Commit aade7f9e authored by Roman Gushchin's avatar Roman Gushchin Committed by Tejun Heo
Browse files

cgroup: implement __cgroup_task_count() helper 



The helper is identical to the existing cgroup_task_count()
except it doesn't take the css_set_lock by itself, assuming
that the caller does.

Also, move cgroup_task_count() implementation into
kernel/cgroup/cgroup.c, as there is nothing specific to cgroup v1.

Signed-off-by: default avatarRoman Gushchin <guro@fb.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: kernel-team@fb.com
parent 50943f3e

kernel/cgroup/cgroup-internal.h

+1 −0
Original line number Diff line number Diff line
@@ -240,6 +240,7 @@ int cgroup_rmdir(struct kernfs_node *kn); 
int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,

		     struct kernfs_root *kf_root);



int __cgroup_task_count(const struct cgroup *cgrp);

int cgroup_task_count(const struct cgroup *cgrp);



/*

kernel/cgroup/cgroup-v1.c

+0 −16
Original line number Diff line number Diff line
@@ -342,22 +342,6 @@ static struct cgroup_pidlist *cgroup_pidlist_find_create(struct cgroup *cgrp, 
	return l;

}



/**

 * cgroup_task_count - count the number of tasks in a cgroup.

 * @cgrp: the cgroup in question

 */

int cgroup_task_count(const struct cgroup *cgrp)

{

	int count = 0;

	struct cgrp_cset_link *link;



	spin_lock_irq(&css_set_lock);

	list_for_each_entry(link, &cgrp->cset_links, cset_link)

		count += link->cset->nr_tasks;

	spin_unlock_irq(&css_set_lock);

	return count;

}



/*

 * Load a cgroup's pidarray with either procs' tgids or tasks' pids

 */

kernel/cgroup/cgroup.c

+33 −0
Original line number Diff line number Diff line
@@ -593,6 +593,39 @@ static void cgroup_get_live(struct cgroup *cgrp) 
	css_get(&cgrp->self);

}



/**

 * __cgroup_task_count - count the number of tasks in a cgroup. The caller

 * is responsible for taking the css_set_lock.

 * @cgrp: the cgroup in question

 */

int __cgroup_task_count(const struct cgroup *cgrp)

{

	int count = 0;

	struct cgrp_cset_link *link;



	lockdep_assert_held(&css_set_lock);



	list_for_each_entry(link, &cgrp->cset_links, cset_link)

		count += link->cset->nr_tasks;



	return count;

}



/**

 * cgroup_task_count - count the number of tasks in a cgroup.

 * @cgrp: the cgroup in question

 */

int cgroup_task_count(const struct cgroup *cgrp)

{

	int count;



	spin_lock_irq(&css_set_lock);

	count = __cgroup_task_count(cgrp);

	spin_unlock_irq(&css_set_lock);



	return count;

}



struct cgroup_subsys_state *of_css(struct kernfs_open_file *of)

{

	struct cgroup *cgrp = of->kn->parent->priv;

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