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> | |
55fa6091 | 11 | #include "internal.h" |
9d0243bc AM |
12 | |
13 | /* A global variable is a bit ugly, but it keeps the code simple */ | |
14 | int sysctl_drop_caches; | |
15 | ||
01a05b33 | 16 | static void drop_pagecache_sb(struct super_block *sb, void *unused) |
9d0243bc | 17 | { |
eccb95ce | 18 | struct inode *inode, *toput_inode = NULL; |
9d0243bc | 19 | |
55fa6091 | 20 | spin_lock(&inode_sb_list_lock); |
9d0243bc | 21 | list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { |
250df6ed DC |
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); | |
af065b8a | 26 | continue; |
250df6ed | 27 | } |
eccb95ce | 28 | __iget(inode); |
250df6ed | 29 | spin_unlock(&inode->i_lock); |
55fa6091 | 30 | spin_unlock(&inode_sb_list_lock); |
28697355 | 31 | invalidate_mapping_pages(inode->i_mapping, 0, -1); |
eccb95ce JK |
32 | iput(toput_inode); |
33 | toput_inode = inode; | |
55fa6091 | 34 | spin_lock(&inode_sb_list_lock); |
9d0243bc | 35 | } |
55fa6091 | 36 | spin_unlock(&inode_sb_list_lock); |
eccb95ce | 37 | iput(toput_inode); |
9d0243bc AM |
38 | } |
39 | ||
07d45da6 | 40 | static void drop_slab(void) |
9d0243bc AM |
41 | { |
42 | int nr_objects; | |
43 | ||
44 | do { | |
6b4f7799 JW |
45 | int nid; |
46 | ||
47 | nr_objects = 0; | |
48 | for_each_online_node(nid) | |
49 | nr_objects += shrink_node_slabs(GFP_KERNEL, nid, | |
50 | 1000, 1000); | |
9d0243bc AM |
51 | } while (nr_objects > 10); |
52 | } | |
53 | ||
1f7e0616 | 54 | int drop_caches_sysctl_handler(struct ctl_table *table, int write, |
8d65af78 | 55 | void __user *buffer, size_t *length, loff_t *ppos) |
9d0243bc | 56 | { |
cb16e95f PH |
57 | int ret; |
58 | ||
59 | ret = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
60 | if (ret) | |
61 | return ret; | |
9d0243bc | 62 | if (write) { |
5509a5d2 DH |
63 | static int stfu; |
64 | ||
65 | if (sysctl_drop_caches & 1) { | |
01a05b33 | 66 | iterate_supers(drop_pagecache_sb, NULL); |
5509a5d2 DH |
67 | count_vm_event(DROP_PAGECACHE); |
68 | } | |
69 | if (sysctl_drop_caches & 2) { | |
9d0243bc | 70 | drop_slab(); |
5509a5d2 DH |
71 | count_vm_event(DROP_SLAB); |
72 | } | |
73 | if (!stfu) { | |
74 | pr_info("%s (%d): drop_caches: %d\n", | |
75 | current->comm, task_pid_nr(current), | |
76 | sysctl_drop_caches); | |
77 | } | |
78 | stfu |= sysctl_drop_caches & 4; | |
9d0243bc AM |
79 | } |
80 | return 0; | |
81 | } |