As reference counting in the root memcg is disabled, there is no need
to get a reference if root memcg is to be returned.
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
mm/memcontrol.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5b009b233ab8..2b3864194042 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1060,8 +1060,10 @@ struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)
rcu_read_lock();
do {
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
- if (unlikely(!memcg))
+ if (unlikely(!memcg)) {
memcg = root_mem_cgroup;
+ break;
+ }
} while (!css_tryget(&memcg->css));
rcu_read_unlock();
return memcg;
--
2.39.3
