From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f179.google.com (mail-lb0-f179.google.com [209.85.217.179]) by kanga.kvack.org (Postfix) with ESMTP id B42B7828DE for ; Thu, 7 Jan 2016 11:28:53 -0500 (EST) Received: by mail-lb0-f179.google.com with SMTP id bc4so209959458lbc.2 for ; Thu, 07 Jan 2016 08:28:53 -0800 (PST) Received: from gum.cmpxchg.org (gum.cmpxchg.org. [85.214.110.215]) by mx.google.com with ESMTPS id sq3si14069121lbb.118.2016.01.07.08.28.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 07 Jan 2016 08:28:52 -0800 (PST) Date: Thu, 7 Jan 2016 11:28:15 -0500 From: Johannes Weiner Subject: Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Message-ID: <20160107162815.GA31729@cmpxchg.org> References: <201512292258.ABF87505.OFOSJLHMFVOQFt@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201512292258.ABF87505.OFOSJLHMFVOQFt@I-love.SAKURA.ne.jp> Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: mhocko@kernel.org, akpm@linux-foundation.org, mgorman@suse.de, rientjes@google.com, torvalds@linux-foundation.org, oleg@redhat.com, hughd@google.com, andrea@kernel.org, riel@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Tue, Dec 29, 2015 at 10:58:22PM +0900, Tetsuo Handa wrote: > >From 8bb9e36891a803e82c589ef78077838026ce0f7d Mon Sep 17 00:00:00 2001 > From: Tetsuo Handa > Date: Tue, 29 Dec 2015 22:20:58 +0900 > Subject: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. > > The OOM reaper kernel thread can reclaim OOM victim's memory before the victim > terminates. But since oom_kill_process() tries to kill children of the memory > hog process first, the OOM reaper can not reclaim enough memory for terminating > the victim if the victim is consuming little memory. The result is OOM livelock > as usual, for timeout based next OOM victim selection is not implemented. What we should be doing is have the OOM reaper clear TIF_MEMDIE after it's done. There is no reason to wait for and prioritize the exit of a task that doesn't even have memory anymore. Once a task's memory has been reaped, subsequent OOM invocations should evaluate anew the most desirable OOM victim. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org