensive, start searching for new cluster from
+ * start of partition, to minimize the span of allocated swap.
+ * But if seek is cheap, search from our current position, so
+ * that swap is allocated from all over the partition: if the
+ * Flash Translation Layer only remaps within limited zones,
+ * we don't want to wear out the first zone too quickly.
+ */
+ if (!(si->flags & SWP_SOLIDSTATE))
+ scan_base = offset = si->lowest_bit;
+ last_in_cluster = offset + SWAPFILE_CLUSTER - 1;
+
+ /* Locate the first empty (unaligned) cluster */
+ for (; last_in_cluster <= si->highest_bit; offset++) {
+ if (si->swap_map[offset])
+ last_in_cluster = offset + SWAPFILE_CLUSTER;
+ else if (offset == last_in_cluster) {
+ spin_lock(&swap_lock);
+ offset -= SWAPFILE_CLUSTER - 1;
+ si->cluster_next = offset;
+ si->cluster_nr = SWAPFILE_CLUSTER - 1;
+ found_free_cluster = 1;
+ goto checks;
+ }
+ if (unlikely(--latency_ration < 0)) {
+ cond_resched();
+ latency_ration = LATENCY_LIMIT;
+ }
+ }
+
+ offset = si->lowest_bit;
+ last_in_cluster = offset + SWAPFILE_CLUSTER - 1;
+
+ /* Locate the first empty (unaligned) cluster */
+ for (; last_in_cluster < scan_base; offset++) {
+ if (si->swap_map[offset])
+ last_in_cluster = offset + SWAPFILE_CLUSTER;
+ else if (offset == last_in_cluster) {
+ spin_lock(&swap_lock);
+ offset -= SWAPFILE_CLUSTER - 1;
+ si->cluster_next = offset;
+ si->cluster_nr = SWAPFILE_CLUSTER - 1;
+ found_free_cluster = 1;
+ goto checks;
+ }
+ if (unlikely(--latency_ration < 0)) {
+ cond_resched();
+ latency_ration = LATENCY_LIMIT;
+ }
+ }
+
+ offset = scan_base;
+ spin_lock(&swap_lock);
+ si->cluster_nr = SWAPFILE_CLUSTER - 1;
+ si->lowest_alloc = 0;
+ }
+
+checks:
+ if (!(si->flags & SWP_WRITEOK))
+ goto no_page;
+ if (!si->highest_bit)
+ goto no_page;
+ if (offset > si->highest_bit)
+ scan_base = offset = si->lowest_bit;
+
+ /* reuse swap entry of cache-only swap if not busy. */
+ if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) {
+ int swap_was_freed;
+ spin_unlock(&swap_lock);
+ swap_was_freed = __try_to_reclaim_swap(si, offset);
+ spin_lock(&swap_lock);
+ /* entry was freed successfully, try to use this again */
+ if (swap_was_freed)
+ goto checks;
+ goto scan; /* check next one */
+ }
+
+ if (si->swap_map[offset])
+ goto scan;
+
+ if (offset == si->lowest_bit)
+ si->lowest_bit++;
+ if (offset == si->highest_bit)
+ si->highest_bit--;
+ si->inuse_pages++;
+ if (si->inuse_pages == si->pages) {
+ si->lowest_bit = si->max;
+ si->highest_bit = 0;
+ }
+ si->swap_map[offset] = usage;
+ si->cluster_next = offset + 1;
+ si->flags -= SWP_SCANNING;
+
+ if (si->lowest_alloc) {
+ /*
+ * Only set when SWP_DISCARDABLE, and there's a scan
+ * for a free cluster in progress or just completed.
+ */
+ if (found_free_cluster) {
+ /*
+ * To optimize wear-levelling, discard the
+ * old data of the cluster, taking care not to
+ * discard any of its pages that have already
+ * been allocated by racing tasks (offset has
+ * already stepped over any at the beginning).
+ */
+ if (offset < si->highest_alloc &&
+ si->lowest_alloc <= last_in_cluster)
+ last_in_cluster = si->lowest_alloc - 1;
+ si->flags |= SWP_DISCARDING;
+ spin_unlock(&swap_lock);
+
+ if (offset < last_in_cluster)
+ discard_swap_cluster(si, offset,
+ last_in_cluster - offset + 1);
+
+ spin_lock(&swap_lock);
+ si->lowest_alloc = 0;
+ si->flags &= ~SWP_DISCARDING;
+
+ smp_mb(); /* wake_up_bit advises this */
+ wake_up_bit(&si->flags, ilog2(SWP_DISCARDING));
+
+ } else if (si->flags & SWP_DISCARDING) {
+ /*
+ * Delay using pages allocated by racing tasks
+ * until the whole discard has been issued. We
+ * could defer that delay until swap_writepage,
+ * but it's easier to keep this self-contained.
+ */
+ spin_unlock(&swap_lock);
+ wait_on_bit(&si->flags, ilog2(SWP_DISCARDING),
+ wait_for_discard, TASK_UNINTERRUPTIBLE);
+ spin_lock(&swap_lock);
+ } else {
+ /*
+ * Note pages allocated by racing tasks while
+ * scan for a free cluster is in progress, so
+ * that its final discard can exclude them.
+ */
+ if (offset < si->lowest_alloc)
+ si->lowest_alloc = offset;
+ if (offset > si->highest_alloc)
+ si->highest_alloc = offset;
+ }
+ }
+ return offset;
+
+scan:
+ spin_unlock(&swap_lock);
+ while (++offset <= si->highest_bit) {
+ if (!si->swap_map[offset]) {
+ spin_lock(&swap_lock);
+ goto checks;
+ }
+ if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) {
+ spin_lock(&swap_lock);
+ goto checks;
+ }
+ if (unlikely(--latency_ration < 0)) {
+ cond_resched();
+ latency_ration = LATENCY_LIMIT;
+ }
+ }
+ offset = si->lowest_bit;
+ while (++offset < scan_base) {
+ if (!si->swap_map[offset]) {
+ spin_lock(&swap_lock);
+ goto checks;
+ }
+ if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) {
+ spin_lock(&swap_lock);
+ goto checks;
+ }
+ if (unlikely(--latency_ration < 0)) {
+ cond_resched();
+ latency_ration = LATENCY_LIMIT;
+ }
+ }
+ spin_lock(&swap_lock);
+
+no_page:
+ si->flags -= SWP_SCANNING;
+ return 0;
+}
+
+swp_entry_t get_swap_page(void)
+{
+ struct swap_info_struct *si;
+ pgoff_t offset;
+ int type, next;
+ int wrapped = 0;
+
+ spin_lock(&swap_lock);
+ if (nr_swap_pages <= 0)
+ goto noswap;
+ nr_swap_pages--;
+
+ for (type = swap_list.next; type >= 0 && wrapped < 2; type = next) {
+ si = swap_info[type];
+ next = si->next;
+ if (next < 0 ||
+ (!wrapped && si->prio != swap_info[next]->prio)) {
+ next = swap_list.head;
+ wrapped++;
+ }
+
+ if (!si->highest_bit)
+ continue;
+ if (!(si->flags & SWP_WRITEOK))
+ continue;
+
+ swap_list.next = next;
+ /* This is called for allocating swap entry for cache */
+ offset = scan_swap_map(si, SWAP_HAS_CACHE);
+ if (offset) {
+ spin_unlock(&swap_lock);
+ return swp_entry(type, offset);
+ }
+ next = swap_list.next;
+ }
+
+ nr_swap_pages++;
+noswap:
+ spin_unlock(&swap_lock);
+ return (swp_entry_t) {0};
+}
+
+/* The only caller of this function is now susupend routine */
+swp_entry_t get_swap_page_of_type(int type)
+{
+ struct swap_info_struct *si;
+ pgoff_t offset;
+
+ spin_lock(&swap_lock);
+ si = swap_info[type];
+ if (si && (si->flags & SWP_WRITEOK)) {
+ nr_swap_pages--;
+ /* This is called for allocating swap entry, not cache */
+ offset = scan_swap_map(si, 1);
+ if (offset) {
+ spin_unlock(&swap_lock);
+ return swp_entry(type, offset);
+ }
+ nr_swap_pages++;
+ }
+ spin_unlock(&swap_lock);
+ return (swp_entry_t) {0};
+}
+
+static struct swap_info_struct *swap_info_get(swp_entry_t entry)
+{
+ struct swap_info_struct *p;
+ unsigned long offset, type;
+
+ if (!entry.val)
+ goto out;
+ type = swp_type(entry);
+ if (type >= nr_swapfiles)
+ goto bad_nofile;
+ p = swap_info[type];
+ if (!(p->flags & SWP_USED))
+ goto bad_device;
+ offset = swp_offset(entry);
+ if (offset >= p->max)
+ goto bad_offset;
+ if (!p->swap_map[offset])
+ goto bad_free;
+ spin_lock(&swap_lock);
+ return p;
+
+bad_free:
+ printk(KERN_ERR "swap_free: %s%08lx\n", Unused_offset, entry.val);
+ goto out;
+bad_offset:
+ printk(KERN_ERR "swap_free: %s%08lx\n", Bad_offset, entry.val);
+ goto out;
+bad_device:
+ printk(KERN_ERR "swap_free: %s%08lx\n", Unused_file, entry.val);
+ goto out;
+bad_nofile:
+ printk(KERN_ERR "swap_free: %s%08lx\n", Bad_file, entry.val);
+out:
+ return NULL;
+}
+
+static unsigned char swap_entry_free(struct swap_info_struct *p,
+ swp_entry_t entry, unsigned char usage)
+{
+ unsigned long offset = swp_offset(entry);
+ unsigned char count;
+ unsigned char has_cache;
+
+ count = p->swap_map[offset];
+ has_cache = count & SWAP_HAS_CACHE;
+ count &= ~SWAP_HAS_CACHE;
+
+ if (usage == SWAP_HAS_CACHE) {
+ VM_BUG_ON(!has_cache);
+ has_cache = 0;
+ } else if (count == SWAP_MAP_SHMEM) {
+ /*
+ * Or we could insist on shmem.c using a special
+ * swap_shmem_free() and free_shmem_swap_and_cache()...
+ */
+ count = 0;
+ } else if ((count & ~COUNT_CONTINUED) <= SWAP_MAP_MAX) {
+ if (count == COUNT_CONTINUED) {
+ if (swap_count_continued(p, offset, count))
+ count = SWAP_MAP_MAX | COUNT_CONTINUED;
+ else
+ count = SWAP_MAP_MAX;
+ } else
+ count--;
+ }
+
+ if (!count)
+ mem_cgroup_uncharge_swap(entry);
+
+ usage = count | has_cache;
+ p->swap_map[offset] = usage;
+
+ /* free if no reference */
+ if (!usage) {
+ struct gendisk *disk = p->bdev->bd_disk;
+ if (offset < p->lowest_bit)
+ p->lowest_bit = offset;
+ if (offset > p->highest_bit)
+ p->highest_bit = offset;
+ if (swap_list.next >= 0 &&
+ p->prio > swap_info[swap_list.next]->prio)
+ swap_list.next = p->type;
+ nr_swap_pages++;
+ p->inuse_pages--;
+ if ((p->flags & SWP_BLKDEV) &&
+ disk->fops->swap_slot_free_notify)
+ disk->fops->swap_slot_free_notify(p->bdev, offset);
+ }
+
+ return usage;
+}
+
+/*
+ * Caller has made sure that the swapdevice corresponding to entry
+ * is still around or has not been recycled.
+ */
+void swap_free(swp_entry_t entry)
+{
+ struct swap_info_struct *p;
+
+ p = swap_info_get(entry);
+ if (p) {
+ swap_entry_free(p, entry, 1);
+ spin_unlock(&swap_lock);
+ }
+}
+
+/*
+ * Called after dropping swapcache to decrease refcnt to swap entries.
+ */
+void swapcache_free(swp_entry_t entry, struct page *page)
+{
+ struct swap_info_struct *p;
+ unsigned char count;
+
+ p = swap_info_get(entry);
+ if (p) {
+ count = swap_entry_free(p, entry, SWAP_HAS_CACHE);
+ if (page)
+ mem_cgroup_uncharge_swapcache(page, entry, count != 0);
+ spin_unlock(&swap_lock);
+ }
+}
+
+/*
+ * How many references to page are currently swapped out?
+ * This does not give an exact answer when swap count is continued,
+ * but does include the high COUNT_CONTINUED flag to allow for that.
+ */
+static inline int page_swapcount(struct page *page)
+{
+ int count = 0;
+ struct swap_info_struct *p;
+ swp_entry_t entry;
+
+ entry.val = page_private(page);
+ p = swap_info_get(entry);
+ if (p) {
+ count = swap_count(p->swap_map[swp_offset(entry)]);
+ spin_unlock(&swap_lock);
+ }
+ return count;
+}
+
+/*
+ * We can write to an anon page without COW if there are no other references
+ * to it. And as a side-effect, free up its swap: because the old content
+ * on disk will never be read, and seeking back there to write new content
+ * later would only waste time away from clustering.
+ */
+int reuse_swap_page(struct page *page)
+{
+ int count;
+
+ VM_BUG_ON(!PageLocked(page));
+ if (unlikely(PageKsm(page)))
+ return 0;
+ count = page_mapcount(page);
+ if (count <= 1 && PageSwapCache(page)) {
+ count += page_swapcount(page);
+ if (count == 1 && !PageWriteback(page)) {
+ delete_from_swap_cache(page);
+ SetPageDirty(page);
+ }
+ }
+ return count <= 1;
+}
+
+/*
+ * If swap is getting full, or if there are no more mappings of this page,
+ * then try_to_free_swap is called to free its swap space.
+ */
+int try_to_free_swap(struct page *page)
+{
+ VM_BUG_ON(!PageLocked(page));
+
+ if (!PageSwapCache(page))
+ return 0;
+ if (PageWriteback(page))
+ return 0;
+ if (page_swapcount(page))
+ return 0;
+
+ /*
+ * Once hibernation has begun to create its image of memory,
+ * there's a danger that one of the calls to try_to_free_swap()
+ * - most probably a call from __try_to_reclaim_swap() while
+ * hibernation is allocating its own swap pages for the image,
+ * but conceivably even a call from memory reclaim - will free
+ * the swap from a page which has already been recorded in the
+ * image as a clean swapcache page, and then reuse its swap for
+ * another page of the image. On waking from hibernation, the
+ * original page might be freed under memory pressure, then
+ * later read back in from swap, now with the wrong data.
+ *
+ * Hibration suspends storage while it is writing the image
+ * to disk so check that here.
+ */
+ if (pm_suspended_storage())
+ return 0;
+
+ delete_from_swap_cache(page);
+ SetPageDirty(page);
+ return 1;
+}
+
+/*
+ * Free the swap entry like above, but also try to
+ * free the page cache entry if it is the last user.
+ */
+int free_swap_and_cache(swp_entry_t entry)
+{
+ struct swap_info_struct *p;
+ struct page *page = NULL;
+
+ if (non_swap_entry(entry))
+ return 1;
+
+ p = swap_info_get(entry);
+ if (p) {
+ if (swap_entry_free(p, entry, 1) == SWAP_HAS_CACHE) {
+ page = find_get_page(&swapper_space, entry.val);
+ if (page && !trylock_page(page)) {
+ page_cache_release(page);
+ page = NULL;
+ }
+ }
+ spin_unlock(&swap_lock);
+ }
+ if (page) {
+ /*
+ * Not mapped elsewhere, or swap space full? Free it!
+ * Also recheck PageSwapCache now page is locked (above).
+ */
+ if (PageSwapCache(page) && !PageWriteback(page) &&
+ (!page_mapped(page) || vm_swap_full())) {
+ delete_from_swap_cache(page);
+ SetPageDirty(page);
+ }
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ return p != NULL;
+}
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+/**
+ * mem_cgroup_count_swap_user - count the user of a swap entry
+ * @ent: the swap entry to be checked
+ * @pagep: the pointer for the swap cache page of the entry to be stored
+ *
+ * Returns the number of the user of the swap entry. The number is valid only
+ * for swaps of anonymous pages.
+ * If the entry is found on swap cache, the page is stored to pagep with
+ * refcount of it being incremented.
+ */
+int mem_cgroup_count_swap_user(swp_entry_t ent, struct page **pagep)
+{
+ struct page *page;
+ struct swap_info_struct *p;
+ int count = 0;
+
+ page = find_get_page(&swapper_space, ent.val);
+ if (page)
+ count += page_mapcount(page);
+ p = swap_info_get(ent);
+ if (p) {
+ count += swap_count(p->swap_map[swp_offset(ent)]);
+ spin_unlock(&swap_lock);
+ }
+
+ *pagep = page;
+ return count;
+}
+#endif
+
+#ifdef CONFIG_HIBERNATION
+/*
+ * Find the swap type that corresponds to given device (if any).
+ *
+ * @offset - number of the PAGE_SIZE-sized block of the device, starting
+ * from 0, in which the swap header is expected to be located.
+ *
+ * This is needed for the suspend to disk (aka swsusp).
+ */
+int swap_type_of(dev_t device, sector_t offset, struct block_device **bdev_p)
+{
+ struct block_device *bdev = NULL;
+ int type;
+
+ if (device)
+ bdev = bdget(device);
+
+ spin_lock(&swap_lock);
+ for (type = 0; type < nr_swapfiles; type++) {
+ struct swap_info_struct *sis = swap_info[type];
+
+ if (!(sis->flags & SWP_WRITEOK))
+ continue;
+
+ if (!bdev) {
+ if (bdev_p)
+ *bdev_p = bdgrab(sis->bdev);
+
+ spin_unlock(&swap_lock);
+ return type;
+ }
+ if (bdev == sis->bdev) {
+ struct swap_extent *se = &sis->first_swap_extent;
+
+ if (se->start_block == offset) {
+ if (bdev_p)
+ *bdev_p = bdgrab(sis->bdev);
+
+ spin_unlock(&swap_lock);
+ bdput(bdev);
+ return type;
+ }
+ }
+ }
+ spin_unlock(&swap_lock);
+ if (bdev)
+ bdput(bdev);
+
+ return -ENODEV;
+}
+
+/*
+ * Get the (PAGE_SIZE) block corresponding to given offset on the swapdev
+ * corresponding to given index in swap_info (swap type).
+ */
+sector_t swapdev_block(int type, pgoff_t offset)
+{
+ struct block_device *bdev;
+
+ if ((unsigned int)type >= nr_swapfiles)
+ return 0;
+ if (!(swap_info[type]->flags & SWP_WRITEOK))
+ return 0;
+ return map_swap_entry(swp_entry(type, offset), &bdev);
+}
+
+/*
+ * Return either the total number of swap pages of given type, or the number
+ * of free pages of that type (depending on @free)
+ *
+ * This is needed for software suspend
+ */
+unsigned int count_swap_pages(int type, int free)
+{
+ unsigned int n = 0;
+
+ spin_lock(&swap_lock);
+ if ((unsigned int)type < nr_swapfiles) {
+ struct swap_info_struct *sis = swap_info[type];
+
+ if (sis->flags & SWP_WRITEOK) {
+ n = sis->pages;
+ if (free)
+ n -= sis->inuse_pages;
+ }
+ }
+ spin_unlock(&swap_lock);
+ return n;
+}
+#endif /* CONFIG_HIBERNATION */
+
+/*
+ * No need to decide whether this PTE shares the swap entry with others,
+ * just let do_wp_page work it out if a write is requested later - to
+ * force COW, vm_page_prot omits write permission from any private vma.
+ */
+static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, swp_entry_t entry, struct page *page)
+{
+ struct mem_cgroup *memcg;
+ spinlock_t *ptl;
+ pte_t *pte;
+ int ret = 1;
+
+ if (mem_cgroup_try_charge_swapin(vma->vm_mm, page,
+ GFP_KERNEL, &memcg)) {
+ ret = -ENOMEM;
+ goto out_nolock;
+ }
+
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ if (unlikely(!pte_same(*pte, swp_entry_to_pte(entry)))) {
+ if (ret > 0)
+ mem_cgroup_cancel_charge_swapin(memcg);
+ ret = 0;
+ goto out;
+ }
+
+ dec_mm_counter(vma->vm_mm, MM_SWAPENTS);
+ inc_mm_counter(vma->vm_mm, MM_ANONPAGES);
+ get_page(page);
+ set_pte_at(vma->vm_mm, addr, pte,
+ pte_mkold(mk_pte(page, vma->vm_page_prot)));
+ page_add_anon_rmap(page, vma, addr);
+ mem_cgroup_commit_charge_swapin(page, memcg);
+ swap_free(entry);
+ /*
+ * Move the page to the active list so it is not
+ * immediately swapped out again after swapon.
+ */
+ activate_page(page);
+out:
+ pte_unmap_unlock(pte, ptl);
+out_nolock:
+ return ret;
+}
+
+static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ swp_entry_t entry, struct page *page)
+{
+ pte_t swp_pte = swp_entry_to_pte(entry);
+ pte_t *pte;
+ int ret = 0;
+
+ /*
+ * We don't actually need pte lock while scanning for swp_pte: since
+ * we hold page lock and mmap_sem, swp_pte cannot be inserted into the
+ * page table while we're scanning; though it could get zapped, and on
+ * some architectures (e.g. x86_32 with PAE) we might catch a glimpse
+ * of unmatched parts which look like swp_pte, so unuse_pte must
+ * recheck under pte lock. Scanning without pte lock lets it be
+ * preemptible whenever CONFIG_PREEMPT but not CONFIG_HIGHPTE.
+ */
+ pte = pte_offset_map(pmd, addr);
+ do {
+ /*
+ * swapoff spends a _lot_ of time in this loop!
+ * Test inline before going to call unuse_pte.
+ */
+ if (unlikely(pte_same(*pte, swp_pte))) {
+ pte_unmap(pte);
+ ret = unuse_pte(vma, pmd, addr, entry, page);
+ if (ret)
+ goto out;
+ pte = pte_offset_map(pmd, addr);
+ }
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ pte_unmap(pte - 1);
+out:
+ return ret;
+}
+
+static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ swp_entry_t entry, struct page *page)
+{
+ pmd_t *pmd;
+ unsigned long next;
+ int ret;
+
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_none_or_trans_huge_or_clear_bad(pmd))
+ continue;
+ ret = unuse_pte_range(vma, pmd, addr, next, entry, page);
+ if (ret)
+ return ret;
+ } while (pmd++, addr = next, addr != end);
+ return 0;
+}
+
+static inline int unuse_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ swp_entry_t entry, struct page *page)
+{
+ pud_t *pud;
+ unsigned long next;
+ int ret;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ ret = unuse_pmd_range(vma, pud, addr, next, entry, page);
+ if (ret)
+ return ret;
+ } while (pud++, addr = next, addr != end);
+ return 0;
+}
+
+static int unuse_vma(struct vm_area_struct *vma,
+ swp_entry_t entry, struct page *page)
+{
+ pgd_t *pgd;
+ unsigned long addr, end, next;
+ int ret;
+
+ if (page_anon_vma(page)) {
+ addr = page_address_in_vma(page, vma);
+ if (addr == -EFAULT)
+ return 0;
+ else
+ end = addr + PAGE_SIZE;
+ } else {
+ addr = vma->vm_start;
+ end = vma->vm_end;
+ }
+
+ pgd = pgd_offset(vma->vm_mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ ret = unuse_pud_range(vma, pgd, addr, next, entry, page);
+ if (ret)
+ return ret;
+ } while (pgd++, addr = next, addr != end);
+ return 0;
+}
+
+static int unuse_mm(struct mm_struct *mm,
+ swp_entry_t entry, struct page *page)
+{
+ struct vm_area_struct *vma;
+ int ret = 0;
+
+ if (!down_read_trylock(&mm->mmap_sem)) {
+ /*
+ * Activate page so shrink_inactive_list is unlikely to unmap
+ * its ptes while lock is dropped, so swapoff can make progress.
+ */
+ activate_page(page);
+ unlock_page(page);
+ down_read(&mm->mmap_sem);
+ lock_page(page);
+ }
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (vma->anon_vma && (ret = unuse_vma(vma, entry, page)))
+ break;
+ }
+ up_read(&mm->mmap_sem);
+ return (ret < 0)? ret: 0;
+}
+
+/*
+ * Scan swap_map from current position to next entry still in use.
+ * Recycle to start on reaching the end, returning 0 when empty.
+ */
+static unsigned int find_next_to_unuse(struct swap_info_struct *si,
+ unsigned int prev)
+{
+ unsigned int max = si->max;
+ unsigned int i = prev;
+ unsigned char count;
+
+ /*
+ * No need for swap_lock here: we're just looking
+ * for whether an entry is in use, not modifying it; false
+ * hits are okay, and sys_swapoff() has already prevented new
+ * allocations from this area (while holding swap_lock).
+ */
+ for (;;) {
+ if (++i >= max) {
+ if (!prev) {
+ i = 0;
+ break;
+ }
+ /*
+ * No entries in use at top of swap_map,
+ * loop back to start and recheck there.
+ */
+ max = prev + 1;
+ prev = 0;
+ i = 1;
+ }
+ count = si->swap_map[i];
+ if (count && swap_count(count) != SWAP_MAP_BAD)
+ break;
+ }
+ return i;
+}
+
+/*
+ * We completely avoid races by reading each swap page in advance,
+ * and then search for the process using it. All the necessary
+ * page table adjustments can then be made atomically.
+ */
+static int try_to_unuse(unsigned int type)
+{
+ struct swap_info_struct *si = swap_info[type];
+ struct mm_struct *start_mm;
+ unsigned char *swap_map;
+ unsigned char swcount;
+ struct page *page;
+ swp_entry_t entry;
+ unsigned int i = 0;
+ int retval = 0;
+
+ /*
+ * When searching mms for an entry, a good strategy is to
+ * start at the first mm we freed the previous entry from
+ * (though actually we don't notice whether we or coincidence
+ * freed the entry). Initialize this start_mm with a hold.
+ *
+ * A simpler strategy would be to start at the last mm we
+ * freed the previous entry from; but that would take less
+ * advantage of mmlist ordering, which clusters forked mms
+ * together, child after parent. If we race with dup_mmap(), we
+ * prefer to resolve parent before child, lest we miss entries
+ * duplicated after we scanned child: using last mm would invert
+ * that.
+ */
+ start_mm = &init_mm;
+ atomic_inc(&init_mm.mm_users);
+
+ /*
+ * Keep on scanning until all entries have gone. Usually,
+ * one pass through swap_map is enough, but not necessarily:
+ * there are races when an instance of an entry might be missed.
+ */
+ while ((i = find_next_to_unuse(si, i)) != 0) {
+ if (signal_pending(current)) {
+ retval = -EINTR;
+ break;
+ }
+
+ /*
+ * Get a page for the entry, using the existing swap
+ * cache page if there is one. Otherwise, get a clean
+ * page and read the swap into it.
+ */
+ swap_map = &si->swap_map[i];
+ entry = swp_entry(type, i);
+ page = read_swap_cache_async(entry,
+ GFP_HIGHUSER_MOVABLE, NULL, 0);
+ if (!page) {
+ /*
+ * Either swap_duplicate() failed because entry
+ * has been freed independently, and will not be
+ * reused since sys_swapoff() already disabled
+ * allocation from here, or alloc_page() failed.
+ */
+ if (!*swap_map)
+ continue;
+ retval = -ENOMEM;
+ break;
+ }
+
+ /*
+ * Don't hold on to start_mm if it looks like exiting.
+ */
+ if (atomic_read(&start_mm->mm_users) == 1) {
+ mmput(start_mm);
+ start_mm = &init_mm;
+ atomic_inc(&init_mm.mm_users);
+ }
+
+ /*
+ * Wait for and lock page. When do_swap_page races with
+ * try_to_unuse, do_swap_page can handle the fault much
+ * faster than try_to_unuse can locate the entry. This
+ * apparently redundant "wait_on_page_locked" lets try_to_unuse
+ * defer to do_swap_page in such a case - in some tests,
+ * do_swap_page and try_to_unuse repeatedly compete.
+ */
+ wait_on_page_locked(page);
+ wait_on_page_writeback(page);
+ lock_page(page);
+ wait_on_page_writeback(page);
+
+ /*
+ * Remove all references to entry.
+ */
+ swcount = *swap_map;
+ if (swap_count(swcount) == SWAP_MAP_SHMEM) {
+ retval = shmem_unuse(entry, page);
+ /* page has already been unlocked and released */
+ if (retval < 0)
+ break;
+ continue;
+ }
+ if (swap_count(swcount) && start_mm != &init_mm)
+ retval = unuse_mm(start_mm, entry, page);
+
+ if (swap_count(*swap_map)) {
+ int set_start_mm = (*swap_map >= swcount);
+ struct list_head *p = &start_mm->mmlist;
+ struct mm_struct *new_start_mm = start_mm;
+ struct mm_struct *prev_mm = start_mm;
+ struct mm_struct *mm;
+
+ atomic_inc(&new_start_mm->mm_users);
+ atomic_inc(&prev_mm->mm_users);
+ spin_lock(&mmlist_lock);
+ while (swap_count(*swap_map) && !retval &&
+ (p = p->next) != &start_mm->mmlist) {
+ mm = list_entry(p, struct mm_struct, mmlist);
+ if (!atomic_inc_not_zero(&mm->mm_users))
+ continue;
+ spin_unlock(&mmlist_lock);
+ mmput(prev_mm);
+ prev_mm = mm;
+
+ cond_resched();
+
+ swcount = *swap_map;
+ if (!swap_count(swcount)) /* any usage ? */
+ ;
+ else if (mm == &init_mm)
+ set_start_mm = 1;
+ else
+ retval = unuse_mm(mm, entry, page);
+
+ if (set_start_mm && *swap_map < swcount) {
+ mmput(new_start_mm);
+ atomic_inc(&mm->mm_users);
+ new_start_mm = mm;
+ set_start_mm = 0;
+ }
+ spin_lock(&mmlist_lock);
+ }
+ spin_unlock(&mmlist_lock);
+ mmput(prev_mm);
+ mmput(start_mm);
+ start_mm = new_start_mm;
+ }
+ if (retval) {
+ unlock_page(page);
+ page_cache_release(page);
+ break;
+ }
+
+ /*
+ * If a reference remains (rare), we would like to leave
+ * the page in the swap cache; but try_to_unmap could
+ * then re-duplicate the entry once we drop page lock,
+ * so we might loop indefinitely; also, that page could
+ * not be swapped out to other storage meanwhile. So:
+ * delete from cache even if there's another reference,
+ * after ensuring that the data has been saved to disk -
+ * since if the reference remains (rarer), it will be
+ * read from disk into another page. Splitting into two
+ * pages would be incorrect if swap supported "shared
+ * private" pages, but they are handled by tmpfs files.
+ *
+ * Given how unuse_vma() targets one particular offset
+ * in an anon_vma, once the anon_vma has been determined,
+ * this splitting happens to be just what is needed to
+ * handle where KSM pages have been swapped out: re-reading
+ * is unnecessarily slow, but we can fix that later on.
+ */
+ if (swap_count(*swap_map) &&
+ PageDirty(page) && PageSwapCache(page)) {
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_NONE,
+ };
+
+ swap_writepage(page, &wbc);
+ lock_page(page);
+ wait_on_page_writeback(page);
+ }
+
+ /*
+ * It is conceivable that a racing task removed this page from
+ * swap cache just before we acquired the page lock at the top,
+ * or while we dropped it in unuse_mm(). The page might even
+ * be back in swap cache on another swap area: that we must not
+ * delete, since it may not have been written out to swap yet.
+ */
+ if (PageSwapCache(page) &&
+ likely(page_private(page) == entry.val))
+ delete_from_swap_cache(page);
+
+ /*
+ * So we could skip searching mms once swap count went
+ * to 1, we did not mark any present ptes as dirty: must
+ * mark page dirty so shrink_page_list will preserve it.
+ */
+ SetPageDirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+
+ /*
+ * Make sure that we aren't completely killing
+ * interactive performance.
+ */
+ cond_resched();
+ }
+
+ mmput(start_mm);
+ return retval;
+}
+
+/*
+ * After a successful try_to_unuse, if no swap is now in use, we know
+ * we can empty the mmlist. swap_lock must be held on entry and exit.
+ * Note that mmlist_lock nests inside swap_lock, and an mm must be
+ * added to the mmlist just after page_duplicate - before would be racy.
+ */
+static void drain_mmlist(void)
+{
+ struct list_head *p, *next;
+ unsigned int type;
+
+ for (type = 0; type < nr_swapfiles; type++)
+ if (swap_info[type]->inuse_pages)
+ return;
+ spin_lock(&mmlist_lock);
+ list_for_each_safe(p, next, &init_mm.mmlist)
+ list_del_init(p);
+ spin_unlock(&mmlist_lock);
+}
+
+/*
+ * Use this swapdev's extent info to locate the (PAGE_SIZE) block which
+ * corresponds to page offset for the specified swap entry.
+ * Note that the type of this function is sector_t, but it returns page offset
+ * into the bdev, not sector offset.
+ */
+static sector_t map_swap_entry(swp_entry_t entry, struct block_device **bdev)
+{
+ struct swap_info_struct *sis;
+ struct swap_extent *start_se;
+ struct swap_extent *se;
+ pgoff_t offset;
+
+ sis = swap_info[swp_type(entry)];
+ *bdev = sis->bdev;
+
+ offset = swp_offset(entry);
+ start_se = sis->curr_swap_extent;
+ se = start_se;
+
+ for ( ; ; ) {
+ struct list_head *lh;
+
+ if (se->start_page <= offset &&
+ offset < (se->start_page + se->nr_pages)) {
+ return se->start_block + (offset - se->start_page);
+ }
+ lh = se->list.next;
+ se = list_entry(lh, struct swap_extent, list);
+ sis->curr_swap_extent = se;
+ BUG_ON(se == start_se); /* It *must* be present */
+ }
+}
+
+/*
+ * Returns the page offset into bdev for the specified page's swap entry.
+ */
+sector_t map_swap_page(struct page *page, struct block_device **bdev)
+{
+ swp_entry_t entry;
+ entry.val = page_private(page);
+ return map_swap_entry(entry, bdev);
+}
+
+/*
+ * Free all of a swapdev's extent information
+ */
+static void destroy_swap_extents(struct swap_info_struct *sis)
+{
+ while (!list_empty(&sis->first_swap_extent.list)) {
+ struct swap_extent *se;
+
+ se = list_entry(sis->first_swap_extent.list.next,
+ struct swap_extent, list);
+ list_del(&se->list);
+ kfree(se);
+ }
+}
+
+/*
+ * Add a block range (and the corresponding page range) into this swapdev's
+ * extent list. The extent list is kept sorted in page order.
+ *
+ * This function rather assumes that it is called in ascending page order.
+ */
+static int
+add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
+ unsigned long nr_pages, sector_t start_block)
+{
+ struct swap_extent *se;
+ struct swap_extent *new_se;
+ struct list_head *lh;
+
+ if (start_page == 0) {
+ se = &sis->first_swap_extent;
+ sis->curr_swap_extent = se;
+ se->start_page = 0;
+ se->nr_pages = nr_pages;
+ se->start_block = start_block;
+ return 1;
+ } else {
+ lh = sis->first_swap_extent.list.prev; /* Highest extent */
+ se = list_entry(lh, struct swap_extent, list);
+ BUG_ON(se->start_page + se->nr_pages != start_page);
+ if (se->start_block + se->nr_pages == start_block) {
+ /* Merge it */
+ se->nr_pages += nr_pages;
+ return 0;
+ }
+ }
+
+ /*
+ * No merge. Insert a new extent, preserving ordering.
+ */
+ new_se = kmalloc(sizeof(*se), GFP_KERNEL);
+ if (new_se == NULL)
+ return -ENOMEM;
+ new_se->start_page = start_page;
+ new_se->nr_pages = nr_pages;
+ new_se->start_block = start_block;
+
+ list_add_tail(&new_se->list, &sis->first_swap_extent.list);
+ return 1;
+}
+
+/*
+ * A `swap extent' is a simple thing which maps a contiguous range of pages
+ * onto a contiguous range of disk blocks. An ordered list of swap extents
+ * is built at swapon time and is then used at swap_writepage/swap_readpage
+ * time for locating where on disk a page belongs.
+ *
+ * If the swapfile is an S_ISBLK block device, a single extent is installed.
+ * This is done so that the main operating code can treat S_ISBLK and S_ISREG
+ * swap files identically.
+ *
+ * Whether the swapdev is an S_ISREG file or an S_ISBLK blockdev, the swap
+ * extent list operates in PAGE_SIZE disk blocks. Both S_ISREG and S_ISBLK
+ * swapfiles are handled *identically* after swapon time.
+ *
+ * For S_ISREG swapfiles, setup_swap_extents() will walk all the file's blocks
+ * and will parse them into an ordered extent list, in PAGE_SIZE chunks. If
+ * some stray blocks are found which do not fall within the PAGE_SIZE alignment
+ * requirements, they are simply tossed out - we will never use those blocks
+ * for swapping.
+ *
+ * For S_ISREG swapfiles we set S_SWAPFILE across the life of the swapon. This
+ * prevents root from shooting her foot off by ftruncating an in-use swapfile,
+ * which will scribble on the fs.
+ *
+ * The amount of disk space which a single swap extent represents varies.
+ * Typically it is in the 1-4 megabyte range. So we can have hundreds of
+ * extents in the list. To avoid much list walking, we cache the previous
+ * search location in `curr_swap_extent', and start new searches from there.
+ * This is extremely effective. The average number of iterations in
+ * map_swap_page() has been measured at about 0.3 per page. - akpm.
+ */
+static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span)
+{
+ struct inode *inode;
+ unsigned blocks_per_page;
+ unsigned long page_no;
+ unsigned blkbits;
+ sector_t probe_block;
+ sector_t last_block;
+ sector_t lowest_block = -1;
+ sector_t highest_block = 0;
+ int nr_extents = 0;
+ int ret;
+
+ inode = sis->swap_file->f_mapping->host;
+ if (S_ISBLK(inode->i_mode)) {
+ ret = add_swap_extent(sis, 0, sis->max, 0);
+ *span = sis->pages;
+ goto out;
+ }
+
+ blkbits = inode->i_blkbits;
+ blocks_per_page = PAGE_SIZE >> blkbits;
+
+ /*
+ * Map all the blocks into the extent list. This code doesn't try
+ * to be very smart.
+ */
+ probe_block = 0;
+ page_no = 0;
+ last_block = i_size_read(inode) >> blkbits;
+ while ((probe_block + blocks_per_page) <= last_block &&
+ page_no < sis->max) {
+ unsigned block_in_page;
+ sector_t first_block;
+
+ first_block = bmap(inode, probe_block);
+ if (first_block == 0)
+ goto bad_bmap;
+
+ /*
+ * It must be PAGE_SIZE aligned on-disk
+ */
+ if (first_block & (blocks_per_page - 1)) {
+ probe_block++;
+ goto reprobe;
+ }
+
+ for (block_in_page = 1; block_in_page < blocks_per_page;
+ block_in_page++) {
+ sector_t block;
+
+ block = bmap(inode, probe_block + block_in_page);
+ if (block == 0)
+ goto bad_bmap;
+ if (block != first_block + block_in_page) {
+ /* Discontiguity */
+ probe_block++;
+ goto reprobe;
+ }
+ }
+
+ first_block >>= (PAGE_SHIFT - blkbits);
+ if (page_no) { /* exclude the header page */
+ if (first_block < lowest_block)
+ lowest_block = first_block;
+ if (first_block > highest_block)
+ highest_block = first_block;
+ }
+
+ /*
+ * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
+ */
+ ret = add_swap_extent(sis, page_no, 1, first_block);
+ if (ret < 0)
+ goto out;
+ nr_extents += ret;
+ page_no++;
+ probe_block += blocks_per_page;
+reprobe:
+ continue;
+ }
+ ret = nr_extents;
+ *span = 1 + highest_block - lowest_block;
+ if (page_no == 0)
+ page_no = 1; /* force Empty message */
+ sis->max = page_no;
+ sis->pages = page_no - 1;
+ sis->highest_bit = page_no - 1;
+out:
+ return ret;
+bad_bmap:
+ printk(KERN_ERR "swapon: swapfile has holes\n");
+ ret = -EINVAL;
+ goto out;
+}
+
+static void enable_swap_info(struct swap_info_struct *p, int prio,
+ unsigned char *swap_map)
+{
+ int i, prev;
+
+ spin_lock(&swap_lock);
+ if (prio >= 0)
+ p->prio = prio;
+ else
+ p->prio = --least_priority;
+ p->swap_map = swap_map;
+ p->flags |= SWP_WRITEOK;
+ nr_swap_pages += p->pages;
+ total_swap_pages += p->pages;
+
+ /* insert swap space into swap_list: */
+ prev = -1;
+ for (i = swap_list.head; i >= 0; i = swap_info[i]->next) {
+ if (p->prio >= swap_info[i]->prio)
+ break;
+ prev = i;
+ }
+ p->next = i;
+ if (prev < 0)
+ swap_list.head = swap_list.next = p->type;
+ else
+ swap_info[prev]->next = p->type;
+ spin_unlock(&swap_lock);
+}
+
+SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
+{
+ struct swap_info_struct *p = NULL;
+ unsigned char *swap_map;
+ struct file *swap_file, *victim;
+ struct address_space *mapping;
+ struct inode *inode;
+ char *pathname;
+ int oom_score_adj;
+ int i, type, prev;
+ int err;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ BUG_ON(!current->mm);
+
+ pathname = getname(specialfile);
+ err = PTR_ERR(pathname);
+ if (IS_ERR(pathname))
+ goto out;
+
+ victim = filp_open(pathname, O_RDWR|O_LARGEFILE, 0);
+ putname(pathname);
+ err = PTR_ERR(victim);
+ if (IS_ERR(victim))
+ goto out;
+
+ mapping = victim->f_mapping;
+ prev = -1;
+ spin_lock(&swap_lock);
+ for (type = swap_list.head; type >= 0; type = swap_info[type]->next) {
+ p = swap_info[type];
+ if (p->flags & SWP_WRITEOK) {
+ if (p->swap_file->f_mapping == mapping)
+ break;
+ }
+ prev = type;
+ }
+ if (type < 0) {
+ err = -EINVAL;
+ spin_unlock(&swap_lock);
+ goto out_dput;
+ }
+ if (!security_vm_enough_memory_mm(current->mm, p->pages))
+ vm_unacct_memory(p->pages);
+ else {
+ err = -ENOMEM;
+ spin_unlock(&swap_lock);
+ goto out_dput;
+ }
+ if (prev < 0)
+ swap_list.head = p->next;
+ else
+ swap_info[prev]->next = p->next;
+ if (type == swap_list.next) {
+ /* just pick something that's safe... */
+ swap_list.next = swap_list.head;
+ }
+ if (p->prio < 0) {
+ for (i = p->next; i >= 0; i = swap_info[i]->next)
+ swap_info[i]->prio = p->prio--;
+ least_priority++;
+ }
+ nr_swap_pages -= p->pages;
+ total_swap_pages -= p->pages;
+ p->flags &= ~SWP_WRITEOK;
+ spin_unlock(&swap_lock);
+
+ oom_score_adj = test_set_oom_score_adj(OOM_SCORE_ADJ_MAX);
+ err = try_to_unuse(type);
+ compare_swap_oom_score_adj(OOM_SCORE_ADJ_MAX, oom_score_adj);
+
+ if (err) {
+ /*
+ * reading p->prio and p->swap_map outside the lock is
+ * safe here because only sys_swapon and sys_swapoff
+ * change them, and there can be no other sys_swapon or
+ * sys_swapoff for this swap_info_struct at this point.
