[Devel] [PATCH -mm v15 03/13] memcg: move initialization to memcg creation

[Vladimir Davydov]

From: Glauber Costa <glommer at openvz.org>

Those structures are only used for memcgs that are effectively using
kmemcg. However, in a later patch I intend to use scan that list
inconditionally (list empty meaning no kmem caches present), which
simplifies the code a lot.

So move the initialization to early kmem creation.

Signed-off-by: Glauber Costa <glommer at openvz.org>
Signed-off-by: Vladimir Davydov <vdavydov at parallels.com>
Cc: Michal Hocko <mhocko at suse.cz>
Cc: Johannes Weiner <hannes at cmpxchg.org>
Cc: Balbir Singh <bsingharora at gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
---
 mm/memcontrol.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9d1245dc993a..deb5b9bb6188 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5210,8 +5210,6 @@ static int __memcg_activate_kmem(struct mem_cgroup *memcg,
 		goto out_rmid;
 
 	memcg->kmemcg_id = memcg_id;
-	INIT_LIST_HEAD(&memcg->memcg_slab_caches);
-	mutex_init(&memcg->slab_caches_mutex);
 
 	/*
 	 * We couldn't have accounted to this cgroup, because it hasn't got the
@@ -5958,6 +5956,9 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
 	int ret;
 
 	memcg->kmemcg_id = -1;
+	INIT_LIST_HEAD(&memcg->memcg_slab_caches);
+	mutex_init(&memcg->slab_caches_mutex);
+
 	ret = memcg_propagate_kmem(memcg);
 	if (ret)
 		return ret;
-- 
1.7.10.4