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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/fs/drop_caches.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/fs/drop_caches.c')
-rw-r--r--kernel/fs/drop_caches.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/kernel/fs/drop_caches.c b/kernel/fs/drop_caches.c
new file mode 100644
index 000000000..5718cb9f7
--- /dev/null
+++ b/kernel/fs/drop_caches.c
@@ -0,0 +1,67 @@
+/*
+ * 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"
+
+/* 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);
+}
+
+int drop_caches_sysctl_handler(struct 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) {
+ static int stfu;
+
+ if (sysctl_drop_caches & 1) {
+ iterate_supers(drop_pagecache_sb, NULL);
+ count_vm_event(DROP_PAGECACHE);
+ }
+ if (sysctl_drop_caches & 2) {
+ drop_slab();
+ count_vm_event(DROP_SLAB);
+ }
+ if (!stfu) {
+ pr_info("%s (%d): drop_caches: %d\n",
+ current->comm, task_pid_nr(current),
+ sysctl_drop_caches);
+ }
+ stfu |= sysctl_drop_caches & 4;
+ }
+ return 0;
+}