+ */
+ /* re-insert swap space back into swap_list */
+ enable_swap_info(p, p->prio, p->swap_map);
+ goto out_dput;
+ }
+
+ destroy_swap_extents(p);
+ if (p->flags & SWP_CONTINUED)
+ free_swap_count_continuations(p);
+
+ mutex_lock(&swapon_mutex);
+ spin_lock(&swap_lock);
+ drain_mmlist();
+
+ /* wait for anyone still in scan_swap_map */
+ p->highest_bit = 0; /* cuts scans short */
+ while (p->flags >= SWP_SCANNING) {
+ spin_unlock(&swap_lock);
+ schedule_timeout_uninterruptible(1);
+ spin_lock(&swap_lock);
+ }
+
+ swap_file = p->swap_file;
+ p->swap_file = NULL;
+ p->max = 0;
+ swap_map = p->swap_map;
+ p->swap_map = NULL;
+ p->flags = 0;
+ spin_unlock(&swap_lock);
+ mutex_unlock(&swapon_mutex);
+ vfree(swap_map);
+ /* Destroy swap account informatin */
+ swap_cgroup_swapoff(type);
+
+ inode = mapping->host;
+ if (S_ISBLK(inode->i_mode)) {
+ struct block_device *bdev = I_BDEV(inode);
+ set_blocksize(bdev, p->old_block_size);
+ blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
+ } else {
+ mutex_lock(&inode->i_mutex);
+ inode->i_flags &= ~S_SWAPFILE;
+ mutex_unlock(&inode->i_mutex);
+ }
+ filp_close(swap_file, NULL);
+ err = 0;
+ atomic_inc(&proc_poll_event);
+ wake_up_interruptible(&proc_poll_wait);
+
+out_dput:
+ filp_close(victim, NULL);
+out:
+ return err;
+}
+
+#ifdef CONFIG_PROC_FS
+static unsigned swaps_poll(struct file *file, poll_table *wait)
+{
+ struct seq_file *seq = file->private_data;
+
+ poll_wait(file, &proc_poll_wait, wait);
+
+ if (seq->poll_event != atomic_read(&proc_poll_event)) {
+ seq->poll_event = atomic_read(&proc_poll_event);
+ return POLLIN | POLLRDNORM | POLLERR | POLLPRI;
+ }
+
+ return POLLIN | POLLRDNORM;
+}
+
+/* iterator */
+static void *swap_start(struct seq_file *swap, loff_t *pos)
+{
+ struct swap_info_struct *si;
+ int type;
+ loff_t l = *pos;
+
+ mutex_lock(&swapon_mutex);
+
+ if (!l)
+ return SEQ_START_TOKEN;
+
+ for (type = 0; type < nr_swapfiles; type++) {
+ smp_rmb(); /* read nr_swapfiles before swap_info[type] */
+ si = swap_info[type];
+ if (!(si->flags & SWP_USED) || !si->swap_map)
+ continue;
+ if (!--l)
+ return si;
+ }
+
+ return NULL;
+}
+
+static void *swap_next(struct seq_file *swap, void *v, loff_t *pos)
+{
+ struct swap_info_struct *si = v;
+ int type;
+
+ if (v == SEQ_START_TOKEN)
+ type = 0;
+ else
+ type = si->type + 1;
+
+ for (; type < nr_swapfiles; type++) {
+ smp_rmb(); /* read nr_swapfiles before swap_info[type] */
+ si = swap_info[type];
+ if (!(si->flags & SWP_USED) || !si->swap_map)
+ continue;
+ ++*pos;
+ return si;
+ }
+
+ return NULL;
+}
+
+static void swap_stop(struct seq_file *swap, void *v)
+{
+ mutex_unlock(&swapon_mutex);
+}
+
+static int swap_show(struct seq_file *swap, void *v)
+{
+ struct swap_info_struct *si = v;
+ struct file *file;
+ int len;
+
+ if (si == SEQ_START_TOKEN) {
+ seq_puts(swap,"Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n");
+ return 0;
+ }
+
+ file = si->swap_file;
+ len = seq_path(swap, &file->f_path, " \t\n\\");
+ seq_printf(swap, "%*s%s\t%u\t%u\t%d\n",
+ len < 40 ? 40 - len : 1, " ",
+ S_ISBLK(file->f_path.dentry->d_inode->i_mode) ?
+ "partition" : "file\t",
+ si->pages << (PAGE_SHIFT - 10),
+ si->inuse_pages << (PAGE_SHIFT - 10),
+ si->prio);
+ return 0;
+}
+
+static const struct seq_operations swaps_op = {
+ .start = swap_start,
+ .next = swap_next,
+ .stop = swap_stop,
+ .show = swap_show
+};
+
+static int swaps_open(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq;
+ int ret;
+
+ ret = seq_open(file, &swaps_op);
+ if (ret)
+ return ret;
+
+ seq = file->private_data;
+ seq->poll_event = atomic_read(&proc_poll_event);
+ return 0;
+}
+
+static const struct file_operations proc_swaps_operations = {
+ .open = swaps_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+ .poll = swaps_poll,
+};
+
+static int __init procswaps_init(void)
+{
+ proc_create("swaps", 0, NULL, &proc_swaps_operations);
+ return 0;
+}
+__initcall(procswaps_init);
+#endif /* CONFIG_PROC_FS */
+
+#ifdef MAX_SWAPFILES_CHECK
+static int __init max_swapfiles_check(void)
+{
+ MAX_SWAPFILES_CHECK();
+ return 0;
+}
+late_initcall(max_swapfiles_check);
+#endif
+
+static struct swap_info_struct *alloc_swap_info(void)
+{
+ struct swap_info_struct *p;
+ unsigned int type;
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return ERR_PTR(-ENOMEM);
+
+ spin_lock(&swap_lock);
+ for (type = 0; type < nr_swapfiles; type++) {
+ if (!(swap_info[type]->flags & SWP_USED))
+ break;
+ }
+ if (type >= MAX_SWAPFILES) {
+ spin_unlock(&swap_lock);
+ kfree(p);
+ return ERR_PTR(-EPERM);
+ }
+ if (type >= nr_swapfiles) {
+ p->type = type;
+ swap_info[type] = p;
+ /*
+ * Write swap_info[type] before nr_swapfiles, in case a
+ * racing procfs swap_start() or swap_next() is reading them.
+ * (We never shrink nr_swapfiles, we never free this entry.)
+ */
+ smp_wmb();
+ nr_swapfiles++;
+ } else {
+ kfree(p);
+ p = swap_info[type];
+ /*
+ * Do not memset this entry: a racing procfs swap_next()
+ * would be relying on p->type to remain valid.
+ */
+ }
+ INIT_LIST_HEAD(&p->first_swap_extent.list);
+ p->flags = SWP_USED;
+ p->next = -1;
+ spin_unlock(&swap_lock);
+
+ return p;
+}
+
+static int claim_swapfile(struct swap_info_struct *p, struct inode *inode)
+{
+ int error;
+
+ if (S_ISBLK(inode->i_mode)) {
+ p->bdev = bdgrab(I_BDEV(inode));
+ error = blkdev_get(p->bdev,
+ FMODE_READ | FMODE_WRITE | FMODE_EXCL,
+ sys_swapon);
+ if (error < 0) {
+ p->bdev = NULL;
+ return -EINVAL;
+ }
+ p->old_block_size = block_size(p->bdev);
+ error = set_blocksize(p->bdev, PAGE_SIZE);
+ if (error < 0)
+ return error;
+ p->flags |= SWP_BLKDEV;
+ } else if (S_ISREG(inode->i_mode)) {
+ p->bdev = inode->i_sb->s_bdev;
+ mutex_lock(&inode->i_mutex);
+ if (IS_SWAPFILE(inode))
+ return -EBUSY;
+ } else
+ return -EINVAL;
+
+ return 0;
+}
+
+static unsigned long read_swap_header(struct swap_info_struct *p,
+ union swap_header *swap_header,
+ struct inode *inode)
+{
+ int i;
+ unsigned long maxpages;
+ unsigned long swapfilepages;
+
+ if (memcmp("SWAPSPACE2", swap_header->magic.magic, 10)) {
+ printk(KERN_ERR "Unable to find swap-space signature\n");
+ return 0;
+ }
+
+ /* swap partition endianess hack... */
+ if (swab32(swap_header->info.version) == 1) {
+ swab32s(&swap_header->info.version);
+ swab32s(&swap_header->info.last_page);
+ swab32s(&swap_header->info.nr_badpages);
+ for (i = 0; i < swap_header->info.nr_badpages; i++)
+ swab32s(&swap_header->info.badpages[i]);
+ }
+ /* Check the swap header's sub-version */
+ if (swap_header->info.version != 1) {
+ printk(KERN_WARNING
+ "Unable to handle swap header version %d\n",
+ swap_header->info.version);
+ return 0;
+ }
+
+ p->lowest_bit = 1;
+ p->cluster_next = 1;
+ p->cluster_nr = 0;
+
+ /*
+ * Find out how many pages are allowed for a single swap
+ * device. There are two limiting factors: 1) the number
+ * of bits for the swap offset in the swp_entry_t type, and
+ * 2) the number of bits in the swap pte as defined by the
+ * different architectures. In order to find the
+ * largest possible bit mask, a swap entry with swap type 0
+ * and swap offset ~0UL is created, encoded to a swap pte,
+ * decoded to a swp_entry_t again, and finally the swap
+ * offset is extracted. This will mask all the bits from
+ * the initial ~0UL mask that can't be encoded in either
+ * the swp_entry_t or the architecture definition of a
+ * swap pte.
+ */
+ maxpages = swp_offset(pte_to_swp_entry(
+ swp_entry_to_pte(swp_entry(0, ~0UL)))) + 1;
+ if (maxpages > swap_header->info.last_page) {
+ maxpages = swap_header->info.last_page + 1;
+ /* p->max is an unsigned int: don't overflow it */
+ if ((unsigned int)maxpages == 0)
+ maxpages = UINT_MAX;
+ }
+ p->highest_bit = maxpages - 1;
+
+ if (!maxpages)
+ return 0;
+ swapfilepages = i_size_read(inode) >> PAGE_SHIFT;
+ if (swapfilepages && maxpages > swapfilepages) {
+ printk(KERN_WARNING
+ "Swap area shorter than signature indicates\n");
+ return 0;
+ }
+ if (swap_header->info.nr_badpages && S_ISREG(inode->i_mode))
+ return 0;
+ if (swap_header->info.nr_badpages > MAX_SWAP_BADPAGES)
+ return 0;
+
+ return maxpages;
+}
+
+static int setup_swap_map_and_extents(struct swap_info_struct *p,
+ union swap_header *swap_header,
+ unsigned char *swap_map,
+ unsigned long maxpages,
+ sector_t *span)
+{
+ int i;
+ unsigned int nr_good_pages;
+ int nr_extents;
+
+ nr_good_pages = maxpages - 1; /* omit header page */
+
+ for (i = 0; i < swap_header->info.nr_badpages; i++) {
+ unsigned int page_nr = swap_header->info.badpages[i];
+ if (page_nr == 0 || page_nr > swap_header->info.last_page)
+ return -EINVAL;
+ if (page_nr < maxpages) {
+ swap_map[page_nr] = SWAP_MAP_BAD;
+ nr_good_pages--;
+ }
+ }
+
+ if (nr_good_pages) {
+ swap_map[0] = SWAP_MAP_BAD;
+ p->max = maxpages;
+ p->pages = nr_good_pages;
+ nr_extents = setup_swap_extents(p, span);
+ if (nr_extents < 0)
+ return nr_extents;
+ nr_good_pages = p->pages;
+ }
+ if (!nr_good_pages) {
+ printk(KERN_WARNING "Empty swap-file\n");
+ return -EINVAL;
+ }
+
+ return nr_extents;
+}
+
+SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
+{
+ struct swap_info_struct *p;
+ char *name;
+ struct file *swap_file = NULL;
+ struct address_space *mapping;
+ int i;
+ int prio;
+ int error;
+ union swap_header *swap_header;
+ int nr_extents;
+ sector_t span;
+ unsigned long maxpages;
+ unsigned char *swap_map = NULL;
+ struct page *page = NULL;
+ struct inode *inode = NULL;
+
+ if (swap_flags & ~SWAP_FLAGS_VALID)
+ return -EINVAL;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ p = alloc_swap_info();
+ if (IS_ERR(p))
+ return PTR_ERR(p);
+
+ name = getname(specialfile);
+ if (IS_ERR(name)) {
+ error = PTR_ERR(name);
+ name = NULL;
+ goto bad_swap;
+ }
+ swap_file = filp_open(name, O_RDWR|O_LARGEFILE, 0);
+ if (IS_ERR(swap_file)) {
+ error = PTR_ERR(swap_file);
+ swap_file = NULL;
+ goto bad_swap;
+ }
+
+ p->swap_file = swap_file;
+ mapping = swap_file->f_mapping;
+
+ for (i = 0; i < nr_swapfiles; i++) {
+ struct swap_info_struct *q = swap_info[i];
+
+ if (q == p || !q->swap_file)
+ continue;
+ if (mapping == q->swap_file->f_mapping) {
+ error = -EBUSY;
+ goto bad_swap;
+ }
+ }
+
+ inode = mapping->host;
+ /* If S_ISREG(inode->i_mode) will do mutex_lock(&inode->i_mutex); */
+ error = claim_swapfile(p, inode);
+ if (unlikely(error))
+ goto bad_swap;
+
+ /*
+ * Read the swap header.
+ */
+ if (!mapping->a_ops->readpage) {
+ error = -EINVAL;
+ goto bad_swap;
+ }
+ page = read_mapping_page(mapping, 0, swap_file);
+ if (IS_ERR(page)) {
+ error = PTR_ERR(page);
+ goto bad_swap;
+ }
+ swap_header = kmap(page);
+
+ maxpages = read_swap_header(p, swap_header, inode);
+ if (unlikely(!maxpages)) {
+ error = -EINVAL;
+ goto bad_swap;
+ }
+
+ /* OK, set up the swap map and apply the bad block list */
+ swap_map = vzalloc(maxpages);
+ if (!swap_map) {
+ error = -ENOMEM;
+ goto bad_swap;
+ }
+
+ error = swap_cgroup_swapon(p->type, maxpages);
+ if (error)
+ goto bad_swap;
+
+ nr_extents = setup_swap_map_and_extents(p, swap_header, swap_map,
+ maxpages, &span);
+ if (unlikely(nr_extents < 0)) {
+ error = nr_extents;
+ goto bad_swap;
+ }
+
+ if (p->bdev) {
+ if (blk_queue_nonrot(bdev_get_queue(p->bdev))) {
+ p->flags |= SWP_SOLIDSTATE;
+ p->cluster_next = 1 + (random32() % p->highest_bit);
+ }
+ if ((swap_flags & SWAP_FLAG_DISCARD) && discard_swap(p) == 0)
+ p->flags |= SWP_DISCARDABLE;
+ }
+
+ mutex_lock(&swapon_mutex);
+ prio = -1;
+ if (swap_flags & SWAP_FLAG_PREFER)
+ prio =
+ (swap_flags & SWAP_FLAG_PRIO_MASK) >> SWAP_FLAG_PRIO_SHIFT;
+ enable_swap_info(p, prio, swap_map);
+
+ printk(KERN_INFO "Adding %uk swap on %s. "
+ "Priority:%d extents:%d across:%lluk %s%s\n",
+ p->pages<<(PAGE_SHIFT-10), name, p->prio,
+ nr_extents, (unsigned long long)span<<(PAGE_SHIFT-10),
+ (p->flags & SWP_SOLIDSTATE) ? "SS" : "",
+ (p->flags & SWP_DISCARDABLE) ? "D" : "");
+
+ mutex_unlock(&swapon_mutex);
+ atomic_inc(&proc_poll_event);
+ wake_up_interruptible(&proc_poll_wait);
+
+ if (S_ISREG(inode->i_mode))
+ inode->i_flags |= S_SWAPFILE;
+ error = 0;
+ goto out;
+bad_swap:
+ if (inode && S_ISBLK(inode->i_mode) && p->bdev) {
+ set_blocksize(p->bdev, p->old_block_size);
+ blkdev_put(p->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
+ }
+ destroy_swap_extents(p);
+ swap_cgroup_swapoff(p->type);
+ spin_lock(&swap_lock);
+ p->swap_file = NULL;
+ p->flags = 0;
+ spin_unlock(&swap_lock);
+ vfree(swap_map);
+ if (swap_file) {
+ if (inode && S_ISREG(inode->i_mode)) {
+ mutex_unlock(&inode->i_mutex);
+ inode = NULL;
+ }
+ filp_close(swap_file, NULL);
+ }
+out:
+ if (page && !IS_ERR(page)) {
+ kunmap(page);
+ page_cache_release(page);
+ }
+ if (name)
+ putname(name);
+ if (inode && S_ISREG(inode->i_mode))
+ mutex_unlock(&inode->i_mutex);
+ return error;
+}
+
+void si_swapinfo(struct sysinfo *val)
+{
+ unsigned int type;
+ unsigned long nr_to_be_unused = 0;
+
+ spin_lock(&swap_lock);
+ for (type = 0; type < nr_swapfiles; type++) {
+ struct swap_info_struct *si = swap_info[type];
+
+ if ((si->flags & SWP_USED) && !(si->flags & SWP_WRITEOK))
+ nr_to_be_unused += si->inuse_pages;
+ }
+ val->freeswap = nr_swap_pages + nr_to_be_unused;
+ val->totalswap = total_swap_pages + nr_to_be_unused;
+ spin_unlock(&swap_lock);
+}
+
+/*
+ * Verify that a swap entry is valid and increment its swap map count.
+ *
+ * Returns error code in following case.
+ * - success -> 0
+ * - swp_entry is invalid -> EINVAL
+ * - swp_entry is migration entry -> EINVAL
+ * - swap-cache reference is requested but there is already one. -> EEXIST
+ * - swap-cache reference is requested but the entry is not used. -> ENOENT
+ * - swap-mapped reference requested but needs continued swap count. -> ENOMEM
+ */
+static int __swap_duplicate(swp_entry_t entry, unsigned char usage)
+{
+ struct swap_info_struct *p;
+ unsigned long offset, type;
+ unsigned char count;
+ unsigned char has_cache;
+ int err = -EINVAL;
+
+ if (non_swap_entry(entry))
+ goto out;
+
+ type = swp_type(entry);
+ if (type >= nr_swapfiles)
+ goto bad_file;
+ p = swap_info[type];
+ offset = swp_offset(entry);
+
+ spin_lock(&swap_lock);
+ if (unlikely(offset >= p->max))
+ goto unlock_out;
+
+ count = p->swap_map[offset];
+ has_cache = count & SWAP_HAS_CACHE;
+ count &= ~SWAP_HAS_CACHE;
+ err = 0;
+
+ if (usage == SWAP_HAS_CACHE) {
+
+ /* set SWAP_HAS_CACHE if there is no cache and entry is used */
+ if (!has_cache && count)
+ has_cache = SWAP_HAS_CACHE;
+ else if (has_cache) /* someone else added cache */
+ err = -EEXIST;
+ else /* no users remaining */
+ err = -ENOENT;
+
+ } else if (count || has_cache) {
+
+ if ((count & ~COUNT_CONTINUED) < SWAP_MAP_MAX)
+ count += usage;
+ else if ((count & ~COUNT_CONTINUED) > SWAP_MAP_MAX)
+ err = -EINVAL;
+ else if (swap_count_continued(p, offset, count))
+ count = COUNT_CONTINUED;
+ else
+ err = -ENOMEM;
+ } else
+ err = -ENOENT; /* unused swap entry */
+
+ p->swap_map[offset] = count | has_cache;
+
+unlock_out:
+ spin_unlock(&swap_lock);
+out:
+ return err;
+
+bad_file:
+ printk(KERN_ERR "swap_dup: %s%08lx\n", Bad_file, entry.val);
+ goto out;
+}
+
+/*
+ * Help swapoff by noting that swap entry belongs to shmem/tmpfs
+ * (in which case its reference count is never incremented).
+ */
+void swap_shmem_alloc(swp_entry_t entry)
+{
+ __swap_duplicate(entry, SWAP_MAP_SHMEM);
+}
+
+/*
+ * Increase reference count of swap entry by 1.
+ * Returns 0 for success, or -ENOMEM if a swap_count_continuation is required
+ * but could not be atomically allocated. Returns 0, just as if it succeeded,
+ * if __swap_duplicate() fails for another reason (-EINVAL or -ENOENT), which
+ * might occur if a page table entry has got corrupted.
+ */
+int swap_duplicate(swp_entry_t entry)
+{
+ int err = 0;
+
+ while (!err && __swap_duplicate(entry, 1) == -ENOMEM)
+ err = add_swap_count_continuation(entry, GFP_ATOMIC);
+ return err;
+}
+
+/*
+ * @entry: swap entry for which we allocate swap cache.
+ *
+ * Called when allocating swap cache for existing swap entry,
+ * This can return error codes. Returns 0 at success.
+ * -EBUSY means there is a swap cache.
+ * Note: return code is different from swap_duplicate().
+ */
+int swapcache_prepare(swp_entry_t entry)
+{
+ return __swap_duplicate(entry, SWAP_HAS_CACHE);
+}
+
+/*
+ * add_swap_count_continuation - called when a swap count is duplicated
+ * beyond SWAP_MAP_MAX, it allocates a new page and links that to the entry's
+ * page of the original vmalloc'ed swap_map, to hold the continuation count
+ * (for that entry and for its neighbouring PAGE_SIZE swap entries). Called
+ * again when count is duplicated beyond SWAP_MAP_MAX * SWAP_CONT_MAX, etc.
+ *
+ * These continuation pages are seldom referenced: the common paths all work
+ * on the original swap_map, only referring to a continuation page when the
+ * low "digit" of a count is incremented or decremented through SWAP_MAP_MAX.
+ *
+ * add_swap_count_continuation(, GFP_ATOMIC) can be called while holding
+ * page table locks; if it fails, add_swap_count_continuation(, GFP_KERNEL)
+ * can be called after dropping locks.
+ */
+int add_swap_count_continuation(swp_entry_t entry, gfp_t gfp_mask)
+{
+ struct swap_info_struct *si;
+ struct page *head;
+ struct page *page;
+ struct page *list_page;
+ pgoff_t offset;
+ unsigned char count;
+
+ /*
+ * When debugging, it's easier to use __GFP_ZERO here; but it's better
+ * for latency not to zero a page while GFP_ATOMIC and holding locks.
+ */
+ page = alloc_page(gfp_mask | __GFP_HIGHMEM);
+
+ si = swap_info_get(entry);
+ if (!si) {
+ /*
+ * An acceptable race has occurred since the failing
+ * __swap_duplicate(): the swap entry has been freed,
+ * perhaps even the whole swap_map cleared for swapoff.
+ */
+ goto outer;
+ }
+
+ offset = swp_offset(entry);
+ count = si->swap_map[offset] & ~SWAP_HAS_CACHE;
+
+ if ((count & ~COUNT_CONTINUED) != SWAP_MAP_MAX) {
+ /*
+ * The higher the swap count, the more likely it is that tasks
+ * will race to add swap count continuation: we need to avoid
+ * over-provisioning.
+ */
+ goto out;
+ }
+
+ if (!page) {
+ spin_unlock(&swap_lock);
+ return -ENOMEM;
+ }
+
+ /*
+ * We are fortunate that although vmalloc_to_page uses pte_offset_map,
+ * no architecture is using highmem pages for kernel pagetables: so it
+ * will not corrupt the GFP_ATOMIC caller's atomic pagetable kmaps.
+ */
+ head = vmalloc_to_page(si->swap_map + offset);
+ offset &= ~PAGE_MASK;
+
+ /*
+ * Page allocation does not initialize the page's lru field,
+ * but it does always reset its private field.
+ */
+ if (!page_private(head)) {
+ BUG_ON(count & COUNT_CONTINUED);
+ INIT_LIST_HEAD(&head->lru);
+ set_page_private(head, SWP_CONTINUED);
+ si->flags |= SWP_CONTINUED;
+ }
+
+ list_for_each_entry(list_page, &head->lru, lru) {
+ unsigned char *map;
+
+ /*
+ * If the previous map said no continuation, but we've found
+ * a continuation page, free our allocation and use this one.
+ */
+ if (!(count & COUNT_CONTINUED))
+ goto out;
+
+ map = kmap_atomic(list_page) + offset;
+ count = *map;
+ kunmap_atomic(map);
+
+ /*
+ * If this continuation count now has some space in it,
+ * free our allocation and use this one.
+ */
+ if ((count & ~COUNT_CONTINUED) != SWAP_CONT_MAX)
+ goto out;
+ }
+
+ list_add_tail(&page->lru, &head->lru);
+ page = NULL; /* now it's attached, don't free it */
+out:
+ spin_unlock(&swap_lock);
+outer:
+ if (page)
+ __free_page(page);
+ return 0;
+}
+
+/*
+ * swap_count_continued - when the original swap_map count is incremented
+ * from SWAP_MAP_MAX, check if there is already a continuation page to carry
+ * into, carry if so, or else fail until a new continuation page is allocated;
+ * when the original swap_map count is decremented from 0 with continuation,
+ * borrow from the continuation and report whether it still holds more.
+ * Called while __swap_duplicate() or swap_entry_free() holds swap_lock.
+ */
+static bool swap_count_continued(struct swap_info_struct *si,
+ pgoff_t offset, unsigned char count)
+{
+ struct page *head;
+ struct page *page;
+ unsigned char *map;
+
+ head = vmalloc_to_page(si->swap_map + offset);
+ if (page_private(head) != SWP_CONTINUED) {
+ BUG_ON(count & COUNT_CONTINUED);
+ return false; /* need to add count continuation */
+ }
+
+ offset &= ~PAGE_MASK;
+ page = list_entry(head->lru.next, struct page, lru);
+ map = kmap_atomic(page) + offset;
+
+ if (count == SWAP_MAP_MAX) /* initial increment from swap_map */
+ goto init_map; /* jump over SWAP_CONT_MAX checks */
+
+ if (count == (SWAP_MAP_MAX | COUNT_CONTINUED)) { /* incrementing */
+ /*
+ * Think of how you add 1 to 999
+ */
+ while (*map == (SWAP_CONT_MAX | COUNT_CONTINUED)) {
+ kunmap_atomic(map);
+ page = list_entry(page->lru.next, struct page, lru);
+ BUG_ON(page == head);
+ map = kmap_atomic(page) + offset;
+ }
+ if (*map == SWAP_CONT_MAX) {
+ kunmap_atomic(map);
+ page = list_entry(page->lru.next, struct page, lru);
+ if (page == head)
+ return false; /* add count continuation */
+ map = kmap_atomic(page) + offset;
+init_map: *map = 0; /* we didn't zero the page */
+ }
+ *map += 1;
+ kunmap_atomic(map);
+ page = list_entry(page->lru.prev, struct page, lru);
+ while (page != head) {
+ map = kmap_atomic(page) + offset;
+ *map = COUNT_CONTINUED;
+ kunmap_atomic(map);
+ page = list_entry(page->lru.prev, struct page, lru);
+ }
+ return true; /* incremented */
+
+ } else { /* decrementing */
+ /*
+ * Think of how you subtract 1 from 1000
+ */
+ BUG_ON(count != COUNT_CONTINUED);
+ while (*map == COUNT_CONTINUED) {
+ kunmap_atomic(map);
+ page = list_entry(page->lru.next, struct page, lru);
+ BUG_ON(page == head);
+ map = kmap_atomic(page) + offset;
+ }
+ BUG_ON(*map == 0);
+ *map -= 1;
+ if (*map == 0)
+ count = 0;
+ kunmap_atomic(map);
+ page = list_entry(page->lru.prev, struct page, lru);
+ while (page != head) {
+ map = kmap_atomic(page) + offset;
+ *map = SWAP_CONT_MAX | count;
+ count = COUNT_CONTINUED;
+ kunmap_atomic(map);
+ page = list_entry(page->lru.prev, struct page, lru);
+ }
+ return count == COUNT_CONTINUED;
+ }
+}
+
+/*
+ * free_swap_count_continuations - swapoff free all the continuation pages
+ * appended to the swap_map, after swap_map is quiesced, before vfree'ing it.
+ */
+static void free_swap_count_continuations(struct swap_info_struct *si)
+{
+ pgoff_t offset;
+
+ for (offset = 0; offset < si->max; offset += PAGE_SIZE) {
+ struct page *head;
+ head = vmalloc_to_page(si->swap_map + offset);
+ if (page_private(head)) {
+ struct list_head *this, *next;
+ list_for_each_safe(this, next, &head->lru) {
+ struct page *page;
+ page = list_entry(this, struct page, lru);
+ list_del(this);
+ __free_page(page);
+ }
+ }
+ }
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/thrash.c b/ap/os/linux/linux-3.4.x/mm/thrash.c
new file mode 100644
index 0000000..57ad495
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/thrash.c
@@ -0,0 +1,155 @@
+/*
+ * mm/thrash.c
+ *
+ * Copyright (C) 2004, Red Hat, Inc.
+ * Copyright (C) 2004, Rik van Riel <riel@redhat.com>
+ * Released under the GPL, see the file COPYING for details.
+ *
+ * Simple token based thrashing protection, using the algorithm
+ * described in: http://www.cse.ohio-state.edu/hpcs/WWW/HTML/publications/abs05-1.html
+ *
+ * Sep 2006, Ashwin Chaugule <ashwin.chaugule@celunite.com>
+ * Improved algorithm to pass token:
+ * Each task has a priority which is incremented if it contended
+ * for the token in an interval less than its previous attempt.
+ * If the token is acquired, that task's priority is boosted to prevent
+ * the token from bouncing around too often and to let the task make
+ * some progress in its execution.
+ */
+
+#include <linux/jiffies.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/swap.h>
+#include <linux/memcontrol.h>
+
+#include <trace/events/vmscan.h>
+
+#define TOKEN_AGING_INTERVAL (0xFF)
+
+static DEFINE_SPINLOCK(swap_token_lock);
+struct mm_struct *swap_token_mm;
+static struct mem_cgroup *swap_token_memcg;
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+static struct mem_cgroup *swap_token_memcg_from_mm(struct mm_struct *mm)
+{
+ struct mem_cgroup *memcg;
+
+ memcg = try_get_mem_cgroup_from_mm(mm);
+ if (memcg)
+ css_put(mem_cgroup_css(memcg));
+
+ return memcg;
+}
+#else
+static struct mem_cgroup *swap_token_memcg_from_mm(struct mm_struct *mm)
+{
+ return NULL;
+}
+#endif
+
+void grab_swap_token(struct mm_struct *mm)
+{
+ int current_interval;
+ unsigned int old_prio = mm->token_priority;
+ static unsigned int global_faults;
+ static unsigned int last_aging;
+
+ global_faults++;
+
+ current_interval = global_faults - mm->faultstamp;
+
+ if (!spin_trylock(&swap_token_lock))
+ return;
+
+ /* First come first served */
+ if (!swap_token_mm)
+ goto replace_token;
+
+ /*
+ * Usually, we don't need priority aging because long interval faults
+ * makes priority decrease quickly. But there is one exception. If the
+ * token owner task is sleeping, it never make long interval faults.
+ * Thus, we need a priority aging mechanism instead. The requirements
+ * of priority aging are
+ * 1) An aging interval is reasonable enough long. Too short aging
+ * interval makes quick swap token lost and decrease performance.
+ * 2) The swap token owner task have to get priority aging even if
+ * it's under sleep.
+ */
+ if ((global_faults - last_aging) > TOKEN_AGING_INTERVAL) {
+ swap_token_mm->token_priority /= 2;
+ last_aging = global_faults;
+ }
+
+ if (mm == swap_token_mm) {
+ mm->token_priority += 2;
+ goto update_priority;
+ }
+
+ if (current_interval < mm->last_interval)
+ mm->token_priority++;
+ else {
+ if (likely(mm->token_priority > 0))
+ mm->token_priority--;
+ }
+
+ /* Check if we deserve the token */
+ if (mm->token_priority > swap_token_mm->token_priority)
+ goto replace_token;
+
+update_priority:
+ trace_update_swap_token_priority(mm, old_prio, swap_token_mm);
+
+out:
+ mm->faultstamp = global_faults;
+ mm->last_interval = current_interval;
+ spin_unlock(&swap_token_lock);
+ return;
+
+replace_token:
+ mm->token_priority += 2;
+ trace_replace_swap_token(swap_token_mm, mm);
+ swap_token_mm = mm;
+ swap_token_memcg = swap_token_memcg_from_mm(mm);
+ last_aging = global_faults;
+ goto out;
+}
+
+/* Called on process exit. */
+void __put_swap_token(struct mm_struct *mm)
+{
+ spin_lock(&swap_token_lock);
+ if (likely(mm == swap_token_mm)) {
+ trace_put_swap_token(swap_token_mm);
+ swap_token_mm = NULL;
+ swap_token_memcg = NULL;
+ }
+ spin_unlock(&swap_token_lock);
+}
+
+static bool match_memcg(struct mem_cgroup *a, struct mem_cgroup *b)
+{
+ if (!a)
+ return true;
+ if (!b)
+ return true;
+ if (a == b)
+ return true;
+ return false;
+}
+
+void disable_swap_token(struct mem_cgroup *memcg)
+{
+ /* memcg reclaim don't disable unrelated mm token. */
+ if (match_memcg(memcg, swap_token_memcg)) {
+ spin_lock(&swap_token_lock);
+ if (match_memcg(memcg, swap_token_memcg)) {
+ trace_disable_swap_token(swap_token_mm);
+ swap_token_mm = NULL;
+ swap_token_memcg = NULL;
+ }
+ spin_unlock(&swap_token_lock);
+ }
+}
diff --git a/ap/os/linux/linux-3.4.x/mm/truncate.c b/ap/os/linux/linux-3.4.x/mm/truncate.c
new file mode 100644
index 0000000..57625f7
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/truncate.c
@@ -0,0 +1,699 @@
+/*
+ * mm/truncate.c - code for taking down pages from address_spaces
+ *
+ * Copyright (C) 2002, Linus Torvalds
+ *
+ * 10Sep2002 Andrew Morton
+ * Initial version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/backing-dev.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/export.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/pagevec.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/buffer_head.h> /* grr. try_to_release_page,
+ do_invalidatepage */
+#include <linux/cleancache.h>
+#include <linux/rmap.h>
+#include "internal.h"
+
+
+/**
+ * do_invalidatepage - invalidate part or all of a page
+ * @page: the page which is affected
+ * @offset: the index of the truncation point
+ *
+ * do_invalidatepage() is called when all or part of the page has become
+ * invalidated by a truncate operation.
+ *
+ * do_invalidatepage() does not have to release all buffers, but it must
+ * ensure that no dirty buffer is left outside @offset and that no I/O
+ * is underway against any of the blocks which are outside the truncation
+ * point. Because the caller is about to free (and possibly reuse) those
+ * blocks on-disk.
+ */
+void do_invalidatepage(struct page *page, unsigned long offset)
+{
+ void (*invalidatepage)(struct page *, unsigned long);
+ invalidatepage = page->mapping->a_ops->invalidatepage;
+#ifdef CONFIG_BLOCK
+ if (!invalidatepage)
+ invalidatepage = block_invalidatepage;
+#endif
+ if (invalidatepage)
+ (*invalidatepage)(page, offset);
+}
+
+static inline void truncate_partial_page(struct page *page, unsigned partial)
+{
+ zero_user_segment(page, partial, PAGE_CACHE_SIZE);
+ cleancache_invalidate_page(page->mapping, page);
+ if (page_has_private(page))
+ do_invalidatepage(page, partial);
+}
+
+/*
+ * This cancels just the dirty bit on the kernel page itself, it
+ * does NOT actually remove dirty bits on any mmap's that may be
+ * around. It also leaves the page tagged dirty, so any sync
+ * activity will still find it on the dirty lists, and in particular,
+ * clear_page_dirty_for_io() will still look at the dirty bits in
+ * the VM.
+ *
+ * Doing this should *normally* only ever be done when a page
+ * is truncated, and is not actually mapped anywhere at all. However,
+ * fs/buffer.c does this when it notices that somebody has cleaned
+ * out all the buffers on a page without actually doing it through
+ * the VM. Can you say "ext3 is horribly ugly"? Tought you could.
+ */
+void cancel_dirty_page(struct page *page, unsigned int account_size)
+{
+ if (TestClearPageDirty(page)) {
+ struct address_space *mapping = page->mapping;
+ if (mapping && mapping_cap_account_dirty(mapping)) {
+ dec_zone_page_state(page, NR_FILE_DIRTY);
+ dec_bdi_stat(mapping->backing_dev_info,
+ BDI_RECLAIMABLE);
+ if (account_size)
+ task_io_account_cancelled_write(account_size);
+ }
+ }
+}
+EXPORT_SYMBOL(cancel_dirty_page);
+
+/*
+ * If truncate cannot remove the fs-private metadata from the page, the page
+ * becomes orphaned. It will be left on the LRU and may even be mapped into
+ * user pagetables if we're racing with filemap_fault().
+ *
+ * We need to bale out if page->mapping is no longer equal to the original
+ * mapping. This happens a) when the VM reclaimed the page while we waited on
+ * its lock, b) when a concurrent invalidate_mapping_pages got there first and
+ * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space.
+ */
+static int
+truncate_complete_page(struct address_space *mapping, struct page *page)
+{
+ if (page->mapping != mapping)
+ return -EIO;
+
+ if (page_has_private(page))
+ do_invalidatepage(page, 0);
+
+ cancel_dirty_page(page, PAGE_CACHE_SIZE);
+
+ clear_page_mlock(page);
+ ClearPageMappedToDisk(page);
+ delete_from_page_cache(page);
+ return 0;
+}
+
+/*
+ * This is for invalidate_mapping_pages(). That function can be called at
+ * any time, and is not supposed to throw away dirty pages. But pages can
+ * be marked dirty at any time too, so use remove_mapping which safely
+ * discards clean, unused pages.
+ *
+ * Returns non-zero if the page was successfully invalidated.
+ */
+static int
+invalidate_complete_page(struct address_space *mapping, struct page *page)
+{
+ int ret;
+
+ if (page->mapping != mapping)
+ return 0;
+
+ if (page_has_private(page) && !try_to_release_page(page, 0))
+ return 0;
+
+ clear_page_mlock(page);
+ ret = remove_mapping(mapping, page);
+
+ return ret;
+}
+
+int truncate_inode_page(struct address_space *mapping, struct page *page)
+{
+ if (page_mapped(page)) {
+ unmap_mapping_range(mapping,
+ (loff_t)page->index << PAGE_CACHE_SHIFT,
+ PAGE_CACHE_SIZE, 0);
+ }
+ return truncate_complete_page(mapping, page);
+}
+
+/*
+ * Used to get rid of pages on hardware memory corruption.
+ */
+int generic_error_remove_page(struct address_space *mapping, struct page *page)
+{
+ if (!mapping)
+ return -EINVAL;
+ /*
+ * Only punch for normal data pages for now.
+ * Handling other types like directories would need more auditing.
+ */
+ if (!S_ISREG(mapping->host->i_mode))
+ return -EIO;
+ return truncate_inode_page(mapping, page);
+}
+EXPORT_SYMBOL(generic_error_remove_page);
+
+/*
+ * Safely invalidate one page from its pagecache mapping.
+ * It only drops clean, unused pages. The page must be locked.
+ *
+ * Returns 1 if the page is successfully invalidated, otherwise 0.
+ */
+int invalidate_inode_page(struct page *page)
+{
+ struct address_space *mapping = page_mapping(page);
+ if (!mapping)
+ return 0;
+ if (PageDirty(page) || PageWriteback(page))
+ return 0;
+ if (page_mapped(page))
+ return 0;
+ return invalidate_complete_page(mapping, page);
+}
+
+/**
+ * truncate_inode_pages_range - truncate range of pages specified by start & end byte offsets
+ * @mapping: mapping to truncate
+ * @lstart: offset from which to truncate
+ * @lend: offset to which to truncate
+ *
+ * Truncate the page cache, removing the pages that are between
+ * specified offsets (and zeroing out partial page
+ * (if lstart is not page aligned)).
+ *
+ * Truncate takes two passes - the first pass is nonblocking. It will not
+ * block on page locks and it will not block on writeback. The second pass
+ * will wait. This is to prevent as much IO as possible in the affected region.
+ * The first pass will remove most pages, so the search cost of the second pass
+ * is low.
+ *
+ * We pass down the cache-hot hint to the page freeing code. Even if the
+ * mapping is large, it is probably the case that the final pages are the most
+ * recently touched, and freeing happens in ascending file offset order.
+ */
+void truncate_inode_pages_range(struct address_space *mapping,
+ loff_t lstart, loff_t lend)
+{
+ const pgoff_t start = (lstart + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT;
+ const unsigned partial = lstart & (PAGE_CACHE_SIZE - 1);
+ struct pagevec pvec;
+ pgoff_t index;
+ pgoff_t end;
+ int i;
+
+ cleancache_invalidate_inode(mapping);
+ if (mapping->nrpages == 0)
+ return;
+
+ BUG_ON((lend & (PAGE_CACHE_SIZE - 1)) != (PAGE_CACHE_SIZE - 1));
+ end = (lend >> PAGE_CACHE_SHIFT);
+
+ pagevec_init(&pvec, 0);
+ index = start;
+ while (index <= end && pagevec_lookup(&pvec, mapping, index,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
+ mem_cgroup_uncharge_start();
+ for (i = 0; i < pagevec_count(&pvec); i++) {
+ struct page *page = pvec.pages[i];
+
+ /* We rely upon deletion not changing page->index */
+ index = page->index;
+ if (index > end)
+ break;
+
+ if (!trylock_page(page))
+ continue;
+ WARN_ON(page->index != index);
+ if (PageWriteback(page)) {
+ unlock_page(page);
+ continue;
+ }
+ truncate_inode_page(mapping, page);
+ unlock_page(page);
+ }
+ pagevec_release(&pvec);
+ mem_cgroup_uncharge_end();
+ cond_resched();
+ index++;
+ }
+
+ if (partial) {
+ struct page *page = find_lock_page(mapping, start - 1);
+ if (page) {
+ wait_on_page_writeback(page);
+ truncate_partial_page(page, partial);
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ }
+
+ index = start;
+ for ( ; ; ) {
+ cond_resched();
+ if (!pagevec_lookup(&pvec, mapping, index,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
+ if (index == start)
+ break;
+ index = start;
+ continue;
+ }
+ if (index == start && pvec.pages[0]->index > end) {
+ pagevec_release(&pvec);
+ break;
+ }
+ mem_cgroup_uncharge_start();
+ for (i = 0; i < pagevec_count(&pvec); i++) {
+ struct page *page = pvec.pages[i];
+
+ /* We rely upon deletion not changing page->index */
+ index = page->index;
+ if (index > end)
+ break;
+
+ lock_page(page);
+ WARN_ON(page->index != index);
+ wait_on_page_writeback(page);
+ truncate_inode_page(mapping, page);
+ unlock_page(page);
+ }
+ pagevec_release(&pvec);
+ mem_cgroup_uncharge_end();
+ index++;
+ }
+ cleancache_invalidate_inode(mapping);
+}
+EXPORT_SYMBOL(truncate_inode_pages_range);
+
+/**
+ * truncate_inode_pages - truncate *all* the pages from an offset
+ * @mapping: mapping to truncate
+ * @lstart: offset from which to truncate
+ *
+ * Called under (and serialised by) inode->i_mutex.
