blob: c3dc3aba4c02a5b243b25b1ed7be971c5ec1ef17 [file] [log] [blame]
Paul Menage006cb992007-10-18 23:39:43 -07001/*
Paul Menage3116f0e2008-04-29 01:00:04 -07002 * kernel/cgroup_debug.c - Example cgroup subsystem that
Paul Menage006cb992007-10-18 23:39:43 -07003 * exposes debug info
4 *
5 * Copyright (C) Google Inc, 2007
6 *
7 * Developed by Paul Menage (menage@google.com)
8 *
9 */
10
11#include <linux/cgroup.h>
12#include <linux/fs.h>
13#include <linux/slab.h>
14#include <linux/rcupdate.h>
15
16#include <asm/atomic.h>
17
18static struct cgroup_subsys_state *debug_create(struct cgroup_subsys *ss,
19 struct cgroup *cont)
20{
21 struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);
22
23 if (!css)
24 return ERR_PTR(-ENOMEM);
25
26 return css;
27}
28
29static void debug_destroy(struct cgroup_subsys *ss, struct cgroup *cont)
30{
31 kfree(cont->subsys[debug_subsys_id]);
32}
33
34static u64 cgroup_refcount_read(struct cgroup *cont, struct cftype *cft)
35{
36 return atomic_read(&cont->count);
37}
38
39static u64 taskcount_read(struct cgroup *cont, struct cftype *cft)
40{
41 u64 count;
42
43 cgroup_lock();
44 count = cgroup_task_count(cont);
45 cgroup_unlock();
46 return count;
47}
48
49static u64 current_css_set_read(struct cgroup *cont, struct cftype *cft)
50{
51 return (u64)(long)current->cgroups;
52}
53
54static u64 current_css_set_refcount_read(struct cgroup *cont,
55 struct cftype *cft)
56{
57 u64 count;
58
59 rcu_read_lock();
60 count = atomic_read(&current->cgroups->ref.refcount);
61 rcu_read_unlock();
62 return count;
63}
64
Paul Menage3116f0e2008-04-29 01:00:04 -070065static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft)
66{
67 return test_bit(CGRP_RELEASABLE, &cgrp->flags);
68}
69
Paul Menage006cb992007-10-18 23:39:43 -070070static struct cftype files[] = {
71 {
72 .name = "cgroup_refcount",
Paul Menagef4c753b2008-04-29 00:59:56 -070073 .read_u64 = cgroup_refcount_read,
Paul Menage006cb992007-10-18 23:39:43 -070074 },
75 {
76 .name = "taskcount",
Paul Menagef4c753b2008-04-29 00:59:56 -070077 .read_u64 = taskcount_read,
Paul Menage006cb992007-10-18 23:39:43 -070078 },
79
80 {
81 .name = "current_css_set",
Paul Menagef4c753b2008-04-29 00:59:56 -070082 .read_u64 = current_css_set_read,
Paul Menage006cb992007-10-18 23:39:43 -070083 },
84
85 {
86 .name = "current_css_set_refcount",
Paul Menagef4c753b2008-04-29 00:59:56 -070087 .read_u64 = current_css_set_refcount_read,
Paul Menage006cb992007-10-18 23:39:43 -070088 },
Paul Menage3116f0e2008-04-29 01:00:04 -070089
90 {
91 .name = "releasable",
92 .read_u64 = releasable_read,
93 }
Paul Menage006cb992007-10-18 23:39:43 -070094};
95
96static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont)
97{
98 return cgroup_add_files(cont, ss, files, ARRAY_SIZE(files));
99}
100
101struct cgroup_subsys debug_subsys = {
102 .name = "debug",
103 .create = debug_create,
104 .destroy = debug_destroy,
105 .populate = debug_populate,
106 .subsys_id = debug_subsys_id,
107};