From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f51.google.com (mail-wm0-f51.google.com [74.125.82.51]) by kanga.kvack.org (Postfix) with ESMTP id E1FF0828DE for ; Fri, 8 Jan 2016 07:37:39 -0500 (EST) Received: by mail-wm0-f51.google.com with SMTP id b14so169303537wmb.1 for ; Fri, 08 Jan 2016 04:37:39 -0800 (PST) Received: from mail-wm0-f41.google.com (mail-wm0-f41.google.com. [74.125.82.41]) by mx.google.com with ESMTPS id h79si27330570wme.86.2016.01.08.04.37.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 08 Jan 2016 04:37:38 -0800 (PST) Received: by mail-wm0-f41.google.com with SMTP id f206so134451400wmf.0 for ; Fri, 08 Jan 2016 04:37:38 -0800 (PST) Date: Fri, 8 Jan 2016 13:37:36 +0100 From: Michal Hocko Subject: Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Message-ID: <20160108123735.GB14657@dhcp22.suse.cz> References: <201512292258.ABF87505.OFOSJLHMFVOQFt@I-love.SAKURA.ne.jp> <20160107162815.GA31729@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160107162815.GA31729@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Tetsuo Handa , 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 Thu 07-01-16 11:28:15, Johannes Weiner wrote: > 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. This is an interesting idea. It definitely sounds better than timeout based solutions. I will cook up a patch for this. The API between oom killer and the reaper has to change slightly but that shouldn't be a big deal. Thanks! -- Michal Hocko SUSE Labs -- 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