[PATCH v2 1/2] memcg, oom: remove unnecessary check in mem_cgroup_oom_synchronize()

From: Haifeng Xu
Date: Tue Apr 18 2023 - 23:08:10 EST


mem_cgroup_oom_synchronize() is only used when the memcg oom handling is
handed over to the edge of the #PF path. Since commit 29ef680ae7c2 ("memcg,
oom: move out_of_memory back to the charge path") this is the case only
when the kernel memcg oom killer is disabled (current->memcg_in_oom is
only set if memcg->oom_kill_disable). Therefore a check for
oom_kill_disable in mem_cgroup_oom_synchronize() is not required.

Signed-off-by: Haifeng Xu <haifeng.xu@xxxxxxxxxx>
Suggested-by: Michal Hocko <mhocko@xxxxxxxx>
---
v2: split original into two and improve patch description
---
mm/memcontrol.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5abffe6f8389..fbf4d2bb1003 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1999,16 +1999,9 @@ bool mem_cgroup_oom_synchronize(bool handle)
if (locked)
mem_cgroup_oom_notify(memcg);

- if (locked && !memcg->oom_kill_disable) {
- mem_cgroup_unmark_under_oom(memcg);
- finish_wait(&memcg_oom_waitq, &owait.wait);
- mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask,
- current->memcg_oom_order);
- } else {
- schedule();
- mem_cgroup_unmark_under_oom(memcg);
- finish_wait(&memcg_oom_waitq, &owait.wait);
- }
+ schedule();
+ mem_cgroup_unmark_under_oom(memcg);
+ finish_wait(&memcg_oom_waitq, &owait.wait);

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