From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f72.google.com (mail-pl0-f72.google.com [209.85.160.72]) by kanga.kvack.org (Postfix) with ESMTP id 30D686B0005 for ; Thu, 31 May 2018 06:44:56 -0400 (EDT) Received: by mail-pl0-f72.google.com with SMTP id x2-v6so13167515plv.0 for ; Thu, 31 May 2018 03:44:56 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id d8-v6si28109040pgn.428.2018.05.31.03.44.54 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 31 May 2018 03:44:54 -0700 (PDT) Date: Thu, 31 May 2018 12:44:50 +0200 From: Michal Hocko Subject: Re: [PATCH] mm,oom: Don't call schedule_timeout_killable() with oom_lock held. Message-ID: <20180531104450.GN15278@dhcp22.suse.cz> References: <20180525083118.GI11881@dhcp22.suse.cz> <201805251957.EJJ09809.LFJHFFVOOSQOtM@I-love.SAKURA.ne.jp> <20180525114213.GJ11881@dhcp22.suse.cz> <201805252046.JFF30222.JHSFOFQFMtVOLO@I-love.SAKURA.ne.jp> <20180528124313.GC27180@dhcp22.suse.cz> <201805290557.BAJ39558.MFLtOJVFOHFOSQ@I-love.SAKURA.ne.jp> <20180529060755.GH27180@dhcp22.suse.cz> <20180529160700.dbc430ebbfac301335ac8cf4@linux-foundation.org> <16eca862-5fa6-2333-8a81-94a2c2692758@i-love.sakura.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <16eca862-5fa6-2333-8a81-94a2c2692758@i-love.sakura.ne.jp> Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: Andrew Morton , torvalds@linux-foundation.org, guro@fb.com, rientjes@google.com, hannes@cmpxchg.org, vdavydov.dev@gmail.com, tj@kernel.org, linux-mm@kvack.org On Thu 31-05-18 19:10:48, Tetsuo Handa wrote: > On 2018/05/30 8:07, Andrew Morton wrote: > > On Tue, 29 May 2018 09:17:41 +0200 Michal Hocko wrote: > > > >>> I suggest applying > >>> this patch first, and then fix "mm, oom: cgroup-aware OOM killer" patch. > >> > >> Well, I hope the whole pile gets merged in the upcoming merge window > >> rather than stall even more. > > > > I'm more inclined to drop it all. David has identified significant > > shortcomings and I'm not seeing a way of addressing those shortcomings > > in a backward-compatible fashion. Therefore there is no way forward > > at present. > > > > Can we apply my patch as-is first? No. As already explained before. Sprinkling new sleeps without a strong reason is not acceptable. The issue you are seeing is pretty artificial and as such doesn're really warrant an immediate fix. We should rather go with a well thought trhough fix. In other words we should simply drop the sleep inside the oom_lock for starter unless it causes some really unexpected behavior change. -- Michal Hocko SUSE Labs