| # |
| # General architecture dependent options |
| # |
| |
| config OPROFILE |
| tristate "OProfile system profiling" |
| depends on PROFILING |
| depends on HAVE_OPROFILE |
| depends on !PREEMPT_RT_FULL |
| select RING_BUFFER |
| select RING_BUFFER_ALLOW_SWAP |
| help |
| OProfile is a profiling system capable of profiling the |
| whole system, include the kernel, kernel modules, libraries, |
| and applications. |
| |
| If unsure, say N. |
| |
| config OPROFILE_EVENT_MULTIPLEX |
| bool "OProfile multiplexing support (EXPERIMENTAL)" |
| default n |
| depends on OPROFILE && X86 |
| help |
| The number of hardware counters is limited. The multiplexing |
| feature enables OProfile to gather more events than counters |
| are provided by the hardware. This is realized by switching |
| between events at an user specified time interval. |
| |
| If unsure, say N. |
| |
| config HAVE_OPROFILE |
| bool |
| |
| config OPROFILE_NMI_TIMER |
| def_bool y |
| depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI |
| |
| config KPROBES |
| bool "Kprobes" |
| depends on MODULES |
| depends on HAVE_KPROBES |
| select KALLSYMS |
| help |
| Kprobes allows you to trap at almost any kernel address and |
| execute a callback function. register_kprobe() establishes |
| a probepoint and specifies the callback. Kprobes is useful |
| for kernel debugging, non-intrusive instrumentation and testing. |
| If in doubt, say "N". |
| |
| config JUMP_LABEL |
| bool "Optimize very unlikely/likely branches" |
| depends on HAVE_ARCH_JUMP_LABEL |
| depends on (!INTERRUPT_OFF_HIST && !PREEMPT_OFF_HIST && !WAKEUP_LATENCY_HIST && !MISSED_TIMER_OFFSETS_HIST) |
| help |
| This option enables a transparent branch optimization that |
| makes certain almost-always-true or almost-always-false branch |
| conditions even cheaper to execute within the kernel. |
| |
| Certain performance-sensitive kernel code, such as trace points, |
| scheduler functionality, networking code and KVM have such |
| branches and include support for this optimization technique. |
| |
| If it is detected that the compiler has support for "asm goto", |
| the kernel will compile such branches with just a nop |
| instruction. When the condition flag is toggled to true, the |
| nop will be converted to a jump instruction to execute the |
| conditional block of instructions. |
| |
| This technique lowers overhead and stress on the branch prediction |
| of the processor and generally makes the kernel faster. The update |
| of the condition is slower, but those are always very rare. |
| |
| ( On 32-bit x86, the necessary options added to the compiler |
| flags may increase the size of the kernel slightly. ) |
| |
| config OPTPROBES |
| def_bool y |
| depends on KPROBES && HAVE_OPTPROBES |
| depends on !PREEMPT |
| |
| config HAVE_EFFICIENT_UNALIGNED_ACCESS |
| bool |
| help |
| Some architectures are unable to perform unaligned accesses |
| without the use of get_unaligned/put_unaligned. Others are |
| unable to perform such accesses efficiently (e.g. trap on |
| unaligned access and require fixing it up in the exception |
| handler.) |
| |
| This symbol should be selected by an architecture if it can |
| perform unaligned accesses efficiently to allow different |
| code paths to be selected for these cases. Some network |
| drivers, for example, could opt to not fix up alignment |
| problems with received packets if doing so would not help |
| much. |
| |
| See Documentation/unaligned-memory-access.txt for more |
| information on the topic of unaligned memory accesses. |
| |
| config HAVE_SYSCALL_WRAPPERS |
| bool |
| |
| config KRETPROBES |
| def_bool y |
| depends on KPROBES && HAVE_KRETPROBES |
| |
| config USER_RETURN_NOTIFIER |
| bool |
| depends on HAVE_USER_RETURN_NOTIFIER |
| help |
| Provide a kernel-internal notification when a cpu is about to |
| switch to user mode. |
| |
| config HAVE_IOREMAP_PROT |
| bool |
| |
| config HAVE_KPROBES |
| bool |
| |
| config HAVE_KRETPROBES |
| bool |
| |
| config HAVE_OPTPROBES |
| bool |
| |
| config HAVE_NMI_WATCHDOG |
| bool |
| # |
| # An arch should select this if it provides all these things: |
| # |
| # task_pt_regs() in asm/processor.h or asm/ptrace.h |
| # arch_has_single_step() if there is hardware single-step support |
| # arch_has_block_step() if there is hardware block-step support |
| # asm/syscall.h supplying asm-generic/syscall.h interface |
| # linux/regset.h user_regset interfaces |
| # CORE_DUMP_USE_REGSET #define'd in linux/elf.h |
| # TIF_SYSCALL_TRACE calls tracehook_report_syscall_{entry,exit} |
| # TIF_NOTIFY_RESUME calls tracehook_notify_resume() |
| # signal delivery calls tracehook_signal_handler() |
| # |
| config HAVE_ARCH_TRACEHOOK |
| bool |
| |
| config HAVE_DMA_ATTRS |
| bool |
| |
| config USE_GENERIC_SMP_HELPERS |
| bool |
| |
| config HAVE_REGS_AND_STACK_ACCESS_API |
| bool |
| help |
| This symbol should be selected by an architecure if it supports |
| the API needed to access registers and stack entries from pt_regs, |
| declared in asm/ptrace.h |
| For example the kprobes-based event tracer needs this API. |
| |
| config HAVE_CLK |
| bool |
| help |
| The <linux/clk.h> calls support software clock gating and |
| thus are a key power management tool on many systems. |
| |
| config HAVE_DMA_API_DEBUG |
| bool |
| |
| config HAVE_HW_BREAKPOINT |
| bool |
| depends on PERF_EVENTS |
| |
| config HAVE_MIXED_BREAKPOINTS_REGS |
| bool |
| depends on HAVE_HW_BREAKPOINT |
| help |
| Depending on the arch implementation of hardware breakpoints, |
| some of them have separate registers for data and instruction |
| breakpoints addresses, others have mixed registers to store |
| them but define the access type in a control register. |
| Select this option if your arch implements breakpoints under the |
| latter fashion. |
| |
| config HAVE_USER_RETURN_NOTIFIER |
| bool |
| |
| config HAVE_PERF_EVENTS_NMI |
| bool |
| help |
| System hardware can generate an NMI using the perf event |
| subsystem. Also has support for calculating CPU cycle events |
| to determine how many clock cycles in a given period. |
| |
| config HAVE_ARCH_JUMP_LABEL |
| bool |
| |
| config HAVE_ARCH_MUTEX_CPU_RELAX |
| bool |
| |
| config HAVE_RCU_TABLE_FREE |
| bool |
| |
| config ARCH_HAVE_NMI_SAFE_CMPXCHG |
| bool |
| |
| config HAVE_ALIGNED_STRUCT_PAGE |
| bool |
| help |
| This makes sure that struct pages are double word aligned and that |
| e.g. the SLUB allocator can perform double word atomic operations |
| on a struct page for better performance. However selecting this |
| might increase the size of a struct page by a word. |
| |
| config HAVE_CMPXCHG_LOCAL |
| bool |
| |
| config HAVE_CMPXCHG_DOUBLE |
| bool |
| |
| config ARCH_WANT_OLD_COMPAT_IPC |
| bool |
| |
| source "kernel/gcov/Kconfig" |