Commit fe693435 authored by Paul Menage's avatar Paul Menage Committed by Linus Torvalds
Browse files

cgroups: move the cgroup debug subsys into cgroup.c to access internal state 



While it's architecturally clean to have the cgroup debug subsystem be
completely independent of the cgroups framework, it limits its usefulness
for debugging the contents of internal data structures.  Move the debug
subsystem code into the scope of all the cgroups data structures to make
more detailed debugging possible.

Signed-off-by: default avatarPaul Menage <menage@google.com>
Reviewed-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Reviewed-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c6d57f33

kernel/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -58,7 +58,6 @@ obj-$(CONFIG_KEXEC) += kexec.o 
obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o

obj-$(CONFIG_COMPAT) += compat.o

obj-$(CONFIG_CGROUPS) += cgroup.o

obj-$(CONFIG_CGROUP_DEBUG) += cgroup_debug.o

obj-$(CONFIG_CGROUP_FREEZER) += cgroup_freezer.o

obj-$(CONFIG_CPUSETS) += cpuset.o

obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o

kernel/cgroup.c

+88 −0
Original line number Diff line number Diff line
@@ -3781,3 +3781,91 @@ css_get_next(struct cgroup_subsys *ss, int id, 
	return ret;

}



#ifdef CONFIG_CGROUP_DEBUG

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 debug_taskcount_read(struct cgroup *cont, struct cftype *cft)

{

	return cgroup_task_count(cont);

}



static u64 current_css_set_read(struct cgroup *cont, struct cftype *cft)

{

	return (u64)(unsigned 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 debug_files[] =  {

	{

		.name = "cgroup_refcount",

		.read_u64 = cgroup_refcount_read,

	},

	{

		.name = "taskcount",

		.read_u64 = debug_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, debug_files,

				ARRAY_SIZE(debug_files));

}



struct cgroup_subsys debug_subsys = {

	.name = "debug",

	.create = debug_create,

	.destroy = debug_destroy,

	.populate = debug_populate,

	.subsys_id = debug_subsys_id,

};

#endif /* CONFIG_CGROUP_DEBUG */

kernel/cgroup_debug.c

deleted100644 → 0
+0 −105
Original line number Diff line number Diff line 
/*

 * kernel/cgroup_debug.c - Example cgroup subsystem that

 * exposes debug info

 *

 * Copyright (C) Google Inc, 2007

 *

 * Developed by Paul Menage (menage@google.com)

 *

 */



#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,

};

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