+ *
+ * Note: When this function returns, there can be a page in the process of
+ * deletion (inside __delete_from_page_cache()) in the specified range. Thus
+ * mapping->nrpages can be non-zero when this function returns even after
+ * truncation of the whole mapping.
+ */
+void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
+{
+ truncate_inode_pages_range(mapping, lstart, (loff_t)-1);
+}
+EXPORT_SYMBOL(truncate_inode_pages);
+
+/**
+ * invalidate_mapping_pages - Invalidate all the unlocked pages of one inode
+ * @mapping: the address_space which holds the pages to invalidate
+ * @start: the offset 'from' which to invalidate
+ * @end: the offset 'to' which to invalidate (inclusive)
+ *
+ * This function only removes the unlocked pages, if you want to
+ * remove all the pages of one inode, you must call truncate_inode_pages.
+ *
+ * invalidate_mapping_pages() will not block on IO activity. It will not
+ * invalidate pages which are dirty, locked, under writeback or mapped into
+ * pagetables.
+ */
+unsigned long invalidate_mapping_pages(struct address_space *mapping,
+ pgoff_t start, pgoff_t end)
+{
+ struct pagevec pvec;
+ pgoff_t index = start;
+ unsigned long ret;
+ unsigned long count = 0;
+ int i;
+
+ /*
+ * Note: this function may get called on a shmem/tmpfs mapping:
+ * pagevec_lookup() might then return 0 prematurely (because it
+ * got a gangful of swap entries); but it's hardly worth worrying
+ * about - it can rarely have anything to free from such a mapping
+ * (most pages are dirty), and already skips over any difficulties.
+ */
+
+ pagevec_init(&pvec, 0);
+ while (index <= end && pagevec_lookup(&pvec, mapping, index,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
+ mem_cgroup_uncharge_start();
+ for (i = 0; i < pagevec_count(&pvec); i++) {
+ struct page *page = pvec.pages[i];
+
+ /* We rely upon deletion not changing page->index */
+ index = page->index;
+ if (index > end)
+ break;
+
+ if (!trylock_page(page))
+ continue;
+ WARN_ON(page->index != index);
+ ret = invalidate_inode_page(page);
+ unlock_page(page);
+ /*
+ * Invalidation is a hint that the page is no longer
+ * of interest and try to speed up its reclaim.
+ */
+ if (!ret)
+ deactivate_page(page);
+ count += ret;
+ }
+ pagevec_release(&pvec);
+ mem_cgroup_uncharge_end();
+ cond_resched();
+ index++;
+ }
+ return count;
+}
+EXPORT_SYMBOL(invalidate_mapping_pages);
+
+/*
+ * This is like invalidate_complete_page(), except it ignores the page's
+ * refcount. We do this because invalidate_inode_pages2() needs stronger
+ * invalidation guarantees, and cannot afford to leave pages behind because
+ * shrink_page_list() has a temp ref on them, or because they're transiently
+ * sitting in the lru_cache_add() pagevecs.
+ */
+static int
+invalidate_complete_page2(struct address_space *mapping, struct page *page)
+{
+ if (page->mapping != mapping)
+ return 0;
+
+ if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL))
+ return 0;
+
+ clear_page_mlock(page);
+
+ spin_lock_irq(&mapping->tree_lock);
+ if (PageDirty(page))
+ goto failed;
+
+ BUG_ON(page_has_private(page));
+ __delete_from_page_cache(page);
+ spin_unlock_irq(&mapping->tree_lock);
+ mem_cgroup_uncharge_cache_page(page);
+
+ if (mapping->a_ops->freepage)
+ mapping->a_ops->freepage(page);
+
+ page_cache_release(page); /* pagecache ref */
+ return 1;
+failed:
+ spin_unlock_irq(&mapping->tree_lock);
+ return 0;
+}
+
+static int do_launder_page(struct address_space *mapping, struct page *page)
+{
+ if (!PageDirty(page))
+ return 0;
+ if (page->mapping != mapping || mapping->a_ops->launder_page == NULL)
+ return 0;
+ return mapping->a_ops->launder_page(page);
+}
+
+/**
+ * invalidate_inode_pages2_range - remove range of pages from an address_space
+ * @mapping: the address_space
+ * @start: the page offset 'from' which to invalidate
+ * @end: the page offset 'to' which to invalidate (inclusive)
+ *
+ * Any pages which are found to be mapped into pagetables are unmapped prior to
+ * invalidation.
+ *
+ * Returns -EBUSY if any pages could not be invalidated.
+ */
+int invalidate_inode_pages2_range(struct address_space *mapping,
+ pgoff_t start, pgoff_t end)
+{
+ struct pagevec pvec;
+ pgoff_t index;
+ int i;
+ int ret = 0;
+ int ret2 = 0;
+ int did_range_unmap = 0;
+
+ cleancache_invalidate_inode(mapping);
+ pagevec_init(&pvec, 0);
+ index = start;
+ while (index <= end && pagevec_lookup(&pvec, mapping, index,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
+ mem_cgroup_uncharge_start();
+ for (i = 0; i < pagevec_count(&pvec); i++) {
+ struct page *page = pvec.pages[i];
+
+ /* We rely upon deletion not changing page->index */
+ index = page->index;
+ if (index > end)
+ break;
+
+ lock_page(page);
+ WARN_ON(page->index != index);
+ if (page->mapping != mapping) {
+ unlock_page(page);
+ continue;
+ }
+ wait_on_page_writeback(page);
+ if (page_mapped(page)) {
+ if (!did_range_unmap) {
+ /*
+ * Zap the rest of the file in one hit.
+ */
+ unmap_mapping_range(mapping,
+ (loff_t)index << PAGE_CACHE_SHIFT,
+ (loff_t)(1 + end - index)
+ << PAGE_CACHE_SHIFT,
+ 0);
+ did_range_unmap = 1;
+ } else {
+ /*
+ * Just zap this page
+ */
+ unmap_mapping_range(mapping,
+ (loff_t)index << PAGE_CACHE_SHIFT,
+ PAGE_CACHE_SIZE, 0);
+ }
+ }
+ BUG_ON(page_mapped(page));
+ ret2 = do_launder_page(mapping, page);
+ if (ret2 == 0) {
+ if (!invalidate_complete_page2(mapping, page))
+ ret2 = -EBUSY;
+ }
+ if (ret2 < 0)
+ ret = ret2;
+ unlock_page(page);
+ }
+ pagevec_release(&pvec);
+ mem_cgroup_uncharge_end();
+ cond_resched();
+ index++;
+ }
+ cleancache_invalidate_inode(mapping);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);
+
+/**
+ * invalidate_inode_pages2 - remove all pages from an address_space
+ * @mapping: the address_space
+ *
+ * Any pages which are found to be mapped into pagetables are unmapped prior to
+ * invalidation.
+ *
+ * Returns -EBUSY if any pages could not be invalidated.
+ */
+int invalidate_inode_pages2(struct address_space *mapping)
+{
+ return invalidate_inode_pages2_range(mapping, 0, -1);
+}
+EXPORT_SYMBOL_GPL(invalidate_inode_pages2);
+
+/**
+ * truncate_pagecache - unmap and remove pagecache that has been truncated
+ * @inode: inode
+ * @oldsize: old file size
+ * @newsize: new file size
+ *
+ * inode's new i_size must already be written before truncate_pagecache
+ * is called.
+ *
+ * This function should typically be called before the filesystem
+ * releases resources associated with the freed range (eg. deallocates
+ * blocks). This way, pagecache will always stay logically coherent
+ * with on-disk format, and the filesystem would not have to deal with
+ * situations such as writepage being called for a page that has already
+ * had its underlying blocks deallocated.
+ */
+void truncate_pagecache(struct inode *inode, loff_t oldsize, loff_t newsize)
+{
+ struct address_space *mapping = inode->i_mapping;
+ loff_t holebegin = round_up(newsize, PAGE_SIZE);
+
+ /*
+ * unmap_mapping_range is called twice, first simply for
+ * efficiency so that truncate_inode_pages does fewer
+ * single-page unmaps. However after this first call, and
+ * before truncate_inode_pages finishes, it is possible for
+ * private pages to be COWed, which remain after
+ * truncate_inode_pages finishes, hence the second
+ * unmap_mapping_range call must be made for correctness.
+ */
+ unmap_mapping_range(mapping, holebegin, 0, 1);
+ truncate_inode_pages(mapping, newsize);
+ unmap_mapping_range(mapping, holebegin, 0, 1);
+}
+EXPORT_SYMBOL(truncate_pagecache);
+
+/**
+ * truncate_setsize - update inode and pagecache for a new file size
+ * @inode: inode
+ * @newsize: new file size
+ *
+ * truncate_setsize updates i_size and performs pagecache truncation (if
+ * necessary) to @newsize. It will be typically be called from the filesystem's
+ * setattr function when ATTR_SIZE is passed in.
+ *
+ * Must be called with inode_mutex held and before all filesystem specific
+ * block truncation has been performed.
+ */
+void truncate_setsize(struct inode *inode, loff_t newsize)
+{
+ loff_t oldsize = inode->i_size;
+ i_size_write(inode, newsize);
+
+ if (newsize > oldsize)
+ pagecache_isize_extended(inode, oldsize, newsize);
+ truncate_pagecache(inode, oldsize, newsize);
+}
+EXPORT_SYMBOL(truncate_setsize);
+
+/**
+ * pagecache_isize_extended - update pagecache after extension of i_size
+ * @inode: inode for which i_size was extended
+ * @from: original inode size
+ * @to: new inode size
+ *
+ * Handle extension of inode size either caused by extending truncate or by
+ * write starting after current i_size. We mark the page straddling current
+ * i_size RO so that page_mkwrite() is called on the nearest write access to
+ * the page. This way filesystem can be sure that page_mkwrite() is called on
+ * the page before user writes to the page via mmap after the i_size has been
+ * changed.
+ *
+ * The function must be called after i_size is updated so that page fault
+ * coming after we unlock the page will already see the new i_size.
+ * The function must be called while we still hold i_mutex - this not only
+ * makes sure i_size is stable but also that userspace cannot observe new
+ * i_size value before we are prepared to store mmap writes at new inode size.
+ */
+void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to)
+{
+ int bsize = 1 << inode->i_blkbits;
+ loff_t rounded_from;
+ struct page *page;
+ pgoff_t index;
+
+ WARN_ON(to > inode->i_size);
+
+ if (from >= to || bsize == PAGE_CACHE_SIZE)
+ return;
+ /* Page straddling @from will not have any hole block created? */
+ rounded_from = round_up(from, bsize);
+ if (to <= rounded_from || !(rounded_from & (PAGE_CACHE_SIZE - 1)))
+ return;
+
+ index = from >> PAGE_CACHE_SHIFT;
+ page = find_lock_page(inode->i_mapping, index);
+ /* Page not cached? Nothing to do */
+ if (!page)
+ return;
+ /*
+ * See clear_page_dirty_for_io() for details why set_page_dirty()
+ * is needed.
+ */
+ if (page_mkclean(page))
+ set_page_dirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+}
+EXPORT_SYMBOL(pagecache_isize_extended);
+
+/**
+ * truncate_pagecache_range - unmap and remove pagecache that is hole-punched
+ * @inode: inode
+ * @lstart: offset of beginning of hole
+ * vmtruncate - unmap mappings "freed" by truncate() syscall
+ * @inode: inode of the file used
+ * @newsize: file offset to start truncating
+ *
+ * This function is deprecated and truncate_setsize or truncate_pagecache
+ * should be used instead, together with filesystem specific block truncation.
+ */
+int vmtruncate(struct inode *inode, loff_t newsize)
+{
+ int error;
+
+ error = inode_newsize_ok(inode, newsize);
+ if (error)
+ return error;
+
+ truncate_setsize(inode, newsize);
+ if (inode->i_op->truncate)
+ inode->i_op->truncate(inode);
+ return 0;
+}
+EXPORT_SYMBOL(vmtruncate);
+
+/**
+ * truncate_pagecache_range - unmap and remove pagecache that is hole-punched
+ * @inode: inode
+ * @lstart: offset of beginning of hole
+ * @lend: offset of last byte of hole
+ *
+ * This function should typically be called before the filesystem
+ * releases resources associated with the freed range (eg. deallocates
+ * blocks). This way, pagecache will always stay logically coherent
+ * with on-disk format, and the filesystem would not have to deal with
+ * situations such as writepage being called for a page that has already
+ * had its underlying blocks deallocated.
+ */
+void truncate_pagecache_range(struct inode *inode, loff_t lstart, loff_t lend)
+{
+ struct address_space *mapping = inode->i_mapping;
+ loff_t unmap_start = round_up(lstart, PAGE_SIZE);
+ loff_t unmap_end = round_down(1 + lend, PAGE_SIZE) - 1;
+ /*
+ * This rounding is currently just for example: unmap_mapping_range
+ * expands its hole outwards, whereas we want it to contract the hole
+ * inwards. However, existing callers of truncate_pagecache_range are
+ * doing their own page rounding first; and truncate_inode_pages_range
+ * currently BUGs if lend is not pagealigned-1 (it handles partial
+ * page at start of hole, but not partial page at end of hole). Note
+ * unmap_mapping_range allows holelen 0 for all, and we allow lend -1.
+ */
+
+ /*
+ * Unlike in truncate_pagecache, unmap_mapping_range is called only
+ * once (before truncating pagecache), and without "even_cows" flag:
+ * hole-punching should not remove private COWed pages from the hole.
+ */
+ if ((u64)unmap_end > (u64)unmap_start)
+ unmap_mapping_range(mapping, unmap_start,
+ 1 + unmap_end - unmap_start, 0);
+ truncate_inode_pages_range(mapping, lstart, lend);
+}
+EXPORT_SYMBOL(truncate_pagecache_range);
diff --git a/ap/os/linux/linux-3.4.x/mm/util.c b/ap/os/linux/linux-3.4.x/mm/util.c
new file mode 100644
index 0000000..ae962b3
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/util.c
@@ -0,0 +1,350 @@
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/export.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <asm/uaccess.h>
+
+#include "internal.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/kmem.h>
+
+/**
+ * kstrdup - allocate space for and copy an existing string
+ * @s: the string to duplicate
+ * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ */
+char *kstrdup(const char *s, gfp_t gfp)
+{
+ size_t len;
+ char *buf;
+
+ if (!s)
+ return NULL;
+
+ len = strlen(s) + 1;
+ buf = kmalloc_track_caller(len, gfp);
+ if (buf)
+ memcpy(buf, s, len);
+ return buf;
+}
+EXPORT_SYMBOL(kstrdup);
+
+/**
+ * kstrndup - allocate space for and copy an existing string
+ * @s: the string to duplicate
+ * @max: read at most @max chars from @s
+ * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ */
+char *kstrndup(const char *s, size_t max, gfp_t gfp)
+{
+ size_t len;
+ char *buf;
+
+ if (!s)
+ return NULL;
+
+ len = strnlen(s, max);
+ buf = kmalloc_track_caller(len+1, gfp);
+ if (buf) {
+ memcpy(buf, s, len);
+ buf[len] = '\0';
+ }
+ return buf;
+}
+EXPORT_SYMBOL(kstrndup);
+
+/**
+ * kmemdup - duplicate region of memory
+ *
+ * @src: memory region to duplicate
+ * @len: memory region length
+ * @gfp: GFP mask to use
+ */
+void *kmemdup(const void *src, size_t len, gfp_t gfp)
+{
+ void *p;
+
+ p = kmalloc_track_caller(len, gfp);
+ if (p)
+ memcpy(p, src, len);
+ return p;
+}
+EXPORT_SYMBOL(kmemdup);
+
+/**
+ * memdup_user - duplicate memory region from user space
+ *
+ * @src: source address in user space
+ * @len: number of bytes to copy
+ *
+ * Returns an ERR_PTR() on failure.
+ */
+void *memdup_user(const void __user *src, size_t len)
+{
+ void *p;
+
+ /*
+ * Always use GFP_KERNEL, since copy_from_user() can sleep and
+ * cause pagefault, which makes it pointless to use GFP_NOFS
+ * or GFP_ATOMIC.
+ */
+ p = kmalloc_track_caller(len, GFP_KERNEL);
+ if (!p)
+ return ERR_PTR(-ENOMEM);
+
+ if (copy_from_user(p, src, len)) {
+ kfree(p);
+ return ERR_PTR(-EFAULT);
+ }
+
+ return p;
+}
+EXPORT_SYMBOL(memdup_user);
+
+/**
+ * __krealloc - like krealloc() but don't free @p.
+ * @p: object to reallocate memory for.
+ * @new_size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * This function is like krealloc() except it never frees the originally
+ * allocated buffer. Use this if you don't want to free the buffer immediately
+ * like, for example, with RCU.
+ */
+void *__krealloc(const void *p, size_t new_size, gfp_t flags)
+{
+ void *ret;
+ size_t ks = 0;
+
+ if (unlikely(!new_size))
+ return ZERO_SIZE_PTR;
+
+ if (p)
+ ks = ksize(p);
+
+ if (ks >= new_size)
+ return (void *)p;
+
+ ret = kmalloc_track_caller(new_size, flags);
+ if (ret && p)
+ memcpy(ret, p, ks);
+
+ return ret;
+}
+EXPORT_SYMBOL(__krealloc);
+
+/**
+ * krealloc - reallocate memory. The contents will remain unchanged.
+ * @p: object to reallocate memory for.
+ * @new_size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * The contents of the object pointed to are preserved up to the
+ * lesser of the new and old sizes. If @p is %NULL, krealloc()
+ * behaves exactly like kmalloc(). If @size is 0 and @p is not a
+ * %NULL pointer, the object pointed to is freed.
+ */
+void *krealloc(const void *p, size_t new_size, gfp_t flags)
+{
+ void *ret;
+
+ if (unlikely(!new_size)) {
+ kfree(p);
+ return ZERO_SIZE_PTR;
+ }
+
+ ret = __krealloc(p, new_size, flags);
+ if (ret && p != ret)
+ kfree(p);
+
+ return ret;
+}
+EXPORT_SYMBOL(krealloc);
+
+/**
+ * kzfree - like kfree but zero memory
+ * @p: object to free memory of
+ *
+ * The memory of the object @p points to is zeroed before freed.
+ * If @p is %NULL, kzfree() does nothing.
+ *
+ * Note: this function zeroes the whole allocated buffer which can be a good
+ * deal bigger than the requested buffer size passed to kmalloc(). So be
+ * careful when using this function in performance sensitive code.
+ */
+void kzfree(const void *p)
+{
+ size_t ks;
+ void *mem = (void *)p;
+
+ if (unlikely(ZERO_OR_NULL_PTR(mem)))
+ return;
+ ks = ksize(mem);
+ memset(mem, 0, ks);
+ kfree(mem);
+}
+EXPORT_SYMBOL(kzfree);
+
+/*
+ * strndup_user - duplicate an existing string from user space
+ * @s: The string to duplicate
+ * @n: Maximum number of bytes to copy, including the trailing NUL.
+ */
+char *strndup_user(const char __user *s, long n)
+{
+ char *p;
+ long length;
+
+ length = strnlen_user(s, n);
+
+ if (!length)
+ return ERR_PTR(-EFAULT);
+
+ if (length > n)
+ return ERR_PTR(-EINVAL);
+
+ p = memdup_user(s, length);
+
+ if (IS_ERR(p))
+ return p;
+
+ p[length - 1] = '\0';
+
+ return p;
+}
+EXPORT_SYMBOL(strndup_user);
+
+void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct vm_area_struct *prev, struct rb_node *rb_parent)
+{
+ struct vm_area_struct *next;
+
+ vma->vm_prev = prev;
+ if (prev) {
+ next = prev->vm_next;
+ prev->vm_next = vma;
+ } else {
+ mm->mmap = vma;
+ if (rb_parent)
+ next = rb_entry(rb_parent,
+ struct vm_area_struct, vm_rb);
+ else
+ next = NULL;
+ }
+ vma->vm_next = next;
+ if (next)
+ next->vm_prev = vma;
+}
+
+/* Check if the vma is being used as a stack by this task */
+static int vm_is_stack_for_task(struct task_struct *t,
+ struct vm_area_struct *vma)
+{
+ return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t));
+}
+
+/*
+ * Check if the vma is being used as a stack.
+ * If is_group is non-zero, check in the entire thread group or else
+ * just check in the current task. Returns the pid of the task that
+ * the vma is stack for.
+ */
+pid_t vm_is_stack(struct task_struct *task,
+ struct vm_area_struct *vma, int in_group)
+{
+ pid_t ret = 0;
+
+ if (vm_is_stack_for_task(task, vma))
+ return task->pid;
+
+ if (in_group) {
+ struct task_struct *t;
+ rcu_read_lock();
+ if (!pid_alive(task))
+ goto done;
+
+ t = task;
+ do {
+ if (vm_is_stack_for_task(t, vma)) {
+ ret = t->pid;
+ goto done;
+ }
+ } while_each_thread(task, t);
+done:
+ rcu_read_unlock();
+ }
+
+ return ret;
+}
+
+#if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT)
+void arch_pick_mmap_layout(struct mm_struct *mm)
+{
+ mm->mmap_base = TASK_UNMAPPED_BASE;
+ mm->get_unmapped_area = arch_get_unmapped_area;
+ mm->unmap_area = arch_unmap_area;
+}
+#endif
+
+/*
+ * Like get_user_pages_fast() except its IRQ-safe in that it won't fall
+ * back to the regular GUP.
+ * If the architecture not support this function, simply return with no
+ * page pinned
+ */
+int __attribute__((weak)) __get_user_pages_fast(unsigned long start,
+ int nr_pages, int write, struct page **pages)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__get_user_pages_fast);
+
+/**
+ * get_user_pages_fast() - pin user pages in memory
+ * @start: starting user address
+ * @nr_pages: number of pages from start to pin
+ * @write: whether pages will be written to
+ * @pages: array that receives pointers to the pages pinned.
+ * Should be at least nr_pages long.
+ *
+ * Returns number of pages pinned. This may be fewer than the number
+ * requested. If nr_pages is 0 or negative, returns 0. If no pages
+ * were pinned, returns -errno.
+ *
+ * get_user_pages_fast provides equivalent functionality to get_user_pages,
+ * operating on current and current->mm, with force=0 and vma=NULL. However
+ * unlike get_user_pages, it must be called without mmap_sem held.
+ *
+ * get_user_pages_fast may take mmap_sem and page table locks, so no
+ * assumptions can be made about lack of locking. get_user_pages_fast is to be
+ * implemented in a way that is advantageous (vs get_user_pages()) when the
+ * user memory area is already faulted in and present in ptes. However if the
+ * pages have to be faulted in, it may turn out to be slightly slower so
+ * callers need to carefully consider what to use. On many architectures,
+ * get_user_pages_fast simply falls back to get_user_pages.
+ */
+int __attribute__((weak)) get_user_pages_fast(unsigned long start,
+ int nr_pages, int write, struct page **pages)
+{
+ struct mm_struct *mm = current->mm;
+ int ret;
+
+ down_read(&mm->mmap_sem);
+ ret = get_user_pages(current, mm, start, nr_pages,
+ write, 0, pages, NULL);
+ up_read(&mm->mmap_sem);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(get_user_pages_fast);
+
+/* Tracepoints definitions. */
+EXPORT_TRACEPOINT_SYMBOL(kmalloc);
+EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
+EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
+EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
+EXPORT_TRACEPOINT_SYMBOL(kfree);
+EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);
diff --git a/ap/os/linux/linux-3.4.x/mm/vmalloc.c b/ap/os/linux/linux-3.4.x/mm/vmalloc.c
new file mode 100755
index 0000000..42eee4c
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/vmalloc.c
@@ -0,0 +1,2690 @@
+/*
+ * linux/mm/vmalloc.c
+ *
+ * Copyright (C) 1993 Linus Torvalds
+ * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
+ * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
+ * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
+ * Numa awareness, Christoph Lameter, SGI, June 2005
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/highmem.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/debugobjects.h>
+#include <linux/kallsyms.h>
+#include <linux/list.h>
+#include <linux/rbtree.h>
+#include <linux/radix-tree.h>
+#include <linux/rcupdate.h>
+#include <linux/pfn.h>
+#include <linux/kmemleak.h>
+#include <linux/atomic.h>
+#include <asm/uaccess.h>
+#include <asm/tlbflush.h>
+#include <asm/shmparam.h>
+
+/*** Page table manipulation functions ***/
+
+static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
+{
+ pte_t *pte;
+
+ pte = pte_offset_kernel(pmd, addr);
+ do {
+ pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
+ WARN_ON(!pte_none(ptent) && !pte_present(ptent));
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+}
+
+static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_none_or_clear_bad(pmd))
+ continue;
+ vunmap_pte_range(pmd, addr, next);
+ } while (pmd++, addr = next, addr != end);
+}
+
+static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ vunmap_pmd_range(pud, addr, next);
+ } while (pud++, addr = next, addr != end);
+}
+
+static void vunmap_page_range(unsigned long addr, unsigned long end)
+{
+ pgd_t *pgd;
+ unsigned long next;
+
+ BUG_ON(addr >= end);
+ pgd = pgd_offset_k(addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ vunmap_pud_range(pgd, addr, next);
+ } while (pgd++, addr = next, addr != end);
+}
+
+static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
+ unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+{
+ pte_t *pte;
+
+ /*
+ * nr is a running index into the array which helps higher level
+ * callers keep track of where we're up to.
+ */
+
+ pte = pte_alloc_kernel(pmd, addr);
+ if (!pte)
+ return -ENOMEM;
+ do {
+ struct page *page = pages[*nr];
+
+ if (WARN_ON(!pte_none(*pte)))
+ return -EBUSY;
+ if (WARN_ON(!page))
+ return -ENOMEM;
+ set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
+ (*nr)++;
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ return 0;
+}
+
+static int vmap_pmd_range(pud_t *pud, unsigned long addr,
+ unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ pmd = pmd_alloc(&init_mm, pud, addr);
+ if (!pmd)
+ return -ENOMEM;
+ do {
+ next = pmd_addr_end(addr, end);
+ if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
+ return -ENOMEM;
+ } while (pmd++, addr = next, addr != end);
+ return 0;
+}
+
+static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
+ unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ pud = pud_alloc(&init_mm, pgd, addr);
+ if (!pud)
+ return -ENOMEM;
+ do {
+ next = pud_addr_end(addr, end);
+ if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
+ return -ENOMEM;
+ } while (pud++, addr = next, addr != end);
+ return 0;
+}
+
+/*
+ * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
+ * will have pfns corresponding to the "pages" array.
+ *
+ * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
+ */
+static int vmap_page_range_noflush(unsigned long start, unsigned long end,
+ pgprot_t prot, struct page **pages)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ unsigned long addr = start;
+ int err = 0;
+ int nr = 0;
+
+ BUG_ON(addr >= end);
+ pgd = pgd_offset_k(addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
+ if (err)
+ return err;
+ } while (pgd++, addr = next, addr != end);
+
+ return nr;
+}
+
+static int vmap_page_range(unsigned long start, unsigned long end,
+ pgprot_t prot, struct page **pages)
+{
+ int ret;
+
+ ret = vmap_page_range_noflush(start, end, prot, pages);
+ flush_cache_vmap(start, end);
+ return ret;
+}
+
+int is_vmalloc_or_module_addr(const void *x)
+{
+ /*
+ * ARM, x86-64 and sparc64 put modules in a special place,
+ * and fall back on vmalloc() if that fails. Others
+ * just put it in the vmalloc space.
+ */
+#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
+ unsigned long addr = (unsigned long)x;
+ if (addr >= MODULES_VADDR && addr < MODULES_END)
+ return 1;
+#endif
+ return is_vmalloc_addr(x);
+}
+
+/*
+ * Walk a vmap address to the struct page it maps.
+ */
+struct page *vmalloc_to_page(const void *vmalloc_addr)
+{
+ unsigned long addr = (unsigned long) vmalloc_addr;
+ struct page *page = NULL;
+ pgd_t *pgd = pgd_offset_k(addr);
+
+ /*
+ * XXX we might need to change this if we add VIRTUAL_BUG_ON for
+ * architectures that do not vmalloc module space
+ */
+ VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
+
+ if (!pgd_none(*pgd)) {
+ pud_t *pud = pud_offset(pgd, addr);
+ if (!pud_none(*pud)) {
+ pmd_t *pmd = pmd_offset(pud, addr);
+ if (!pmd_none(*pmd)) {
+ pte_t *ptep, pte;
+
+ ptep = pte_offset_map(pmd, addr);
+ pte = *ptep;
+ if (pte_present(pte))
+ page = pte_page(pte);
+ pte_unmap(ptep);
+ }
+ }
+ }
+ return page;
+}
+EXPORT_SYMBOL(vmalloc_to_page);
+
+/*
+ * Map a vmalloc()-space virtual address to the physical page frame number.
+ */
+unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
+{
+ return page_to_pfn(vmalloc_to_page(vmalloc_addr));
+}
+EXPORT_SYMBOL(vmalloc_to_pfn);
+
+
+/*** Global kva allocator ***/
+
+#define VM_LAZY_FREE 0x01
+#define VM_LAZY_FREEING 0x02
+#define VM_VM_AREA 0x04
+
+struct vmap_area {
+ unsigned long va_start;
+ unsigned long va_end;
+ unsigned long flags;
+ struct rb_node rb_node; /* address sorted rbtree */
+ struct list_head list; /* address sorted list */
+ struct list_head purge_list; /* "lazy purge" list */
+ struct vm_struct *vm;
+ struct rcu_head rcu_head;
+};
+
+static DEFINE_SPINLOCK(vmap_area_lock);
+static LIST_HEAD(vmap_area_list);
+static struct rb_root vmap_area_root = RB_ROOT;
+
+/* The vmap cache globals are protected by vmap_area_lock */
+static struct rb_node *free_vmap_cache;
+static unsigned long cached_hole_size;
+static unsigned long cached_vstart;
+static unsigned long cached_align;
+
+static unsigned long vmap_area_pcpu_hole;
+
+static struct vmap_area *__find_vmap_area(unsigned long addr)
+{
+ struct rb_node *n = vmap_area_root.rb_node;
+
+ while (n) {
+ struct vmap_area *va;
+
+ va = rb_entry(n, struct vmap_area, rb_node);
+ if (addr < va->va_start)
+ n = n->rb_left;
+ else if (addr > va->va_start)
+ n = n->rb_right;
+ else
+ return va;
+ }
+
+ return NULL;
+}
+
+static void __insert_vmap_area(struct vmap_area *va)
+{
+ struct rb_node **p = &vmap_area_root.rb_node;
+ struct rb_node *parent = NULL;
+ struct rb_node *tmp;
+
+ while (*p) {
+ struct vmap_area *tmp_va;
+
+ parent = *p;
+ tmp_va = rb_entry(parent, struct vmap_area, rb_node);
+ if (va->va_start < tmp_va->va_end)
+ p = &(*p)->rb_left;
+ else if (va->va_end > tmp_va->va_start)
+ p = &(*p)->rb_right;
+ else
+ BUG();
+ }
+
+ rb_link_node(&va->rb_node, parent, p);
+ rb_insert_color(&va->rb_node, &vmap_area_root);
+
+ /* address-sort this list so it is usable like the vmlist */
+ tmp = rb_prev(&va->rb_node);
+ if (tmp) {
+ struct vmap_area *prev;
+ prev = rb_entry(tmp, struct vmap_area, rb_node);
+ list_add_rcu(&va->list, &prev->list);
+ } else
+ list_add_rcu(&va->list, &vmap_area_list);
+}
+
+static void purge_vmap_area_lazy(void);
+
+/*
+ * Allocate a region of KVA of the specified size and alignment, within the
+ * vstart and vend.
+ */
+static struct vmap_area *alloc_vmap_area(unsigned long size,
+ unsigned long align,
+ unsigned long vstart, unsigned long vend,
+ int node, gfp_t gfp_mask)
+{
+ struct vmap_area *va;
+ struct rb_node *n;
+ unsigned long addr;
+ int purged = 0;
+ struct vmap_area *first;
+
+ BUG_ON(!size);
+ BUG_ON(size & ~PAGE_MASK);
+ BUG_ON(!is_power_of_2(align));
+
+ va = kmalloc_node(sizeof(struct vmap_area),
+ gfp_mask & GFP_RECLAIM_MASK, node);
+ if (unlikely(!va))
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * Only scan the relevant parts containing pointers to other objects
+ * to avoid false negatives.
+ */
+ kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);
+
+retry:
+ spin_lock(&vmap_area_lock);
+ /*
+ * Invalidate cache if we have more permissive parameters.
+ * cached_hole_size notes the largest hole noticed _below_
+ * the vmap_area cached in free_vmap_cache: if size fits
+ * into that hole, we want to scan from vstart to reuse
+ * the hole instead of allocating above free_vmap_cache.
+ * Note that __free_vmap_area may update free_vmap_cache
+ * without updating cached_hole_size or cached_align.
+ */
+ if (!free_vmap_cache ||
+ size < cached_hole_size ||
+ vstart < cached_vstart ||
+ align < cached_align) {
+nocache:
+ cached_hole_size = 0;
+ free_vmap_cache = NULL;
+ }
+ /* record if we encounter less permissive parameters */
+ cached_vstart = vstart;
+ cached_align = align;
+
+ /* find starting point for our search */
+ if (free_vmap_cache) {
+ first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
+ addr = ALIGN(first->va_end, align);
+ if (addr < vstart)
+ goto nocache;
+ if (addr + size - 1 < addr)
+ goto overflow;
+
+ } else {
+ addr = ALIGN(vstart, align);
+ if (addr + size - 1 < addr)
+ goto overflow;
+
+ n = vmap_area_root.rb_node;
+ first = NULL;
+
+ while (n) {
+ struct vmap_area *tmp;
+ tmp = rb_entry(n, struct vmap_area, rb_node);
+ if (tmp->va_end >= addr) {
+ first = tmp;
+ if (tmp->va_start <= addr)
+ break;
+ n = n->rb_left;
+ } else
+ n = n->rb_right;
+ }
+
+ if (!first)
+ goto found;
+ }
+
+ /* from the starting point, walk areas until a suitable hole is found */
+ while (addr + size > first->va_start && addr + size <= vend) {
+ if (addr + cached_hole_size < first->va_start)
+ cached_hole_size = first->va_start - addr;
+ addr = ALIGN(first->va_end, align);
+ if (addr + size - 1 < addr)
+ goto overflow;
+
+ n = rb_next(&first->rb_node);
+ if (n)
+ first = rb_entry(n, struct vmap_area, rb_node);
+ else
+ goto found;
+ }
+
+found:
+ if (addr + size > vend)
+ goto overflow;
+
+ va->va_start = addr;
+ va->va_end = addr + size;
+ va->flags = 0;
+ __insert_vmap_area(va);
+ free_vmap_cache = &va->rb_node;
+ spin_unlock(&vmap_area_lock);
+
+ BUG_ON(va->va_start & (align-1));
+ BUG_ON(va->va_start < vstart);
+ BUG_ON(va->va_end > vend);
+
+ return va;
+
+overflow:
+ spin_unlock(&vmap_area_lock);
+ if (!purged) {
+ purge_vmap_area_lazy();
+ purged = 1;
+ goto retry;
+ }
+ if (printk_ratelimit())
+ printk(KERN_WARNING
+ "vmap allocation for size %lu failed: "
+ "use vmalloc=<size> to increase size.\n", size);
+ kfree(va);
+ return ERR_PTR(-EBUSY);
+}
+
+static void __free_vmap_area(struct vmap_area *va)
+{
+ BUG_ON(RB_EMPTY_NODE(&va->rb_node));
+
+ if (free_vmap_cache) {
+ if (va->va_end < cached_vstart) {
+ free_vmap_cache = NULL;
+ } else {
+ struct vmap_area *cache;
+ cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
+ if (va->va_start <= cache->va_start) {
+ free_vmap_cache = rb_prev(&va->rb_node);
+ /*
+ * We don't try to update cached_hole_size or
+ * cached_align, but it won't go very wrong.
+ */
+ }
+ }
+ }
+ rb_erase(&va->rb_node, &vmap_area_root);
+ RB_CLEAR_NODE(&va->rb_node);
+ list_del_rcu(&va->list);
+
+ /*
+ * Track the highest possible candidate for pcpu area
+ * allocation. Areas outside of vmalloc area can be returned
+ * here too, consider only end addresses which fall inside
+ * vmalloc area proper.
+ */
+ if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
+ vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
+
+ kfree_rcu(va, rcu_head);
+}
+
+/*
+ * Free a region of KVA allocated by alloc_vmap_area
+ */
+static void free_vmap_area(struct vmap_area *va)
+{
+ spin_lock(&vmap_area_lock);
+ __free_vmap_area(va);
+ spin_unlock(&vmap_area_lock);
+}
+
+/*
+ * Clear the pagetable entries of a given vmap_area
+ */
+static void unmap_vmap_area(struct vmap_area *va)
+{
+ vunmap_page_range(va->va_start, va->va_end);
+}
+
+static void vmap_debug_free_range(unsigned long start, unsigned long end)
+{
+ /*
+ * Unmap page tables and force a TLB flush immediately if
+ * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
+ * bugs similarly to those in linear kernel virtual address
+ * space after a page has been freed.
+ *
+ * All the lazy freeing logic is still retained, in order to
+ * minimise intrusiveness of this debugging feature.
+ *
+ * This is going to be *slow* (linear kernel virtual address
+ * debugging doesn't do a broadcast TLB flush so it is a lot
+ * faster).
+ */
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ vunmap_page_range(start, end);
+ flush_tlb_kernel_range(start, end);
+#endif
+}
+
+/*
+ * lazy_max_pages is the maximum amount of virtual address space we gather up
+ * before attempting to purge with a TLB flush.
+ *
+ * There is a tradeoff here: a larger number will cover more kernel page tables
+ * and take slightly longer to purge, but it will linearly reduce the number of
+ * global TLB flushes that must be performed. It would seem natural to scale
+ * this number up linearly with the number of CPUs (because vmapping activity
+ * could also scale linearly with the number of CPUs), however it is likely
+ * that in practice, workloads might be constrained in other ways that mean
+ * vmap activity will not scale linearly with CPUs. Also, I want to be
+ * conservative and not introduce a big latency on huge systems, so go with
+ * a less aggressive log scale. It will still be an improvement over the old
+ * code, and it will be simple to change the scale factor if we find that it
+ * becomes a problem on bigger systems.
+ */
+static unsigned long lazy_max_pages(void)
+{
+ unsigned int log;
+
+ log = fls(num_online_cpus());
+
+ return log * (32UL * 1024 * 1024 / PAGE_SIZE);
+}
+
+static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
+
+/* for per-CPU blocks */
+static void purge_fragmented_blocks_allcpus(void);
+
+/*
+ * called before a call to iounmap() if the caller wants vm_area_struct's
+ * immediately freed.
+ */
+void set_iounmap_nonlazy(void)
+{
+ atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
+}
+
+/*
+ * Purges all lazily-freed vmap areas.
+ *
+ * If sync is 0 then don't purge if there is already a purge in progress.
+ * If force_flush is 1, then flush kernel TLBs between *start and *end even
+ * if we found no lazy vmap areas to unmap (callers can use this to optimise
+ * their own TLB flushing).
+ * Returns with *start = min(*start, lowest purged address)
+ * *end = max(*end, highest purged address)
+ */
+static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
+ int sync, int force_flush)
+{
+ static DEFINE_SPINLOCK(purge_lock);
+ LIST_HEAD(valist);
+ struct vmap_area *va;
+ struct vmap_area *n_va;
+ int nr = 0;
+
+ /*
+ * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
+ * should not expect such behaviour. This just simplifies locking for
+ * the case that isn't actually used at the moment anyway.
+ */
+ if (!sync && !force_flush) {
+ if (!spin_trylock(&purge_lock))
+ return;
+ } else
+ spin_lock(&purge_lock);
+
+ if (sync)
+ purge_fragmented_blocks_allcpus();
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(va, &vmap_area_list, list) {
+ if (va->flags & VM_LAZY_FREE) {
+ if (va->va_start < *start)
+ *start = va->va_start;
+ if (va->va_end > *end)
+ *end = va->va_end;
+ nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
+ list_add_tail(&va->purge_list, &valist);
+ va->flags |= VM_LAZY_FREEING;
+ va->flags &= ~VM_LAZY_FREE;
+ }
+ }
+ rcu_read_unlock();
+
+ if (nr)
+ atomic_sub(nr, &vmap_lazy_nr);
+
+ if (nr || force_flush)
+ flush_tlb_kernel_range(*start, *end);
+
+ if (nr) {
+ spin_lock(&vmap_area_lock);
+ list_for_each_entry_safe(va, n_va, &valist, purge_list)
+ __free_vmap_area(va);
+ spin_unlock(&vmap_area_lock);
+ }
+ spin_unlock(&purge_lock);
+}
+
+/*
+ * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
+ * is already purging.
+ */
+static void try_purge_vmap_area_lazy(void)
+{
+ unsigned long start = ULONG_MAX, end = 0;
+
+ __purge_vmap_area_lazy(&start, &end, 0, 0);
+}
+
+/*
+ * Kick off a purge of the outstanding lazy areas.
+ */
+static void purge_vmap_area_lazy(void)
+{
+ unsigned long start = ULONG_MAX, end = 0;
+
+ __purge_vmap_area_lazy(&start, &end, 1, 0);
+}
+
+/*
+ * Free a vmap area, caller ensuring that the area has been unmapped
+ * and flush_cache_vunmap had been called for the correct range
+ * previously.
+ */
+static void free_vmap_area_noflush(struct vmap_area *va)
+{
+ va->flags |= VM_LAZY_FREE;
+ atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
+ if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
+ try_purge_vmap_area_lazy();
+}
+
+/*
+ * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
+ * called for the correct range previously.
+ */
+static void free_unmap_vmap_area_noflush(struct vmap_area *va)
+{
+ unmap_vmap_area(va);
+ free_vmap_area_noflush(va);
+}
+
+/*
+ * Free and unmap a vmap area
+ */
+static void free_unmap_vmap_area(struct vmap_area *va)
+{
+ flush_cache_vunmap(va->va_start, va->va_end);
+ free_unmap_vmap_area_noflush(va);
+}
+
+static struct vmap_area *find_vmap_area(unsigned long addr)
+{
+ struct vmap_area *va;
+
+ spin_lock(&vmap_area_lock);
+ va = __find_vmap_area(addr);
+ spin_unlock(&vmap_area_lock);
+
+ return va;
+}
+
+static void free_unmap_vmap_area_addr(unsigned long addr)
+{
+ struct vmap_area *va;
+
+ va = find_vmap_area(addr);
+ BUG_ON(!va);
+ free_unmap_vmap_area(va);
+}
+
+
+/*** Per cpu kva allocator ***/
+
+/*
+ * vmap space is limited especially on 32 bit architectures. Ensure there is
+ * room for at least 16 percpu vmap blocks per CPU.
