[linux.git] / kernel / cgroup_debug.c

/*
 * kernel/cgroup_debug.c - Example cgroup subsystem that
 * exposes debug info
 *
 * Copyright (C) Google Inc, 2007
 *
 * Developed by Paul Menage ([email protected])
 *
 */

#include <linux/cgroup.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/rcupdate.h>

#include <asm/atomic.h>

static struct cgroup_subsys_state *debug_create(struct cgroup_subsys *ss,
						   struct cgroup *cont)
{
	struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);

	if (!css)
		return ERR_PTR(-ENOMEM);

	return css;
}

static void debug_destroy(struct cgroup_subsys *ss, struct cgroup *cont)
{
	kfree(cont->subsys[debug_subsys_id]);
}

static u64 cgroup_refcount_read(struct cgroup *cont, struct cftype *cft)
{
	return atomic_read(&cont->count);
}

static u64 taskcount_read(struct cgroup *cont, struct cftype *cft)
{
	u64 count;

	count = cgroup_task_count(cont);
	return count;
}

static u64 current_css_set_read(struct cgroup *cont, struct cftype *cft)
{
	return (u64)(long)current->cgroups;
}

static u64 current_css_set_refcount_read(struct cgroup *cont,
					   struct cftype *cft)
{
	u64 count;

	rcu_read_lock();
	count = atomic_read(&current->cgroups->refcount);
	rcu_read_unlock();
	return count;
}

static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft)
{
	return test_bit(CGRP_RELEASABLE, &cgrp->flags);
}

static struct cftype files[] =  {
	{
		.name = "cgroup_refcount",
		.read_u64 = cgroup_refcount_read,
	},
	{
		.name = "taskcount",
		.read_u64 = taskcount_read,
	},

	{
		.name = "current_css_set",
		.read_u64 = current_css_set_read,
	},

	{
		.name = "current_css_set_refcount",
		.read_u64 = current_css_set_refcount_read,
	},

	{
		.name = "releasable",
		.read_u64 = releasable_read,
	},
};

static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont)
{
	return cgroup_add_files(cont, ss, files, ARRAY_SIZE(files));
}

struct cgroup_subsys debug_subsys = {
	.name = "debug",
	.create = debug_create,
	.destroy = debug_destroy,
	.populate = debug_populate,
	.subsys_id = debug_subsys_id,
};
Commit	Line	Data
006cb992	1	/*
3116f0e3	2	* kernel/cgroup_debug.c - Example cgroup subsystem that
006cb992 PM	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
	18	static 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
	29	static void debug_destroy(struct cgroup_subsys ss, struct cgroup cont)
	30	{
	31	kfree(cont->subsys[debug_subsys_id]);
	32	}
	33
	34	static u64 cgroup_refcount_read(struct cgroup cont, struct cftype cft)
	35	{
	36	return atomic_read(&cont->count);
	37	}
	38
	39	static u64 taskcount_read(struct cgroup cont, struct cftype cft)
	40	{
	41	u64 count;
	42
006cb992	43	count = cgroup_task_count(cont);
006cb992 PM	44	return count;
	45	}
	46
	47	static u64 current_css_set_read(struct cgroup cont, struct cftype cft)
	48	{
	49	return (u64)(long)current->cgroups;
	50	}
	51
	52	static u64 current_css_set_refcount_read(struct cgroup *cont,
	53	struct cftype *cft)
	54	{
	55	u64 count;
	56
	57	rcu_read_lock();
146aa1bd	58	count = atomic_read(&current->cgroups->refcount);
006cb992 PM	59	rcu_read_unlock();
	60	return count;
	61	}
	62
3116f0e3 PM	63	static u64 releasable_read(struct cgroup cgrp, struct cftype cft)
	64	{
	65	return test_bit(CGRP_RELEASABLE, &cgrp->flags);
	66	}
	67
006cb992 PM	68	static struct cftype files[] = {
	69	{
	70	.name = "cgroup_refcount",
f4c753b7	71	.read_u64 = cgroup_refcount_read,
006cb992 PM	72	},
	73	{
	74	.name = "taskcount",
f4c753b7	75	.read_u64 = taskcount_read,
006cb992 PM	76	},
	77
	78	{
	79	.name = "current_css_set",
f4c753b7	80	.read_u64 = current_css_set_read,
006cb992 PM	81	},
	82
	83	{
	84	.name = "current_css_set_refcount",
f4c753b7	85	.read_u64 = current_css_set_refcount_read,
006cb992	86	},
3116f0e3 PM	87
	88	{
	89	.name = "releasable",
	90	.read_u64 = releasable_read,
146aa1bd	91	},
006cb992 PM	92	};
	93
	94	static int debug_populate(struct cgroup_subsys ss, struct cgroup cont)
	95	{
	96	return cgroup_add_files(cont, ss, files, ARRAY_SIZE(files));
	97	}
	98
	99	struct 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	};