mm: memcontrol: pull the NULL check from __mem_cgroup_same_or_subtree()
The NULL in mm_match_cgroup() comes from a possibly exiting mm->owner. It
makes a lot more sense to check where it's looked up, rather than check
for it in __mem_cgroup_same_or_subtree() where it's unexpected.
No other callsite passes NULL to __mem_cgroup_same_or_subtree().
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 367cc57..e5dcebd 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1337,7 +1337,7 @@
{
if (root_memcg == memcg)
return true;
- if (!root_memcg->use_hierarchy || !memcg)
+ if (!root_memcg->use_hierarchy)
return false;
return cgroup_is_descendant(memcg->css.cgroup, root_memcg->css.cgroup);
}