+ */
+/*
+ * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
+ * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
+ * instead (we just need a rough idea)
+ */
+#if BITS_PER_LONG == 32
+#define VMALLOC_SPACE (128UL*1024*1024)
+#else
+#define VMALLOC_SPACE (128UL*1024*1024*1024)
+#endif
+
+#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
+#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
+#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
+#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
+#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
+#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
+#define VMAP_BBMAP_BITS \
+ VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
+ VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
+ VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
+
+#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
+
+static bool vmap_initialized __read_mostly = false;
+
+struct vmap_block_queue {
+ spinlock_t lock;
+ struct list_head free;
+};
+
+struct vmap_block {
+ spinlock_t lock;
+ struct vmap_area *va;
+ struct vmap_block_queue *vbq;
+ unsigned long free, dirty;
+ DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
+ DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
+ struct list_head free_list;
+ struct rcu_head rcu_head;
+ struct list_head purge;
+};
+
+/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
+static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
+
+/*
+ * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
+ * in the free path. Could get rid of this if we change the API to return a
+ * "cookie" from alloc, to be passed to free. But no big deal yet.
+ */
+static DEFINE_SPINLOCK(vmap_block_tree_lock);
+static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
+
+/*
+ * We should probably have a fallback mechanism to allocate virtual memory
+ * out of partially filled vmap blocks. However vmap block sizing should be
+ * fairly reasonable according to the vmalloc size, so it shouldn't be a
+ * big problem.
+ */
+
+static unsigned long addr_to_vb_idx(unsigned long addr)
+{
+ addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
+ addr /= VMAP_BLOCK_SIZE;
+ return addr;
+}
+
+static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
+{
+ struct vmap_block_queue *vbq;
+ struct vmap_block *vb;
+ struct vmap_area *va;
+ unsigned long vb_idx;
+ int node, err, cpu;
+
+ node = numa_node_id();
+
+ vb = kmalloc_node(sizeof(struct vmap_block),
+ gfp_mask & GFP_RECLAIM_MASK, node);
+ if (unlikely(!vb))
+ return ERR_PTR(-ENOMEM);
+
+ va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
+ VMALLOC_START, VMALLOC_END,
+ node, gfp_mask);
+ if (IS_ERR(va)) {
+ kfree(vb);
+ return ERR_CAST(va);
+ }
+
+ err = radix_tree_preload(gfp_mask);
+ if (unlikely(err)) {
+ kfree(vb);
+ free_vmap_area(va);
+ return ERR_PTR(err);
+ }
+
+ spin_lock_init(&vb->lock);
+ vb->va = va;
+ vb->free = VMAP_BBMAP_BITS;
+ vb->dirty = 0;
+ bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
+ bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
+ INIT_LIST_HEAD(&vb->free_list);
+
+ vb_idx = addr_to_vb_idx(va->va_start);
+ spin_lock(&vmap_block_tree_lock);
+ err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
+ spin_unlock(&vmap_block_tree_lock);
+ BUG_ON(err);
+ radix_tree_preload_end();
+
+ cpu = get_cpu_light();
+ vbq = &__get_cpu_var(vmap_block_queue);
+ vb->vbq = vbq;
+ spin_lock(&vbq->lock);
+ list_add_rcu(&vb->free_list, &vbq->free);
+ spin_unlock(&vbq->lock);
+ put_cpu_light();
+
+ return vb;
+}
+
+static void free_vmap_block(struct vmap_block *vb)
+{
+ struct vmap_block *tmp;
+ unsigned long vb_idx;
+
+ vb_idx = addr_to_vb_idx(vb->va->va_start);
+ spin_lock(&vmap_block_tree_lock);
+ tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
+ spin_unlock(&vmap_block_tree_lock);
+ BUG_ON(tmp != vb);
+
+ free_vmap_area_noflush(vb->va);
+ kfree_rcu(vb, rcu_head);
+}
+
+static void purge_fragmented_blocks(int cpu)
+{
+ LIST_HEAD(purge);
+ struct vmap_block *vb;
+ struct vmap_block *n_vb;
+ struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+
+ if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
+ continue;
+
+ spin_lock(&vb->lock);
+ if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
+ vb->free = 0; /* prevent further allocs after releasing lock */
+ vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
+ bitmap_fill(vb->alloc_map, VMAP_BBMAP_BITS);
+ bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
+ spin_lock(&vbq->lock);
+ list_del_rcu(&vb->free_list);
+ spin_unlock(&vbq->lock);
+ spin_unlock(&vb->lock);
+ list_add_tail(&vb->purge, &purge);
+ } else
+ spin_unlock(&vb->lock);
+ }
+ rcu_read_unlock();
+
+ list_for_each_entry_safe(vb, n_vb, &purge, purge) {
+ list_del(&vb->purge);
+ free_vmap_block(vb);
+ }
+}
+
+static void purge_fragmented_blocks_thiscpu(void)
+{
+ purge_fragmented_blocks(smp_processor_id());
+}
+
+static void purge_fragmented_blocks_allcpus(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ purge_fragmented_blocks(cpu);
+}
+
+static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
+{
+ struct vmap_block_queue *vbq;
+ struct vmap_block *vb;
+ unsigned long addr = 0;
+ unsigned int order;
+ int purge = 0, cpu;
+
+ BUG_ON(size & ~PAGE_MASK);
+ BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
+ order = get_order(size);
+
+again:
+ rcu_read_lock();
+ cpu = get_cpu_light();
+ vbq = &__get_cpu_var(vmap_block_queue);
+ list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+ int i;
+
+ spin_lock(&vb->lock);
+ if (vb->free < 1UL << order)
+ goto next;
+
+ i = bitmap_find_free_region(vb->alloc_map,
+ VMAP_BBMAP_BITS, order);
+
+ if (i < 0) {
+ if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
+ /* fragmented and no outstanding allocations */
+ BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
+ purge = 1;
+ }
+ goto next;
+ }
+ addr = vb->va->va_start + (i << PAGE_SHIFT);
+ BUG_ON(addr_to_vb_idx(addr) !=
+ addr_to_vb_idx(vb->va->va_start));
+ vb->free -= 1UL << order;
+ if (vb->free == 0) {
+ spin_lock(&vbq->lock);
+ list_del_rcu(&vb->free_list);
+ spin_unlock(&vbq->lock);
+ }
+ spin_unlock(&vb->lock);
+ break;
+next:
+ spin_unlock(&vb->lock);
+ }
+
+ if (purge)
+ purge_fragmented_blocks_thiscpu();
+
+ put_cpu_light();
+ rcu_read_unlock();
+
+ if (!addr) {
+ vb = new_vmap_block(gfp_mask);
+ if (IS_ERR(vb))
+ return vb;
+ goto again;
+ }
+
+ return (void *)addr;
+}
+
+static void vb_free(const void *addr, unsigned long size)
+{
+ unsigned long offset;
+ unsigned long vb_idx;
+ unsigned int order;
+ struct vmap_block *vb;
+
+ BUG_ON(size & ~PAGE_MASK);
+ BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
+
+ flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
+
+ order = get_order(size);
+
+ offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
+
+ vb_idx = addr_to_vb_idx((unsigned long)addr);
+ rcu_read_lock();
+ vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
+ rcu_read_unlock();
+ BUG_ON(!vb);
+
+ vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
+
+ spin_lock(&vb->lock);
+ BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
+
+ vb->dirty += 1UL << order;
+ if (vb->dirty == VMAP_BBMAP_BITS) {
+ BUG_ON(vb->free);
+ spin_unlock(&vb->lock);
+ free_vmap_block(vb);
+ } else
+ spin_unlock(&vb->lock);
+}
+
+/**
+ * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
+ *
+ * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
+ * to amortize TLB flushing overheads. What this means is that any page you
+ * have now, may, in a former life, have been mapped into kernel virtual
+ * address by the vmap layer and so there might be some CPUs with TLB entries
+ * still referencing that page (additional to the regular 1:1 kernel mapping).
+ *
+ * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
+ * be sure that none of the pages we have control over will have any aliases
+ * from the vmap layer.
+ */
+void vm_unmap_aliases(void)
+{
+ unsigned long start = ULONG_MAX, end = 0;
+ int cpu;
+ int flush = 0;
+
+ if (unlikely(!vmap_initialized))
+ return;
+
+ for_each_possible_cpu(cpu) {
+ struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
+ struct vmap_block *vb;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+ int i;
+
+ spin_lock(&vb->lock);
+ i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
+ while (i < VMAP_BBMAP_BITS) {
+ unsigned long s, e;
+ int j;
+ j = find_next_zero_bit(vb->dirty_map,
+ VMAP_BBMAP_BITS, i);
+
+ s = vb->va->va_start + (i << PAGE_SHIFT);
+ e = vb->va->va_start + (j << PAGE_SHIFT);
+ flush = 1;
+
+ if (s < start)
+ start = s;
+ if (e > end)
+ end = e;
+
+ i = j;
+ i = find_next_bit(vb->dirty_map,
+ VMAP_BBMAP_BITS, i);
+ }
+ spin_unlock(&vb->lock);
+ }
+ rcu_read_unlock();
+ }
+
+ __purge_vmap_area_lazy(&start, &end, 1, flush);
+}
+EXPORT_SYMBOL_GPL(vm_unmap_aliases);
+
+/**
+ * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
+ * @mem: the pointer returned by vm_map_ram
+ * @count: the count passed to that vm_map_ram call (cannot unmap partial)
+ */
+void vm_unmap_ram(const void *mem, unsigned int count)
+{
+ unsigned long size = count << PAGE_SHIFT;
+ unsigned long addr = (unsigned long)mem;
+
+ BUG_ON(!addr);
+ BUG_ON(addr < VMALLOC_START);
+ BUG_ON(addr > VMALLOC_END);
+ BUG_ON(addr & (PAGE_SIZE-1));
+
+ debug_check_no_locks_freed(mem, size);
+ vmap_debug_free_range(addr, addr+size);
+
+ if (likely(count <= VMAP_MAX_ALLOC))
+ vb_free(mem, size);
+ else
+ free_unmap_vmap_area_addr(addr);
+}
+EXPORT_SYMBOL(vm_unmap_ram);
+
+/**
+ * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
+ * @pages: an array of pointers to the pages to be mapped
+ * @count: number of pages
+ * @node: prefer to allocate data structures on this node
+ * @prot: memory protection to use. PAGE_KERNEL for regular RAM
+ *
+ * Returns: a pointer to the address that has been mapped, or %NULL on failure
+ */
+void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
+{
+ unsigned long size = count << PAGE_SHIFT;
+ unsigned long addr;
+ void *mem;
+
+ if (likely(count <= VMAP_MAX_ALLOC)) {
+ mem = vb_alloc(size, GFP_KERNEL);
+ if (IS_ERR(mem))
+ return NULL;
+ addr = (unsigned long)mem;
+ } else {
+ struct vmap_area *va;
+ va = alloc_vmap_area(size, PAGE_SIZE,
+ VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
+ if (IS_ERR(va))
+ return NULL;
+
+ addr = va->va_start;
+ mem = (void *)addr;
+ }
+ if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
+ vm_unmap_ram(mem, count);
+ return NULL;
+ }
+ return mem;
+}
+EXPORT_SYMBOL(vm_map_ram);
+
+/**
+ * vm_area_add_early - add vmap area early during boot
+ * @vm: vm_struct to add
+ *
+ * This function is used to add fixed kernel vm area to vmlist before
+ * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
+ * should contain proper values and the other fields should be zero.
+ *
+ * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
+ */
+void __init vm_area_add_early(struct vm_struct *vm)
+{
+ struct vm_struct *tmp, **p;
+
+ BUG_ON(vmap_initialized);
+ for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
+ if (tmp->addr >= vm->addr) {
+ BUG_ON(tmp->addr < vm->addr + vm->size);
+ break;
+ } else
+ BUG_ON(tmp->addr + tmp->size > vm->addr);
+ }
+ vm->next = *p;
+ *p = vm;
+}
+
+/**
+ * vm_area_register_early - register vmap area early during boot
+ * @vm: vm_struct to register
+ * @align: requested alignment
+ *
+ * This function is used to register kernel vm area before
+ * vmalloc_init() is called. @vm->size and @vm->flags should contain
+ * proper values on entry and other fields should be zero. On return,
+ * vm->addr contains the allocated address.
+ *
+ * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
+ */
+void __init vm_area_register_early(struct vm_struct *vm, size_t align)
+{
+ static size_t vm_init_off __initdata;
+ unsigned long addr;
+
+ addr = ALIGN(VMALLOC_START + vm_init_off, align);
+ vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
+
+ vm->addr = (void *)addr;
+
+ vm_area_add_early(vm);
+}
+
+void __init vmalloc_init(void)
+{
+ struct vmap_area *va;
+ struct vm_struct *tmp;
+ int i;
+
+ for_each_possible_cpu(i) {
+ struct vmap_block_queue *vbq;
+
+ vbq = &per_cpu(vmap_block_queue, i);
+ spin_lock_init(&vbq->lock);
+ INIT_LIST_HEAD(&vbq->free);
+ }
+
+ /* Import existing vmlist entries. */
+ for (tmp = vmlist; tmp; tmp = tmp->next) {
+ va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
+ va->flags = VM_VM_AREA;
+ va->va_start = (unsigned long)tmp->addr;
+ va->va_end = va->va_start + tmp->size;
+ va->vm = tmp;
+ __insert_vmap_area(va);
+ }
+
+ vmap_area_pcpu_hole = VMALLOC_END;
+
+ vmap_initialized = true;
+}
+
+/**
+ * map_kernel_range_noflush - map kernel VM area with the specified pages
+ * @addr: start of the VM area to map
+ * @size: size of the VM area to map
+ * @prot: page protection flags to use
+ * @pages: pages to map
+ *
+ * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
+ * specify should have been allocated using get_vm_area() and its
+ * friends.
+ *
+ * NOTE:
+ * This function does NOT do any cache flushing. The caller is
+ * responsible for calling flush_cache_vmap() on to-be-mapped areas
+ * before calling this function.
+ *
+ * RETURNS:
+ * The number of pages mapped on success, -errno on failure.
+ */
+int map_kernel_range_noflush(unsigned long addr, unsigned long size,
+ pgprot_t prot, struct page **pages)
+{
+ return vmap_page_range_noflush(addr, addr + size, prot, pages);
+}
+
+/**
+ * unmap_kernel_range_noflush - unmap kernel VM area
+ * @addr: start of the VM area to unmap
+ * @size: size of the VM area to unmap
+ *
+ * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
+ * specify should have been allocated using get_vm_area() and its
+ * friends.
+ *
+ * NOTE:
+ * This function does NOT do any cache flushing. The caller is
+ * responsible for calling flush_cache_vunmap() on to-be-mapped areas
+ * before calling this function and flush_tlb_kernel_range() after.
+ */
+void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
+{
+ vunmap_page_range(addr, addr + size);
+}
+EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
+
+/**
+ * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
+ * @addr: start of the VM area to unmap
+ * @size: size of the VM area to unmap
+ *
+ * Similar to unmap_kernel_range_noflush() but flushes vcache before
+ * the unmapping and tlb after.
+ */
+void unmap_kernel_range(unsigned long addr, unsigned long size)
+{
+ unsigned long end = addr + size;
+
+ flush_cache_vunmap(addr, end);
+ vunmap_page_range(addr, end);
+ flush_tlb_kernel_range(addr, end);
+}
+
+int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
+{
+ unsigned long addr = (unsigned long)area->addr;
+ unsigned long end = addr + area->size - PAGE_SIZE;
+ int err;
+
+ err = vmap_page_range(addr, end, prot, *pages);
+ if (err > 0) {
+ *pages += err;
+ err = 0;
+ }
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(map_vm_area);
+
+/*** Old vmalloc interfaces ***/
+DEFINE_RWLOCK(vmlist_lock);
+struct vm_struct *vmlist;
+
+static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
+ unsigned long flags, void *caller)
+{
+ vm->flags = flags;
+ vm->addr = (void *)va->va_start;
+ vm->size = va->va_end - va->va_start;
+ vm->caller = caller;
+ va->vm = vm;
+ va->flags |= VM_VM_AREA;
+}
+
+static void insert_vmalloc_vmlist(struct vm_struct *vm)
+{
+ struct vm_struct *tmp, **p;
+
+ vm->flags &= ~VM_UNLIST;
+ write_lock(&vmlist_lock);
+ for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
+ if (tmp->addr >= vm->addr)
+ break;
+ }
+ vm->next = *p;
+ *p = vm;
+ write_unlock(&vmlist_lock);
+}
+
+static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
+ unsigned long flags, void *caller)
+{
+ setup_vmalloc_vm(vm, va, flags, caller);
+ insert_vmalloc_vmlist(vm);
+}
+
+static struct vm_struct *__get_vm_area_node(unsigned long size,
+ unsigned long align, unsigned long flags, unsigned long start,
+ unsigned long end, int node, gfp_t gfp_mask, void *caller)
+{
+ struct vmap_area *va;
+ struct vm_struct *area;
+
+ BUG_ON(in_interrupt());
+ if (flags & VM_IOREMAP) {
+ int bit = fls(size);
+
+ if (bit > IOREMAP_MAX_ORDER)
+ bit = IOREMAP_MAX_ORDER;
+ else if (bit < PAGE_SHIFT)
+ bit = PAGE_SHIFT;
+
+ align = 1ul << bit;
+ }
+
+ size = PAGE_ALIGN(size);
+ if (unlikely(!size))
+ return NULL;
+
+ area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
+ if (unlikely(!area))
+ return NULL;
+
+ /*
+ * We always allocate a guard page.
+ */
+ size += PAGE_SIZE;
+
+ va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
+ if (IS_ERR(va)) {
+ kfree(area);
+ return NULL;
+ }
+
+ /*
+ * When this function is called from __vmalloc_node_range,
+ * we do not add vm_struct to vmlist here to avoid
+ * accessing uninitialized members of vm_struct such as
+ * pages and nr_pages fields. They will be set later.
+ * To distinguish it from others, we use a VM_UNLIST flag.
+ */
+ if (flags & VM_UNLIST)
+ setup_vmalloc_vm(area, va, flags, caller);
+ else
+ insert_vmalloc_vm(area, va, flags, caller);
+
+ return area;
+}
+
+struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
+ unsigned long start, unsigned long end)
+{
+ return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL_GPL(__get_vm_area);
+
+struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
+ unsigned long start, unsigned long end,
+ void *caller)
+{
+ return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
+ caller);
+}
+
+/**
+ * get_vm_area - reserve a contiguous kernel virtual area
+ * @size: size of the area
+ * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
+ *
+ * Search an area of @size in the kernel virtual mapping area,
+ * and reserved it for out purposes. Returns the area descriptor
+ * on success or %NULL on failure.
+ */
+struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
+{
+ return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
+ -1, GFP_KERNEL, __builtin_return_address(0));
+}
+
+struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
+ void *caller)
+{
+ return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
+ -1, GFP_KERNEL, caller);
+}
+
+static struct vm_struct *find_vm_area(const void *addr)
+{
+ struct vmap_area *va;
+
+ va = find_vmap_area((unsigned long)addr);
+ if (va && va->flags & VM_VM_AREA)
+ return va->vm;
+
+ return NULL;
+}
+
+/**
+ * remove_vm_area - find and remove a continuous kernel virtual area
+ * @addr: base address
+ *
+ * Search for the kernel VM area starting at @addr, and remove it.
+ * This function returns the found VM area, but using it is NOT safe
+ * on SMP machines, except for its size or flags.
+ */
+struct vm_struct *remove_vm_area(const void *addr)
+{
+ struct vmap_area *va;
+
+ va = find_vmap_area((unsigned long)addr);
+ if (va && va->flags & VM_VM_AREA) {
+ struct vm_struct *vm = va->vm;
+
+ if (!(vm->flags & VM_UNLIST)) {
+ struct vm_struct *tmp, **p;
+ /*
+ * remove from list and disallow access to
+ * this vm_struct before unmap. (address range
+ * confliction is maintained by vmap.)
+ */
+ write_lock(&vmlist_lock);
+ for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
+ ;
+ *p = tmp->next;
+ write_unlock(&vmlist_lock);
+ }
+
+ vmap_debug_free_range(va->va_start, va->va_end);
+ free_unmap_vmap_area(va);
+ vm->size -= PAGE_SIZE;
+
+ return vm;
+ }
+ return NULL;
+}
+
+static void __vunmap(const void *addr, int deallocate_pages)
+{
+ struct vm_struct *area;
+
+ if (!addr)
+ return;
+
+ if ((PAGE_SIZE-1) & (unsigned long)addr) {
+ WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
+ return;
+ }
+
+ area = remove_vm_area(addr);
+ if (unlikely(!area)) {
+ WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
+ addr);
+ return;
+ }
+
+ debug_check_no_locks_freed(addr, area->size);
+ debug_check_no_obj_freed(addr, area->size);
+
+ if (deallocate_pages) {
+ int i;
+
+ for (i = 0; i < area->nr_pages; i++) {
+ struct page *page = area->pages[i];
+
+ BUG_ON(!page);
+ __free_page(page);
+ }
+
+ if (area->flags & VM_VPAGES)
+ vfree(area->pages);
+ else
+ kfree(area->pages);
+ }
+
+ kfree(area);
+ return;
+}
+
+/**
+ * vfree - release memory allocated by vmalloc()
+ * @addr: memory base address
+ *
+ * Free the virtually continuous memory area starting at @addr, as
+ * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
+ * NULL, no operation is performed.
+ *
+ * Must not be called in interrupt context.
+ */
+void vfree(const void *addr)
+{
+ BUG_ON(in_interrupt());
+
+ kmemleak_free(addr);
+
+ __vunmap(addr, 1);
+}
+EXPORT_SYMBOL(vfree);
+
+#ifdef CONFIG_MODEM_CODE_IS_MAPPING
+void vfree_modem_section(unsigned long start,unsigned long end)
+{
+ struct vmap_area *va;
+ if (!start)
+ return;
+ if ((PAGE_SIZE-1) & (unsigned long)start)
+ {
+ WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", start);
+ return;
+ }
+
+ va = find_vmap_area(MODULES_VADDR);
+ if (va && va->flags & VM_VM_AREA)
+ {
+ struct vm_struct *vm = va->vm;
+ int i = 0;
+ unsigned long nr_pages = 0;
+ flush_icache_range(start,end);
+ flush_cache_vunmap(start, end);
+ vunmap_page_range(start, end);
+ flush_tlb_kernel_range(start, end);
+
+ nr_pages = (end-MODULES_VADDR) >> PAGE_SHIFT;
+ for (i = (start-MODULES_VADDR) >> PAGE_SHIFT; i < nr_pages; i++)
+ {
+ struct page *page = vm->pages[i];
+ BUG_ON(!page);
+ __free_page(page);
+ }
+ }
+}
+EXPORT_SYMBOL(vfree_modem_section);
+#endif
+/**
+ * vunmap - release virtual mapping obtained by vmap()
+ * @addr: memory base address
+ *
+ * Free the virtually contiguous memory area starting at @addr,
+ * which was created from the page array passed to vmap().
+ *
+ * Must not be called in interrupt context.
+ */
+void vunmap(const void *addr)
+{
+ BUG_ON(in_interrupt());
+ might_sleep();
+ __vunmap(addr, 0);
+}
+EXPORT_SYMBOL(vunmap);
+
+/**
+ * vmap - map an array of pages into virtually contiguous space
+ * @pages: array of page pointers
+ * @count: number of pages to map
+ * @flags: vm_area->flags
+ * @prot: page protection for the mapping
+ *
+ * Maps @count pages from @pages into contiguous kernel virtual
+ * space.
+ */
+void *vmap(struct page **pages, unsigned int count,
+ unsigned long flags, pgprot_t prot)
+{
+ struct vm_struct *area;
+
+ might_sleep();
+
+ if (count > totalram_pages)
+ return NULL;
+
+ area = get_vm_area_caller((count << PAGE_SHIFT), flags,
+ __builtin_return_address(0));
+ if (!area)
+ return NULL;
+
+ if (map_vm_area(area, prot, &pages)) {
+ vunmap(area->addr);
+ return NULL;
+ }
+
+ return area->addr;
+}
+EXPORT_SYMBOL(vmap);
+
+static void *__vmalloc_node(unsigned long size, unsigned long align,
+ gfp_t gfp_mask, pgprot_t prot,
+ int node, void *caller);
+static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
+ pgprot_t prot, int node, void *caller)
+{
+ const int order = 0;
+ struct page **pages;
+ unsigned int nr_pages, array_size, i;
+ gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
+
+ nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
+ array_size = (nr_pages * sizeof(struct page *));
+
+ area->nr_pages = nr_pages;
+ /* Please note that the recursion is strictly bounded. */
+ if (array_size > PAGE_SIZE) {
+ pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
+ PAGE_KERNEL, node, caller);
+ area->flags |= VM_VPAGES;
+ } else {
+ pages = kmalloc_node(array_size, nested_gfp, node);
+ }
+ area->pages = pages;
+ area->caller = caller;
+ if (!area->pages) {
+ remove_vm_area(area->addr);
+ kfree(area);
+ return NULL;
+ }
+
+ for (i = 0; i < area->nr_pages; i++) {
+ struct page *page;
+ gfp_t tmp_mask = gfp_mask | __GFP_NOWARN;
+
+ if (node < 0)
+ page = alloc_page(tmp_mask);
+ else
+ page = alloc_pages_node(node, tmp_mask, order);
+
+ if (unlikely(!page)) {
+ /* Successfully allocated i pages, free them in __vunmap() */
+ area->nr_pages = i;
+ goto fail;
+ }
+ area->pages[i] = page;
+ }
+
+ if (map_vm_area(area, prot, &pages))
+ goto fail;
+ return area->addr;
+
+fail:
+ warn_alloc_failed(gfp_mask, order,
+ "vmalloc: allocation failure, allocated %ld of %ld bytes\n",
+ (area->nr_pages*PAGE_SIZE), area->size);
+ vfree(area->addr);
+ return NULL;
+}
+
+/**
+ * __vmalloc_node_range - allocate virtually contiguous memory
+ * @size: allocation size
+ * @align: desired alignment
+ * @start: vm area range start
+ * @end: vm area range end
+ * @gfp_mask: flags for the page level allocator
+ * @prot: protection mask for the allocated pages
+ * @node: node to use for allocation or -1
+ * @caller: caller's return address
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator with @gfp_mask flags. Map them into contiguous
+ * kernel virtual space, using a pagetable protection of @prot.
+ */
+void *__vmalloc_node_range(unsigned long size, unsigned long align,
+ unsigned long start, unsigned long end, gfp_t gfp_mask,
+ pgprot_t prot, int node, void *caller)
+{
+ struct vm_struct *area;
+ void *addr;
+ unsigned long real_size = size;
+
+#ifdef CONFIG_MEM_CHECK
+ if (size > CONFIG_MEM_CHECK_SIZE) {
+ printk(KERN_ALERT"memcheck_vmalloc %d %s (%pS)\n", size, current->comm, __builtin_return_address(0));
+ if (strcmp(current->comm,MEM_CHECK_THREAD_NAME)==0)
+ dump_stack();
+ }
+#endif
+
+ size = PAGE_ALIGN(size);
+ if (!size || (size >> PAGE_SHIFT) > totalram_pages)
+ goto fail;
+
+ area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNLIST,
+ start, end, node, gfp_mask, caller);
+ if (!area)
+ goto fail;
+
+ addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
+ if (!addr)
+ return NULL;
+
+ /*
+ * In this function, newly allocated vm_struct is not added
+ * to vmlist at __get_vm_area_node(). so, it is added here.
+ */
+ insert_vmalloc_vmlist(area);
+
+ /*
+ * A ref_count = 2 is needed because vm_struct allocated in
+ * __get_vm_area_node() contains a reference to the virtual address of
+ * the vmalloc'ed block.
+ */
+ kmemleak_alloc(addr, real_size, 2, gfp_mask);
+
+ return addr;
+
+fail:
+ warn_alloc_failed(gfp_mask, 0,
+ "vmalloc: allocation failure: %lu bytes\n",
+ real_size);
+ return NULL;
+}
+
+/**
+ * __vmalloc_node - allocate virtually contiguous memory
+ * @size: allocation size
+ * @align: desired alignment
+ * @gfp_mask: flags for the page level allocator
+ * @prot: protection mask for the allocated pages
+ * @node: node to use for allocation or -1
+ * @caller: caller's return address
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator with @gfp_mask flags. Map them into contiguous
+ * kernel virtual space, using a pagetable protection of @prot.
+ */
+static void *__vmalloc_node(unsigned long size, unsigned long align,
+ gfp_t gfp_mask, pgprot_t prot,
+ int node, void *caller)
+{
+ return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
+ gfp_mask, prot, node, caller);
+}
+
+void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
+{
+ return __vmalloc_node(size, 1, gfp_mask, prot, -1,
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL(__vmalloc);
+
+static inline void *__vmalloc_node_flags(unsigned long size,
+ int node, gfp_t flags)
+{
+ return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
+ node, __builtin_return_address(0));
+}
+
+/**
+ * vmalloc - allocate virtually contiguous memory
+ * @size: allocation size
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+void *vmalloc(unsigned long size)
+{
+ return __vmalloc_node_flags(size, -1, GFP_KERNEL | __GFP_HIGHMEM);
+}
+EXPORT_SYMBOL(vmalloc);
+
+/**
+ * vzalloc - allocate virtually contiguous memory with zero fill
+ * @size: allocation size
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ * The memory allocated is set to zero.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+void *vzalloc(unsigned long size)
+{
+ return __vmalloc_node_flags(size, -1,
+ GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+}
+EXPORT_SYMBOL(vzalloc);
+
+/**
+ * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
+ * @size: allocation size
+ *
+ * The resulting memory area is zeroed so it can be mapped to userspace
+ * without leaking data.
+ */
+void *vmalloc_user(unsigned long size)
+{
+ struct vm_struct *area;
+ void *ret;
+
+ ret = __vmalloc_node(size, SHMLBA,
+ GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
+ PAGE_KERNEL, -1, __builtin_return_address(0));
+ if (ret) {
+ area = find_vm_area(ret);
+ if (area)
+ area->flags |= VM_USERMAP;
+ }
+ return ret;
+}
+EXPORT_SYMBOL(vmalloc_user);
+
+/**
+ * vmalloc_node - allocate memory on a specific node
+ * @size: allocation size
+ * @node: numa node
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+void *vmalloc_node(unsigned long size, int node)
+{
+ return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
+ node, __builtin_return_address(0));
+}
+EXPORT_SYMBOL(vmalloc_node);
+
+/**
+ * vzalloc_node - allocate memory on a specific node with zero fill
+ * @size: allocation size
+ * @node: numa node
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ * The memory allocated is set to zero.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc_node() instead.
+ */
+void *vzalloc_node(unsigned long size, int node)
+{
+ return __vmalloc_node_flags(size, node,
+ GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+}
+EXPORT_SYMBOL(vzalloc_node);
+
+#ifndef PAGE_KERNEL_EXEC
+# define PAGE_KERNEL_EXEC PAGE_KERNEL
+#endif
+
+/**
+ * vmalloc_exec - allocate virtually contiguous, executable memory
+ * @size: allocation size
+ *
+ * Kernel-internal function to allocate enough pages to cover @size
+ * the page level allocator and map them into contiguous and
+ * executable kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ */
+
+void *vmalloc_exec(unsigned long size)
+{
+ return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
+ -1, __builtin_return_address(0));
+}
+
+#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
+#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
+#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
+#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
+#else
+#define GFP_VMALLOC32 GFP_KERNEL
+#endif
+
+/**
+ * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
+ * @size: allocation size
+ *
+ * Allocate enough 32bit PA addressable pages to cover @size from the
+ * page level allocator and map them into contiguous kernel virtual space.
+ */
+void *vmalloc_32(unsigned long size)
+{
+ return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
+ -1, __builtin_return_address(0));
+}
+EXPORT_SYMBOL(vmalloc_32);
+
+/**
+ * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
+ * @size: allocation size
+ *
+ * The resulting memory area is 32bit addressable and zeroed so it can be
+ * mapped to userspace without leaking data.
+ */
+void *vmalloc_32_user(unsigned long size)
+{
+ struct vm_struct *area;
+ void *ret;
+
+ ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
+ -1, __builtin_return_address(0));
+ if (ret) {
+ area = find_vm_area(ret);
+ if (area)
+ area->flags |= VM_USERMAP;
+ }
+ return ret;
+}
+EXPORT_SYMBOL(vmalloc_32_user);
+
+/*
+ * small helper routine , copy contents to buf from addr.
+ * If the page is not present, fill zero.
+ */
+
+static int aligned_vread(char *buf, char *addr, unsigned long count)
+{
+ struct page *p;
+ int copied = 0;
+
+ while (count) {
+ unsigned long offset, length;
+
+ offset = (unsigned long)addr & ~PAGE_MASK;
+ length = PAGE_SIZE - offset;
+ if (length > count)
+ length = count;
+ p = vmalloc_to_page(addr);
+ /*
+ * To do safe access to this _mapped_ area, we need
+ * lock. But adding lock here means that we need to add
+ * overhead of vmalloc()/vfree() calles for this _debug_
+ * interface, rarely used. Instead of that, we'll use
+ * kmap() and get small overhead in this access function.
+ */
+ if (p) {
+ /*
+ * we can expect USER0 is not used (see vread/vwrite's
+ * function description)
+ */
+ void *map = kmap_atomic(p);
+ memcpy(buf, map + offset, length);
+ kunmap_atomic(map);
+ } else
+ memset(buf, 0, length);
+
+ addr += length;
+ buf += length;
+ copied += length;
+ count -= length;
+ }
+ return copied;
+}
+
+static int aligned_vwrite(char *buf, char *addr, unsigned long count)
+{
+ struct page *p;
+ int copied = 0;
+
+ while (count) {
+ unsigned long offset, length;
+
+ offset = (unsigned long)addr & ~PAGE_MASK;
+ length = PAGE_SIZE - offset;
+ if (length > count)
+ length = count;
+ p = vmalloc_to_page(addr);
+ /*
+ * To do safe access to this _mapped_ area, we need
+ * lock. But adding lock here means that we need to add
+ * overhead of vmalloc()/vfree() calles for this _debug_
+ * interface, rarely used. Instead of that, we'll use
+ * kmap() and get small overhead in this access function.
+ */
+ if (p) {
+ /*
+ * we can expect USER0 is not used (see vread/vwrite's
+ * function description)
+ */
+ void *map = kmap_atomic(p);
+ memcpy(map + offset, buf, length);
+ kunmap_atomic(map);
+ }
+ addr += length;
+ buf += length;
+ copied += length;
+ count -= length;
+ }
+ return copied;
+}
+
+/**
+ * vread() - read vmalloc area in a safe way.
+ * @buf: buffer for reading data
+ * @addr: vm address.
+ * @count: number of bytes to be read.
+ *
+ * Returns # of bytes which addr and buf should be increased.
+ * (same number to @count). Returns 0 if [addr...addr+count) doesn't
+ * includes any intersect with alive vmalloc area.
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * copy data from that area to a given buffer. If the given memory range
+ * of [addr...addr+count) includes some valid address, data is copied to
+ * proper area of @buf. If there are memory holes, they'll be zero-filled.
+ * IOREMAP area is treated as memory hole and no copy is done.
+ *
+ * If [addr...addr+count) doesn't includes any intersects with alive
+ * vm_struct area, returns 0.
+ * @buf should be kernel's buffer. Because this function uses KM_USER0,
+ * the caller should guarantee KM_USER0 is not used.
+ *
+ * Note: In usual ops, vread() is never necessary because the caller
+ * should know vmalloc() area is valid and can use memcpy().
+ * This is for routines which have to access vmalloc area without
+ * any informaion, as /dev/kmem.
+ *
+ */
+
+long vread(char *buf, char *addr, unsigned long count)
+{
+ struct vm_struct *tmp;
+ char *vaddr, *buf_start = buf;
+ unsigned long buflen = count;
+ unsigned long n;
+
+ /* Don't allow overflow */
+ if ((unsigned long) addr + count < count)
+ count = -(unsigned long) addr;
+
+ read_lock(&vmlist_lock);
+ for (tmp = vmlist; count && tmp; tmp = tmp->next) {
+ vaddr = (char *) tmp->addr;
+ if (addr >= vaddr + tmp->size - PAGE_SIZE)
+ continue;
+ while (addr < vaddr) {
+ if (count == 0)
+ goto finished;
+ *buf = '\0';
+ buf++;
+ addr++;
+ count--;
+ }
+ n = vaddr + tmp->size - PAGE_SIZE - addr;
+ if (n > count)
+ n = count;
+ if (!(tmp->flags & VM_IOREMAP))
+ aligned_vread(buf, addr, n);
+ else /* IOREMAP area is treated as memory hole */
+ memset(buf, 0, n);
+ buf += n;
+ addr += n;
+ count -= n;
+ }
+finished:
+ read_unlock(&vmlist_lock);
+
+ if (buf == buf_start)
+ return 0;
+ /* zero-fill memory holes */
+ if (buf != buf_start + buflen)
+ memset(buf, 0, buflen - (buf - buf_start));
+
+ return buflen;
+}
+
+/**
+ * vwrite() - write vmalloc area in a safe way.
+ * @buf: buffer for source data
+ * @addr: vm address.
+ * @count: number of bytes to be read.
+ *
+ * Returns # of bytes which addr and buf should be incresed.
+ * (same number to @count).
+ * If [addr...addr+count) doesn't includes any intersect with valid
+ * vmalloc area, returns 0.
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * copy data from a buffer to the given addr. If specified range of
+ * [addr...addr+count) includes some valid address, data is copied from
+ * proper area of @buf. If there are memory holes, no copy to hole.
+ * IOREMAP area is treated as memory hole and no copy is done.
+ *
+ * If [addr...addr+count) doesn't includes any intersects with alive
+ * vm_struct area, returns 0.
+ * @buf should be kernel's buffer. Because this function uses KM_USER0,
+ * the caller should guarantee KM_USER0 is not used.
+ *
+ * Note: In usual ops, vwrite() is never necessary because the caller
+ * should know vmalloc() area is valid and can use memcpy().
+ * This is for routines which have to access vmalloc area without
+ * any informaion, as /dev/kmem.
+ */
+
+long vwrite(char *buf, char *addr, unsigned long count)
+{
+ struct vm_struct *tmp;
+ char *vaddr;
+ unsigned long n, buflen;
+ int copied = 0;
+
+ /* Don't allow overflow */
+ if ((unsigned long) addr + count < count)
+ count = -(unsigned long) addr;
+ buflen = count;
+
+ read_lock(&vmlist_lock);
+ for (tmp = vmlist; count && tmp; tmp = tmp->next) {
+ vaddr = (char *) tmp->addr;
+ if (addr >= vaddr + tmp->size - PAGE_SIZE)
+ continue;
+ while (addr < vaddr) {
+ if (count == 0)
+ goto finished;
+ buf++;
+ addr++;
+ count--;
+ }
+ n = vaddr + tmp->size - PAGE_SIZE - addr;
+ if (n > count)
+ n = count;
+ if (!(tmp->flags & VM_IOREMAP)) {
+ aligned_vwrite(buf, addr, n);
+ copied++;
+ }
+ buf += n;
+ addr += n;
+ count -= n;
+ }
+finished:
+ read_unlock(&vmlist_lock);
+ if (!copied)
+ return 0;
+ return buflen;
+}
+
+/**
+ * remap_vmalloc_range - map vmalloc pages to userspace
+ * @vma: vma to cover (map full range of vma)
+ * @addr: vmalloc memory
+ * @pgoff: number of pages into addr before first page to map
+ *
+ * Returns: 0 for success, -Exxx on failure
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * that it is big enough to cover the vma. Will return failure if
+ * that criteria isn't met.
+ *
+ * Similar to remap_pfn_range() (see mm/memory.c)
+ */
+int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
+ unsigned long pgoff)
+{
+ struct vm_struct *area;
+ unsigned long uaddr = vma->vm_start;
+ unsigned long usize = vma->vm_end - vma->vm_start;
+
+ if ((PAGE_SIZE-1) & (unsigned long)addr)
+ return -EINVAL;
+
+ area = find_vm_area(addr);
+ if (!area)
+ return -EINVAL;
+
+ if (!(area->flags & VM_USERMAP))
+ return -EINVAL;
+
+ if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
+ return -EINVAL;
+
+ addr += pgoff << PAGE_SHIFT;
+ do {
+ struct page *page = vmalloc_to_page(addr);
+ int ret;
+
+ ret = vm_insert_page(vma, uaddr, page);
+ if (ret)
+ return ret;
+
+ uaddr += PAGE_SIZE;
+ addr += PAGE_SIZE;
+ usize -= PAGE_SIZE;
+ } while (usize > 0);
+
+ /* Prevent "things" like memory migration? VM_flags need a cleanup... */
+ vma->vm_flags |= VM_RESERVED;
+
+ return 0;
+}
+EXPORT_SYMBOL(remap_vmalloc_range);
+
+/*
+ * Implement a stub for vmalloc_sync_all() if the architecture chose not to
+ * have one.
+ */
+void __attribute__((weak)) vmalloc_sync_all(void)
+{
+}
+
+
+static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
+{
+ pte_t ***p = data;
+
+ if (p) {
+ *(*p) = pte;
+ (*p)++;
+ }
+ return 0;
+}
+
+/**
+ * alloc_vm_area - allocate a range of kernel address space
+ * @size: size of the area
+ * @ptes: returns the PTEs for the address space
+ *
+ * Returns: NULL on failure, vm_struct on success
+ *
+ * This function reserves a range of kernel address space, and
+ * allocates pagetables to map that range. No actual mappings
+ * are created.
+ *
+ * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
+ * allocated for the VM area are returned.
+ */
+struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
+{
+ struct vm_struct *area;
+
+ area = get_vm_area_caller(size, VM_IOREMAP,
+ __builtin_return_address(0));
+ if (area == NULL)
+ return NULL;
+
+ /*
+ * This ensures that page tables are constructed for this region
+ * of kernel virtual address space and mapped into init_mm.
