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, void *unused)
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 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);
28 spin_unlock(&inode->i_lock);
29 spin_unlock(&inode_lock);
30 invalidate_mapping_pages(inode->i_mapping, 0, -1);
33 spin_lock(&inode_lock);
35 spin_unlock(&inode_lock);
39 static void drop_slab(void)
44 nr_objects = shrink_slab(1000, GFP_KERNEL, 1000);
45 } while (nr_objects > 10);
48 int drop_caches_sysctl_handler(ctl_table *table, int write,
49 void __user *buffer, size_t *length, loff_t *ppos)
53 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
57 if (sysctl_drop_caches & 1)
58 iterate_supers(drop_pagecache_sb, NULL);
59 if (sysctl_drop_caches & 2)