Re: [PATCH 3/3] mm, oom_reaper: clear TIF_MEMDIE for all tasks queued for oom_reaper

From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 3/3] mm, oom_reaper: clear TIF_MEMDIE for all tasks queued for oom_reaper
Date: Fri, 8 Apr 2016 15:07:16 +0200	[thread overview]
Message-ID: <20160408130716.GI29820@dhcp22.suse.cz> (raw)
In-Reply-To: <1459951996-12875-4-git-send-email-mhocko@kernel.org>

Andrew, could you please fold this in?
---
>From 4e23df3584966f6d7885245f3071c15669b8a5fc Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.com>
Date: Fri, 8 Apr 2016 15:04:29 +0200
Subject: [PATCH] mm, oom_reaper: clear oom_reaper_list before clearing
 TIF_MEMDIE

As per Tetsuo:
: oom_reaper() will need to do "tsk->oom_reaper_list = NULL;" due to
:
:         if (tsk == oom_reaper_list || tsk->oom_reaper_list)
:                 return;
:
: test in wake_oom_reaper() if "[PATCH 3/3] mm, oom_reaper: clear
: TIF_MEMDIE for all tasks queued for oom_reaper" will select the same
: thread again

Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 mm/oom_kill.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 7098104b7475..ca34036f3ae1 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -540,6 +540,7 @@ static void oom_reap_task(struct task_struct *tsk)
 	 * for the oom victim right now because it cannot release its memory
 	 * itself nor by the oom reaper.
 	 */
+	tsk->oom_reaper_list = NULL;
 	exit_oom_victim(tsk);
 
 	/* Drop a reference taken by wake_oom_reaper */
-- 
2.8.0.rc3

-- 
Michal Hocko
SUSE Labs