+ */
+ if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
+ size, f, ptes ? &ptes : NULL)) {
+ free_vm_area(area);
+ return NULL;
+ }
+
+ return area;
+}
+EXPORT_SYMBOL_GPL(alloc_vm_area);
+
+void free_vm_area(struct vm_struct *area)
+{
+ struct vm_struct *ret;
+ ret = remove_vm_area(area->addr);
+ BUG_ON(ret != area);
+ kfree(area);
+}
+EXPORT_SYMBOL_GPL(free_vm_area);
+
+#ifdef CONFIG_SMP
+static struct vmap_area *node_to_va(struct rb_node *n)
+{
+ return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
+}
+
+/**
+ * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
+ * @end: target address
+ * @pnext: out arg for the next vmap_area
+ * @pprev: out arg for the previous vmap_area
+ *
+ * Returns: %true if either or both of next and prev are found,
+ * %false if no vmap_area exists
+ *
+ * Find vmap_areas end addresses of which enclose @end. ie. if not
+ * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
+ */
+static bool pvm_find_next_prev(unsigned long end,
+ struct vmap_area **pnext,
+ struct vmap_area **pprev)
+{
+ struct rb_node *n = vmap_area_root.rb_node;
+ struct vmap_area *va = NULL;
+
+ while (n) {
+ va = rb_entry(n, struct vmap_area, rb_node);
+ if (end < va->va_end)
+ n = n->rb_left;
+ else if (end > va->va_end)
+ n = n->rb_right;
+ else
+ break;
+ }
+
+ if (!va)
+ return false;
+
+ if (va->va_end > end) {
+ *pnext = va;
+ *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
+ } else {
+ *pprev = va;
+ *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
+ }
+ return true;
+}
+
+/**
+ * pvm_determine_end - find the highest aligned address between two vmap_areas
+ * @pnext: in/out arg for the next vmap_area
+ * @pprev: in/out arg for the previous vmap_area
+ * @align: alignment
+ *
+ * Returns: determined end address
+ *
+ * Find the highest aligned address between *@pnext and *@pprev below
+ * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
+ * down address is between the end addresses of the two vmap_areas.
+ *
+ * Please note that the address returned by this function may fall
+ * inside *@pnext vmap_area. The caller is responsible for checking
+ * that.
+ */
+static unsigned long pvm_determine_end(struct vmap_area **pnext,
+ struct vmap_area **pprev,
+ unsigned long align)
+{
+ const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+ unsigned long addr;
+
+ if (*pnext)
+ addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
+ else
+ addr = vmalloc_end;
+
+ while (*pprev && (*pprev)->va_end > addr) {
+ *pnext = *pprev;
+ *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
+ }
+
+ return addr;
+}
+
+/**
+ * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
+ * @offsets: array containing offset of each area
+ * @sizes: array containing size of each area
+ * @nr_vms: the number of areas to allocate
+ * @align: alignment, all entries in @offsets and @sizes must be aligned to this
+ *
+ * Returns: kmalloc'd vm_struct pointer array pointing to allocated
+ * vm_structs on success, %NULL on failure
+ *
+ * Percpu allocator wants to use congruent vm areas so that it can
+ * maintain the offsets among percpu areas. This function allocates
+ * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
+ * be scattered pretty far, distance between two areas easily going up
+ * to gigabytes. To avoid interacting with regular vmallocs, these
+ * areas are allocated from top.
+ *
+ * Despite its complicated look, this allocator is rather simple. It
+ * does everything top-down and scans areas from the end looking for
+ * matching slot. While scanning, if any of the areas overlaps with
+ * existing vmap_area, the base address is pulled down to fit the
+ * area. Scanning is repeated till all the areas fit and then all
+ * necessary data structres are inserted and the result is returned.
+ */
+struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
+ const size_t *sizes, int nr_vms,
+ size_t align)
+{
+ const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
+ const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+ struct vmap_area **vas, *prev, *next;
+ struct vm_struct **vms;
+ int area, area2, last_area, term_area;
+ unsigned long base, start, end, last_end;
+ bool purged = false;
+
+ /* verify parameters and allocate data structures */
+ BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
+ for (last_area = 0, area = 0; area < nr_vms; area++) {
+ start = offsets[area];
+ end = start + sizes[area];
+
+ /* is everything aligned properly? */
+ BUG_ON(!IS_ALIGNED(offsets[area], align));
+ BUG_ON(!IS_ALIGNED(sizes[area], align));
+
+ /* detect the area with the highest address */
+ if (start > offsets[last_area])
+ last_area = area;
+
+ for (area2 = 0; area2 < nr_vms; area2++) {
+ unsigned long start2 = offsets[area2];
+ unsigned long end2 = start2 + sizes[area2];
+
+ if (area2 == area)
+ continue;
+
+ BUG_ON(start2 >= start && start2 < end);
+ BUG_ON(end2 <= end && end2 > start);
+ }
+ }
+ last_end = offsets[last_area] + sizes[last_area];
+
+ if (vmalloc_end - vmalloc_start < last_end) {
+ WARN_ON(true);
+ return NULL;
+ }
+
+ vms = kzalloc(sizeof(vms[0]) * nr_vms, GFP_KERNEL);
+ vas = kzalloc(sizeof(vas[0]) * nr_vms, GFP_KERNEL);
+ if (!vas || !vms)
+ goto err_free2;
+
+ for (area = 0; area < nr_vms; area++) {
+ vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
+ vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
+ if (!vas[area] || !vms[area])
+ goto err_free;
+ }
+retry:
+ spin_lock(&vmap_area_lock);
+
+ /* start scanning - we scan from the top, begin with the last area */
+ area = term_area = last_area;
+ start = offsets[area];
+ end = start + sizes[area];
+
+ if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
+ base = vmalloc_end - last_end;
+ goto found;
+ }
+ base = pvm_determine_end(&next, &prev, align) - end;
+
+ while (true) {
+ BUG_ON(next && next->va_end <= base + end);
+ BUG_ON(prev && prev->va_end > base + end);
+
+ /*
+ * base might have underflowed, add last_end before
+ * comparing.
+ */
+ if (base + last_end < vmalloc_start + last_end) {
+ spin_unlock(&vmap_area_lock);
+ if (!purged) {
+ purge_vmap_area_lazy();
+ purged = true;
+ goto retry;
+ }
+ goto err_free;
+ }
+
+ /*
+ * If next overlaps, move base downwards so that it's
+ * right below next and then recheck.
+ */
+ if (next && next->va_start < base + end) {
+ base = pvm_determine_end(&next, &prev, align) - end;
+ term_area = area;
+ continue;
+ }
+
+ /*
+ * If prev overlaps, shift down next and prev and move
+ * base so that it's right below new next and then
+ * recheck.
+ */
+ if (prev && prev->va_end > base + start) {
+ next = prev;
+ prev = node_to_va(rb_prev(&next->rb_node));
+ base = pvm_determine_end(&next, &prev, align) - end;
+ term_area = area;
+ continue;
+ }
+
+ /*
+ * This area fits, move on to the previous one. If
+ * the previous one is the terminal one, we're done.
+ */
+ area = (area + nr_vms - 1) % nr_vms;
+ if (area == term_area)
+ break;
+ start = offsets[area];
+ end = start + sizes[area];
+ pvm_find_next_prev(base + end, &next, &prev);
+ }
+found:
+ /* we've found a fitting base, insert all va's */
+ for (area = 0; area < nr_vms; area++) {
+ struct vmap_area *va = vas[area];
+
+ va->va_start = base + offsets[area];
+ va->va_end = va->va_start + sizes[area];
+ __insert_vmap_area(va);
+ }
+
+ vmap_area_pcpu_hole = base + offsets[last_area];
+
+ spin_unlock(&vmap_area_lock);
+
+ /* insert all vm's */
+ for (area = 0; area < nr_vms; area++)
+ insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
+ pcpu_get_vm_areas);
+
+ kfree(vas);
+ return vms;
+
+err_free:
+ for (area = 0; area < nr_vms; area++) {
+ kfree(vas[area]);
+ kfree(vms[area]);
+ }
+err_free2:
+ kfree(vas);
+ kfree(vms);
+ return NULL;
+}
+
+/**
+ * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
+ * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
+ * @nr_vms: the number of allocated areas
+ *
+ * Free vm_structs and the array allocated by pcpu_get_vm_areas().
+ */
+void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
+{
+ int i;
+
+ for (i = 0; i < nr_vms; i++)
+ free_vm_area(vms[i]);
+ kfree(vms);
+}
+#endif /* CONFIG_SMP */
+
+#ifdef CONFIG_PROC_FS
+static void *s_start(struct seq_file *m, loff_t *pos)
+ __acquires(&vmlist_lock)
+{
+ loff_t n = *pos;
+ struct vm_struct *v;
+
+ read_lock(&vmlist_lock);
+ v = vmlist;
+ while (n > 0 && v) {
+ n--;
+ v = v->next;
+ }
+ if (!n)
+ return v;
+
+ return NULL;
+
+}
+
+static void *s_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ struct vm_struct *v = p;
+
+ ++*pos;
+ return v->next;
+}
+
+static void s_stop(struct seq_file *m, void *p)
+ __releases(&vmlist_lock)
+{
+ read_unlock(&vmlist_lock);
+}
+
+static void show_numa_info(struct seq_file *m, struct vm_struct *v)
+{
+ if (NUMA_BUILD) {
+ unsigned int nr, *counters = m->private;
+
+ if (!counters)
+ return;
+
+ memset(counters, 0, nr_node_ids * sizeof(unsigned int));
+
+ for (nr = 0; nr < v->nr_pages; nr++)
+ counters[page_to_nid(v->pages[nr])]++;
+
+ for_each_node_state(nr, N_HIGH_MEMORY)
+ if (counters[nr])
+ seq_printf(m, " N%u=%u", nr, counters[nr]);
+ }
+}
+
+static int s_show(struct seq_file *m, void *p)
+{
+ struct vm_struct *v = p;
+
+ seq_printf(m, "0x%p-0x%p %7ld",
+ v->addr, v->addr + v->size, v->size);
+
+ if (v->caller)
+ seq_printf(m, " %pS", v->caller);
+
+ if (v->nr_pages)
+ seq_printf(m, " pages=%d", v->nr_pages);
+
+ if (v->phys_addr)
+ seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
+
+ if (v->flags & VM_IOREMAP)
+ seq_printf(m, " ioremap");
+
+ if (v->flags & VM_ALLOC)
+ seq_printf(m, " vmalloc");
+
+ if (v->flags & VM_MAP)
+ seq_printf(m, " vmap");
+
+ if (v->flags & VM_USERMAP)
+ seq_printf(m, " user");
+
+ if (v->flags & VM_VPAGES)
+ seq_printf(m, " vpages");
+
+ show_numa_info(m, v);
+ seq_putc(m, '\n');
+ return 0;
+}
+
+static const struct seq_operations vmalloc_op = {
+ .start = s_start,
+ .next = s_next,
+ .stop = s_stop,
+ .show = s_show,
+};
+
+static int vmalloc_open(struct inode *inode, struct file *file)
+{
+ unsigned int *ptr = NULL;
+ int ret;
+
+ if (NUMA_BUILD) {
+ ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
+ if (ptr == NULL)
+ return -ENOMEM;
+ }
+ ret = seq_open(file, &vmalloc_op);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = ptr;
+ } else
+ kfree(ptr);
+ return ret;
+}
+
+static const struct file_operations proc_vmalloc_operations = {
+ .open = vmalloc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+static int __init proc_vmalloc_init(void)
+{
+ if (IS_ENABLED(CONFIG_PROC_STRIPPED))
+ return 0;
+
+ proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
+ return 0;
+}
+module_init(proc_vmalloc_init);
+#endif
+
diff --git a/ap/os/linux/linux-3.4.x/mm/vmscan.c b/ap/os/linux/linux-3.4.x/mm/vmscan.c
new file mode 100644
index 0000000..5888e29
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/vmscan.c
@@ -0,0 +1,3745 @@
+/*
+ * linux/mm/vmscan.c
+ *
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * Swap reorganised 29.12.95, Stephen Tweedie.
+ * kswapd added: 7.1.96 sct
+ * Removed kswapd_ctl limits, and swap out as many pages as needed
+ * to bring the system back to freepages.high: 2.4.97, Rik van Riel.
+ * Zone aware kswapd started 02/00, Kanoj Sarcar (kanoj@sgi.com).
+ * Multiqueue VM started 5.8.00, Rik van Riel.
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/gfp.h>
+#include <linux/kernel_stat.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+#include <linux/highmem.h>
+#include <linux/vmstat.h>
+#include <linux/file.h>
+#include <linux/writeback.h>
+#include <linux/blkdev.h>
+#include <linux/buffer_head.h> /* for try_to_release_page(),
+ buffer_heads_over_limit */
+#include <linux/mm_inline.h>
+#include <linux/backing-dev.h>
+#include <linux/rmap.h>
+#include <linux/topology.h>
+#include <linux/cpu.h>
+#include <linux/cpuset.h>
+#include <linux/compaction.h>
+#include <linux/notifier.h>
+#include <linux/rwsem.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/freezer.h>
+#include <linux/memcontrol.h>
+#include <linux/delayacct.h>
+#include <linux/sysctl.h>
+#include <linux/oom.h>
+#include <linux/prefetch.h>
+#include <linux/debugfs.h>
+
+#include <asm/tlbflush.h>
+#include <asm/div64.h>
+
+#include <linux/swapops.h>
+
+#include "internal.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/vmscan.h>
+
+/*
+ * reclaim_mode determines how the inactive list is shrunk
+ * RECLAIM_MODE_SINGLE: Reclaim only order-0 pages
+ * RECLAIM_MODE_ASYNC: Do not block
+ * RECLAIM_MODE_SYNC: Allow blocking e.g. call wait_on_page_writeback
+ * RECLAIM_MODE_LUMPYRECLAIM: For high-order allocations, take a reference
+ * page from the LRU and reclaim all pages within a
+ * naturally aligned range
+ * RECLAIM_MODE_COMPACTION: For high-order allocations, reclaim a number of
+ * order-0 pages and then compact the zone
+ */
+typedef unsigned __bitwise__ reclaim_mode_t;
+#define RECLAIM_MODE_SINGLE ((__force reclaim_mode_t)0x01u)
+#define RECLAIM_MODE_ASYNC ((__force reclaim_mode_t)0x02u)
+#define RECLAIM_MODE_SYNC ((__force reclaim_mode_t)0x04u)
+#define RECLAIM_MODE_LUMPYRECLAIM ((__force reclaim_mode_t)0x08u)
+#define RECLAIM_MODE_COMPACTION ((__force reclaim_mode_t)0x10u)
+
+struct scan_control {
+ /* Incremented by the number of inactive pages that were scanned */
+ unsigned long nr_scanned;
+
+ /* Number of pages freed so far during a call to shrink_zones() */
+ unsigned long nr_reclaimed;
+
+ /* How many pages shrink_list() should reclaim */
+ unsigned long nr_to_reclaim;
+
+ unsigned long hibernation_mode;
+
+ /* This context's GFP mask */
+ gfp_t gfp_mask;
+
+ int may_writepage;
+
+ /* Can mapped pages be reclaimed? */
+ int may_unmap;
+
+ /* Can pages be swapped as part of reclaim? */
+ int may_swap;
+
+ int order;
+
+ /*
+ * Intend to reclaim enough continuous memory rather than reclaim
+ * enough amount of memory. i.e, mode for high order allocation.
+ */
+ reclaim_mode_t reclaim_mode;
+
+ /*
+ * The memory cgroup that hit its limit and as a result is the
+ * primary target of this reclaim invocation.
+ */
+ struct mem_cgroup *target_mem_cgroup;
+
+ /*
+ * Nodemask of nodes allowed by the caller. If NULL, all nodes
+ * are scanned.
+ */
+ nodemask_t *nodemask;
+};
+
+struct mem_cgroup_zone {
+ struct mem_cgroup *mem_cgroup;
+ struct zone *zone;
+};
+
+#define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
+
+#ifdef ARCH_HAS_PREFETCH
+#define prefetch_prev_lru_page(_page, _base, _field) \
+ do { \
+ if ((_page)->lru.prev != _base) { \
+ struct page *prev; \
+ \
+ prev = lru_to_page(&(_page->lru)); \
+ prefetch(&prev->_field); \
+ } \
+ } while (0)
+#else
+#define prefetch_prev_lru_page(_page, _base, _field) do { } while (0)
+#endif
+
+#ifdef ARCH_HAS_PREFETCHW
+#define prefetchw_prev_lru_page(_page, _base, _field) \
+ do { \
+ if ((_page)->lru.prev != _base) { \
+ struct page *prev; \
+ \
+ prev = lru_to_page(&(_page->lru)); \
+ prefetchw(&prev->_field); \
+ } \
+ } while (0)
+#else
+#define prefetchw_prev_lru_page(_page, _base, _field) do { } while (0)
+#endif
+
+/*
+ * From 0 .. 100. Higher means more swappy.
+ */
+int vm_swappiness = 60;
+long vm_total_pages; /* The total number of pages which the VM controls */
+
+static LIST_HEAD(shrinker_list);
+static DECLARE_RWSEM(shrinker_rwsem);
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+static bool global_reclaim(struct scan_control *sc)
+{
+ return !sc->target_mem_cgroup;
+}
+
+static bool scanning_global_lru(struct mem_cgroup_zone *mz)
+{
+ return !mz->mem_cgroup;
+}
+#else
+static bool global_reclaim(struct scan_control *sc)
+{
+ return true;
+}
+
+static bool scanning_global_lru(struct mem_cgroup_zone *mz)
+{
+ return true;
+}
+#endif
+
+static struct zone_reclaim_stat *get_reclaim_stat(struct mem_cgroup_zone *mz)
+{
+ if (!scanning_global_lru(mz))
+ return mem_cgroup_get_reclaim_stat(mz->mem_cgroup, mz->zone);
+
+ return &mz->zone->reclaim_stat;
+}
+
+static unsigned long zone_nr_lru_pages(struct mem_cgroup_zone *mz,
+ enum lru_list lru)
+{
+ if (!scanning_global_lru(mz))
+ return mem_cgroup_zone_nr_lru_pages(mz->mem_cgroup,
+ zone_to_nid(mz->zone),
+ zone_idx(mz->zone),
+ BIT(lru));
+
+ return zone_page_state(mz->zone, NR_LRU_BASE + lru);
+}
+
+struct dentry *debug_file;
+
+static int debug_shrinker_show(struct seq_file *s, void *unused)
+{
+ struct shrinker *shrinker;
+ struct shrink_control sc;
+
+ sc.gfp_mask = -1;
+ sc.nr_to_scan = 0;
+
+ down_read(&shrinker_rwsem);
+ list_for_each_entry(shrinker, &shrinker_list, list) {
+ char name[64];
+ int num_objs;
+
+ num_objs = shrinker->shrink(shrinker, &sc);
+ seq_printf(s, "%pf %d\n", shrinker->shrink, num_objs);
+ }
+ up_read(&shrinker_rwsem);
+ return 0;
+}
+
+static int debug_shrinker_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, debug_shrinker_show, inode->i_private);
+}
+
+static const struct file_operations debug_shrinker_fops = {
+ .open = debug_shrinker_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+/*
+ * Add a shrinker callback to be called from the vm
+ */
+void register_shrinker(struct shrinker *shrinker)
+{
+ atomic_long_set(&shrinker->nr_in_batch, 0);
+ down_write(&shrinker_rwsem);
+ list_add_tail(&shrinker->list, &shrinker_list);
+ up_write(&shrinker_rwsem);
+}
+EXPORT_SYMBOL(register_shrinker);
+
+static int __init add_shrinker_debug(void)
+{
+ debugfs_create_file("shrinker", 0644, NULL, NULL,
+ &debug_shrinker_fops);
+ return 0;
+}
+
+late_initcall(add_shrinker_debug);
+
+/*
+ * Remove one
+ */
+void unregister_shrinker(struct shrinker *shrinker)
+{
+ down_write(&shrinker_rwsem);
+ list_del(&shrinker->list);
+ up_write(&shrinker_rwsem);
+}
+EXPORT_SYMBOL(unregister_shrinker);
+
+static inline int do_shrinker_shrink(struct shrinker *shrinker,
+ struct shrink_control *sc,
+ unsigned long nr_to_scan)
+{
+ sc->nr_to_scan = nr_to_scan;
+ return (*shrinker->shrink)(shrinker, sc);
+}
+
+#define SHRINK_BATCH 128
+/*
+ * Call the shrink functions to age shrinkable caches
+ *
+ * Here we assume it costs one seek to replace a lru page and that it also
+ * takes a seek to recreate a cache object. With this in mind we age equal
+ * percentages of the lru and ageable caches. This should balance the seeks
+ * generated by these structures.
+ *
+ * If the vm encountered mapped pages on the LRU it increase the pressure on
+ * slab to avoid swapping.
+ *
+ * We do weird things to avoid (scanned*seeks*entries) overflowing 32 bits.
+ *
+ * `lru_pages' represents the number of on-LRU pages in all the zones which
+ * are eligible for the caller's allocation attempt. It is used for balancing
+ * slab reclaim versus page reclaim.
+ *
+ * Returns the number of slab objects which we shrunk.
+ */
+unsigned long shrink_slab(struct shrink_control *shrink,
+ unsigned long nr_pages_scanned,
+ unsigned long lru_pages)
+{
+ struct shrinker *shrinker;
+ unsigned long ret = 0;
+
+ if (nr_pages_scanned == 0)
+ nr_pages_scanned = SWAP_CLUSTER_MAX;
+
+ if (!down_read_trylock(&shrinker_rwsem)) {
+ /* Assume we'll be able to shrink next time */
+ ret = 1;
+ goto out;
+ }
+
+ list_for_each_entry(shrinker, &shrinker_list, list) {
+ unsigned long long delta;
+ long total_scan;
+ long max_pass;
+ int shrink_ret = 0;
+ long nr;
+ long new_nr;
+ long batch_size = shrinker->batch ? shrinker->batch
+ : SHRINK_BATCH;
+
+ max_pass = do_shrinker_shrink(shrinker, shrink, 0);
+ if (max_pass <= 0)
+ continue;
+
+ /*
+ * copy the current shrinker scan count into a local variable
+ * and zero it so that other concurrent shrinker invocations
+ * don't also do this scanning work.
+ */
+ nr = atomic_long_xchg(&shrinker->nr_in_batch, 0);
+
+ total_scan = nr;
+ delta = (4 * nr_pages_scanned) / shrinker->seeks;
+ delta *= max_pass;
+ do_div(delta, lru_pages + 1);
+ total_scan += delta;
+ if (total_scan < 0) {
+ printk(KERN_ERR "shrink_slab: %pF negative objects to "
+ "delete nr=%ld\n",
+ shrinker->shrink, total_scan);
+ total_scan = max_pass;
+ }
+
+ /*
+ * We need to avoid excessive windup on filesystem shrinkers
+ * due to large numbers of GFP_NOFS allocations causing the
+ * shrinkers to return -1 all the time. This results in a large
+ * nr being built up so when a shrink that can do some work
+ * comes along it empties the entire cache due to nr >>>
+ * max_pass. This is bad for sustaining a working set in
+ * memory.
+ *
+ * Hence only allow the shrinker to scan the entire cache when
+ * a large delta change is calculated directly.
+ */
+ if (delta < max_pass / 4)
+ total_scan = min(total_scan, max_pass / 2);
+
+ /*
+ * Avoid risking looping forever due to too large nr value:
+ * never try to free more than twice the estimate number of
+ * freeable entries.
+ */
+ if (total_scan > max_pass * 2)
+ total_scan = max_pass * 2;
+
+ trace_mm_shrink_slab_start(shrinker, shrink, nr,
+ nr_pages_scanned, lru_pages,
+ max_pass, delta, total_scan);
+
+ while (total_scan >= batch_size) {
+ int nr_before;
+
+ nr_before = do_shrinker_shrink(shrinker, shrink, 0);
+ shrink_ret = do_shrinker_shrink(shrinker, shrink,
+ batch_size);
+ if (shrink_ret == -1)
+ break;
+ if (shrink_ret < nr_before)
+ ret += nr_before - shrink_ret;
+ count_vm_events(SLABS_SCANNED, batch_size);
+ total_scan -= batch_size;
+
+ cond_resched();
+ }
+
+ /*
+ * move the unused scan count back into the shrinker in a
+ * manner that handles concurrent updates. If we exhausted the
+ * scan, there is no need to do an update.
+ */
+ if (total_scan > 0)
+ new_nr = atomic_long_add_return(total_scan,
+ &shrinker->nr_in_batch);
+ else
+ new_nr = atomic_long_read(&shrinker->nr_in_batch);
+
+ trace_mm_shrink_slab_end(shrinker, shrink_ret, nr, new_nr);
+ }
+ up_read(&shrinker_rwsem);
+out:
+ cond_resched();
+ return ret;
+}
+
+static void set_reclaim_mode(int priority, struct scan_control *sc,
+ bool sync)
+{
+ reclaim_mode_t syncmode = sync ? RECLAIM_MODE_SYNC : RECLAIM_MODE_ASYNC;
+
+ /*
+ * Initially assume we are entering either lumpy reclaim or
+ * reclaim/compaction.Depending on the order, we will either set the
+ * sync mode or just reclaim order-0 pages later.
+ */
+ if (COMPACTION_BUILD)
+ sc->reclaim_mode = RECLAIM_MODE_COMPACTION;
+ else
+ sc->reclaim_mode = RECLAIM_MODE_LUMPYRECLAIM;
+
+ /*
+ * Avoid using lumpy reclaim or reclaim/compaction if possible by
+ * restricting when its set to either costly allocations or when
+ * under memory pressure
+ */
+ if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
+ sc->reclaim_mode |= syncmode;
+ else if (sc->order && priority < DEF_PRIORITY - 2)
+ sc->reclaim_mode |= syncmode;
+ else
+ sc->reclaim_mode = RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC;
+}
+
+static void reset_reclaim_mode(struct scan_control *sc)
+{
+ sc->reclaim_mode = RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC;
+}
+
+static inline int is_page_cache_freeable(struct page *page)
+{
+ /*
+ * A freeable page cache page is referenced only by the caller
+ * that isolated the page, the page cache radix tree and
+ * optional buffer heads at page->private.
+ */
+ return page_count(page) - page_has_private(page) == 2;
+}
+
+static int may_write_to_queue(struct backing_dev_info *bdi,
+ struct scan_control *sc)
+{
+ if (current->flags & PF_SWAPWRITE)
+ return 1;
+ if (!bdi_write_congested(bdi))
+ return 1;
+ if (bdi == current->backing_dev_info)
+ return 1;
+
+ /* lumpy reclaim for hugepage often need a lot of write */
+ if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
+ return 1;
+ return 0;
+}
+
+/*
+ * We detected a synchronous write error writing a page out. Probably
+ * -ENOSPC. We need to propagate that into the address_space for a subsequent
+ * fsync(), msync() or close().
+ *
+ * The tricky part is that after writepage we cannot touch the mapping: nothing
+ * prevents it from being freed up. But we have a ref on the page and once
+ * that page is locked, the mapping is pinned.
+ *
+ * We're allowed to run sleeping lock_page() here because we know the caller has
+ * __GFP_FS.
+ */
+static void handle_write_error(struct address_space *mapping,
+ struct page *page, int error)
+{
+ lock_page(page);
+ if (page_mapping(page) == mapping)
+ mapping_set_error(mapping, error);
+ unlock_page(page);
+}
+
+/* possible outcome of pageout() */
+typedef enum {
+ /* failed to write page out, page is locked */
+ PAGE_KEEP,
+ /* move page to the active list, page is locked */
+ PAGE_ACTIVATE,
+ /* page has been sent to the disk successfully, page is unlocked */
+ PAGE_SUCCESS,
+ /* page is clean and locked */
+ PAGE_CLEAN,
+} pageout_t;
+
+/*
+ * pageout is called by shrink_page_list() for each dirty page.
+ * Calls ->writepage().
+ */
+static pageout_t pageout(struct page *page, struct address_space *mapping,
+ struct scan_control *sc)
+{
+ /*
+ * If the page is dirty, only perform writeback if that write
+ * will be non-blocking. To prevent this allocation from being
+ * stalled by pagecache activity. But note that there may be
+ * stalls if we need to run get_block(). We could test
+ * PagePrivate for that.
+ *
+ * If this process is currently in __generic_file_aio_write() against
+ * this page's queue, we can perform writeback even if that
+ * will block.
+ *
+ * If the page is swapcache, write it back even if that would
+ * block, for some throttling. This happens by accident, because
+ * swap_backing_dev_info is bust: it doesn't reflect the
+ * congestion state of the swapdevs. Easy to fix, if needed.
+ */
+ if (!is_page_cache_freeable(page))
+ return PAGE_KEEP;
+ if (!mapping) {
+ /*
+ * Some data journaling orphaned pages can have
+ * page->mapping == NULL while being dirty with clean buffers.
+ */
+ if (page_has_private(page)) {
+ if (try_to_free_buffers(page)) {
+ ClearPageDirty(page);
+ printk("%s: orphaned page\n", __func__);
+ return PAGE_CLEAN;
+ }
+ }
+ return PAGE_KEEP;
+ }
+ if (mapping->a_ops->writepage == NULL)
+ return PAGE_ACTIVATE;
+ if (!may_write_to_queue(mapping->backing_dev_info, sc))
+ return PAGE_KEEP;
+
+ if (clear_page_dirty_for_io(page)) {
+ int res;
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_NONE,
+ .nr_to_write = SWAP_CLUSTER_MAX,
+ .range_start = 0,
+ .range_end = LLONG_MAX,
+ .for_reclaim = 1,
+ };
+
+ SetPageReclaim(page);
+ res = mapping->a_ops->writepage(page, &wbc);
+ if (res < 0)
+ handle_write_error(mapping, page, res);
+ if (res == AOP_WRITEPAGE_ACTIVATE) {
+ ClearPageReclaim(page);
+ return PAGE_ACTIVATE;
+ }
+
+ if (!PageWriteback(page)) {
+ /* synchronous write or broken a_ops? */
+ ClearPageReclaim(page);
+ }
+ trace_mm_vmscan_writepage(page,
+ trace_reclaim_flags(page, sc->reclaim_mode));
+ inc_zone_page_state(page, NR_VMSCAN_WRITE);
+ return PAGE_SUCCESS;
+ }
+
+ return PAGE_CLEAN;
+}
+
+/*
+ * Same as remove_mapping, but if the page is removed from the mapping, it
+ * gets returned with a refcount of 0.
+ */
+static int __remove_mapping(struct address_space *mapping, struct page *page)
+{
+ BUG_ON(!PageLocked(page));
+ BUG_ON(mapping != page_mapping(page));
+
+ unsigned long flags;
+
+ spin_lock_irq(&mapping->tree_lock);
+ local_irq_save(flags);
+ /*
+ * The non racy check for a busy page.
+ *
+ * Must be careful with the order of the tests. When someone has
+ * a ref to the page, it may be possible that they dirty it then
+ * drop the reference. So if PageDirty is tested before page_count
+ * here, then the following race may occur:
+ *
+ * get_user_pages(&page);
+ * [user mapping goes away]
+ * write_to(page);
+ * !PageDirty(page) [good]
+ * SetPageDirty(page);
+ * put_page(page);
+ * !page_count(page) [good, discard it]
+ *
+ * [oops, our write_to data is lost]
+ *
+ * Reversing the order of the tests ensures such a situation cannot
+ * escape unnoticed. The smp_rmb is needed to ensure the page->flags
+ * load is not satisfied before that of page->_count.
+ *
+ * Note that if SetPageDirty is always performed via set_page_dirty,
+ * and thus under tree_lock, then this ordering is not required.
+ */
+ if (!page_freeze_refs(page, 2))
+ goto cannot_free;
+ /* note: atomic_cmpxchg in page_freeze_refs provides the smp_rmb */
+ if (unlikely(PageDirty(page))) {
+ page_unfreeze_refs(page, 2);
+ goto cannot_free;
+ }
+
+ if (PageSwapCache(page)) {
+ swp_entry_t swap = { .val = page_private(page) };
+ __delete_from_swap_cache(page);
+ local_irq_restore(flags);
+ spin_unlock_irq(&mapping->tree_lock);
+ swapcache_free(swap, page);
+ } else {
+ void (*freepage)(struct page *);
+
+ freepage = mapping->a_ops->freepage;
+
+ __delete_from_page_cache(page);
+ local_irq_restore(flags);
+ spin_unlock_irq(&mapping->tree_lock);
+ mem_cgroup_uncharge_cache_page(page);
+
+ if (freepage != NULL)
+ freepage(page);
+ }
+
+ return 1;
+
+cannot_free:
+ local_irq_restore(flags);
+ spin_unlock_irq(&mapping->tree_lock);
+ return 0;
+}
+
+/*
+ * Attempt to detach a locked page from its ->mapping. If it is dirty or if
+ * someone else has a ref on the page, abort and return 0. If it was
+ * successfully detached, return 1. Assumes the caller has a single ref on
+ * this page.
+ */
+int remove_mapping(struct address_space *mapping, struct page *page)
+{
+ if (__remove_mapping(mapping, page)) {
+ /*
+ * Unfreezing the refcount with 1 rather than 2 effectively
+ * drops the pagecache ref for us without requiring another
+ * atomic operation.
+ */
+ page_unfreeze_refs(page, 1);
+ return 1;
+ }
+ return 0;
+}
+
+/**
+ * putback_lru_page - put previously isolated page onto appropriate LRU list
+ * @page: page to be put back to appropriate lru list
+ *
+ * Add previously isolated @page to appropriate LRU list.
+ * Page may still be unevictable for other reasons.
+ *
+ * lru_lock must not be held, interrupts must be enabled.
+ */
+void putback_lru_page(struct page *page)
+{
+ int lru;
+ int active = !!TestClearPageActive(page);
+ int was_unevictable = PageUnevictable(page);
+
+ VM_BUG_ON(PageLRU(page));
+
+redo:
+ ClearPageUnevictable(page);
+
+ if (page_evictable(page, NULL)) {
+ /*
+ * For evictable pages, we can use the cache.
+ * In event of a race, worst case is we end up with an
+ * unevictable page on [in]active list.
+ * We know how to handle that.
+ */
+ lru = active + page_lru_base_type(page);
+ lru_cache_add_lru(page, lru);
+ } else {
+ /*
+ * Put unevictable pages directly on zone's unevictable
+ * list.
+ */
+ lru = LRU_UNEVICTABLE;
+ add_page_to_unevictable_list(page);
+ /*
+ * When racing with an mlock or AS_UNEVICTABLE clearing
+ * (page is unlocked) make sure that if the other thread
+ * does not observe our setting of PG_lru and fails
+ * isolation/check_move_unevictable_pages,
+ * we see PG_mlocked/AS_UNEVICTABLE cleared below and move
+ * the page back to the evictable list.
+ *
+ * The other side is TestClearPageMlocked() or shmem_lock().
+ */
+ smp_mb();
+ }
+
+ /*
+ * page's status can change while we move it among lru. If an evictable
+ * page is on unevictable list, it never be freed. To avoid that,
+ * check after we added it to the list, again.
+ */
+ if (lru == LRU_UNEVICTABLE && page_evictable(page, NULL)) {
+ if (!isolate_lru_page(page)) {
+ put_page(page);
+ goto redo;
+ }
+ /* This means someone else dropped this page from LRU
+ * So, it will be freed or putback to LRU again. There is
+ * nothing to do here.
+ */
+ }
+
+ if (was_unevictable && lru != LRU_UNEVICTABLE)
+ count_vm_event(UNEVICTABLE_PGRESCUED);
+ else if (!was_unevictable && lru == LRU_UNEVICTABLE)
+ count_vm_event(UNEVICTABLE_PGCULLED);
+
+ put_page(page); /* drop ref from isolate */
+}
+
+enum page_references {
+ PAGEREF_RECLAIM,
+ PAGEREF_RECLAIM_CLEAN,
+ PAGEREF_KEEP,
+ PAGEREF_ACTIVATE,
+};
+
+static enum page_references page_check_references(struct page *page,
+ struct mem_cgroup_zone *mz,
+ struct scan_control *sc)
+{
+ int referenced_ptes, referenced_page;
+ unsigned long vm_flags;
+
+ referenced_ptes = page_referenced(page, 1, mz->mem_cgroup, &vm_flags);
+ referenced_page = TestClearPageReferenced(page);
+
+ /* Lumpy reclaim - ignore references */
+ if (sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM)
+ return PAGEREF_RECLAIM;
+
+ /*
+ * Mlock lost the isolation race with us. Let try_to_unmap()
+ * move the page to the unevictable list.
+ */
+ if (vm_flags & VM_LOCKED)
+ return PAGEREF_RECLAIM;
+
+ if (referenced_ptes) {
+ if (PageSwapBacked(page))
+ return PAGEREF_ACTIVATE;
+ /*
+ * All mapped pages start out with page table
+ * references from the instantiating fault, so we need
+ * to look twice if a mapped file page is used more
+ * than once.
+ *
+ * Mark it and spare it for another trip around the
+ * inactive list. Another page table reference will
+ * lead to its activation.
+ *
+ * Note: the mark is set for activated pages as well
+ * so that recently deactivated but used pages are
+ * quickly recovered.
+ */
+ SetPageReferenced(page);
+
+ if (referenced_page || referenced_ptes > 1)
+ return PAGEREF_ACTIVATE;
+
+ /*
+ * Activate file-backed executable pages after first usage.
+ */
+ if (vm_flags & VM_EXEC)
+ return PAGEREF_ACTIVATE;
+
+ return PAGEREF_KEEP;
+ }
+
+ /* Reclaim if clean, defer dirty pages to writeback */
+ if (referenced_page && !PageSwapBacked(page))
+ return PAGEREF_RECLAIM_CLEAN;
+
+ return PAGEREF_RECLAIM;
+}
+
+/*
+ * shrink_page_list() returns the number of reclaimed pages
+ */
+static unsigned long shrink_page_list(struct list_head *page_list,
+ struct mem_cgroup_zone *mz,
+ struct scan_control *sc,
+ int priority,
+ unsigned long *ret_nr_dirty,
+ unsigned long *ret_nr_writeback)
+{
+ LIST_HEAD(ret_pages);
+ LIST_HEAD(free_pages);
+ int pgactivate = 0;
+ unsigned long nr_dirty = 0;
+ unsigned long nr_congested = 0;
+ unsigned long nr_reclaimed = 0;
+ unsigned long nr_writeback = 0;
+
+ cond_resched();
+
+ while (!list_empty(page_list)) {
+ enum page_references references;
+ struct address_space *mapping;
+ struct page *page;
+ int may_enter_fs;
+
+ cond_resched();
+
+ page = lru_to_page(page_list);
+ list_del(&page->lru);
+
+ if (!trylock_page(page))
+ goto keep;
+
+ VM_BUG_ON(PageActive(page));
+ VM_BUG_ON(page_zone(page) != mz->zone);
+
+ sc->nr_scanned++;
+
+ if (unlikely(!page_evictable(page, NULL)))
+ goto cull_mlocked;
+
+ if (!sc->may_unmap && page_mapped(page))
+ goto keep_locked;
+
+ /* Double the slab pressure for mapped and swapcache pages */
+ if (page_mapped(page) || PageSwapCache(page))
+ sc->nr_scanned++;
+
+ may_enter_fs = (sc->gfp_mask & __GFP_FS) ||
+ (PageSwapCache(page) && (sc->gfp_mask & __GFP_IO));
+
+ if (PageWriteback(page)) {
+ nr_writeback++;
+ /*
+ * Synchronous reclaim cannot queue pages for
+ * writeback due to the possibility of stack overflow
+ * but if it encounters a page under writeback, wait
+ * for the IO to complete.
+ */
+ if ((sc->reclaim_mode & RECLAIM_MODE_SYNC) &&
+ may_enter_fs)
+ wait_on_page_writeback(page);
+ else {
+ unlock_page(page);
+ goto keep_lumpy;
+ }
+ }
+
+ references = page_check_references(page, mz, sc);
+ switch (references) {
+ case PAGEREF_ACTIVATE:
+ goto activate_locked;
+ case PAGEREF_KEEP:
+ goto keep_locked;
+ case PAGEREF_RECLAIM:
+ case PAGEREF_RECLAIM_CLEAN:
+ ; /* try to reclaim the page below */
+ }
+
+ /*
+ * Anonymous process memory has backing store?
+ * Try to allocate it some swap space here.
+ */
+ if (PageAnon(page) && !PageSwapCache(page)) {
+ if (!(sc->gfp_mask & __GFP_IO))
+ goto keep_locked;
+ if (!add_to_swap(page))
+ goto activate_locked;
+ may_enter_fs = 1;
+ }
+
+ mapping = page_mapping(page);
+
+ /*
+ * The page is mapped into the page tables of one or more
+ * processes. Try to unmap it here.
+ */
+ if (page_mapped(page) && mapping) {
+ switch (try_to_unmap(page, TTU_UNMAP)) {
+ case SWAP_FAIL:
+ goto activate_locked;
+ case SWAP_AGAIN:
+ goto keep_locked;
+ case SWAP_MLOCK:
+ goto cull_mlocked;
+ case SWAP_SUCCESS:
+ ; /* try to free the page below */
+ }
+ }
+
+ if (PageDirty(page)) {
+ nr_dirty++;
+
+ /*
+ * Only kswapd can writeback filesystem pages to
+ * avoid risk of stack overflow but do not writeback
+ * unless under significant pressure.
+ */
+ if (page_is_file_cache(page) &&
+ (!current_is_kswapd() || priority >= DEF_PRIORITY - 2)) {
+ /*
+ * Immediately reclaim when written back.
+ * Similar in principal to deactivate_page()
+ * except we already have the page isolated
+ * and know it's dirty
+ */
+ inc_zone_page_state(page, NR_VMSCAN_IMMEDIATE);
+ SetPageReclaim(page);
+
+ goto keep_locked;
+ }
+
+ if (references == PAGEREF_RECLAIM_CLEAN)
+ goto keep_locked;
+ if (!may_enter_fs)
+ goto keep_locked;
+ if (!sc->may_writepage)
+ goto keep_locked;
+
+ /* Page is dirty, try to write it out here */
+ switch (pageout(page, mapping, sc)) {
+ case PAGE_KEEP:
+ nr_congested++;
+ goto keep_locked;
+ case PAGE_ACTIVATE:
+ goto activate_locked;
+ case PAGE_SUCCESS:
+ if (PageWriteback(page))
+ goto keep_lumpy;
+ if (PageDirty(page))
+ goto keep;
+
+ /*
+ * A synchronous write - probably a ramdisk. Go
+ * ahead and try to reclaim the page.
+ */
+ if (!trylock_page(page))
+ goto keep;
+ if (PageDirty(page) || PageWriteback(page))
+ goto keep_locked;
+ mapping = page_mapping(page);
+ case PAGE_CLEAN:
+ ; /* try to free the page below */
+ }
+ }
+
+ /*
+ * If the page has buffers, try to free the buffer mappings
+ * associated with this page. If we succeed we try to free
+ * the page as well.
+ *
+ * We do this even if the page is PageDirty().
+ * try_to_release_page() does not perform I/O, but it is
+ * possible for a page to have PageDirty set, but it is actually
+ * clean (all its buffers are clean). This happens if the
+ * buffers were written out directly, with submit_bh(). ext3
+ * will do this, as well as the blockdev mapping.
+ * try_to_release_page() will discover that cleanness and will
+ * drop the buffers and mark the page clean - it can be freed.
+ *
+ * Rarely, pages can have buffers and no ->mapping. These are
+ * the pages which were not successfully invalidated in
+ * truncate_complete_page(). We try to drop those buffers here
+ * and if that worked, and the page is no longer mapped into
+ * process address space (page_count == 1) it can be freed.
+ * Otherwise, leave the page on the LRU so it is swappable.
+ */
+ if (page_has_private(page)) {
+ if (!try_to_release_page(page, sc->gfp_mask))
+ goto activate_locked;
+ if (!mapping && page_count(page) == 1) {
+ unlock_page(page);
+ if (put_page_testzero(page))
+ goto free_it;
+ else {
+ /*
+ * rare race with speculative reference.
