From da51b14adb671829077da3aeb9e9edd6f8c80afe Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes@cmpxchg.org>
Date: Wed, 24 Jun 2015 16:57:16 -0700
Subject: mm: oom_kill: remove unnecessary locking in exit_oom_victim()

Disabling the OOM killer needs to exclude allocators from entering, not
existing victims from exiting.

Right now the only waiter is suspend code, which achieves quiescence by
disabling the OOM killer.  But later on we want to add waits that hold
the lock instead to stop new victims from showing up.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/oom_kill.c | 2 --
 1 file changed, 2 deletions(-)

(limited to 'mm')

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 472f124e5f08..d3490b019d46 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -437,10 +437,8 @@ void exit_oom_victim(void)
 {
 	clear_thread_flag(TIF_MEMDIE);
 
-	down_read(&oom_sem);
 	if (!atomic_dec_return(&oom_victims))
 		wake_up_all(&oom_victims_wait);
-	up_read(&oom_sem);
 }
 
 /**
-- 
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