memcg, oom: remove unnecessary check in mem_cgroup_oom_synchronize()

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.

Link: https://lkml.kernel.org/r/20230419030739.115845-1-haifeng.xu@shopee.com
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2184a9c566f1f5a75521b6a39ff0e3df38e262b4..e8aead97454bd8ea80defecac348be275cb64ea6 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2024,16 +2024,9 @@ bool mem_cgroup_oom_synchronize(bool handle)
        if (locked)
                mem_cgroup_oom_notify(memcg);
 
-       if (locked && !READ_ONCE(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);