+ * the speculative reference will free
+ * this page shortly, so we may
+ * increment nr_reclaimed here (and
+ * leave it off the LRU).
+ */
+ nr_reclaimed++;
+ continue;
+ }
+ }
+ }
+
+ if (!mapping || !__remove_mapping(mapping, page))
+ goto keep_locked;
+
+ /*
+ * At this point, we have no other references and there is
+ * no way to pick any more up (removed from LRU, removed
+ * from pagecache). Can use non-atomic bitops now (and
+ * we obviously don't have to worry about waking up a process
+ * waiting on the page lock, because there are no references.
+ */
+ __clear_page_locked(page);
+free_it:
+ nr_reclaimed++;
+
+ /*
+ * Is there need to periodically free_page_list? It would
+ * appear not as the counts should be low
+ */
+ list_add(&page->lru, &free_pages);
+ continue;
+
+cull_mlocked:
+ if (PageSwapCache(page))
+ try_to_free_swap(page);
+ unlock_page(page);
+ putback_lru_page(page);
+ reset_reclaim_mode(sc);
+ continue;
+
+activate_locked:
+ /* Not a candidate for swapping, so reclaim swap space. */
+ if (PageSwapCache(page) && vm_swap_full())
+ try_to_free_swap(page);
+ VM_BUG_ON(PageActive(page));
+ SetPageActive(page);
+ pgactivate++;
+keep_locked:
+ unlock_page(page);
+keep:
+ reset_reclaim_mode(sc);
+keep_lumpy:
+ list_add(&page->lru, &ret_pages);
+ VM_BUG_ON(PageLRU(page) || PageUnevictable(page));
+ }
+
+ /*
+ * Tag a zone as congested if all the dirty pages encountered were
+ * backed by a congested BDI. In this case, reclaimers should just
+ * back off and wait for congestion to clear because further reclaim
+ * will encounter the same problem
+ */
+ if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc))
+ zone_set_flag(mz->zone, ZONE_CONGESTED);
+
+ free_hot_cold_page_list(&free_pages, 1);
+
+ list_splice(&ret_pages, page_list);
+ count_vm_events(PGACTIVATE, pgactivate);
+ *ret_nr_dirty += nr_dirty;
+ *ret_nr_writeback += nr_writeback;
+ return nr_reclaimed;
+}
+
+/*
+ * Attempt to remove the specified page from its LRU. Only take this page
+ * if it is of the appropriate PageActive status. Pages which are being
+ * freed elsewhere are also ignored.
+ *
+ * page: page to consider
+ * mode: one of the LRU isolation modes defined above
+ *
+ * returns 0 on success, -ve errno on failure.
+ */
+int __isolate_lru_page(struct page *page, isolate_mode_t mode, int file)
+{
+ bool all_lru_mode;
+ int ret = -EINVAL;
+
+ /* Only take pages on the LRU. */
+ if (!PageLRU(page))
+ return ret;
+
+ all_lru_mode = (mode & (ISOLATE_ACTIVE|ISOLATE_INACTIVE)) ==
+ (ISOLATE_ACTIVE|ISOLATE_INACTIVE);
+
+ /*
+ * When checking the active state, we need to be sure we are
+ * dealing with comparible boolean values. Take the logical not
+ * of each.
+ */
+ if (!all_lru_mode && !PageActive(page) != !(mode & ISOLATE_ACTIVE))
+ return ret;
+
+ if (!all_lru_mode && !!page_is_file_cache(page) != file)
+ return ret;
+
+ /*
+ * When this function is being called for lumpy reclaim, we
+ * initially look into all LRU pages, active, inactive and
+ * unevictable; only give shrink_page_list evictable pages.
+ */
+ if (PageUnevictable(page))
+ return ret;
+
+ ret = -EBUSY;
+
+ /*
+ * To minimise LRU disruption, the caller can indicate that it only
+ * wants to isolate pages it will be able to operate on without
+ * blocking - clean pages for the most part.
+ *
+ * ISOLATE_CLEAN means that only clean pages should be isolated. This
+ * is used by reclaim when it is cannot write to backing storage
+ *
+ * ISOLATE_ASYNC_MIGRATE is used to indicate that it only wants to pages
+ * that it is possible to migrate without blocking
+ */
+ if (mode & (ISOLATE_CLEAN|ISOLATE_ASYNC_MIGRATE)) {
+ /* All the caller can do on PageWriteback is block */
+ if (PageWriteback(page))
+ return ret;
+
+ if (PageDirty(page)) {
+ struct address_space *mapping;
+
+ /* ISOLATE_CLEAN means only clean pages */
+ if (mode & ISOLATE_CLEAN)
+ return ret;
+
+ /*
+ * Only pages without mappings or that have a
+ * ->migratepage callback are possible to migrate
+ * without blocking
+ */
+ mapping = page_mapping(page);
+ if (mapping && !mapping->a_ops->migratepage)
+ return ret;
+ }
+ }
+
+ if ((mode & ISOLATE_UNMAPPED) && page_mapped(page))
+ return ret;
+
+ if (likely(get_page_unless_zero(page))) {
+ /*
+ * Be careful not to clear PageLRU until after we're
+ * sure the page is not being freed elsewhere -- the
+ * page release code relies on it.
+ */
+ ClearPageLRU(page);
+ ret = 0;
+ }
+
+ return ret;
+}
+
+/*
+ * zone->lru_lock is heavily contended. Some of the functions that
+ * shrink the lists perform better by taking out a batch of pages
+ * and working on them outside the LRU lock.
+ *
+ * For pagecache intensive workloads, this function is the hottest
+ * spot in the kernel (apart from copy_*_user functions).
+ *
+ * Appropriate locks must be held before calling this function.
+ *
+ * @nr_to_scan: The number of pages to look through on the list.
+ * @mz: The mem_cgroup_zone to pull pages from.
+ * @dst: The temp list to put pages on to.
+ * @nr_scanned: The number of pages that were scanned.
+ * @sc: The scan_control struct for this reclaim session
+ * @mode: One of the LRU isolation modes
+ * @active: True [1] if isolating active pages
+ * @file: True [1] if isolating file [!anon] pages
+ *
+ * returns how many pages were moved onto *@dst.
+ */
+static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
+ struct mem_cgroup_zone *mz, struct list_head *dst,
+ unsigned long *nr_scanned, struct scan_control *sc,
+ isolate_mode_t mode, int active, int file)
+{
+ struct lruvec *lruvec;
+ struct list_head *src;
+ unsigned long nr_taken = 0;
+ unsigned long nr_lumpy_taken = 0;
+ unsigned long nr_lumpy_dirty = 0;
+ unsigned long nr_lumpy_failed = 0;
+ unsigned long scan;
+ int lru = LRU_BASE;
+
+ lruvec = mem_cgroup_zone_lruvec(mz->zone, mz->mem_cgroup);
+ if (active)
+ lru += LRU_ACTIVE;
+ if (file)
+ lru += LRU_FILE;
+ src = &lruvec->lists[lru];
+
+ for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {
+ struct page *page;
+ unsigned long pfn;
+ unsigned long end_pfn;
+ unsigned long page_pfn;
+ int zone_id;
+
+ page = lru_to_page(src);
+ prefetchw_prev_lru_page(page, src, flags);
+
+ VM_BUG_ON(!PageLRU(page));
+
+ switch (__isolate_lru_page(page, mode, file)) {
+ case 0:
+ mem_cgroup_lru_del(page);
+ list_move(&page->lru, dst);
+ nr_taken += hpage_nr_pages(page);
+ break;
+
+ case -EBUSY:
+ /* else it is being freed elsewhere */
+ list_move(&page->lru, src);
+ continue;
+
+ default:
+ BUG();
+ }
+
+ if (!sc->order || !(sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM))
+ continue;
+
+ /*
+ * Attempt to take all pages in the order aligned region
+ * surrounding the tag page. Only take those pages of
+ * the same active state as that tag page. We may safely
+ * round the target page pfn down to the requested order
+ * as the mem_map is guaranteed valid out to MAX_ORDER,
+ * where that page is in a different zone we will detect
+ * it from its zone id and abort this block scan.
+ */
+ zone_id = page_zone_id(page);
+ page_pfn = page_to_pfn(page);
+ pfn = page_pfn & ~((1 << sc->order) - 1);
+ end_pfn = pfn + (1 << sc->order);
+ for (; pfn < end_pfn; pfn++) {
+ struct page *cursor_page;
+
+ /* The target page is in the block, ignore it. */
+ if (unlikely(pfn == page_pfn))
+ continue;
+
+ /* Avoid holes within the zone. */
+ if (unlikely(!pfn_valid_within(pfn)))
+ break;
+
+ cursor_page = pfn_to_page(pfn);
+
+ /* Check that we have not crossed a zone boundary. */
+ if (unlikely(page_zone_id(cursor_page) != zone_id))
+ break;
+
+ /*
+ * If we don't have enough swap space, reclaiming of
+ * anon page which don't already have a swap slot is
+ * pointless.
+ */
+ if (nr_swap_pages <= 0 && PageSwapBacked(cursor_page) &&
+ !PageSwapCache(cursor_page))
+ break;
+
+ if (__isolate_lru_page(cursor_page, mode, file) == 0) {
+ unsigned int isolated_pages;
+
+ mem_cgroup_lru_del(cursor_page);
+ list_move(&cursor_page->lru, dst);
+ isolated_pages = hpage_nr_pages(cursor_page);
+ nr_taken += isolated_pages;
+ nr_lumpy_taken += isolated_pages;
+ if (PageDirty(cursor_page))
+ nr_lumpy_dirty += isolated_pages;
+ scan++;
+ pfn += isolated_pages - 1;
+ } else {
+ /*
+ * Check if the page is freed already.
+ *
+ * We can't use page_count() as that
+ * requires compound_head and we don't
+ * have a pin on the page here. If a
+ * page is tail, we may or may not
+ * have isolated the head, so assume
+ * it's not free, it'd be tricky to
+ * track the head status without a
+ * page pin.
+ */
+ if (!PageTail(cursor_page) &&
+ !atomic_read(&cursor_page->_count))
+ continue;
+ break;
+ }
+ }
+
+ /* If we break out of the loop above, lumpy reclaim failed */
+ if (pfn < end_pfn)
+ nr_lumpy_failed++;
+ }
+
+ *nr_scanned = scan;
+
+ trace_mm_vmscan_lru_isolate(sc->order,
+ nr_to_scan, scan,
+ nr_taken,
+ nr_lumpy_taken, nr_lumpy_dirty, nr_lumpy_failed,
+ mode, file);
+ return nr_taken;
+}
+
+/**
+ * isolate_lru_page - tries to isolate a page from its LRU list
+ * @page: page to isolate from its LRU list
+ *
+ * Isolates a @page from an LRU list, clears PageLRU and adjusts the
+ * vmstat statistic corresponding to whatever LRU list the page was on.
+ *
+ * Returns 0 if the page was removed from an LRU list.
+ * Returns -EBUSY if the page was not on an LRU list.
+ *
+ * The returned page will have PageLRU() cleared. If it was found on
+ * the active list, it will have PageActive set. If it was found on
+ * the unevictable list, it will have the PageUnevictable bit set. That flag
+ * may need to be cleared by the caller before letting the page go.
+ *
+ * The vmstat statistic corresponding to the list on which the page was
+ * found will be decremented.
+ *
+ * Restrictions:
+ * (1) Must be called with an elevated refcount on the page. This is a
+ * fundamentnal difference from isolate_lru_pages (which is called
+ * without a stable reference).
+ * (2) the lru_lock must not be held.
+ * (3) interrupts must be enabled.
+ */
+int isolate_lru_page(struct page *page)
+{
+ int ret = -EBUSY;
+
+ VM_BUG_ON(!page_count(page));
+
+ if (PageLRU(page)) {
+ struct zone *zone = page_zone(page);
+
+ spin_lock_irq(&zone->lru_lock);
+ if (PageLRU(page)) {
+ int lru = page_lru(page);
+ ret = 0;
+ get_page(page);
+ ClearPageLRU(page);
+
+ del_page_from_lru_list(zone, page, lru);
+ }
+ spin_unlock_irq(&zone->lru_lock);
+ }
+ return ret;
+}
+
+/*
+ * Are there way too many processes in the direct reclaim path already?
+ */
+static int too_many_isolated(struct zone *zone, int file,
+ struct scan_control *sc)
+{
+ unsigned long inactive, isolated;
+
+ if (current_is_kswapd())
+ return 0;
+
+ if (!global_reclaim(sc))
+ return 0;
+
+ if (file) {
+ inactive = zone_page_state(zone, NR_INACTIVE_FILE);
+ isolated = zone_page_state(zone, NR_ISOLATED_FILE);
+ } else {
+ inactive = zone_page_state(zone, NR_INACTIVE_ANON);
+ isolated = zone_page_state(zone, NR_ISOLATED_ANON);
+ }
+
+ return isolated > inactive;
+}
+
+static noinline_for_stack void
+putback_inactive_pages(struct mem_cgroup_zone *mz,
+ struct list_head *page_list)
+{
+ struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
+ struct zone *zone = mz->zone;
+ LIST_HEAD(pages_to_free);
+
+ /*
+ * Put back any unfreeable pages.
+ */
+ while (!list_empty(page_list)) {
+ struct page *page = lru_to_page(page_list);
+ int lru;
+
+ VM_BUG_ON(PageLRU(page));
+ list_del(&page->lru);
+ if (unlikely(!page_evictable(page, NULL))) {
+ spin_unlock_irq(&zone->lru_lock);
+ putback_lru_page(page);
+ spin_lock_irq(&zone->lru_lock);
+ continue;
+ }
+ SetPageLRU(page);
+ lru = page_lru(page);
+ add_page_to_lru_list(zone, page, lru);
+ if (is_active_lru(lru)) {
+ int file = is_file_lru(lru);
+ int numpages = hpage_nr_pages(page);
+ reclaim_stat->recent_rotated[file] += numpages;
+ }
+ if (put_page_testzero(page)) {
+ __ClearPageLRU(page);
+ __ClearPageActive(page);
+ del_page_from_lru_list(zone, page, lru);
+
+ if (unlikely(PageCompound(page))) {
+ spin_unlock_irq(&zone->lru_lock);
+ (*get_compound_page_dtor(page))(page);
+ spin_lock_irq(&zone->lru_lock);
+ } else
+ list_add(&page->lru, &pages_to_free);
+ }
+ }
+
+ /*
+ * To save our caller's stack, now use input list for pages to free.
+ */
+ list_splice(&pages_to_free, page_list);
+}
+
+static noinline_for_stack void
+update_isolated_counts(struct mem_cgroup_zone *mz,
+ struct list_head *page_list,
+ unsigned long *nr_anon,
+ unsigned long *nr_file)
+{
+ struct zone *zone = mz->zone;
+ unsigned int count[NR_LRU_LISTS] = { 0, };
+ unsigned long nr_active = 0;
+ struct page *page;
+ int lru;
+
+ /*
+ * Count pages and clear active flags
+ */
+ list_for_each_entry(page, page_list, lru) {
+ int numpages = hpage_nr_pages(page);
+ lru = page_lru_base_type(page);
+ if (PageActive(page)) {
+ lru += LRU_ACTIVE;
+ ClearPageActive(page);
+ nr_active += numpages;
+ }
+ count[lru] += numpages;
+ }
+
+ preempt_disable();
+ __count_vm_events(PGDEACTIVATE, nr_active);
+
+ __mod_zone_page_state(zone, NR_ACTIVE_FILE,
+ -count[LRU_ACTIVE_FILE]);
+ __mod_zone_page_state(zone, NR_INACTIVE_FILE,
+ -count[LRU_INACTIVE_FILE]);
+ __mod_zone_page_state(zone, NR_ACTIVE_ANON,
+ -count[LRU_ACTIVE_ANON]);
+ __mod_zone_page_state(zone, NR_INACTIVE_ANON,
+ -count[LRU_INACTIVE_ANON]);
+
+ *nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON];
+ *nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE];
+
+ __mod_zone_page_state(zone, NR_ISOLATED_ANON, *nr_anon);
+ __mod_zone_page_state(zone, NR_ISOLATED_FILE, *nr_file);
+ preempt_enable();
+}
+
+/*
+ * Returns true if a direct reclaim should wait on pages under writeback.
+ *
+ * If we are direct reclaiming for contiguous pages and we do not reclaim
+ * everything in the list, try again and wait for writeback IO to complete.
+ * This will stall high-order allocations noticeably. Only do that when really
+ * need to free the pages under high memory pressure.
+ */
+static inline bool should_reclaim_stall(unsigned long nr_taken,
+ unsigned long nr_freed,
+ int priority,
+ struct scan_control *sc)
+{
+ int lumpy_stall_priority;
+
+ /* kswapd should not stall on sync IO */
+ if (current_is_kswapd())
+ return false;
+
+ /* Only stall on lumpy reclaim */
+ if (sc->reclaim_mode & RECLAIM_MODE_SINGLE)
+ return false;
+
+ /* If we have reclaimed everything on the isolated list, no stall */
+ if (nr_freed == nr_taken)
+ return false;
+
+ /*
+ * For high-order allocations, there are two stall thresholds.
+ * High-cost allocations stall immediately where as lower
+ * order allocations such as stacks require the scanning
+ * priority to be much higher before stalling.
+ */
+ if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
+ lumpy_stall_priority = DEF_PRIORITY;
+ else
+ lumpy_stall_priority = DEF_PRIORITY / 3;
+
+ return priority <= lumpy_stall_priority;
+}
+
+/*
+ * shrink_inactive_list() is a helper for shrink_zone(). It returns the number
+ * of reclaimed pages
+ */
+static noinline_for_stack unsigned long
+shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
+ struct scan_control *sc, int priority, int file)
+{
+ LIST_HEAD(page_list);
+ unsigned long nr_scanned;
+ unsigned long nr_reclaimed = 0;
+ unsigned long nr_taken;
+ unsigned long nr_anon;
+ unsigned long nr_file;
+ unsigned long nr_dirty = 0;
+ unsigned long nr_writeback = 0;
+ isolate_mode_t isolate_mode = ISOLATE_INACTIVE;
+ struct zone *zone = mz->zone;
+ struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
+
+ while (unlikely(too_many_isolated(zone, file, sc))) {
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+
+ /* We are about to die and free our memory. Return now. */
+ if (fatal_signal_pending(current))
+ return SWAP_CLUSTER_MAX;
+ }
+
+ set_reclaim_mode(priority, sc, false);
+ if (sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM)
+ isolate_mode |= ISOLATE_ACTIVE;
+
+ lru_add_drain();
+
+ if (!sc->may_unmap)
+ isolate_mode |= ISOLATE_UNMAPPED;
+ if (!sc->may_writepage)
+ isolate_mode |= ISOLATE_CLEAN;
+
+ spin_lock_irq(&zone->lru_lock);
+
+ nr_taken = isolate_lru_pages(nr_to_scan, mz, &page_list, &nr_scanned,
+ sc, isolate_mode, 0, file);
+ if (global_reclaim(sc)) {
+ zone->pages_scanned += nr_scanned;
+ if (current_is_kswapd())
+ __count_zone_vm_events(PGSCAN_KSWAPD, zone,
+ nr_scanned);
+ else
+ __count_zone_vm_events(PGSCAN_DIRECT, zone,
+ nr_scanned);
+ }
+ spin_unlock_irq(&zone->lru_lock);
+
+ if (nr_taken == 0)
+ return 0;
+
+ update_isolated_counts(mz, &page_list, &nr_anon, &nr_file);
+
+ nr_reclaimed = shrink_page_list(&page_list, mz, sc, priority,
+ &nr_dirty, &nr_writeback);
+
+ /* Check if we should syncronously wait for writeback */
+ if (should_reclaim_stall(nr_taken, nr_reclaimed, priority, sc)) {
+ set_reclaim_mode(priority, sc, true);
+ nr_reclaimed += shrink_page_list(&page_list, mz, sc,
+ priority, &nr_dirty, &nr_writeback);
+ }
+
+ spin_lock_irq(&zone->lru_lock);
+
+ reclaim_stat->recent_scanned[0] += nr_anon;
+ reclaim_stat->recent_scanned[1] += nr_file;
+
+ if (global_reclaim(sc)) {
+ if (current_is_kswapd())
+ __count_zone_vm_events(PGSTEAL_KSWAPD, zone,
+ nr_reclaimed);
+ else
+ __count_zone_vm_events(PGSTEAL_DIRECT, zone,
+ nr_reclaimed);
+ }
+
+ putback_inactive_pages(mz, &page_list);
+
+ __mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon);
+ __mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file);
+
+ spin_unlock_irq(&zone->lru_lock);
+
+ free_hot_cold_page_list(&page_list, 1);
+
+ /*
+ * If reclaim is isolating dirty pages under writeback, it implies
+ * that the long-lived page allocation rate is exceeding the page
+ * laundering rate. Either the global limits are not being effective
+ * at throttling processes due to the page distribution throughout
+ * zones or there is heavy usage of a slow backing device. The
+ * only option is to throttle from reclaim context which is not ideal
+ * as there is no guarantee the dirtying process is throttled in the
+ * same way balance_dirty_pages() manages.
+ *
+ * This scales the number of dirty pages that must be under writeback
+ * before throttling depending on priority. It is a simple backoff
+ * function that has the most effect in the range DEF_PRIORITY to
+ * DEF_PRIORITY-2 which is the priority reclaim is considered to be
+ * in trouble and reclaim is considered to be in trouble.
+ *
+ * DEF_PRIORITY 100% isolated pages must be PageWriteback to throttle
+ * DEF_PRIORITY-1 50% must be PageWriteback
+ * DEF_PRIORITY-2 25% must be PageWriteback, kswapd in trouble
+ * ...
+ * DEF_PRIORITY-6 For SWAP_CLUSTER_MAX isolated pages, throttle if any
+ * isolated page is PageWriteback
+ */
+ if (nr_writeback && nr_writeback >= (nr_taken >> (DEF_PRIORITY-priority)))
+ wait_iff_congested(zone, BLK_RW_ASYNC, HZ/10);
+
+ trace_mm_vmscan_lru_shrink_inactive(zone->zone_pgdat->node_id,
+ zone_idx(zone),
+ nr_scanned, nr_reclaimed,
+ priority,
+ trace_shrink_flags(file, sc->reclaim_mode));
+ return nr_reclaimed;
+}
+
+/*
+ * This moves pages from the active list to the inactive list.
+ *
+ * We move them the other way if the page is referenced by one or more
+ * processes, from rmap.
+ *
+ * If the pages are mostly unmapped, the processing is fast and it is
+ * appropriate to hold zone->lru_lock across the whole operation. But if
+ * the pages are mapped, the processing is slow (page_referenced()) so we
+ * should drop zone->lru_lock around each page. It's impossible to balance
+ * this, so instead we remove the pages from the LRU while processing them.
+ * It is safe to rely on PG_active against the non-LRU pages in here because
+ * nobody will play with that bit on a non-LRU page.
+ *
+ * The downside is that we have to touch page->_count against each page.
+ * But we had to alter page->flags anyway.
+ */
+
+static void move_active_pages_to_lru(struct zone *zone,
+ struct list_head *list,
+ struct list_head *pages_to_free,
+ enum lru_list lru)
+{
+ unsigned long pgmoved = 0;
+ struct page *page;
+
+ while (!list_empty(list)) {
+ struct lruvec *lruvec;
+
+ page = lru_to_page(list);
+
+ VM_BUG_ON(PageLRU(page));
+ SetPageLRU(page);
+
+ lruvec = mem_cgroup_lru_add_list(zone, page, lru);
+ list_move(&page->lru, &lruvec->lists[lru]);
+ pgmoved += hpage_nr_pages(page);
+
+ if (put_page_testzero(page)) {
+ __ClearPageLRU(page);
+ __ClearPageActive(page);
+ del_page_from_lru_list(zone, page, lru);
+
+ if (unlikely(PageCompound(page))) {
+ spin_unlock_irq(&zone->lru_lock);
+ (*get_compound_page_dtor(page))(page);
+ spin_lock_irq(&zone->lru_lock);
+ } else
+ list_add(&page->lru, pages_to_free);
+ }
+ }
+ __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
+ if (!is_active_lru(lru))
+ __count_vm_events(PGDEACTIVATE, pgmoved);
+}
+
+static void shrink_active_list(unsigned long nr_to_scan,
+ struct mem_cgroup_zone *mz,
+ struct scan_control *sc,
+ int priority, int file)
+{
+ unsigned long nr_taken;
+ unsigned long nr_scanned;
+ unsigned long vm_flags;
+ LIST_HEAD(l_hold); /* The pages which were snipped off */
+ LIST_HEAD(l_active);
+ LIST_HEAD(l_inactive);
+ struct page *page;
+ struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
+ unsigned long nr_rotated = 0;
+ isolate_mode_t isolate_mode = ISOLATE_ACTIVE;
+ struct zone *zone = mz->zone;
+
+ lru_add_drain();
+
+ reset_reclaim_mode(sc);
+
+ if (!sc->may_unmap)
+ isolate_mode |= ISOLATE_UNMAPPED;
+ if (!sc->may_writepage)
+ isolate_mode |= ISOLATE_CLEAN;
+
+ spin_lock_irq(&zone->lru_lock);
+
+ nr_taken = isolate_lru_pages(nr_to_scan, mz, &l_hold, &nr_scanned, sc,
+ isolate_mode, 1, file);
+ if (global_reclaim(sc))
+ zone->pages_scanned += nr_scanned;
+
+ reclaim_stat->recent_scanned[file] += nr_taken;
+
+ __count_zone_vm_events(PGREFILL, zone, nr_scanned);
+ if (file)
+ __mod_zone_page_state(zone, NR_ACTIVE_FILE, -nr_taken);
+ else
+ __mod_zone_page_state(zone, NR_ACTIVE_ANON, -nr_taken);
+ __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, nr_taken);
+ spin_unlock_irq(&zone->lru_lock);
+
+ while (!list_empty(&l_hold)) {
+ cond_resched();
+ page = lru_to_page(&l_hold);
+ list_del(&page->lru);
+
+ if (unlikely(!page_evictable(page, NULL))) {
+ putback_lru_page(page);
+ continue;
+ }
+
+ if (unlikely(buffer_heads_over_limit)) {
+ if (page_has_private(page) && trylock_page(page)) {
+ if (page_has_private(page))
+ try_to_release_page(page, 0);
+ unlock_page(page);
+ }
+ }
+
+ if (page_referenced(page, 0, mz->mem_cgroup, &vm_flags)) {
+ nr_rotated += hpage_nr_pages(page);
+ /*
+ * Identify referenced, file-backed active pages and
+ * give them one more trip around the active list. So
+ * that executable code get better chances to stay in
+ * memory under moderate memory pressure. Anon pages
+ * are not likely to be evicted by use-once streaming
+ * IO, plus JVM can create lots of anon VM_EXEC pages,
+ * so we ignore them here.
+ */
+ if ((vm_flags & VM_EXEC) && page_is_file_cache(page)) {
+ list_add(&page->lru, &l_active);
+ continue;
+ }
+ }
+
+ ClearPageActive(page); /* we are de-activating */
+ list_add(&page->lru, &l_inactive);
+ }
+
+ /*
+ * Move pages back to the lru list.
+ */
+ spin_lock_irq(&zone->lru_lock);
+ /*
+ * Count referenced pages from currently used mappings as rotated,
+ * even though only some of them are actually re-activated. This
+ * helps balance scan pressure between file and anonymous pages in
+ * get_scan_ratio.
+ */
+ reclaim_stat->recent_rotated[file] += nr_rotated;
+
+ move_active_pages_to_lru(zone, &l_active, &l_hold,
+ LRU_ACTIVE + file * LRU_FILE);
+ move_active_pages_to_lru(zone, &l_inactive, &l_hold,
+ LRU_BASE + file * LRU_FILE);
+ __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, -nr_taken);
+ spin_unlock_irq(&zone->lru_lock);
+
+ free_hot_cold_page_list(&l_hold, 1);
+}
+
+#ifdef CONFIG_SWAP
+static int inactive_anon_is_low_global(struct zone *zone)
+{
+ unsigned long active, inactive;
+
+ active = zone_page_state(zone, NR_ACTIVE_ANON);
+ inactive = zone_page_state(zone, NR_INACTIVE_ANON);
+
+ if (inactive * zone->inactive_ratio < active)
+ return 1;
+
+ return 0;
+}
+
+/**
+ * inactive_anon_is_low - check if anonymous pages need to be deactivated
+ * @zone: zone to check
+ * @sc: scan control of this context
+ *
+ * Returns true if the zone does not have enough inactive anon pages,
+ * meaning some active anon pages need to be deactivated.
+ */
+static int inactive_anon_is_low(struct mem_cgroup_zone *mz)
+{
+ /*
+ * If we don't have swap space, anonymous page deactivation
+ * is pointless.
+ */
+ if (!total_swap_pages)
+ return 0;
+
+ if (!scanning_global_lru(mz))
+ return mem_cgroup_inactive_anon_is_low(mz->mem_cgroup,
+ mz->zone);
+
+ return inactive_anon_is_low_global(mz->zone);
+}
+#else
+static inline int inactive_anon_is_low(struct mem_cgroup_zone *mz)
+{
+ return 0;
+}
+#endif
+
+static int inactive_file_is_low_global(struct zone *zone)
+{
+ unsigned long active, inactive;
+
+ active = zone_page_state(zone, NR_ACTIVE_FILE);
+ inactive = zone_page_state(zone, NR_INACTIVE_FILE);
+
+ return (active > inactive);
+}
+
+/**
+ * inactive_file_is_low - check if file pages need to be deactivated
+ * @mz: memory cgroup and zone to check
+ *
+ * When the system is doing streaming IO, memory pressure here
+ * ensures that active file pages get deactivated, until more
+ * than half of the file pages are on the inactive list.
+ *
+ * Once we get to that situation, protect the system's working
+ * set from being evicted by disabling active file page aging.
+ *
+ * This uses a different ratio than the anonymous pages, because
+ * the page cache uses a use-once replacement algorithm.
+ */
+static int inactive_file_is_low(struct mem_cgroup_zone *mz)
+{
+ if (!scanning_global_lru(mz))
+ return mem_cgroup_inactive_file_is_low(mz->mem_cgroup,
+ mz->zone);
+
+ return inactive_file_is_low_global(mz->zone);
+}
+
+static int inactive_list_is_low(struct mem_cgroup_zone *mz, int file)
+{
+ if (file)
+ return inactive_file_is_low(mz);
+ else
+ return inactive_anon_is_low(mz);
+}
+
+static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
+ struct mem_cgroup_zone *mz,
+ struct scan_control *sc, int priority)
+{
+ int file = is_file_lru(lru);
+
+ if (is_active_lru(lru)) {
+ if (inactive_list_is_low(mz, file))
+ shrink_active_list(nr_to_scan, mz, sc, priority, file);
+ return 0;
+ }
+
+ return shrink_inactive_list(nr_to_scan, mz, sc, priority, file);
+}
+
+static int vmscan_swappiness(struct mem_cgroup_zone *mz,
+ struct scan_control *sc)
+{
+ if (global_reclaim(sc))
+ return vm_swappiness;
+ return mem_cgroup_swappiness(mz->mem_cgroup);
+}
+
+/*
+ * Determine how aggressively the anon and file LRU lists should be
+ * scanned. The relative value of each set of LRU lists is determined
+ * by looking at the fraction of the pages scanned we did rotate back
+ * onto the active list instead of evict.
+ *
+ * nr[0] = anon pages to scan; nr[1] = file pages to scan
+ */
+static void get_scan_count(struct mem_cgroup_zone *mz, struct scan_control *sc,
+ unsigned long *nr, int priority)
+{
+ unsigned long anon, file, free;
+ unsigned long anon_prio, file_prio;
+ unsigned long ap, fp;
+ struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
+ u64 fraction[2], denominator;
+ enum lru_list lru;
+ int noswap = 0;
+ bool force_scan = false;
+
+ /*
+ * If the zone or memcg is small, nr[l] can be 0. This
+ * results in no scanning on this priority and a potential
+ * priority drop. Global direct reclaim can go to the next
+ * zone and tends to have no problems. Global kswapd is for
+ * zone balancing and it needs to scan a minimum amount. When
+ * reclaiming for a memcg, a priority drop can cause high
+ * latencies, so it's better to scan a minimum amount there as
+ * well.
+ */
+ if (current_is_kswapd() && mz->zone->all_unreclaimable)
+ force_scan = true;
+ if (!global_reclaim(sc))
+ force_scan = true;
+
+ /* If we have no swap space, do not bother scanning anon pages. */
+ if (!sc->may_swap || (nr_swap_pages <= 0)) {
+ noswap = 1;
+ fraction[0] = 0;
+ fraction[1] = 1;
+ denominator = 1;
+ goto out;
+ }
+
+ anon = zone_nr_lru_pages(mz, LRU_ACTIVE_ANON) +
+ zone_nr_lru_pages(mz, LRU_INACTIVE_ANON);
+ file = zone_nr_lru_pages(mz, LRU_ACTIVE_FILE) +
+ zone_nr_lru_pages(mz, LRU_INACTIVE_FILE);
+
+ if (global_reclaim(sc)) {
+ free = zone_page_state(mz->zone, NR_FREE_PAGES);
+ /* If we have very few page cache pages,
+ force-scan anon pages. */
+ if (unlikely(file + free <= high_wmark_pages(mz->zone))) {
+ fraction[0] = 1;
+ fraction[1] = 0;
+ denominator = 1;
+ goto out;
+ }
+ }
+
+ /*
+ * With swappiness at 100, anonymous and file have the same priority.
+ * This scanning priority is essentially the inverse of IO cost.
+ */
+ anon_prio = vmscan_swappiness(mz, sc);
+ file_prio = 200 - vmscan_swappiness(mz, sc);
+
+ /*
+ * OK, so we have swap space and a fair amount of page cache
+ * pages. We use the recently rotated / recently scanned
+ * ratios to determine how valuable each cache is.
+ *
+ * Because workloads change over time (and to avoid overflow)
+ * we keep these statistics as a floating average, which ends
+ * up weighing recent references more than old ones.
+ *
+ * anon in [0], file in [1]
+ */
+ spin_lock_irq(&mz->zone->lru_lock);
+ if (unlikely(reclaim_stat->recent_scanned[0] > anon / 4)) {
+ reclaim_stat->recent_scanned[0] /= 2;
+ reclaim_stat->recent_rotated[0] /= 2;
+ }
+
+ if (unlikely(reclaim_stat->recent_scanned[1] > file / 4)) {
+ reclaim_stat->recent_scanned[1] /= 2;
+ reclaim_stat->recent_rotated[1] /= 2;
+ }
+
+ /*
+ * The amount of pressure on anon vs file pages is inversely
+ * proportional to the fraction of recently scanned pages on
+ * each list that were recently referenced and in active use.
+ */
+ ap = anon_prio * (reclaim_stat->recent_scanned[0] + 1);
+ ap /= reclaim_stat->recent_rotated[0] + 1;
+
+ fp = file_prio * (reclaim_stat->recent_scanned[1] + 1);
+ fp /= reclaim_stat->recent_rotated[1] + 1;
+ spin_unlock_irq(&mz->zone->lru_lock);
+
+ fraction[0] = ap;
+ fraction[1] = fp;
+ denominator = ap + fp + 1;
+out:
+ for_each_evictable_lru(lru) {
+ int file = is_file_lru(lru);
+ unsigned long scan;
+
+ scan = zone_nr_lru_pages(mz, lru);
+ if (priority || noswap || !vmscan_swappiness(mz, sc)) {
+ scan >>= priority;
+ if (!scan && force_scan)
+ scan = SWAP_CLUSTER_MAX;
+ scan = div64_u64(scan * fraction[file], denominator);
+ }
+ nr[lru] = scan;
+ }
+}
+
+/*
+ * Reclaim/compaction depends on a number of pages being freed. To avoid
+ * disruption to the system, a small number of order-0 pages continue to be
+ * rotated and reclaimed in the normal fashion. However, by the time we get
+ * back to the allocator and call try_to_compact_zone(), we ensure that
+ * there are enough free pages for it to be likely successful
+ */
+static inline bool should_continue_reclaim(struct mem_cgroup_zone *mz,
+ unsigned long nr_reclaimed,
+ unsigned long nr_scanned,
+ struct scan_control *sc)
+{
+ unsigned long pages_for_compaction;
+ unsigned long inactive_lru_pages;
+
+ /* If not in reclaim/compaction mode, stop */
+ if (!(sc->reclaim_mode & RECLAIM_MODE_COMPACTION))
+ return false;
+
+ /* Consider stopping depending on scan and reclaim activity */
+ if (sc->gfp_mask & __GFP_REPEAT) {
+ /*
+ * For __GFP_REPEAT allocations, stop reclaiming if the
+ * full LRU list has been scanned and we are still failing
+ * to reclaim pages. This full LRU scan is potentially
+ * expensive but a __GFP_REPEAT caller really wants to succeed
+ */
+ if (!nr_reclaimed && !nr_scanned)
+ return false;
+ } else {
+ /*
+ * For non-__GFP_REPEAT allocations which can presumably
+ * fail without consequence, stop if we failed to reclaim
+ * any pages from the last SWAP_CLUSTER_MAX number of
+ * pages that were scanned. This will return to the
+ * caller faster at the risk reclaim/compaction and
+ * the resulting allocation attempt fails
+ */
+ if (!nr_reclaimed)
+ return false;
+ }
+
+ /*
+ * If we have not reclaimed enough pages for compaction and the
+ * inactive lists are large enough, continue reclaiming
+ */
+ pages_for_compaction = (2UL << sc->order);
+ inactive_lru_pages = zone_nr_lru_pages(mz, LRU_INACTIVE_FILE);
+ if (nr_swap_pages > 0)
+ inactive_lru_pages += zone_nr_lru_pages(mz, LRU_INACTIVE_ANON);
+ if (sc->nr_reclaimed < pages_for_compaction &&
+ inactive_lru_pages > pages_for_compaction)
+ return true;
+
+ /* If compaction would go ahead or the allocation would succeed, stop */
+ switch (compaction_suitable(mz->zone, sc->order)) {
+ case COMPACT_PARTIAL:
+ case COMPACT_CONTINUE:
+ return false;
+ default:
+ return true;
+ }
+}
+
+/*
+ * This is a basic per-zone page freer. Used by both kswapd and direct reclaim.
+ */
+static void shrink_mem_cgroup_zone(int priority, struct mem_cgroup_zone *mz,
+ struct scan_control *sc)
+{
+ unsigned long nr[NR_LRU_LISTS];
+ unsigned long nr_to_scan;
+ enum lru_list lru;
+ unsigned long nr_reclaimed, nr_scanned;
+ unsigned long nr_to_reclaim = sc->nr_to_reclaim;
+ struct blk_plug plug;
+
+restart:
+ nr_reclaimed = 0;
+ nr_scanned = sc->nr_scanned;
+ get_scan_count(mz, sc, nr, priority);
+
+ blk_start_plug(&plug);
+ while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
+ nr[LRU_INACTIVE_FILE]) {
+ for_each_evictable_lru(lru) {
+ if (nr[lru]) {
+ nr_to_scan = min_t(unsigned long,
+ nr[lru], SWAP_CLUSTER_MAX);
+ nr[lru] -= nr_to_scan;
+
+ nr_reclaimed += shrink_list(lru, nr_to_scan,
+ mz, sc, priority);
+ }
+ }
+ /*
+ * On large memory systems, scan >> priority can become
+ * really large. This is fine for the starting priority;
+ * we want to put equal scanning pressure on each zone.
+ * However, if the VM has a harder time of freeing pages,
+ * with multiple processes reclaiming pages, the total
+ * freeing target can get unreasonably large.
+ */
+ if (nr_reclaimed >= nr_to_reclaim && priority < DEF_PRIORITY)
+ break;
+ }
+ blk_finish_plug(&plug);
+ sc->nr_reclaimed += nr_reclaimed;
+
+ /*
+ * Even if we did not try to evict anon pages at all, we want to
+ * rebalance the anon lru active/inactive ratio.
+ */
+ if (inactive_anon_is_low(mz))
+ shrink_active_list(SWAP_CLUSTER_MAX, mz, sc, priority, 0);
+
+ /* reclaim/compaction might need reclaim to continue */
+ if (should_continue_reclaim(mz, nr_reclaimed,
+ sc->nr_scanned - nr_scanned, sc))
+ goto restart;
+
+ throttle_vm_writeout(sc->gfp_mask);
+}
+
+static void shrink_zone(int priority, struct zone *zone,
+ struct scan_control *sc)
+{
+ struct mem_cgroup *root = sc->target_mem_cgroup;
+ struct mem_cgroup_reclaim_cookie reclaim = {
+ .zone = zone,
+ .priority = priority,
+ };
+ struct mem_cgroup *memcg;
+
+#ifdef CONFIG_LIMIT_PAGE_CACHE
+ /*
+ * If the page cache is too big then focus on page cache
+ * and ignore anonymous pages
+ */
+ if (sc->may_swap && zone_page_state(zone, NR_FILE_PAGES)
+ > zone->max_pagecache_pages)
+ sc->may_swap = 0;
+#endif
+
+ memcg = mem_cgroup_iter(root, NULL, &reclaim);
+ do {
+ struct mem_cgroup_zone mz = {
+ .mem_cgroup = memcg,
+ .zone = zone,
+ };
+
+ shrink_mem_cgroup_zone(priority, &mz, sc);
+ /*
+ * Limit reclaim has historically picked one memcg and
+ * scanned it with decreasing priority levels until
+ * nr_to_reclaim had been reclaimed. This priority
+ * cycle is thus over after a single memcg.
+ *
+ * Direct reclaim and kswapd, on the other hand, have
+ * to scan all memory cgroups to fulfill the overall
+ * scan target for the zone.
+ */
+ if (!global_reclaim(sc)) {
+ mem_cgroup_iter_break(root, memcg);
+ break;
+ }
+ memcg = mem_cgroup_iter(root, memcg, &reclaim);
+ } while (memcg);
+}
+
+/* Returns true if compaction should go ahead for a high-order request */
+static inline bool compaction_ready(struct zone *zone, struct scan_control *sc)
+{
+ unsigned long balance_gap, watermark;
+ bool watermark_ok;
+
+ /* Do not consider compaction for orders reclaim is meant to satisfy */
+ if (sc->order <= PAGE_ALLOC_COSTLY_ORDER)
+ return false;
+
+ /*
+ * Compaction takes time to run and there are potentially other
+ * callers using the pages just freed. Continue reclaiming until
+ * there is a buffer of free pages available to give compaction
+ * a reasonable chance of completing and allocating the page
+ */
+ balance_gap = min(low_wmark_pages(zone),
+ (zone->present_pages + KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
+ KSWAPD_ZONE_BALANCE_GAP_RATIO);
+ watermark = high_wmark_pages(zone) + balance_gap + (2UL << sc->order);
+ watermark_ok = zone_watermark_ok_safe(zone, 0, watermark, 0, 0);
+
+ /*
+ * If compaction is deferred, reclaim up to a point where
+ * compaction will have a chance of success when re-enabled
+ */
+ if (compaction_deferred(zone, sc->order))
+ return watermark_ok;
+
+ /* If compaction is not ready to start, keep reclaiming */
+ if (!compaction_suitable(zone, sc->order))
+ return false;
+
+ return watermark_ok;
+}
+
+/*
+ * This is the direct reclaim path, for page-allocating processes. We only
+ * try to reclaim pages from zones which will satisfy the caller's allocation
+ * request.
