From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751542AbeA2TLp (ORCPT ); Mon, 29 Jan 2018 14:11:45 -0500 Received: from mail-qk0-f194.google.com ([209.85.220.194]:38781 "EHLO mail-qk0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751377AbeA2TLn (ORCPT ); Mon, 29 Jan 2018 14:11:43 -0500 X-Google-Smtp-Source: AH8x224M7wS5PkQQy932KJ3ho1s1KUl8F11OVXzC+mQCbGjC/e1W+A+yvHUZ7nte63AO80BPP2tVcg== Date: Mon, 29 Jan 2018 11:11:39 -0800 From: Tejun Heo To: Michal Hocko Cc: Andrew Morton , David Rientjes , Roman Gushchin , Vladimir Davydov , Johannes Weiner , Tetsuo Handa , kernel-team@fb.com, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [patch -mm v2 2/3] mm, memcg: replace cgroup aware oom killer mount option with tunable Message-ID: <20180129191139.GA1121507@devbig577.frc2.facebook.com> References: <20180125160016.30e019e546125bb13b5b6b4f@linux-foundation.org> <20180126143950.719912507bd993d92188877f@linux-foundation.org> <20180126161735.b999356fbe96c0acd33aaa66@linux-foundation.org> <20180129104657.GC21609@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180129104657.GC21609@dhcp22.suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Michal. On Mon, Jan 29, 2018 at 11:46:57AM +0100, Michal Hocko wrote: > @@ -1292,7 +1292,11 @@ the memory controller considers only cgroups belonging to the sub-tree > of the OOM'ing cgroup. > > The root cgroup is treated as a leaf memory cgroup, so it's compared > -with other leaf memory cgroups and cgroups with oom_group option set. > +with other leaf memory cgroups and cgroups with oom_group option > +set. Due to internal implementation restrictions the size of the root > +cgroup is a cumulative sum of oom_badness of all its tasks (in other > +words oom_score_adj of each task is obeyed). This might change in the > +future. Thanks, we can definitely use more documentation. However, it's a bit difficult to follow. Maybe expand it to a separate paragraph on the current behavior with a clear warning that the default OOM heuristics is subject to changes? Thanks. -- tejun