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 if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
23 if (inode->i_mapping->nrpages == 0)
26 spin_unlock(&inode_lock);
27 invalidate_mapping_pages(inode->i_mapping, 0, -1);
30 spin_lock(&inode_lock);
32 spin_unlock(&inode_lock);
36 static void drop_slab(void)
41 nr_objects = shrink_slab(1000, GFP_KERNEL, 1000);
42 } while (nr_objects > 10);
45 int drop_caches_sysctl_handler(ctl_table *table, int write,
46 void __user *buffer, size_t *length, loff_t *ppos)
48 proc_dointvec_minmax(table, write, buffer, length, ppos);
50 if (sysctl_drop_caches & 1)
51 iterate_supers(drop_pagecache_sb, NULL);
52 if (sysctl_drop_caches & 2)