+ *
+ * We reclaim from a zone even if that zone is over high_wmark_pages(zone).
+ * Because:
+ * a) The caller may be trying to free *extra* pages to satisfy a higher-order
+ * allocation or
+ * b) The target zone may be at high_wmark_pages(zone) but the lower zones
+ * must go *over* high_wmark_pages(zone) to satisfy the `incremental min'
+ * zone defense algorithm.
+ *
+ * If a zone is deemed to be full of pinned pages then just give it a light
+ * scan then give up on it.
+ *
+ * This function returns true if a zone is being reclaimed for a costly
+ * high-order allocation and compaction is ready to begin. This indicates to
+ * the caller that it should consider retrying the allocation instead of
+ * further reclaim.
+ */
+static bool shrink_zones(int priority, struct zonelist *zonelist,
+ struct scan_control *sc)
+{
+ struct zoneref *z;
+ struct zone *zone;
+ unsigned long nr_soft_reclaimed;
+ unsigned long nr_soft_scanned;
+ bool aborted_reclaim = false;
+
+ /*
+ * If the number of buffer_heads in the machine exceeds the maximum
+ * allowed level, force direct reclaim to scan the highmem zone as
+ * highmem pages could be pinning lowmem pages storing buffer_heads
+ */
+ if (buffer_heads_over_limit)
+ sc->gfp_mask |= __GFP_HIGHMEM;
+
+ for_each_zone_zonelist_nodemask(zone, z, zonelist,
+ gfp_zone(sc->gfp_mask), sc->nodemask) {
+ if (!populated_zone(zone))
+ continue;
+ /*
+ * Take care memory controller reclaiming has small influence
+ * to global LRU.
+ */
+ if (global_reclaim(sc)) {
+ if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
+ continue;
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
+ continue; /* Let kswapd poll it */
+ if (COMPACTION_BUILD) {
+ /*
+ * If we already have plenty of memory free for
+ * compaction in this zone, don't free any more.
+ * Even though compaction is invoked for any
+ * non-zero order, only frequent costly order
+ * reclamation is disruptive enough to become a
+ * noticeable problem, like transparent huge
+ * page allocations.
+ */
+ if (compaction_ready(zone, sc)) {
+ aborted_reclaim = true;
+ continue;
+ }
+ }
+ /*
+ * This steals pages from memory cgroups over softlimit
+ * and returns the number of reclaimed pages and
+ * scanned pages. This works for global memory pressure
+ * and balancing, not for a memcg's limit.
+ */
+ nr_soft_scanned = 0;
+ nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone,
+ sc->order, sc->gfp_mask,
+ &nr_soft_scanned);
+ sc->nr_reclaimed += nr_soft_reclaimed;
+ sc->nr_scanned += nr_soft_scanned;
+ /* need some check for avoid more shrink_zone() */
+ }
+
+ shrink_zone(priority, zone, sc);
+ }
+
+ return aborted_reclaim;
+}
+
+static bool zone_reclaimable(struct zone *zone)
+{
+ return zone->pages_scanned < zone_reclaimable_pages(zone) * 6;
+}
+
+/* All zones in zonelist are unreclaimable? */
+static bool all_unreclaimable(struct zonelist *zonelist,
+ struct scan_control *sc)
+{
+ struct zoneref *z;
+ struct zone *zone;
+
+ for_each_zone_zonelist_nodemask(zone, z, zonelist,
+ gfp_zone(sc->gfp_mask), sc->nodemask) {
+ if (!populated_zone(zone))
+ continue;
+ if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
+ continue;
+ if (!zone->all_unreclaimable)
+ return false;
+ }
+
+ return true;
+}
+
+/*
+ * This is the main entry point to direct page reclaim.
+ *
+ * If a full scan of the inactive list fails to free enough memory then we
+ * are "out of memory" and something needs to be killed.
+ *
+ * If the caller is !__GFP_FS then the probability of a failure is reasonably
+ * high - the zone may be full of dirty or under-writeback pages, which this
+ * caller can't do much about. We kick the writeback threads and take explicit
+ * naps in the hope that some of these pages can be written. But if the
+ * allocating task holds filesystem locks which prevent writeout this might not
+ * work, and the allocation attempt will fail.
+ *
+ * returns: 0, if no pages reclaimed
+ * else, the number of pages reclaimed
+ */
+static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
+ struct scan_control *sc,
+ struct shrink_control *shrink)
+{
+ int priority;
+ unsigned long total_scanned = 0;
+ struct reclaim_state *reclaim_state = current->reclaim_state;
+ struct zoneref *z;
+ struct zone *zone;
+ unsigned long writeback_threshold;
+ bool aborted_reclaim;
+
+ delayacct_freepages_start();
+
+ if (global_reclaim(sc))
+ count_vm_event(ALLOCSTALL);
+
+ for (priority = DEF_PRIORITY; priority >= 0; priority--) {
+#ifdef CONFIG_SPEED_OPT_DYNAMIC_POOL
+ extern void skb_sys_pool_delete(void);
+ skb_sys_pool_delete();
+#endif
+ sc->nr_scanned = 0;
+ if (!priority)
+ disable_swap_token(sc->target_mem_cgroup);
+ aborted_reclaim = shrink_zones(priority, zonelist, sc);
+
+ /*
+ * Don't shrink slabs when reclaiming memory from
+ * over limit cgroups
+ */
+ if (global_reclaim(sc)) {
+ unsigned long lru_pages = 0;
+ for_each_zone_zonelist(zone, z, zonelist,
+ gfp_zone(sc->gfp_mask)) {
+ if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
+ continue;
+
+ lru_pages += zone_reclaimable_pages(zone);
+ }
+
+ shrink_slab(shrink, sc->nr_scanned, lru_pages);
+ if (reclaim_state) {
+ sc->nr_reclaimed += reclaim_state->reclaimed_slab;
+ reclaim_state->reclaimed_slab = 0;
+ }
+ }
+ total_scanned += sc->nr_scanned;
+ if (sc->nr_reclaimed >= sc->nr_to_reclaim)
+ goto out;
+
+ /*
+ * Try to write back as many pages as we just scanned. This
+ * tends to cause slow streaming writers to write data to the
+ * disk smoothly, at the dirtying rate, which is nice. But
+ * that's undesirable in laptop mode, where we *want* lumpy
+ * writeout. So in laptop mode, write out the whole world.
+ */
+ writeback_threshold = sc->nr_to_reclaim + sc->nr_to_reclaim / 2;
+ if (total_scanned > writeback_threshold) {
+ wakeup_flusher_threads(laptop_mode ? 0 : total_scanned,
+ WB_REASON_TRY_TO_FREE_PAGES);
+ sc->may_writepage = 1;
+ }
+
+ /* Take a nap, wait for some writeback to complete */
+ if (!sc->hibernation_mode && sc->nr_scanned &&
+ priority < DEF_PRIORITY - 2) {
+ struct zone *preferred_zone;
+
+ first_zones_zonelist(zonelist, gfp_zone(sc->gfp_mask),
+ &cpuset_current_mems_allowed,
+ &preferred_zone);
+ wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/10);
+ }
+ }
+
+out:
+ delayacct_freepages_end();
+
+ if (sc->nr_reclaimed)
+ return sc->nr_reclaimed;
+
+ /*
+ * As hibernation is going on, kswapd is freezed so that it can't mark
+ * the zone into all_unreclaimable. Thus bypassing all_unreclaimable
+ * check.
+ */
+ if (oom_killer_disabled)
+ return 0;
+
+ /* Aborted reclaim to try compaction? don't OOM, then */
+ if (aborted_reclaim)
+ return 1;
+
+ /* top priority shrink_zones still had more to do? don't OOM, then */
+ if (global_reclaim(sc) && !all_unreclaimable(zonelist, sc))
+ return 1;
+
+ return 0;
+}
+
+unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
+ gfp_t gfp_mask, nodemask_t *nodemask)
+{
+ unsigned long nr_reclaimed;
+ struct scan_control sc = {
+ .gfp_mask = gfp_mask,
+ .may_writepage = !laptop_mode,
+ .nr_to_reclaim = SWAP_CLUSTER_MAX,
+ .may_unmap = 1,
+ .may_swap = 1,
+ .order = order,
+ .target_mem_cgroup = NULL,
+ .nodemask = nodemask,
+ };
+ struct shrink_control shrink = {
+ .gfp_mask = sc.gfp_mask,
+ };
+
+ trace_mm_vmscan_direct_reclaim_begin(order,
+ sc.may_writepage,
+ gfp_mask);
+
+ nr_reclaimed = do_try_to_free_pages(zonelist, &sc, &shrink);
+
+ trace_mm_vmscan_direct_reclaim_end(nr_reclaimed);
+
+ return nr_reclaimed;
+}
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+
+unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *memcg,
+ gfp_t gfp_mask, bool noswap,
+ struct zone *zone,
+ unsigned long *nr_scanned)
+{
+ struct scan_control sc = {
+ .nr_scanned = 0,
+ .nr_to_reclaim = SWAP_CLUSTER_MAX,
+ .may_writepage = !laptop_mode,
+ .may_unmap = 1,
+ .may_swap = !noswap,
+ .order = 0,
+ .target_mem_cgroup = memcg,
+ };
+ struct mem_cgroup_zone mz = {
+ .mem_cgroup = memcg,
+ .zone = zone,
+ };
+
+ sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
+ (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
+
+ trace_mm_vmscan_memcg_softlimit_reclaim_begin(0,
+ sc.may_writepage,
+ sc.gfp_mask);
+
+ /*
+ * NOTE: Although we can get the priority field, using it
+ * here is not a good idea, since it limits the pages we can scan.
+ * if we don't reclaim here, the shrink_zone from balance_pgdat
+ * will pick up pages from other mem cgroup's as well. We hack
+ * the priority and make it zero.
+ */
+ shrink_mem_cgroup_zone(0, &mz, &sc);
+
+ trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed);
+
+ *nr_scanned = sc.nr_scanned;
+ return sc.nr_reclaimed;
+}
+
+unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
+ gfp_t gfp_mask,
+ bool noswap)
+{
+ struct zonelist *zonelist;
+ unsigned long nr_reclaimed;
+ int nid;
+ struct scan_control sc = {
+ .may_writepage = !laptop_mode,
+ .may_unmap = 1,
+ .may_swap = !noswap,
+ .nr_to_reclaim = SWAP_CLUSTER_MAX,
+ .order = 0,
+ .target_mem_cgroup = memcg,
+ .nodemask = NULL, /* we don't care the placement */
+ .gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
+ (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK),
+ };
+ struct shrink_control shrink = {
+ .gfp_mask = sc.gfp_mask,
+ };
+
+ /*
+ * Unlike direct reclaim via alloc_pages(), memcg's reclaim doesn't
+ * take care of from where we get pages. So the node where we start the
+ * scan does not need to be the current node.
+ */
+ nid = mem_cgroup_select_victim_node(memcg);
+
+ zonelist = NODE_DATA(nid)->node_zonelists;
+
+ trace_mm_vmscan_memcg_reclaim_begin(0,
+ sc.may_writepage,
+ sc.gfp_mask);
+
+ nr_reclaimed = do_try_to_free_pages(zonelist, &sc, &shrink);
+
+ trace_mm_vmscan_memcg_reclaim_end(nr_reclaimed);
+
+ return nr_reclaimed;
+}
+#endif
+
+static void age_active_anon(struct zone *zone, struct scan_control *sc,
+ int priority)
+{
+ struct mem_cgroup *memcg;
+
+ if (!total_swap_pages)
+ return;
+
+ memcg = mem_cgroup_iter(NULL, NULL, NULL);
+ do {
+ struct mem_cgroup_zone mz = {
+ .mem_cgroup = memcg,
+ .zone = zone,
+ };
+
+ if (inactive_anon_is_low(&mz))
+ shrink_active_list(SWAP_CLUSTER_MAX, &mz,
+ sc, priority, 0);
+
+ memcg = mem_cgroup_iter(NULL, memcg, NULL);
+ } while (memcg);
+}
+
+static bool zone_balanced(struct zone *zone, int order,
+ unsigned long balance_gap, int classzone_idx)
+{
+ if (!zone_watermark_ok_safe(zone, order, high_wmark_pages(zone) +
+ balance_gap, classzone_idx, 0))
+ return false;
+
+ if (COMPACTION_BUILD && order && !compaction_suitable(zone, order))
+ return false;
+
+ return true;
+}
+
+/*
+ * pgdat_balanced is used when checking if a node is balanced for high-order
+ * allocations. Only zones that meet watermarks and are in a zone allowed
+ * by the callers classzone_idx are added to balanced_pages. The total of
+ * balanced pages must be at least 25% of the zones allowed by classzone_idx
+ * for the node to be considered balanced. Forcing all zones to be balanced
+ * for high orders can cause excessive reclaim when there are imbalanced zones.
+ * The choice of 25% is due to
+ * o a 16M DMA zone that is balanced will not balance a zone on any
+ * reasonable sized machine
+ * o On all other machines, the top zone must be at least a reasonable
+ * percentage of the middle zones. For example, on 32-bit x86, highmem
+ * would need to be at least 256M for it to be balance a whole node.
+ * Similarly, on x86-64 the Normal zone would need to be at least 1G
+ * to balance a node on its own. These seemed like reasonable ratios.
+ */
+static bool pgdat_balanced(pg_data_t *pgdat, unsigned long balanced_pages,
+ int classzone_idx)
+{
+ unsigned long present_pages = 0;
+ int i;
+
+ for (i = 0; i <= classzone_idx; i++)
+ present_pages += pgdat->node_zones[i].present_pages;
+
+ /* A special case here: if zone has no page, we think it's balanced */
+ return balanced_pages >= (present_pages >> 2);
+}
+
+/* is kswapd sleeping prematurely? */
+static bool sleeping_prematurely(pg_data_t *pgdat, int order, long remaining,
+ int classzone_idx)
+{
+ int i;
+ unsigned long balanced = 0;
+ bool all_zones_ok = true;
+
+ /* If a direct reclaimer woke kswapd within HZ/10, it's premature */
+ if (remaining)
+ return true;
+
+ /* Check the watermark levels */
+ for (i = 0; i <= classzone_idx; i++) {
+ struct zone *zone = pgdat->node_zones + i;
+
+ if (!populated_zone(zone))
+ continue;
+
+ /*
+ * balance_pgdat() skips over all_unreclaimable after
+ * DEF_PRIORITY. Effectively, it considers them balanced so
+ * they must be considered balanced here as well if kswapd
+ * is to sleep
+ */
+ if (zone->all_unreclaimable) {
+ balanced += zone->present_pages;
+ continue;
+ }
+
+ if (!zone_balanced(zone, order, 0, i))
+ all_zones_ok = false;
+ else
+ balanced += zone->present_pages;
+ }
+
+ /*
+ * For high-order requests, the balanced zones must contain at least
+ * 25% of the nodes pages for kswapd to sleep. For order-0, all zones
+ * must be balanced
+ */
+ if (order)
+ return !pgdat_balanced(pgdat, balanced, classzone_idx);
+ else
+ return !all_zones_ok;
+}
+
+/*
+ * For kswapd, balance_pgdat() will work across all this node's zones until
+ * they are all at high_wmark_pages(zone).
+ *
+ * Returns the final order kswapd was reclaiming at
+ *
+ * There is special handling here for zones which are full of pinned pages.
+ * This can happen if the pages are all mlocked, or if they are all used by
+ * device drivers (say, ZONE_DMA). Or if they are all in use by hugetlb.
+ * What we do is to detect the case where all pages in the zone have been
+ * scanned twice and there has been zero successful reclaim. Mark the zone as
+ * dead and from now on, only perform a short scan. Basically we're polling
+ * the zone for when the problem goes away.
+ *
+ * kswapd scans the zones in the highmem->normal->dma direction. It skips
+ * zones which have free_pages > high_wmark_pages(zone), but once a zone is
+ * found to have free_pages <= high_wmark_pages(zone), we scan that zone and the
+ * lower zones regardless of the number of free pages in the lower zones. This
+ * interoperates with the page allocator fallback scheme to ensure that aging
+ * of pages is balanced across the zones.
+ */
+static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
+ int *classzone_idx)
+{
+ int all_zones_ok;
+ unsigned long balanced;
+ int priority;
+ int i;
+ int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */
+ unsigned long total_scanned;
+ struct reclaim_state *reclaim_state = current->reclaim_state;
+ unsigned long nr_soft_reclaimed;
+ unsigned long nr_soft_scanned;
+ struct scan_control sc = {
+ .gfp_mask = GFP_KERNEL,
+ .may_unmap = 1,
+ .may_swap = 1,
+ /*
+ * kswapd doesn't want to be bailed out while reclaim. because
+ * we want to put equal scanning pressure on each zone.
+ */
+ .nr_to_reclaim = ULONG_MAX,
+ .order = order,
+ .target_mem_cgroup = NULL,
+ };
+ struct shrink_control shrink = {
+ .gfp_mask = sc.gfp_mask,
+ };
+loop_again:
+ total_scanned = 0;
+ sc.nr_reclaimed = 0;
+ sc.may_writepage = !laptop_mode;
+ count_vm_event(PAGEOUTRUN);
+
+ for (priority = DEF_PRIORITY; priority >= 0; priority--) {
+ unsigned long lru_pages = 0;
+ int has_under_min_watermark_zone = 0;
+
+ /* The swap token gets in the way of swapout... */
+ if (!priority)
+ disable_swap_token(NULL);
+
+ all_zones_ok = 1;
+ balanced = 0;
+
+ /*
+ * Scan in the highmem->dma direction for the highest
+ * zone which needs scanning
+ */
+ for (i = pgdat->nr_zones - 1; i >= 0; i--) {
+ struct zone *zone = pgdat->node_zones + i;
+
+ if (!populated_zone(zone))
+ continue;
+
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
+ continue;
+
+ /*
+ * Do some background aging of the anon list, to give
+ * pages a chance to be referenced before reclaiming.
+ */
+ age_active_anon(zone, &sc, priority);
+
+ /*
+ * If the number of buffer_heads in the machine
+ * exceeds the maximum allowed level and this node
+ * has a highmem zone, force kswapd to reclaim from
+ * it to relieve lowmem pressure.
+ */
+ if (buffer_heads_over_limit && is_highmem_idx(i)) {
+ end_zone = i;
+ break;
+ }
+
+ if (!zone_balanced(zone, order, 0, 0)) {
+ end_zone = i;
+ break;
+ } else {
+ /* If balanced, clear the congested flag */
+ zone_clear_flag(zone, ZONE_CONGESTED);
+ }
+ }
+ if (i < 0)
+ goto out;
+
+ for (i = 0; i <= end_zone; i++) {
+ struct zone *zone = pgdat->node_zones + i;
+
+ lru_pages += zone_reclaimable_pages(zone);
+ }
+
+ /*
+ * Now scan the zone in the dma->highmem direction, stopping
+ * at the last zone which needs scanning.
+ *
+ * We do this because the page allocator works in the opposite
+ * direction. This prevents the page allocator from allocating
+ * pages behind kswapd's direction of progress, which would
+ * cause too much scanning of the lower zones.
+ */
+ for (i = 0; i <= end_zone; i++) {
+ struct zone *zone = pgdat->node_zones + i;
+ int nr_slab, testorder;
+ unsigned long balance_gap;
+
+ if (!populated_zone(zone))
+ continue;
+
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
+ continue;
+
+ sc.nr_scanned = 0;
+
+ nr_soft_scanned = 0;
+ /*
+ * Call soft limit reclaim before calling shrink_zone.
+ */
+ nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone,
+ order, sc.gfp_mask,
+ &nr_soft_scanned);
+ sc.nr_reclaimed += nr_soft_reclaimed;
+ total_scanned += nr_soft_scanned;
+
+ /*
+ * We put equal pressure on every zone, unless
+ * one zone has way too many pages free
+ * already. The "too many pages" is defined
+ * as the high wmark plus a "gap" where the
+ * gap is either the low watermark or 1%
+ * of the zone, whichever is smaller.
+ */
+ balance_gap = min(low_wmark_pages(zone),
+ (zone->present_pages +
+ KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
+ KSWAPD_ZONE_BALANCE_GAP_RATIO);
+ /*
+ * Kswapd reclaims only single pages with compaction
+ * enabled. Trying too hard to reclaim until contiguous
+ * free pages have become available can hurt performance
+ * by evicting too much useful data from memory.
+ * Do not reclaim more than needed for compaction.
+ */
+ testorder = order;
+ if (COMPACTION_BUILD && order &&
+ compaction_suitable(zone, order) !=
+ COMPACT_SKIPPED)
+ testorder = 0;
+
+ if ((buffer_heads_over_limit && is_highmem_idx(i)) ||
+ !zone_balanced(zone, testorder,
+ balance_gap, end_zone)) {
+ shrink_zone(priority, zone, &sc);
+
+ reclaim_state->reclaimed_slab = 0;
+ nr_slab = shrink_slab(&shrink, sc.nr_scanned, lru_pages);
+ sc.nr_reclaimed += reclaim_state->reclaimed_slab;
+ total_scanned += sc.nr_scanned;
+
+ if (nr_slab == 0 && !zone_reclaimable(zone))
+ zone->all_unreclaimable = 1;
+ }
+
+ /*
+ * If we've done a decent amount of scanning and
+ * the reclaim ratio is low, start doing writepage
+ * even in laptop mode
+ */
+ if (total_scanned > SWAP_CLUSTER_MAX * 2 &&
+ total_scanned > sc.nr_reclaimed + sc.nr_reclaimed / 2)
+ sc.may_writepage = 1;
+
+ if (zone->all_unreclaimable) {
+ if (end_zone && end_zone == i)
+ end_zone--;
+ continue;
+ }
+
+ if (!zone_balanced(zone, testorder, 0, end_zone)) {
+ all_zones_ok = 0;
+ /*
+ * We are still under min water mark. This
+ * means that we have a GFP_ATOMIC allocation
+ * failure risk. Hurry up!
+ */
+ if (!zone_watermark_ok_safe(zone, order,
+ min_wmark_pages(zone), end_zone, 0))
+ has_under_min_watermark_zone = 1;
+ } else {
+ /*
+ * If a zone reaches its high watermark,
+ * consider it to be no longer congested. It's
+ * possible there are dirty pages backed by
+ * congested BDIs but as pressure is relieved,
+ * spectulatively avoid congestion waits
+ */
+ zone_clear_flag(zone, ZONE_CONGESTED);
+ if (i <= *classzone_idx)
+ balanced += zone->present_pages;
+ }
+
+ }
+ if (all_zones_ok || (order && pgdat_balanced(pgdat, balanced, *classzone_idx)))
+ break; /* kswapd: all done */
+ /*
+ * OK, kswapd is getting into trouble. Take a nap, then take
+ * another pass across the zones.
+ */
+ if (total_scanned && (priority < DEF_PRIORITY - 2)) {
+ if (has_under_min_watermark_zone)
+ count_vm_event(KSWAPD_SKIP_CONGESTION_WAIT);
+ else
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+ }
+
+ /*
+ * We do this so kswapd doesn't build up large priorities for
+ * example when it is freeing in parallel with allocators. It
+ * matches the direct reclaim path behaviour in terms of impact
+ * on zone->*_priority.
+ */
+ if (sc.nr_reclaimed >= SWAP_CLUSTER_MAX)
+ break;
+ }
+out:
+
+ /*
+ * order-0: All zones must meet high watermark for a balanced node
+ * high-order: Balanced zones must make up at least 25% of the node
+ * for the node to be balanced
+ */
+ if (!(all_zones_ok || (order && pgdat_balanced(pgdat, balanced, *classzone_idx)))) {
+ cond_resched();
+
+ try_to_freeze();
+
+ /*
+ * Fragmentation may mean that the system cannot be
+ * rebalanced for high-order allocations in all zones.
+ * At this point, if nr_reclaimed < SWAP_CLUSTER_MAX,
+ * it means the zones have been fully scanned and are still
+ * not balanced. For high-order allocations, there is
+ * little point trying all over again as kswapd may
+ * infinite loop.
+ *
+ * Instead, recheck all watermarks at order-0 as they
+ * are the most important. If watermarks are ok, kswapd will go
+ * back to sleep. High-order users can still perform direct
+ * reclaim if they wish.
+ */
+ if (sc.nr_reclaimed < SWAP_CLUSTER_MAX)
+ order = sc.order = 0;
+
+ goto loop_again;
+ }
+
+ /*
+ * If kswapd was reclaiming at a higher order, it has the option of
+ * sleeping without all zones being balanced. Before it does, it must
+ * ensure that the watermarks for order-0 on *all* zones are met and
+ * that the congestion flags are cleared. The congestion flag must
+ * be cleared as kswapd is the only mechanism that clears the flag
+ * and it is potentially going to sleep here.
+ */
+ if (order) {
+ int zones_need_compaction = 1;
+
+ for (i = 0; i <= end_zone; i++) {
+ struct zone *zone = pgdat->node_zones + i;
+
+ if (!populated_zone(zone))
+ continue;
+
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
+ continue;
+
+ /* Would compaction fail due to lack of free memory? */
+ if (COMPACTION_BUILD &&
+ compaction_suitable(zone, order) == COMPACT_SKIPPED)
+ goto loop_again;
+
+ /* Confirm the zone is balanced for order-0 */
+ if (!zone_watermark_ok(zone, 0,
+ high_wmark_pages(zone), 0, 0)) {
+ order = sc.order = 0;
+ goto loop_again;
+ }
+
+ /* Check if the memory needs to be defragmented. */
+ if (zone_watermark_ok(zone, order,
+ low_wmark_pages(zone), *classzone_idx, 0))
+ zones_need_compaction = 0;
+
+ /* If balanced, clear the congested flag */
+ zone_clear_flag(zone, ZONE_CONGESTED);
+ }
+
+ if (zones_need_compaction)
+ compact_pgdat(pgdat, order);
+ }
+
+ /*
+ * Return the order we were reclaiming at so sleeping_prematurely()
+ * makes a decision on the order we were last reclaiming at. However,
+ * if another caller entered the allocator slow path while kswapd
+ * was awake, order will remain at the higher level
+ */
+ *classzone_idx = end_zone;
+ return order;
+}
+
+static void kswapd_try_to_sleep(pg_data_t *pgdat, int order, int classzone_idx)
+{
+ long remaining = 0;
+ DEFINE_WAIT(wait);
+
+ if (freezing(current) || kthread_should_stop())
+ return;
+
+ prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
+
+ /* Try to sleep for a short interval */
+ if (!sleeping_prematurely(pgdat, order, remaining, classzone_idx)) {
+ remaining = schedule_timeout(HZ/10);
+ finish_wait(&pgdat->kswapd_wait, &wait);
+ prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
+ }
+
+ /*
+ * After a short sleep, check if it was a premature sleep. If not, then
+ * go fully to sleep until explicitly woken up.
+ */
+ if (!sleeping_prematurely(pgdat, order, remaining, classzone_idx)) {
+ trace_mm_vmscan_kswapd_sleep(pgdat->node_id);
+
+ /*
+ * vmstat counters are not perfectly accurate and the estimated
+ * value for counters such as NR_FREE_PAGES can deviate from the
+ * true value by nr_online_cpus * threshold. To avoid the zone
+ * watermarks being breached while under pressure, we reduce the
+ * per-cpu vmstat threshold while kswapd is awake and restore
+ * them before going back to sleep.
+ */
+ set_pgdat_percpu_threshold(pgdat, calculate_normal_threshold);
+
+ if (!kthread_should_stop())
+ schedule();
+
+ set_pgdat_percpu_threshold(pgdat, calculate_pressure_threshold);
+ } else {
+ if (remaining)
+ count_vm_event(KSWAPD_LOW_WMARK_HIT_QUICKLY);
+ else
+ count_vm_event(KSWAPD_HIGH_WMARK_HIT_QUICKLY);
+ }
+ finish_wait(&pgdat->kswapd_wait, &wait);
+}
+
+/*
+ * The background pageout daemon, started as a kernel thread
+ * from the init process.
+ *
+ * This basically trickles out pages so that we have _some_
+ * free memory available even if there is no other activity
+ * that frees anything up. This is needed for things like routing
+ * etc, where we otherwise might have all activity going on in
+ * asynchronous contexts that cannot page things out.
+ *
+ * If there are applications that are active memory-allocators
+ * (most normal use), this basically shouldn't matter.
+ */
+static int kswapd(void *p)
+{
+ unsigned long order, new_order;
+ unsigned balanced_order;
+ int classzone_idx, new_classzone_idx;
+ int balanced_classzone_idx;
+ pg_data_t *pgdat = (pg_data_t*)p;
+ struct task_struct *tsk = current;
+
+ struct reclaim_state reclaim_state = {
+ .reclaimed_slab = 0,
+ };
+ const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
+
+ lockdep_set_current_reclaim_state(GFP_KERNEL);
+
+ if (!cpumask_empty(cpumask))
+ set_cpus_allowed_ptr(tsk, cpumask);
+ current->reclaim_state = &reclaim_state;
+
+ /*
+ * Tell the memory management that we're a "memory allocator",
+ * and that if we need more memory we should get access to it
+ * regardless (see "__alloc_pages()"). "kswapd" should
+ * never get caught in the normal page freeing logic.
+ *
+ * (Kswapd normally doesn't need memory anyway, but sometimes
+ * you need a small amount of memory in order to be able to
+ * page out something else, and this flag essentially protects
+ * us from recursively trying to free more memory as we're
+ * trying to free the first piece of memory in the first place).
+ */
+ tsk->flags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
+ set_freezable();
+
+ order = new_order = 0;
+ balanced_order = 0;
+ classzone_idx = new_classzone_idx = pgdat->nr_zones - 1;
+ balanced_classzone_idx = classzone_idx;
+ for ( ; ; ) {
+ int ret;
+
+ /*
+ * If the last balance_pgdat was unsuccessful it's unlikely a
+ * new request of a similar or harder type will succeed soon
+ * so consider going to sleep on the basis we reclaimed at
+ */
+ if (balanced_classzone_idx >= new_classzone_idx &&
+ balanced_order == new_order) {
+ new_order = pgdat->kswapd_max_order;
+ new_classzone_idx = pgdat->classzone_idx;
+ pgdat->kswapd_max_order = 0;
+ pgdat->classzone_idx = pgdat->nr_zones - 1;
+ }
+
+ if (order < new_order || classzone_idx > new_classzone_idx) {
+ /*
+ * Don't sleep if someone wants a larger 'order'
+ * allocation or has tigher zone constraints
+ */
+ order = new_order;
+ classzone_idx = new_classzone_idx;
+ } else {
+ kswapd_try_to_sleep(pgdat, balanced_order,
+ balanced_classzone_idx);
+ order = pgdat->kswapd_max_order;
+ classzone_idx = pgdat->classzone_idx;
+ new_order = order;
+ new_classzone_idx = classzone_idx;
+ pgdat->kswapd_max_order = 0;
+ pgdat->classzone_idx = pgdat->nr_zones - 1;
+ }
+
+ ret = try_to_freeze();
+ if (kthread_should_stop())
+ break;
+
+ /*
+ * We can speed up thawing tasks if we don't call balance_pgdat
+ * after returning from the refrigerator
+ */
+ if (!ret) {
+ trace_mm_vmscan_kswapd_wake(pgdat->node_id, order);
+ balanced_classzone_idx = classzone_idx;
+ balanced_order = balance_pgdat(pgdat, order,
+ &balanced_classzone_idx);
+ }
+ }
+
+ tsk->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD);
+ current->reclaim_state = NULL;
+ lockdep_clear_current_reclaim_state();
+
+ return 0;
+}
+
+/*
+ * A zone is low on free memory, so wake its kswapd task to service it.
+ */
+void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx)
+{
+ pg_data_t *pgdat;
+
+ if (!populated_zone(zone))
+ return;
+
+ if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
+ return;
+ pgdat = zone->zone_pgdat;
+ if (pgdat->kswapd_max_order < order) {
+ pgdat->kswapd_max_order = order;
+ pgdat->classzone_idx = min(pgdat->classzone_idx, classzone_idx);
+ }
+ if (!waitqueue_active(&pgdat->kswapd_wait))
+ return;
+ if (zone_watermark_ok_safe(zone, order, low_wmark_pages(zone), 0, 0))
+ return;
+
+ trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, zone_idx(zone), order);
+ wake_up_interruptible(&pgdat->kswapd_wait);
+}
+
+/*
+ * The reclaimable count would be mostly accurate.
+ * The less reclaimable pages may be
+ * - mlocked pages, which will be moved to unevictable list when encountered
+ * - mapped pages, which may require several travels to be reclaimed
+ * - dirty pages, which is not "instantly" reclaimable
+ */
+unsigned long global_reclaimable_pages(void)
+{
+ int nr;
+
+ nr = global_page_state(NR_ACTIVE_FILE) +
+ global_page_state(NR_INACTIVE_FILE);
+
+ if (nr_swap_pages > 0)
+ nr += global_page_state(NR_ACTIVE_ANON) +
+ global_page_state(NR_INACTIVE_ANON);
+
+ return nr;
+}
+
+unsigned long zone_reclaimable_pages(struct zone *zone)
+{
+ int nr;
+
+ nr = zone_page_state(zone, NR_ACTIVE_FILE) +
+ zone_page_state(zone, NR_INACTIVE_FILE);
+
+ if (nr_swap_pages > 0)
+ nr += zone_page_state(zone, NR_ACTIVE_ANON) +
+ zone_page_state(zone, NR_INACTIVE_ANON);
+
+ return nr;
+}
+
+#ifdef CONFIG_HIBERNATION
+/*
+ * Try to free `nr_to_reclaim' of memory, system-wide, and return the number of
+ * freed pages.
+ *
+ * Rather than trying to age LRUs the aim is to preserve the overall
+ * LRU order by reclaiming preferentially
+ * inactive > active > active referenced > active mapped
+ */
+unsigned long shrink_all_memory(unsigned long nr_to_reclaim)
+{
+ struct reclaim_state reclaim_state;
+ struct scan_control sc = {
+ .gfp_mask = GFP_HIGHUSER_MOVABLE,
+ .may_swap = 1,
+ .may_unmap = 1,
+ .may_writepage = 1,
+ .nr_to_reclaim = nr_to_reclaim,
+ .hibernation_mode = 1,
+ .order = 0,
+ };
+ struct shrink_control shrink = {
+ .gfp_mask = sc.gfp_mask,
+ };
+ struct zonelist *zonelist = node_zonelist(numa_node_id(), sc.gfp_mask);
+ struct task_struct *p = current;
+ unsigned long nr_reclaimed;
+
+ p->flags |= PF_MEMALLOC;
+ lockdep_set_current_reclaim_state(sc.gfp_mask);
+ reclaim_state.reclaimed_slab = 0;
+ p->reclaim_state = &reclaim_state;
+
+ nr_reclaimed = do_try_to_free_pages(zonelist, &sc, &shrink);
+
+ p->reclaim_state = NULL;
+ lockdep_clear_current_reclaim_state();
+ p->flags &= ~PF_MEMALLOC;
+
+ return nr_reclaimed;
+}
+#endif /* CONFIG_HIBERNATION */
+
+/* It's optimal to keep kswapds on the same CPUs as their memory, but
+ not required for correctness. So if the last cpu in a node goes
+ away, we get changed to run anywhere: as the first one comes back,
+ restore their cpu bindings. */
+static int __devinit cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ int nid;
+
+ if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) {
+ for_each_node_state(nid, N_HIGH_MEMORY) {
+ pg_data_t *pgdat = NODE_DATA(nid);
+ const struct cpumask *mask;
+
+ mask = cpumask_of_node(pgdat->node_id);
+
+ if (cpumask_any_and(cpu_online_mask, mask) < nr_cpu_ids)
+ /* One of our CPUs online: restore mask */
+ set_cpus_allowed_ptr(pgdat->kswapd, mask);
+ }
+ }
+ return NOTIFY_OK;
+}
+
+/*
+ * This kswapd start function will be called by init and node-hot-add.
+ * On node-hot-add, kswapd will moved to proper cpus if cpus are hot-added.
+ */
+int kswapd_run(int nid)
+{
+ pg_data_t *pgdat = NODE_DATA(nid);
+ int ret = 0;
+
+ if (pgdat->kswapd)
+ return 0;
+
+ pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid);
+ if (IS_ERR(pgdat->kswapd)) {
+ /* failure at boot is fatal */
+ BUG_ON(system_state == SYSTEM_BOOTING);
+ printk("Failed to start kswapd on node %d\n",nid);
+ ret = -1;
+ }
+ return ret;
+}
+
+/*
+ * Called by memory hotplug when all memory in a node is offlined. Caller must
+ * hold lock_memory_hotplug().
+ */
+void kswapd_stop(int nid)
+{
+ struct task_struct *kswapd = NODE_DATA(nid)->kswapd;
+
+ if (kswapd) {
+ kthread_stop(kswapd);
+ NODE_DATA(nid)->kswapd = NULL;
+ }
+}
+
+static int __init kswapd_init(void)
+{
+ int nid;
+
+ swap_setup();
+ for_each_node_state(nid, N_HIGH_MEMORY)
+ kswapd_run(nid);
+ hotcpu_notifier(cpu_callback, 0);
+ return 0;
+}
+
+module_init(kswapd_init)
+
+#ifdef CONFIG_NUMA
+/*
+ * Zone reclaim mode
+ *
+ * If non-zero call zone_reclaim when the number of free pages falls below
+ * the watermarks.
+ */
+int zone_reclaim_mode __read_mostly;
+
+#define RECLAIM_OFF 0
+#define RECLAIM_ZONE (1<<0) /* Run shrink_inactive_list on the zone */
+#define RECLAIM_WRITE (1<<1) /* Writeout pages during reclaim */
+#define RECLAIM_SWAP (1<<2) /* Swap pages out during reclaim */
+
+/*
+ * Priority for ZONE_RECLAIM. This determines the fraction of pages
+ * of a node considered for each zone_reclaim. 4 scans 1/16th of
+ * a zone.
+ */
+#define ZONE_RECLAIM_PRIORITY 4
+
+/*
+ * Percentage of pages in a zone that must be unmapped for zone_reclaim to
+ * occur.
+ */
+int sysctl_min_unmapped_ratio = 1;
+
+/*
+ * If the number of slab pages in a zone grows beyond this percentage then
+ * slab reclaim needs to occur.
+ */
+int sysctl_min_slab_ratio = 5;
+
+static inline unsigned long zone_unmapped_file_pages(struct zone *zone)
+{
+ unsigned long file_mapped = zone_page_state(zone, NR_FILE_MAPPED);
+ unsigned long file_lru = zone_page_state(zone, NR_INACTIVE_FILE) +
+ zone_page_state(zone, NR_ACTIVE_FILE);
+
+ /*
+ * It's possible for there to be more file mapped pages than
+ * accounted for by the pages on the file LRU lists because
+ * tmpfs pages accounted for as ANON can also be FILE_MAPPED
+ */
+ return (file_lru > file_mapped) ? (file_lru - file_mapped) : 0;
+}
+
+/* Work out how many page cache pages we can reclaim in this reclaim_mode */
+static long zone_pagecache_reclaimable(struct zone *zone)
+{
+ long nr_pagecache_reclaimable;
+ long delta = 0;
+
+ /*
+ * If RECLAIM_SWAP is set, then all file pages are considered
+ * potentially reclaimable. Otherwise, we have to worry about
+ * pages like swapcache and zone_unmapped_file_pages() provides
+ * a better estimate
+ */
+ if (zone_reclaim_mode & RECLAIM_SWAP)
+ nr_pagecache_reclaimable = zone_page_state(zone, NR_FILE_PAGES);
+ else
+ nr_pagecache_reclaimable = zone_unmapped_file_pages(zone);
+
+ /* If we can't clean pages, remove dirty pages from consideration */
+ if (!(zone_reclaim_mode & RECLAIM_WRITE))
+ delta += zone_page_state(zone, NR_FILE_DIRTY);
+
+ /* Watch for any possible underflows due to delta */
+ if (unlikely(delta > nr_pagecache_reclaimable))
+ delta = nr_pagecache_reclaimable;
+
+ return nr_pagecache_reclaimable - delta;
+}
+
+/*
+ * Try to free up some pages from this zone through reclaim.
+ */
+static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
+{
+ /* Minimum pages needed in order to stay on node */
+ const unsigned long nr_pages = 1 << order;
+ struct task_struct *p = current;
+ struct reclaim_state reclaim_state;
+ int priority;
+ struct scan_control sc = {
+ .may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE),
+ .may_unmap = !!(zone_reclaim_mode & RECLAIM_SWAP),
+ .may_swap = 1,
+ .nr_to_reclaim = max_t(unsigned long, nr_pages,
+ SWAP_CLUSTER_MAX),
+ .gfp_mask = gfp_mask,
+ .order = order,
+ };
+ struct shrink_control shrink = {
+ .gfp_mask = sc.gfp_mask,
+ };
+ unsigned long nr_slab_pages0, nr_slab_pages1;
+
+ cond_resched();
+ /*
+ * We need to be able to allocate from the reserves for RECLAIM_SWAP
+ * and we also need to be able to write out pages for RECLAIM_WRITE
+ * and RECLAIM_SWAP.
+ */
+ p->flags |= PF_MEMALLOC | PF_SWAPWRITE;
+ lockdep_set_current_reclaim_state(gfp_mask);
+ reclaim_state.reclaimed_slab = 0;
+ p->reclaim_state = &reclaim_state;
+
+ if (zone_pagecache_reclaimable(zone) > zone->min_unmapped_pages) {
+ /*
+ * Free memory by calling shrink zone with increasing
+ * priorities until we have enough memory freed.
+ */
+ priority = ZONE_RECLAIM_PRIORITY;
+ do {
+ shrink_zone(priority, zone, &sc);
+ priority--;
+ } while (priority >= 0 && sc.nr_reclaimed < nr_pages);
+ }
+
+ nr_slab_pages0 = zone_page_state(zone, NR_SLAB_RECLAIMABLE);
+ if (nr_slab_pages0 > zone->min_slab_pages) {
+ /*
+ * shrink_slab() does not currently allow us to determine how
+ * many pages were freed in this zone. So we take the current
+ * number of slab pages and shake the slab until it is reduced
+ * by the same nr_pages that we used for reclaiming unmapped
+ * pages.
+ *
+ * Note that shrink_slab will free memory on all zones and may
+ * take a long time.
+ */
+ for (;;) {
+ unsigned long lru_pages = zone_reclaimable_pages(zone);
+
+ /* No reclaimable slab or very low memory pressure */
+ if (!shrink_slab(&shrink, sc.nr_scanned, lru_pages))
+ break;
+
+ /* Freed enough memory */
+ nr_slab_pages1 = zone_page_state(zone,
+ NR_SLAB_RECLAIMABLE);
+ if (nr_slab_pages1 + nr_pages <= nr_slab_pages0)
+ break;
+ }
+
+ /*
+ * Update nr_reclaimed by the number of slab pages we
+ * reclaimed from this zone.
