Commit | Line | Data |
---|---|---|
9d0243bc AM |
1 | /* |
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 */ | |
13 | int sysctl_drop_caches; | |
14 | ||
15 | static void drop_pagecache_sb(struct super_block *sb) | |
16 | { | |
eccb95ce | 17 | struct inode *inode, *toput_inode = NULL; |
9d0243bc AM |
18 | |
19 | spin_lock(&inode_lock); | |
20 | list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { | |
21 | if (inode->i_state & (I_FREEING|I_WILL_FREE)) | |
22 | continue; | |
eccb95ce JK |
23 | __iget(inode); |
24 | spin_unlock(&inode_lock); | |
fc9a07e7 | 25 | __invalidate_mapping_pages(inode->i_mapping, 0, -1, true); |
eccb95ce JK |
26 | iput(toput_inode); |
27 | toput_inode = inode; | |
28 | spin_lock(&inode_lock); | |
9d0243bc AM |
29 | } |
30 | spin_unlock(&inode_lock); | |
eccb95ce | 31 | iput(toput_inode); |
9d0243bc AM |
32 | } |
33 | ||
07d45da6 | 34 | static void drop_pagecache(void) |
9d0243bc AM |
35 | { |
36 | struct super_block *sb; | |
37 | ||
38 | spin_lock(&sb_lock); | |
39 | restart: | |
40 | list_for_each_entry(sb, &super_blocks, s_list) { | |
41 | sb->s_count++; | |
42 | spin_unlock(&sb_lock); | |
43 | down_read(&sb->s_umount); | |
44 | if (sb->s_root) | |
45 | drop_pagecache_sb(sb); | |
46 | up_read(&sb->s_umount); | |
47 | spin_lock(&sb_lock); | |
48 | if (__put_super_and_need_restart(sb)) | |
49 | goto restart; | |
50 | } | |
51 | spin_unlock(&sb_lock); | |
52 | } | |
53 | ||
07d45da6 | 54 | static void drop_slab(void) |
9d0243bc AM |
55 | { |
56 | int nr_objects; | |
57 | ||
58 | do { | |
59 | nr_objects = shrink_slab(1000, GFP_KERNEL, 1000); | |
60 | } while (nr_objects > 10); | |
61 | } | |
62 | ||
63 | int drop_caches_sysctl_handler(ctl_table *table, int write, | |
64 | struct file *file, void __user *buffer, size_t *length, loff_t *ppos) | |
65 | { | |
66 | proc_dointvec_minmax(table, write, file, buffer, length, ppos); | |
67 | if (write) { | |
68 | if (sysctl_drop_caches & 1) | |
69 | drop_pagecache(); | |
70 | if (sysctl_drop_caches & 2) | |
71 | drop_slab(); | |
72 | } | |
73 | return 0; | |
74 | } |