blob: 816f88e6b9ceaa08c8ff443e3e54035c567b3a2e [file] [log] [blame]
Andrew Morton9d0243b2006-01-08 01:00:39 -08001/*
2 * Implement the manual drop-all-pagecache function
3 */
4
5#include <linux/kernel.h>
6#include <linux/mm.h>
7#include <linux/fs.h>
8#include <linux/writeback.h>
9#include <linux/sysctl.h>
10#include <linux/gfp.h>
11
12/* A global variable is a bit ugly, but it keeps the code simple */
13int sysctl_drop_caches;
14
Al Viro01a05b32010-03-23 06:06:58 -040015static void drop_pagecache_sb(struct super_block *sb, void *unused)
Andrew Morton9d0243b2006-01-08 01:00:39 -080016{
Jan Karaeccb95c2008-04-29 00:59:37 -070017 struct inode *inode, *toput_inode = NULL;
Andrew Morton9d0243b2006-01-08 01:00:39 -080018
19 spin_lock(&inode_lock);
20 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
Al Viroa4ffdde2010-06-02 17:38:30 -040021 if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
Andrew Morton9d0243b2006-01-08 01:00:39 -080022 continue;
Jan Karaaf065b82008-04-29 00:59:39 -070023 if (inode->i_mapping->nrpages == 0)
24 continue;
Jan Karaeccb95c2008-04-29 00:59:37 -070025 __iget(inode);
26 spin_unlock(&inode_lock);
Mike Waychison28697352009-06-16 15:32:59 -070027 invalidate_mapping_pages(inode->i_mapping, 0, -1);
Jan Karaeccb95c2008-04-29 00:59:37 -070028 iput(toput_inode);
29 toput_inode = inode;
30 spin_lock(&inode_lock);
Andrew Morton9d0243b2006-01-08 01:00:39 -080031 }
32 spin_unlock(&inode_lock);
Jan Karaeccb95c2008-04-29 00:59:37 -070033 iput(toput_inode);
Andrew Morton9d0243b2006-01-08 01:00:39 -080034}
35
Adrian Bunk07d45da2008-04-29 00:58:57 -070036static void drop_slab(void)
Andrew Morton9d0243b2006-01-08 01:00:39 -080037{
38 int nr_objects;
39
40 do {
41 nr_objects = shrink_slab(1000, GFP_KERNEL, 1000);
42 } while (nr_objects > 10);
43}
44
45int drop_caches_sysctl_handler(ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -070046 void __user *buffer, size_t *length, loff_t *ppos)
Andrew Morton9d0243b2006-01-08 01:00:39 -080047{
Petr Holasekcb16e952011-03-23 16:43:09 -070048 int ret;
49
50 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
51 if (ret)
52 return ret;
Andrew Morton9d0243b2006-01-08 01:00:39 -080053 if (write) {
54 if (sysctl_drop_caches & 1)
Al Viro01a05b32010-03-23 06:06:58 -040055 iterate_supers(drop_pagecache_sb, NULL);
Andrew Morton9d0243b2006-01-08 01:00:39 -080056 if (sysctl_drop_caches & 2)
57 drop_slab();
58 }
59 return 0;
60}