From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753885AbbI1W2v (ORCPT ); Mon, 28 Sep 2015 18:28:51 -0400 Received: from mail-pa0-f44.google.com ([209.85.220.44]:35546 "EHLO mail-pa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752717AbbI1W2u (ORCPT ); Mon, 28 Sep 2015 18:28:50 -0400 Date: Mon, 28 Sep 2015 15:28:48 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Tetsuo Handa cc: mhocko@kernel.org, oleg@redhat.com, torvalds@linux-foundation.org, kwalker@redhat.com, cl@linux.com, akpm@linux-foundation.org, hannes@cmpxchg.org, vdavydov@parallels.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, skozina@redhat.com Subject: Re: can't oom-kill zap the victim's memory? In-Reply-To: <201509290118.BCJ43256.tSFFFMOLHVOJOQ@I-love.SAKURA.ne.jp> Message-ID: References: <20150922160608.GA2716@redhat.com> <20150923205923.GB19054@dhcp22.suse.cz> <20150925093556.GF16497@dhcp22.suse.cz> <201509260114.ADI35946.OtHOVFOMJQFLFS@I-love.SAKURA.ne.jp> <201509290118.BCJ43256.tSFFFMOLHVOJOQ@I-love.SAKURA.ne.jp> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 29 Sep 2015, Tetsuo Handa wrote: > > The point I've tried to made is that oom unmapper running in a detached > > context (e.g. kernel thread) vs. directly in the oom context doesn't > > make any difference wrt. lock because the holders of the lock would loop > > inside the allocator anyway because we do not fail small allocations. > > We tried to allow small allocations to fail. It resulted in unstable system > with obscure bugs. > These are helpful to identify regardless of the outcome of this discussion. I'm not sure where the best place to report them would be, or whether its even feasible to dig through looking for possibilities, but I think it would be interesting to see which callers are relying on internal page allocator implementation to work properly since it may uncover bugs that would occur later if it were changed.