Since commit 79dfdaccd1d5 ("memcg: make oom_lock 0 and 1 based rather than
counter"), the mem_cgroup_unmark_under_oom() is added and the comment of
the mem_cgroup_oom_unlock() is moved here. But this comment make no sense
here because mem_cgroup_oom_lock() does not operate on under_oom field. So
we reword the comment as this would be helpful.
[Thanks Michal Hocko for rewording this comment.]
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
---
mm/memcontrol.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6877c765b8d0..4f0c14cb8690 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1817,8 +1817,8 @@ static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
struct mem_cgroup *iter;
/*
- * When a new child is created while the hierarchy is under oom,
- * mem_cgroup_oom_lock() may not be called. Watch for underflow.
+ * Be careful about under_oom underflows becase a child memcg
+ * could have been added after mem_cgroup_mark_under_oom.
*/
spin_lock(&memcg_oom_lock);
for_each_mem_cgroup_tree(iter, memcg)
--
2.19.1
