2 * Implement the manual drop-all-pagecache function
5 #include <linux/kernel.h>
8 #include <linux/writeback.h>
9 #include <linux/sysctl.h>
10 #include <linux/gfp.h>
13 /* A global variable is a bit ugly, but it keeps the code simple */
14 int sysctl_drop_caches
;
16 static void drop_pagecache_sb(struct super_block
*sb
, void *unused
)
18 struct inode
*inode
, *toput_inode
= NULL
;
20 spin_lock(&inode_sb_list_lock
);
21 list_for_each_entry(inode
, &sb
->s_inodes
, i_sb_list
) {
22 spin_lock(&inode
->i_lock
);
23 if ((inode
->i_state
& (I_FREEING
|I_WILL_FREE
|I_NEW
)) ||
24 (inode
->i_mapping
->nrpages
== 0)) {
25 spin_unlock(&inode
->i_lock
);
29 spin_unlock(&inode
->i_lock
);
30 spin_unlock(&inode_sb_list_lock
);
31 invalidate_mapping_pages(inode
->i_mapping
, 0, -1);
34 spin_lock(&inode_sb_list_lock
);
36 spin_unlock(&inode_sb_list_lock
);
40 static void drop_slab(void)
43 struct shrink_control shrink
= {
44 .gfp_mask
= GFP_KERNEL
,
48 nr_objects
= shrink_slab(&shrink
, 1000, 1000);
49 } while (nr_objects
> 10);
52 int drop_caches_sysctl_handler(ctl_table
*table
, int write
,
53 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
57 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
61 if (sysctl_drop_caches
& 1)
62 iterate_supers(drop_pagecache_sb
, NULL
);
63 if (sysctl_drop_caches
& 2)
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