memcg: add interface to move charge at task migration
[linux-2.6.git] / mm / failslab.c
1 #include <linux/fault-inject.h>
2 #include <linux/gfp.h>
3 #include <linux/slab.h>
4
5 static struct {
6         struct fault_attr attr;
7         u32 ignore_gfp_wait;
8         int cache_filter;
9 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
10         struct dentry *ignore_gfp_wait_file;
11         struct dentry *cache_filter_file;
12 #endif
13 } failslab = {
14         .attr = FAULT_ATTR_INITIALIZER,
15         .ignore_gfp_wait = 1,
16         .cache_filter = 0,
17 };
18
19 bool should_failslab(size_t size, gfp_t gfpflags, unsigned long cache_flags)
20 {
21         if (gfpflags & __GFP_NOFAIL)
22                 return false;
23
24         if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT))
25                 return false;
26
27         if (failslab.cache_filter && !(cache_flags & SLAB_FAILSLAB))
28                 return false;
29
30         return should_fail(&failslab.attr, size);
31 }
32
33 static int __init setup_failslab(char *str)
34 {
35         return setup_fault_attr(&failslab.attr, str);
36 }
37 __setup("failslab=", setup_failslab);
38
39 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
40 static int __init failslab_debugfs_init(void)
41 {
42         mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
43         struct dentry *dir;
44         int err;
45
46         err = init_fault_attr_dentries(&failslab.attr, "failslab");
47         if (err)
48                 return err;
49         dir = failslab.attr.dentries.dir;
50
51         failslab.ignore_gfp_wait_file =
52                 debugfs_create_bool("ignore-gfp-wait", mode, dir,
53                                       &failslab.ignore_gfp_wait);
54
55         failslab.cache_filter_file =
56                 debugfs_create_bool("cache-filter", mode, dir,
57                                       &failslab.cache_filter);
58
59         if (!failslab.ignore_gfp_wait_file ||
60             !failslab.cache_filter_file) {
61                 err = -ENOMEM;
62                 debugfs_remove(failslab.cache_filter_file);
63                 debugfs_remove(failslab.ignore_gfp_wait_file);
64                 cleanup_fault_attr_dentries(&failslab.attr);
65         }
66
67         return err;
68 }
69
70 late_initcall(failslab_debugfs_init);
71
72 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */