memory.{min, low} keeps protecting pages in a memcg even if there're no
process running in this memcg. That makes nonsense, because if there're
no processes running in this memcg there may be something wrong happens
and these protected pages are not useful now.
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
---
mm/memcontrol.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1c4c08b..c96c282 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6376,6 +6376,9 @@ enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root,
if (memcg == root)
return MEMCG_PROT_NONE;
+ if (!cgroup_is_populated(memcg->css.cgroup))
+ return MEMCG_PROT_NONE;
+
usage = page_counter_read(&memcg->memory);
if (!usage)
return MEMCG_PROT_NONE;
--
1.8.3.1