+ */
+ nr_slab_pages1 = zone_page_state(zone, NR_SLAB_RECLAIMABLE);
+ if (nr_slab_pages1 < nr_slab_pages0)
+ sc.nr_reclaimed += nr_slab_pages0 - nr_slab_pages1;
+ }
+
+ p->reclaim_state = NULL;
+ current->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE);
+ lockdep_clear_current_reclaim_state();
+ return sc.nr_reclaimed >= nr_pages;
+}
+
+int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
+{
+ int node_id;
+ int ret;
+
+ /*
+ * Zone reclaim reclaims unmapped file backed pages and
+ * slab pages if we are over the defined limits.
+ *
+ * A small portion of unmapped file backed pages is needed for
+ * file I/O otherwise pages read by file I/O will be immediately
+ * thrown out if the zone is overallocated. So we do not reclaim
+ * if less than a specified percentage of the zone is used by
+ * unmapped file backed pages.
+ */
+ if (zone_pagecache_reclaimable(zone) <= zone->min_unmapped_pages &&
+ zone_page_state(zone, NR_SLAB_RECLAIMABLE) <= zone->min_slab_pages)
+ return ZONE_RECLAIM_FULL;
+
+ if (zone->all_unreclaimable)
+ return ZONE_RECLAIM_FULL;
+
+ /*
+ * Do not scan if the allocation should not be delayed.
+ */
+ if (!(gfp_mask & __GFP_WAIT) || (current->flags & PF_MEMALLOC))
+ return ZONE_RECLAIM_NOSCAN;
+
+ /*
+ * Only run zone reclaim on the local zone or on zones that do not
+ * have associated processors. This will favor the local processor
+ * over remote processors and spread off node memory allocations
+ * as wide as possible.
+ */
+ node_id = zone_to_nid(zone);
+ if (node_state(node_id, N_CPU) && node_id != numa_node_id())
+ return ZONE_RECLAIM_NOSCAN;
+
+ if (zone_test_and_set_flag(zone, ZONE_RECLAIM_LOCKED))
+ return ZONE_RECLAIM_NOSCAN;
+
+ ret = __zone_reclaim(zone, gfp_mask, order);
+ zone_clear_flag(zone, ZONE_RECLAIM_LOCKED);
+
+ if (!ret)
+ count_vm_event(PGSCAN_ZONE_RECLAIM_FAILED);
+
+ return ret;
+}
+#endif
+
+/*
+ * page_evictable - test whether a page is evictable
+ * @page: the page to test
+ * @vma: the VMA in which the page is or will be mapped, may be NULL
+ *
+ * Test whether page is evictable--i.e., should be placed on active/inactive
+ * lists vs unevictable list. The vma argument is !NULL when called from the
+ * fault path to determine how to instantate a new page.
+ *
+ * Reasons page might not be evictable:
+ * (1) page's mapping marked unevictable
+ * (2) page is part of an mlocked VMA
+ *
+ */
+int page_evictable(struct page *page, struct vm_area_struct *vma)
+{
+
+ if (mapping_unevictable(page_mapping(page)))
+ return 0;
+
+ if (PageMlocked(page) || (vma && is_mlocked_vma(vma, page)))
+ return 0;
+
+ return 1;
+}
+
+#ifdef CONFIG_SHMEM
+/**
+ * check_move_unevictable_pages - check pages for evictability and move to appropriate zone lru list
+ * @pages: array of pages to check
+ * @nr_pages: number of pages to check
+ *
+ * Checks pages for evictability and moves them to the appropriate lru list.
+ *
+ * This function is only used for SysV IPC SHM_UNLOCK.
+ */
+void check_move_unevictable_pages(struct page **pages, int nr_pages)
+{
+ struct lruvec *lruvec;
+ struct zone *zone = NULL;
+ int pgscanned = 0;
+ int pgrescued = 0;
+ int i;
+
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page = pages[i];
+ struct zone *pagezone;
+
+ pgscanned++;
+ pagezone = page_zone(page);
+ if (pagezone != zone) {
+ if (zone)
+ spin_unlock_irq(&zone->lru_lock);
+ zone = pagezone;
+ spin_lock_irq(&zone->lru_lock);
+ }
+
+ if (!PageLRU(page) || !PageUnevictable(page))
+ continue;
+
+ if (page_evictable(page, NULL)) {
+ enum lru_list lru = page_lru_base_type(page);
+
+ VM_BUG_ON(PageActive(page));
+ ClearPageUnevictable(page);
+ __dec_zone_state(zone, NR_UNEVICTABLE);
+ lruvec = mem_cgroup_lru_move_lists(zone, page,
+ LRU_UNEVICTABLE, lru);
+ list_move(&page->lru, &lruvec->lists[lru]);
+ __inc_zone_state(zone, NR_INACTIVE_ANON + lru);
+ pgrescued++;
+ }
+ }
+
+ if (zone) {
+ __count_vm_events(UNEVICTABLE_PGRESCUED, pgrescued);
+ __count_vm_events(UNEVICTABLE_PGSCANNED, pgscanned);
+ spin_unlock_irq(&zone->lru_lock);
+ }
+}
+#endif /* CONFIG_SHMEM */
+
+static void warn_scan_unevictable_pages(void)
+{
+ printk_once(KERN_WARNING
+ "%s: The scan_unevictable_pages sysctl/node-interface has been "
+ "disabled for lack of a legitimate use case. If you have "
+ "one, please send an email to linux-mm@kvack.org.\n",
+ current->comm);
+}
+
+/*
+ * scan_unevictable_pages [vm] sysctl handler. On demand re-scan of
+ * all nodes' unevictable lists for evictable pages
+ */
+unsigned long scan_unevictable_pages;
+
+int scan_unevictable_handler(struct ctl_table *table, int write,
+ void __user *buffer,
+ size_t *length, loff_t *ppos)
+{
+ warn_scan_unevictable_pages();
+ proc_doulongvec_minmax(table, write, buffer, length, ppos);
+ scan_unevictable_pages = 0;
+ return 0;
+}
+
+#ifdef CONFIG_NUMA
+/*
+ * per node 'scan_unevictable_pages' attribute. On demand re-scan of
+ * a specified node's per zone unevictable lists for evictable pages.
+ */
+
+static ssize_t read_scan_unevictable_node(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ warn_scan_unevictable_pages();
+ return sprintf(buf, "0\n"); /* always zero; should fit... */
+}
+
+static ssize_t write_scan_unevictable_node(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ warn_scan_unevictable_pages();
+ return 1;
+}
+
+
+static DEVICE_ATTR(scan_unevictable_pages, S_IRUGO | S_IWUSR,
+ read_scan_unevictable_node,
+ write_scan_unevictable_node);
+
+int scan_unevictable_register_node(struct node *node)
+{
+ return device_create_file(&node->dev, &dev_attr_scan_unevictable_pages);
+}
+
+void scan_unevictable_unregister_node(struct node *node)
+{
+ device_remove_file(&node->dev, &dev_attr_scan_unevictable_pages);
+}
+#endif
diff --git a/ap/os/linux/linux-3.4.x/mm/vmstat.c b/ap/os/linux/linux-3.4.x/mm/vmstat.c
new file mode 100755
index 0000000..e59d494
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/vmstat.c
@@ -0,0 +1,1385 @@
+/*
+ * linux/mm/vmstat.c
+ *
+ * Manages VM statistics
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * zoned VM statistics
+ * Copyright (C) 2006 Silicon Graphics, Inc.,
+ * Christoph Lameter <christoph@lameter.com>
+ */
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/vmstat.h>
+#include <linux/sched.h>
+#include <linux/math64.h>
+#include <linux/writeback.h>
+#include <linux/compaction.h>
+
+#ifdef CONFIG_VM_EVENT_COUNTERS
+DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
+EXPORT_PER_CPU_SYMBOL(vm_event_states);
+
+static void sum_vm_events(unsigned long *ret)
+{
+ int cpu;
+ int i;
+
+ memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
+
+ for_each_online_cpu(cpu) {
+ struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
+
+ for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
+ ret[i] += this->event[i];
+ }
+}
+
+/*
+ * Accumulate the vm event counters across all CPUs.
+ * The result is unavoidably approximate - it can change
+ * during and after execution of this function.
+*/
+void all_vm_events(unsigned long *ret)
+{
+ get_online_cpus();
+ sum_vm_events(ret);
+ put_online_cpus();
+}
+EXPORT_SYMBOL_GPL(all_vm_events);
+
+#ifdef CONFIG_HOTPLUG
+/*
+ * Fold the foreign cpu events into our own.
+ *
+ * This is adding to the events on one processor
+ * but keeps the global counts constant.
+ */
+void vm_events_fold_cpu(int cpu)
+{
+ struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
+ int i;
+
+ for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
+ count_vm_events(i, fold_state->event[i]);
+ fold_state->event[i] = 0;
+ }
+}
+#endif /* CONFIG_HOTPLUG */
+
+#endif /* CONFIG_VM_EVENT_COUNTERS */
+
+/*
+ * Manage combined zone based / global counters
+ *
+ * vm_stat contains the global counters
+ */
+atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
+EXPORT_SYMBOL(vm_stat);
+
+#ifdef CONFIG_SMP
+
+int calculate_pressure_threshold(struct zone *zone)
+{
+ int threshold;
+ int watermark_distance;
+
+ /*
+ * As vmstats are not up to date, there is drift between the estimated
+ * and real values. For high thresholds and a high number of CPUs, it
+ * is possible for the min watermark to be breached while the estimated
+ * value looks fine. The pressure threshold is a reduced value such
+ * that even the maximum amount of drift will not accidentally breach
+ * the min watermark
+ */
+ watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
+ threshold = max(1, (int)(watermark_distance / num_online_cpus()));
+
+ /*
+ * Maximum threshold is 125
+ */
+ threshold = min(125, threshold);
+
+ return threshold;
+}
+
+int calculate_normal_threshold(struct zone *zone)
+{
+ int threshold;
+ int mem; /* memory in 128 MB units */
+
+ /*
+ * The threshold scales with the number of processors and the amount
+ * of memory per zone. More memory means that we can defer updates for
+ * longer, more processors could lead to more contention.
+ * fls() is used to have a cheap way of logarithmic scaling.
+ *
+ * Some sample thresholds:
+ *
+ * Threshold Processors (fls) Zonesize fls(mem+1)
+ * ------------------------------------------------------------------
+ * 8 1 1 0.9-1 GB 4
+ * 16 2 2 0.9-1 GB 4
+ * 20 2 2 1-2 GB 5
+ * 24 2 2 2-4 GB 6
+ * 28 2 2 4-8 GB 7
+ * 32 2 2 8-16 GB 8
+ * 4 2 2 <128M 1
+ * 30 4 3 2-4 GB 5
+ * 48 4 3 8-16 GB 8
+ * 32 8 4 1-2 GB 4
+ * 32 8 4 0.9-1GB 4
+ * 10 16 5 <128M 1
+ * 40 16 5 900M 4
+ * 70 64 7 2-4 GB 5
+ * 84 64 7 4-8 GB 6
+ * 108 512 9 4-8 GB 6
+ * 125 1024 10 8-16 GB 8
+ * 125 1024 10 16-32 GB 9
+ */
+
+ mem = zone->present_pages >> (27 - PAGE_SHIFT);
+
+ threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
+
+ /*
+ * Maximum threshold is 125
+ */
+ threshold = min(125, threshold);
+
+ return threshold;
+}
+
+/*
+ * Refresh the thresholds for each zone.
+ */
+void refresh_zone_stat_thresholds(void)
+{
+ struct zone *zone;
+ int cpu;
+ int threshold;
+
+ for_each_populated_zone(zone) {
+ unsigned long max_drift, tolerate_drift;
+
+ threshold = calculate_normal_threshold(zone);
+
+ for_each_online_cpu(cpu)
+ per_cpu_ptr(zone->pageset, cpu)->stat_threshold
+ = threshold;
+
+ /*
+ * Only set percpu_drift_mark if there is a danger that
+ * NR_FREE_PAGES reports the low watermark is ok when in fact
+ * the min watermark could be breached by an allocation
+ */
+ tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
+ max_drift = num_online_cpus() * threshold;
+ if (max_drift > tolerate_drift)
+ zone->percpu_drift_mark = high_wmark_pages(zone) +
+ max_drift;
+ }
+}
+
+void set_pgdat_percpu_threshold(pg_data_t *pgdat,
+ int (*calculate_pressure)(struct zone *))
+{
+ struct zone *zone;
+ int cpu;
+ int threshold;
+ int i;
+
+ for (i = 0; i < pgdat->nr_zones; i++) {
+ zone = &pgdat->node_zones[i];
+ if (!zone->percpu_drift_mark)
+ continue;
+
+ threshold = (*calculate_pressure)(zone);
+ for_each_possible_cpu(cpu)
+ per_cpu_ptr(zone->pageset, cpu)->stat_threshold
+ = threshold;
+ }
+}
+
+/*
+ * For use when we know that interrupts are disabled.
+ */
+void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
+ int delta)
+{
+ struct per_cpu_pageset __percpu *pcp = zone->pageset;
+ s8 __percpu *p = pcp->vm_stat_diff + item;
+ long x;
+ long t;
+
+ preempt_disable_rt();
+ x = delta + __this_cpu_read(*p);
+
+ t = __this_cpu_read(pcp->stat_threshold);
+
+ if (unlikely(x > t || x < -t)) {
+ zone_page_state_add(x, zone, item);
+ x = 0;
+ }
+ __this_cpu_write(*p, x);
+ preempt_enable_rt();
+}
+EXPORT_SYMBOL(__mod_zone_page_state);
+
+/*
+ * Optimized increment and decrement functions.
+ *
+ * These are only for a single page and therefore can take a struct page *
+ * argument instead of struct zone *. This allows the inclusion of the code
+ * generated for page_zone(page) into the optimized functions.
+ *
+ * No overflow check is necessary and therefore the differential can be
+ * incremented or decremented in place which may allow the compilers to
+ * generate better code.
+ * The increment or decrement is known and therefore one boundary check can
+ * be omitted.
+ *
+ * NOTE: These functions are very performance sensitive. Change only
+ * with care.
+ *
+ * Some processors have inc/dec instructions that are atomic vs an interrupt.
+ * However, the code must first determine the differential location in a zone
+ * based on the processor number and then inc/dec the counter. There is no
+ * guarantee without disabling preemption that the processor will not change
+ * in between and therefore the atomicity vs. interrupt cannot be exploited
+ * in a useful way here.
+ */
+void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
+{
+ struct per_cpu_pageset __percpu *pcp = zone->pageset;
+ s8 __percpu *p = pcp->vm_stat_diff + item;
+ s8 v, t;
+
+ preempt_disable_rt();
+ v = __this_cpu_inc_return(*p);
+ t = __this_cpu_read(pcp->stat_threshold);
+ if (unlikely(v > t)) {
+ s8 overstep = t >> 1;
+
+ zone_page_state_add(v + overstep, zone, item);
+ __this_cpu_write(*p, -overstep);
+ }
+ preempt_enable_rt();
+}
+
+void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ __inc_zone_state(page_zone(page), item);
+}
+EXPORT_SYMBOL(__inc_zone_page_state);
+
+void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
+{
+ struct per_cpu_pageset __percpu *pcp = zone->pageset;
+ s8 __percpu *p = pcp->vm_stat_diff + item;
+ s8 v, t;
+
+ preempt_disable_rt();
+ v = __this_cpu_dec_return(*p);
+ t = __this_cpu_read(pcp->stat_threshold);
+ if (unlikely(v < - t)) {
+ s8 overstep = t >> 1;
+
+ zone_page_state_add(v - overstep, zone, item);
+ __this_cpu_write(*p, overstep);
+ }
+ preempt_enable_rt();
+}
+
+void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ __dec_zone_state(page_zone(page), item);
+}
+EXPORT_SYMBOL(__dec_zone_page_state);
+
+#ifdef CONFIG_HAVE_CMPXCHG_LOCAL
+/*
+ * If we have cmpxchg_local support then we do not need to incur the overhead
+ * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
+ *
+ * mod_state() modifies the zone counter state through atomic per cpu
+ * operations.
+ *
+ * Overstep mode specifies how overstep should handled:
+ * 0 No overstepping
+ * 1 Overstepping half of threshold
+ * -1 Overstepping minus half of threshold
+*/
+static inline void mod_state(struct zone *zone,
+ enum zone_stat_item item, int delta, int overstep_mode)
+{
+ struct per_cpu_pageset __percpu *pcp = zone->pageset;
+ s8 __percpu *p = pcp->vm_stat_diff + item;
+ long o, n, t, z;
+
+ do {
+ z = 0; /* overflow to zone counters */
+
+ /*
+ * The fetching of the stat_threshold is racy. We may apply
+ * a counter threshold to the wrong the cpu if we get
+ * rescheduled while executing here. However, the next
+ * counter update will apply the threshold again and
+ * therefore bring the counter under the threshold again.
+ *
+ * Most of the time the thresholds are the same anyways
+ * for all cpus in a zone.
+ */
+ t = this_cpu_read(pcp->stat_threshold);
+
+ o = this_cpu_read(*p);
+ n = delta + o;
+
+ if (n > t || n < -t) {
+ int os = overstep_mode * (t >> 1) ;
+
+ /* Overflow must be added to zone counters */
+ z = n + os;
+ n = -os;
+ }
+ } while (this_cpu_cmpxchg(*p, o, n) != o);
+
+ if (z)
+ zone_page_state_add(z, zone, item);
+}
+
+void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
+ int delta)
+{
+ mod_state(zone, item, delta, 0);
+}
+EXPORT_SYMBOL(mod_zone_page_state);
+
+void inc_zone_state(struct zone *zone, enum zone_stat_item item)
+{
+ mod_state(zone, item, 1, 1);
+}
+
+void inc_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ mod_state(page_zone(page), item, 1, 1);
+}
+EXPORT_SYMBOL(inc_zone_page_state);
+
+void dec_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ mod_state(page_zone(page), item, -1, -1);
+}
+EXPORT_SYMBOL(dec_zone_page_state);
+#else
+/*
+ * Use interrupt disable to serialize counter updates
+ */
+void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
+ int delta)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __mod_zone_page_state(zone, item, delta);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(mod_zone_page_state);
+
+void inc_zone_state(struct zone *zone, enum zone_stat_item item)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __inc_zone_state(zone, item);
+ local_irq_restore(flags);
+}
+
+void inc_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ unsigned long flags;
+ struct zone *zone;
+
+ zone = page_zone(page);
+ local_irq_save(flags);
+ __inc_zone_state(zone, item);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(inc_zone_page_state);
+
+void dec_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __dec_zone_page_state(page, item);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(dec_zone_page_state);
+#endif
+
+/*
+ * Update the zone counters for one cpu.
+ *
+ * The cpu specified must be either the current cpu or a processor that
+ * is not online. If it is the current cpu then the execution thread must
+ * be pinned to the current cpu.
+ *
+ * Note that refresh_cpu_vm_stats strives to only access
+ * node local memory. The per cpu pagesets on remote zones are placed
+ * in the memory local to the processor using that pageset. So the
+ * loop over all zones will access a series of cachelines local to
+ * the processor.
+ *
+ * The call to zone_page_state_add updates the cachelines with the
+ * statistics in the remote zone struct as well as the global cachelines
+ * with the global counters. These could cause remote node cache line
+ * bouncing and will have to be only done when necessary.
+ */
+void refresh_cpu_vm_stats(int cpu)
+{
+ struct zone *zone;
+ int i;
+ int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+
+ for_each_populated_zone(zone) {
+ struct per_cpu_pageset *p;
+
+ p = per_cpu_ptr(zone->pageset, cpu);
+
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ if (p->vm_stat_diff[i]) {
+ unsigned long flags;
+ int v;
+
+ local_irq_save(flags);
+ v = p->vm_stat_diff[i];
+ p->vm_stat_diff[i] = 0;
+ local_irq_restore(flags);
+ atomic_long_add(v, &zone->vm_stat[i]);
+ global_diff[i] += v;
+#ifdef CONFIG_NUMA
+ /* 3 seconds idle till flush */
+ p->expire = 3;
+#endif
+ }
+ cond_resched();
+#ifdef CONFIG_NUMA
+ /*
+ * Deal with draining the remote pageset of this
+ * processor
+ *
+ * Check if there are pages remaining in this pageset
+ * if not then there is nothing to expire.
+ */
+ if (!p->expire || !p->pcp.count)
+ continue;
+
+ /*
+ * We never drain zones local to this processor.
+ */
+ if (zone_to_nid(zone) == numa_node_id()) {
+ p->expire = 0;
+ continue;
+ }
+
+ p->expire--;
+ if (p->expire)
+ continue;
+
+ if (p->pcp.count)
+ drain_zone_pages(zone, &p->pcp);
+#endif
+ }
+
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ if (global_diff[i])
+ atomic_long_add(global_diff[i], &vm_stat[i]);
+}
+
+#endif
+
+#ifdef CONFIG_NUMA
+/*
+ * zonelist = the list of zones passed to the allocator
+ * z = the zone from which the allocation occurred.
+ *
+ * Must be called with interrupts disabled.
+ *
+ * When __GFP_OTHER_NODE is set assume the node of the preferred
+ * zone is the local node. This is useful for daemons who allocate
+ * memory on behalf of other processes.
+ */
+void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
+{
+ if (z->zone_pgdat == preferred_zone->zone_pgdat) {
+ __inc_zone_state(z, NUMA_HIT);
+ } else {
+ __inc_zone_state(z, NUMA_MISS);
+ __inc_zone_state(preferred_zone, NUMA_FOREIGN);
+ }
+ if (z->node == ((flags & __GFP_OTHER_NODE) ?
+ preferred_zone->node : numa_node_id()))
+ __inc_zone_state(z, NUMA_LOCAL);
+ else
+ __inc_zone_state(z, NUMA_OTHER);
+}
+#endif
+
+#ifdef CONFIG_COMPACTION
+
+struct contig_page_info {
+ unsigned long free_pages;
+ unsigned long free_blocks_total;
+ unsigned long free_blocks_suitable;
+};
+
+/*
+ * Calculate the number of free pages in a zone, how many contiguous
+ * pages are free and how many are large enough to satisfy an allocation of
+ * the target size. Note that this function makes no attempt to estimate
+ * how many suitable free blocks there *might* be if MOVABLE pages were
+ * migrated. Calculating that is possible, but expensive and can be
+ * figured out from userspace
+ */
+static void fill_contig_page_info(struct zone *zone,
+ unsigned int suitable_order,
+ struct contig_page_info *info)
+{
+ unsigned int order;
+
+ info->free_pages = 0;
+ info->free_blocks_total = 0;
+ info->free_blocks_suitable = 0;
+
+ for (order = 0; order < MAX_ORDER; order++) {
+ unsigned long blocks;
+
+ /* Count number of free blocks */
+ blocks = zone->free_area[order].nr_free;
+ info->free_blocks_total += blocks;
+
+ /* Count free base pages */
+ info->free_pages += blocks << order;
+
+ /* Count the suitable free blocks */
+ if (order >= suitable_order)
+ info->free_blocks_suitable += blocks <<
+ (order - suitable_order);
+ }
+}
+
+/*
+ * A fragmentation index only makes sense if an allocation of a requested
+ * size would fail. If that is true, the fragmentation index indicates
+ * whether external fragmentation or a lack of memory was the problem.
+ * The value can be used to determine if page reclaim or compaction
+ * should be used
+ */
+static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
+{
+ unsigned long requested = 1UL << order;
+
+ if (!info->free_blocks_total)
+ return 0;
+
+ /* Fragmentation index only makes sense when a request would fail */
+ if (info->free_blocks_suitable)
+ return -1000;
+
+ /*
+ * Index is between 0 and 1 so return within 3 decimal places
+ *
+ * 0 => allocation would fail due to lack of memory
+ * 1 => allocation would fail due to fragmentation
+ */
+ return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
+}
+
+/* Same as __fragmentation index but allocs contig_page_info on stack */
+int fragmentation_index(struct zone *zone, unsigned int order)
+{
+ struct contig_page_info info;
+
+ fill_contig_page_info(zone, order, &info);
+ return __fragmentation_index(order, &info);
+}
+#endif
+
+#if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+static char * const migratetype_names[MIGRATE_TYPES] = {
+ "Unmovable",
+ "Reclaimable",
+ "Movable",
+ "Reserve",
+ "Isolate",
+};
+
+static void *frag_start(struct seq_file *m, loff_t *pos)
+{
+ pg_data_t *pgdat;
+ loff_t node = *pos;
+ for (pgdat = first_online_pgdat();
+ pgdat && node;
+ pgdat = next_online_pgdat(pgdat))
+ --node;
+
+ return pgdat;
+}
+
+static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ (*pos)++;
+ return next_online_pgdat(pgdat);
+}
+
+static void frag_stop(struct seq_file *m, void *arg)
+{
+}
+
+/* Walk all the zones in a node and print using a callback */
+static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
+ void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
+{
+ struct zone *zone;
+ struct zone *node_zones = pgdat->node_zones;
+ unsigned long flags;
+
+ for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
+ if (!populated_zone(zone))
+ continue;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ print(m, pgdat, zone);
+ spin_unlock_irqrestore(&zone->lock, flags);
+ }
+}
+#endif
+
+#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
+#ifdef CONFIG_ZONE_DMA
+#define TEXT_FOR_DMA(xx) xx "_dma",
+#else
+#define TEXT_FOR_DMA(xx)
+#endif
+
+#ifdef CONFIG_ZONE_DMA32
+#define TEXT_FOR_DMA32(xx) xx "_dma32",
+#else
+#define TEXT_FOR_DMA32(xx)
+#endif
+
+#ifdef CONFIG_HIGHMEM
+#define TEXT_FOR_HIGHMEM(xx) xx "_high",
+#else
+#define TEXT_FOR_HIGHMEM(xx)
+#endif
+
+#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
+ TEXT_FOR_HIGHMEM(xx) xx "_movable",
+
+const char * const vmstat_text[] = {
+ /* Zoned VM counters */
+ "nr_free_pages",
+ "nr_inactive_anon",
+ "nr_active_anon",
+ "nr_inactive_file",
+ "nr_active_file",
+ "nr_unevictable",
+ "nr_mlock",
+ "nr_anon_pages",
+ "nr_mapped",
+ "nr_file_pages",
+ "nr_dirty",
+ "nr_writeback",
+ "nr_slab_reclaimable",
+ "nr_slab_unreclaimable",
+ "nr_page_table_pages",
+ "nr_kernel_stack",
+ "nr_unstable",
+ "nr_bounce",
+ "nr_vmscan_write",
+ "nr_vmscan_immediate_reclaim",
+ "nr_writeback_temp",
+ "nr_isolated_anon",
+ "nr_isolated_file",
+ "nr_shmem",
+ "nr_dirtied",
+ "nr_written",
+
+#ifdef CONFIG_NUMA
+ "numa_hit",
+ "numa_miss",
+ "numa_foreign",
+ "numa_interleave",
+ "numa_local",
+ "numa_other",
+#endif
+ "nr_anon_transparent_hugepages",
+ "nr_dirty_threshold",
+ "nr_dirty_background_threshold",
+
+#ifdef CONFIG_VM_EVENT_COUNTERS
+ "pgpgin",
+ "pgpgout",
+ "pswpin",
+ "pswpout",
+
+ TEXTS_FOR_ZONES("pgalloc")
+
+ "pgfree",
+ "pgactivate",
+ "pgdeactivate",
+
+ "pgfault",
+ "pgmajfault",
+
+ TEXTS_FOR_ZONES("pgrefill")
+ TEXTS_FOR_ZONES("pgsteal_kswapd")
+ TEXTS_FOR_ZONES("pgsteal_direct")
+ TEXTS_FOR_ZONES("pgscan_kswapd")
+ TEXTS_FOR_ZONES("pgscan_direct")
+
+#ifdef CONFIG_NUMA
+ "zone_reclaim_failed",
+#endif
+ "pginodesteal",
+ "slabs_scanned",
+ "kswapd_inodesteal",
+ "kswapd_low_wmark_hit_quickly",
+ "kswapd_high_wmark_hit_quickly",
+ "kswapd_skip_congestion_wait",
+ "pageoutrun",
+ "allocstall",
+
+ "pgrotated",
+
+#ifdef CONFIG_COMPACTION
+ "compact_blocks_moved",
+ "compact_pages_moved",
+ "compact_pagemigrate_failed",
+ "compact_stall",
+ "compact_fail",
+ "compact_success",
+#endif
+
+#ifdef CONFIG_HUGETLB_PAGE
+ "htlb_buddy_alloc_success",
+ "htlb_buddy_alloc_fail",
+#endif
+ "unevictable_pgs_culled",
+ "unevictable_pgs_scanned",
+ "unevictable_pgs_rescued",
+ "unevictable_pgs_mlocked",
+ "unevictable_pgs_munlocked",
+ "unevictable_pgs_cleared",
+ "unevictable_pgs_stranded",
+ "unevictable_pgs_mlockfreed",
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ "thp_fault_alloc",
+ "thp_fault_fallback",
+ "thp_collapse_alloc",
+ "thp_collapse_alloc_failed",
+ "thp_split",
+#endif
+
+#endif /* CONFIG_VM_EVENTS_COUNTERS */
+};
+#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
+
+
+#ifdef CONFIG_PROC_FS
+static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
+ struct zone *zone)
+{
+ int order;
+
+ seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
+ for (order = 0; order < MAX_ORDER; ++order)
+ seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
+ seq_putc(m, '\n');
+}
+
+/*
+ * This walks the free areas for each zone.
+ */
+static int frag_show(struct seq_file *m, void *arg)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+ walk_zones_in_node(m, pgdat, frag_show_print);
+ return 0;
+}
+
+static void pagetypeinfo_showfree_print(struct seq_file *m,
+ pg_data_t *pgdat, struct zone *zone)
+{
+ int order, mtype;
+
+ for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
+ seq_printf(m, "Node %4d, zone %8s, type %12s ",
+ pgdat->node_id,
+ zone->name,
+ migratetype_names[mtype]);
+ for (order = 0; order < MAX_ORDER; ++order) {
+ unsigned long freecount = 0;
+ struct free_area *area;
+ struct list_head *curr;
+
+ area = &(zone->free_area[order]);
+
+ list_for_each(curr, &area->free_list[mtype])
+ freecount++;
+ seq_printf(m, "%6lu ", freecount);
+ }
+ seq_putc(m, '\n');
+ }
+}
+
+/* Print out the free pages at each order for each migatetype */
+static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
+{
+ int order;
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ /* Print header */
+ seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
+ for (order = 0; order < MAX_ORDER; ++order)
+ seq_printf(m, "%6d ", order);
+ seq_putc(m, '\n');
+
+ walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
+
+ return 0;
+}
+
+static void pagetypeinfo_showblockcount_print(struct seq_file *m,
+ pg_data_t *pgdat, struct zone *zone)
+{
+ int mtype;
+ unsigned long pfn;
+ unsigned long start_pfn = zone->zone_start_pfn;
+ unsigned long end_pfn = start_pfn + zone->spanned_pages;
+ unsigned long count[MIGRATE_TYPES] = { 0, };
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
+ struct page *page;
+
+ if (!pfn_valid(pfn))
+ continue;
+
+ page = pfn_to_page(pfn);
+
+ /* Watch for unexpected holes punched in the memmap */
+ if (!memmap_valid_within(pfn, page, zone))
+ continue;
+
+ mtype = get_pageblock_migratetype(page);
+
+ if (mtype < MIGRATE_TYPES)
+ count[mtype]++;
+ }
+
+ /* Print counts */
+ seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
+ for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
+ seq_printf(m, "%12lu ", count[mtype]);
+ seq_putc(m, '\n');
+}
+
+/* Print out the free pages at each order for each migratetype */
+static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
+{
+ int mtype;
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ seq_printf(m, "\n%-23s", "Number of blocks type ");
+ for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
+ seq_printf(m, "%12s ", migratetype_names[mtype]);
+ seq_putc(m, '\n');
+ walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
+
+ return 0;
+}
+
+/*
+ * This prints out statistics in relation to grouping pages by mobility.
+ * It is expensive to collect so do not constantly read the file.
+ */
+static int pagetypeinfo_show(struct seq_file *m, void *arg)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ /* check memoryless node */
+ if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
+ return 0;
+
+ seq_printf(m, "Page block order: %d\n", pageblock_order);
+ seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
+ seq_putc(m, '\n');
+ pagetypeinfo_showfree(m, pgdat);
+ pagetypeinfo_showblockcount(m, pgdat);
+
+ return 0;
+}
+
+static const struct seq_operations fragmentation_op = {
+ .start = frag_start,
+ .next = frag_next,
+ .stop = frag_stop,
+ .show = frag_show,
+};
+
+static int fragmentation_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &fragmentation_op);
+}
+
+static const struct file_operations fragmentation_file_operations = {
+ .open = fragmentation_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static const struct seq_operations pagetypeinfo_op = {
+ .start = frag_start,
+ .next = frag_next,
+ .stop = frag_stop,
+ .show = pagetypeinfo_show,
+};
+
+static int pagetypeinfo_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &pagetypeinfo_op);
+}
+
+static const struct file_operations pagetypeinfo_file_ops = {
+ .open = pagetypeinfo_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
+ struct zone *zone)
+{
+ int i;
+ seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
+ seq_printf(m,
+ "\n pages free %lu"
+ "\n min %lu"
+ "\n low %lu"
+ "\n high %lu"
+ "\n scanned %lu"
+ "\n spanned %lu"
+ "\n present %lu",
+ zone_page_state(zone, NR_FREE_PAGES),
+ min_wmark_pages(zone),
+ low_wmark_pages(zone),
+ high_wmark_pages(zone),
+ zone->pages_scanned,
+ zone->spanned_pages,
+ zone->present_pages);
+
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ seq_printf(m, "\n %-12s %lu", vmstat_text[i],
+ zone_page_state(zone, i));
+
+ seq_printf(m,
+ "\n protection: (%lu",
+ zone->lowmem_reserve[0]);
+ for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
+ seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
+ seq_printf(m,
+ ")"
+ "\n pagesets");
+ for_each_online_cpu(i) {
+ struct per_cpu_pageset *pageset;
+
+ pageset = per_cpu_ptr(zone->pageset, i);
+ seq_printf(m,
+ "\n cpu: %i"
+ "\n count: %i"
+ "\n high: %i"
+ "\n batch: %i",
+ i,
+ pageset->pcp.count,
+ pageset->pcp.high,
+ pageset->pcp.batch);
+#ifdef CONFIG_SMP
+ seq_printf(m, "\n vm stats threshold: %d",
+ pageset->stat_threshold);
+#endif
+ }
+ seq_printf(m,
+ "\n all_unreclaimable: %u"
+ "\n start_pfn: %lu"
+ "\n inactive_ratio: %u",
+ zone->all_unreclaimable,
+ zone->zone_start_pfn,
+ zone->inactive_ratio);
+ seq_putc(m, '\n');
+}
+
+/*
+ * Output information about zones in @pgdat.
+ */
+static int zoneinfo_show(struct seq_file *m, void *arg)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+ walk_zones_in_node(m, pgdat, zoneinfo_show_print);
+ return 0;
+}
+
+static const struct seq_operations zoneinfo_op = {
+ .start = frag_start, /* iterate over all zones. The same as in
+ * fragmentation. */
+ .next = frag_next,
+ .stop = frag_stop,
+ .show = zoneinfo_show,
+};
+
+static int zoneinfo_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &zoneinfo_op);
+}
+
+static const struct file_operations proc_zoneinfo_file_operations = {
+ .open = zoneinfo_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+enum writeback_stat_item {
+ NR_DIRTY_THRESHOLD,
+ NR_DIRTY_BG_THRESHOLD,
+ NR_VM_WRITEBACK_STAT_ITEMS,
+};
+
+static void *vmstat_start(struct seq_file *m, loff_t *pos)
+{
+ unsigned long *v;
+ int i, stat_items_size;
+
+ if (*pos >= ARRAY_SIZE(vmstat_text))
+ return NULL;
+ stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
+ NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
+
+#ifdef CONFIG_VM_EVENT_COUNTERS
+ stat_items_size += sizeof(struct vm_event_state);
+#endif
+
+ v = kmalloc(stat_items_size, GFP_KERNEL);
+ m->private = v;
+ if (!v)
+ return ERR_PTR(-ENOMEM);
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ v[i] = global_page_state(i);
+ v += NR_VM_ZONE_STAT_ITEMS;
+
+ global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
+ v + NR_DIRTY_THRESHOLD);
+ v += NR_VM_WRITEBACK_STAT_ITEMS;
+
+#ifdef CONFIG_VM_EVENT_COUNTERS
+ all_vm_events(v);
+ v[PGPGIN] /= 2; /* sectors -> kbytes */
+ v[PGPGOUT] /= 2;
+#endif
+ return (unsigned long *)m->private + *pos;
+}
+
+static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
+{
+ (*pos)++;
+ if (*pos >= ARRAY_SIZE(vmstat_text))
+ return NULL;
+ return (unsigned long *)m->private + *pos;
+}
+
+static int vmstat_show(struct seq_file *m, void *arg)
+{
+ unsigned long *l = arg;
+ unsigned long off = l - (unsigned long *)m->private;
+
+ seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
+ return 0;
+}
+
+static void vmstat_stop(struct seq_file *m, void *arg)
+{
+ kfree(m->private);
+ m->private = NULL;
+}
+
+static const struct seq_operations vmstat_op = {
+ .start = vmstat_start,
+ .next = vmstat_next,
+ .stop = vmstat_stop,
+ .show = vmstat_show,
+};
+
+static int vmstat_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &vmstat_op);
+}
+
+static const struct file_operations proc_vmstat_file_operations = {
+ .open = vmstat_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+#endif /* CONFIG_PROC_FS */
+
+#ifdef CONFIG_SMP
+static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
+int sysctl_stat_interval __read_mostly = HZ;
+
+static void vmstat_update(struct work_struct *w)
+{
+ refresh_cpu_vm_stats(smp_processor_id());
+ schedule_delayed_work(&__get_cpu_var(vmstat_work),
+ round_jiffies_relative(sysctl_stat_interval));
+}
+
+static void __cpuinit start_cpu_timer(int cpu)
+{
+ struct delayed_work *work = &per_cpu(vmstat_work, cpu);
+
+ INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
+ schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
+}
+
+/*
+ * Use the cpu notifier to insure that the thresholds are recalculated
+ * when necessary.
+ */
+static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
+ unsigned long action,
+ void *hcpu)
+{
+ long cpu = (long)hcpu;
+
+ switch (action) {
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ refresh_zone_stat_thresholds();
+ start_cpu_timer(cpu);
+ node_set_state(cpu_to_node(cpu), N_CPU);
+ break;
+ case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
+ cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
+ per_cpu(vmstat_work, cpu).work.func = NULL;
+ break;
+ case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
+ start_cpu_timer(cpu);
+ break;
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ refresh_zone_stat_thresholds();
+ break;
+ default:
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata vmstat_notifier =
+ { &vmstat_cpuup_callback, NULL, 0 };
+#endif
+
+static int __init setup_vmstat(void)
+{
+#ifdef CONFIG_SMP
+ int cpu;
+
+ register_cpu_notifier(&vmstat_notifier);
+
+ for_each_online_cpu(cpu)
+ start_cpu_timer(cpu);
+#endif
+#ifdef CONFIG_PROC_FS
+ if (!IS_ENABLED(CONFIG_PROC_STRIPPED)) {
+ proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
+ proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
+ proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
+ }
+ proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
+#endif
+ return 0;
+}
+module_init(setup_vmstat)
+
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
+#include <linux/debugfs.h>
+
+static struct dentry *extfrag_debug_root;
+
+/*
+ * Return an index indicating how much of the available free memory is
+ * unusable for an allocation of the requested size.
+ */
+static int unusable_free_index(unsigned int order,
+ struct contig_page_info *info)
+{
+ /* No free memory is interpreted as all free memory is unusable */
+ if (info->free_pages == 0)
+ return 1000;
+
+ /*
+ * Index should be a value between 0 and 1. Return a value to 3
+ * decimal places.
+ *
+ * 0 => no fragmentation
+ * 1 => high fragmentation
+ */
+ return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
+
+}
+
+static void unusable_show_print(struct seq_file *m,
+ pg_data_t *pgdat, struct zone *zone)
+{
+ unsigned int order;
+ int index;
+ struct contig_page_info info;
+
+ seq_printf(m, "Node %d, zone %8s ",
+ pgdat->node_id,
+ zone->name);
+ for (order = 0; order < MAX_ORDER; ++order) {
+ fill_contig_page_info(zone, order, &info);
+ index = unusable_free_index(order, &info);
+ seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
+ }
+
+ seq_putc(m, '\n');
+}
+
+/*
+ * Display unusable free space index
+ *
+ * The unusable free space index measures how much of the available free
+ * memory cannot be used to satisfy an allocation of a given size and is a
+ * value between 0 and 1. The higher the value, the more of free memory is
+ * unusable and by implication, the worse the external fragmentation is. This
+ * can be expressed as a percentage by multiplying by 100.
+ */
+static int unusable_show(struct seq_file *m, void *arg)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ /* check memoryless node */
+ if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
+ return 0;
+
+ walk_zones_in_node(m, pgdat, unusable_show_print);
+
+ return 0;
+}
+
+static const struct seq_operations unusable_op = {
+ .start = frag_start,
+ .next = frag_next,
+ .stop = frag_stop,
+ .show = unusable_show,
+};
+
+static int unusable_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &unusable_op);
+}
+
+static const struct file_operations unusable_file_ops = {
+ .open = unusable_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static void extfrag_show_print(struct seq_file *m,
+ pg_data_t *pgdat, struct zone *zone)
+{
+ unsigned int order;
+ int index;
+
+ /* Alloc on stack as interrupts are disabled for zone walk */
+ struct contig_page_info info;
+
+ seq_printf(m, "Node %d, zone %8s ",
+ pgdat->node_id,
+ zone->name);
+ for (order = 0; order < MAX_ORDER; ++order) {
+ fill_contig_page_info(zone, order, &info);
+ index = __fragmentation_index(order, &info);
+ seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
+ }
+
+ seq_putc(m, '\n');
+}
+
+/*
+ * Display fragmentation index for orders that allocations would fail for
+ */
+static int extfrag_show(struct seq_file *m, void *arg)
+{
+ pg_data_t *pgdat = (pg_data_t *)arg;
+
+ walk_zones_in_node(m, pgdat, extfrag_show_print);
+
+ return 0;
+}
+
+static const struct seq_operations extfrag_op = {
+ .start = frag_start,
+ .next = frag_next,
+ .stop = frag_stop,
+ .show = extfrag_show,
+};
+
+static int extfrag_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &extfrag_op);
+}
+
+static const struct file_operations extfrag_file_ops = {
+ .open = extfrag_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static int __init extfrag_debug_init(void)
+{
+ extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
+ if (!extfrag_debug_root)
+ return -ENOMEM;
+
+ if (!debugfs_create_file("unusable_index", 0444,
+ extfrag_debug_root, NULL, &unusable_file_ops))
+ return -ENOMEM;
+
+ if (!debugfs_create_file("extfrag_index", 0444,
+ extfrag_debug_root, NULL, &extfrag_file_ops))
+ return -ENOMEM;
+
+ return 0;
+}
+
+module_init(extfrag_debug_init);
+#endif