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Commit 3e92041d authored by Michal Hocko's avatar Michal Hocko Committed by Linus Torvalds
Browse files

memcg: add mem_cgroup_same_or_subtree() helper 



We are checking whether a given two groups are same or at least in the
same subtree of a hierarchy at several places.  Let's make a helper for
it to make code easier to read.

Signed-off-by: default avatarMichal Hocko <mhocko@suse.cz>
Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d38144b7

mm/memcontrol.c

+26 −25
Original line number Diff line number Diff line
@@ -1108,6 +1108,21 @@ void mem_cgroup_move_lists(struct page *page, 
	mem_cgroup_add_lru_list(page, to);

}



/*

 * Checks whether given mem is same or in the root_mem's

 * hierarchy subtree

 */

static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_mem,

		struct mem_cgroup *mem)

{

	if (root_mem != mem) {

		return (root_mem->use_hierarchy &&

			css_is_ancestor(&mem->css, &root_mem->css));

	}



	return true;

}



int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)

{

	int ret;
@@ -1127,10 +1142,7 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) 
	 * enabled in "curr" and "curr" is a child of "mem" in *cgroup*

	 * hierarchy(even if use_hierarchy is disabled in "mem").

	 */

	if (mem->use_hierarchy)

		ret = css_is_ancestor(&curr->css, &mem->css);

	else

		ret = (curr == mem);

	ret = mem_cgroup_same_or_subtree(mem, curr);

	css_put(&curr->css);

	return ret;

}
@@ -1369,10 +1381,9 @@ static bool mem_cgroup_under_move(struct mem_cgroup *mem) 
	to = mc.to;

	if (!from)

		goto unlock;

	if (from == mem || to == mem

	    || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css))

	    || (mem->use_hierarchy && css_is_ancestor(&to->css,	&mem->css)))

		ret = true;



	ret = mem_cgroup_same_or_subtree(mem, from)

		|| mem_cgroup_same_or_subtree(mem, to);

unlock:

	spin_unlock(&mc.lock);

	return ret;
@@ -1915,25 +1926,20 @@ struct oom_wait_info { 
static int memcg_oom_wake_function(wait_queue_t *wait,

	unsigned mode, int sync, void *arg)

{

	struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg;

	struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg,

			  *oom_wait_mem;

	struct oom_wait_info *oom_wait_info;



	oom_wait_info = container_of(wait, struct oom_wait_info, wait);

	oom_wait_mem = oom_wait_info->mem;



	if (oom_wait_info->mem == wake_mem)

		goto wakeup;

	/* if no hierarchy, no match */

	if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy)

		return 0;

	/*

	 * Both of oom_wait_info->mem and wake_mem are stable under us.

	 * Then we can use css_is_ancestor without taking care of RCU.

	 */

	if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) &&

	    !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css))

	if (!mem_cgroup_same_or_subtree(oom_wait_mem, wake_mem)

			&& !mem_cgroup_same_or_subtree(wake_mem, oom_wait_mem))

		return 0;



wakeup:

	return autoremove_wake_function(wait, mode, sync, arg);

}
@@ -2178,13 +2184,8 @@ static void drain_all_stock(struct mem_cgroup *root_mem, bool sync) 
		mem = stock->cached;

		if (!mem || !stock->nr_pages)

			continue;

		if (mem != root_mem) {

			if (!root_mem->use_hierarchy)

				continue;

			/* check whether "mem" is under tree of "root_mem" */

			if (!css_is_ancestor(&mem->css, &root_mem->css))

		if (!mem_cgroup_same_or_subtree(root_mem, mem))

			continue;

		}

		if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {

			if (cpu == curcpu)

				drain_local_stock(&stock->work);