[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/fs/drop_caches.c b/ap/os/linux/linux-3.4.x/fs/drop_caches.c
new file mode 100644
index 0000000..f5f18aa
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/drop_caches.c
@@ -0,0 +1,82 @@
+/*
+ * Implement the manual drop-all-pagecache function
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/writeback.h>
+#include <linux/sysctl.h>
+#include <linux/gfp.h>
+#include "internal.h"
+#include <linux/slab.h>
+/* A global variable is a bit ugly, but it keeps the code simple */
+int sysctl_drop_caches;
+
+static void drop_pagecache_sb(struct super_block *sb, void *unused)
+{
+ struct inode *inode, *toput_inode = NULL;
+
+ spin_lock(&inode_sb_list_lock);
+ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
+ spin_lock(&inode->i_lock);
+ if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
+ (inode->i_mapping->nrpages == 0)) {
+ spin_unlock(&inode->i_lock);
+ continue;
+ }
+ __iget(inode);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_sb_list_lock);
+ invalidate_mapping_pages(inode->i_mapping, 0, -1);
+ iput(toput_inode);
+ toput_inode = inode;
+ spin_lock(&inode_sb_list_lock);
+ }
+ spin_unlock(&inode_sb_list_lock);
+ iput(toput_inode);
+}
+
+static void drop_slab(void)
+{
+ int nr_objects;
+ struct shrink_control shrink = {
+ .gfp_mask = GFP_KERNEL,
+ };
+
+ do {
+ nr_objects = shrink_slab(&shrink, 1000, 1000);
+ } while (nr_objects > 10);
+#ifdef CONFIG_SLOB_OPT
+ kmem_cache_shrink(NULL);
+#endif
+}
+#ifdef CONFIG_SPEED_OPT_DYNAMIC_POOL
+extern void skb_sys_pool_delete(void);
+#endif
+extern void shrink_modem_mem(unsigned int access_type);
+int drop_caches_sysctl_handler(ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ int ret;
+
+ ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (ret)
+ return ret;
+ if (write) {
+ if (sysctl_drop_caches & 1)
+ iterate_supers(drop_pagecache_sb, NULL);
+ if (sysctl_drop_caches & 2)
+ {
+ drop_slab();
+#ifdef CONFIG_SPEED_OPT_DYNAMIC_POOL
+ skb_sys_pool_delete();
+#endif
+ }
+#ifdef CONFIG_MODEM_CODE_IS_MAPPING
+ if (sysctl_drop_caches & 4)
+ shrink_modem_mem(4);
+#endif
+ }
+ return 0;
+}