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 | ||
01a05b33 | 15 | static void drop_pagecache_sb(struct super_block *sb, void *unused) |
9d0243bc | 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) { | |
250df6ed DC |
21 | spin_lock(&inode->i_lock); |
22 | if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || | |
23 | (inode->i_mapping->nrpages == 0)) { | |
24 | spin_unlock(&inode->i_lock); | |
af065b8a | 25 | continue; |
250df6ed | 26 | } |
eccb95ce | 27 | __iget(inode); |
250df6ed | 28 | spin_unlock(&inode->i_lock); |
eccb95ce | 29 | spin_unlock(&inode_lock); |
28697355 | 30 | invalidate_mapping_pages(inode->i_mapping, 0, -1); |
eccb95ce JK |
31 | iput(toput_inode); |
32 | toput_inode = inode; | |
33 | spin_lock(&inode_lock); | |
9d0243bc AM |
34 | } |
35 | spin_unlock(&inode_lock); | |
eccb95ce | 36 | iput(toput_inode); |
9d0243bc AM |
37 | } |
38 | ||
07d45da6 | 39 | static void drop_slab(void) |
9d0243bc AM |
40 | { |
41 | int nr_objects; | |
42 | ||
43 | do { | |
44 | nr_objects = shrink_slab(1000, GFP_KERNEL, 1000); | |
45 | } while (nr_objects > 10); | |
46 | } | |
47 | ||
48 | int drop_caches_sysctl_handler(ctl_table *table, int write, | |
8d65af78 | 49 | void __user *buffer, size_t *length, loff_t *ppos) |
9d0243bc | 50 | { |
cb16e95f PH |
51 | int ret; |
52 | ||
53 | ret = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
54 | if (ret) | |
55 | return ret; | |
9d0243bc AM |
56 | if (write) { |
57 | if (sysctl_drop_caches & 1) | |
01a05b33 | 58 | iterate_supers(drop_pagecache_sb, NULL); |
9d0243bc AM |
59 | if (sysctl_drop_caches & 2) |
60 | drop_slab(); | |
61 | } | |
62 | return 0; | |
63 | } |