projects/linux·blob v2.6.30-rc5 · refs

105 lines · 2.0 KiB

1/*
2 * kernel/cgroup_debug.c - Example cgroup subsystem that
3 * exposes debug info
4 *
5 * Copyright (C) Google Inc, 2007
6 *
7 * Developed by Paul Menage ([email protected])
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 count = cgroup_task_count(cont);
44 return count;
45}
46
47static u64 current_css_set_read(struct cgroup *cont, struct cftype *cft)
48{
49 return (u64)(long)current->cgroups;
50}
51
52static u64 current_css_set_refcount_read(struct cgroup *cont,
53 struct cftype *cft)
54{
55 u64 count;
56
57 rcu_read_lock();
58 count = atomic_read(&current->cgroups->refcount);
59 rcu_read_unlock();
60 return count;
61}
62
63static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft)
64{
65 return test_bit(CGRP_RELEASABLE, &cgrp->flags);
66}
67
68static struct cftype files[] = {
69 {
70 .name = "cgroup_refcount",
71 .read_u64 = cgroup_refcount_read,
72 },
73 {
74 .name = "taskcount",
75 .read_u64 = taskcount_read,
76 },
77
78 {
79 .name = "current_css_set",
80 .read_u64 = current_css_set_read,
81 },
82
83 {
84 .name = "current_css_set_refcount",
85 .read_u64 = current_css_set_refcount_read,
86 },
87
88 {
89 .name = "releasable",
90 .read_u64 = releasable_read,
91 },
92};
93
94static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont)
95{
96 return cgroup_add_files(cont, ss, files, ARRAY_SIZE(files));
97}
98
99struct cgroup_subsys debug_subsys = {
100 .name = "debug",
101 .create = debug_create,
102 .destroy = debug_destroy,
103 .populate = debug_populate,
104 .subsys_id = debug_subsys_id,
105};