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>
12 /* A global variable is a bit ugly, but it keeps the code simple */
13 int sysctl_drop_caches;
15 static void drop_pagecache_sb(struct super_block *sb)
17 struct inode *inode, *toput_inode = NULL;
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))
24 spin_unlock(&inode_lock);
25 __invalidate_mapping_pages(inode->i_mapping, 0, -1, true);
28 spin_lock(&inode_lock);
30 spin_unlock(&inode_lock);
34 static void drop_pagecache(void)
36 struct super_block *sb;
40 list_for_each_entry(sb, &super_blocks, s_list) {
42 spin_unlock(&sb_lock);
43 down_read(&sb->s_umount);
45 drop_pagecache_sb(sb);
46 up_read(&sb->s_umount);
48 if (__put_super_and_need_restart(sb))
51 spin_unlock(&sb_lock);
54 static void drop_slab(void)
59 nr_objects = shrink_slab(1000, GFP_KERNEL, 1000);
60 } while (nr_objects > 10);
63 int drop_caches_sysctl_handler(ctl_table *table, int write,
64 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
66 proc_dointvec_minmax(table, write, file, buffer, length, ppos);
68 if (sysctl_drop_caches & 1)
70 if (sysctl_drop_caches & 2)