[PATCH RESEND] memcg, oom: unmark under_oom after the oom killer is done

From: Haifeng Xu
Date: Sat Sep 23 2023 - 04:19:14 EST


When application in userland receives oom notification from kernel
and reads the oom_control file, it's confusing that under_oom is 0
though the omm killer hasn't finished. The reason is that under_oom
is cleared before invoking mem_cgroup_out_of_memory(), so move the
action that unmark under_oom after completing oom handler. Therefore
the value of under_oom won't mislead users.

Signed-off-by: Haifeng Xu <haifeng.xu@xxxxxxxxxx>
---
mm/memcontrol.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e8ca4bdcb03c..0b6ed63504ca 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1970,8 +1970,8 @@ static bool mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
if (locked)
mem_cgroup_oom_notify(memcg);

- mem_cgroup_unmark_under_oom(memcg);
ret = mem_cgroup_out_of_memory(memcg, mask, order);
+ mem_cgroup_unmark_under_oom(memcg);

if (locked)
mem_cgroup_oom_unlock(memcg);
--
2.25.1