From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752396AbdJSTpx (ORCPT ); Thu, 19 Oct 2017 15:45:53 -0400 Received: from gum.cmpxchg.org ([85.214.110.215]:44036 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751720AbdJSTpv (ORCPT ); Thu, 19 Oct 2017 15:45:51 -0400 Date: Thu, 19 Oct 2017 15:45:34 -0400 From: Johannes Weiner To: Andrew Morton Cc: linux-mm@kvack.org, Michal Hocko , Vladimir Davydov , Tetsuo Handa , David Rientjes , Tejun Heo , kernel-team@fb.com, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Roman Gushchin Subject: Re: [RESEND v12 0/6] cgroup-aware OOM killer Message-ID: <20171019194534.GA5502@cmpxchg.org> References: <20171019185218.12663-1-guro@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171019185218.12663-1-guro@fb.com> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 19, 2017 at 07:52:12PM +0100, Roman Gushchin wrote: > This patchset makes the OOM killer cgroup-aware. Hi Andrew, I believe this code is ready for merging upstream, and it seems Michal is in agreement. There are two main things to consider, however. David would have really liked for this patchset to include knobs to influence how the algorithm picks cgroup victims. The rest of us agreed that this is beyond the scope of these patches, that the patches don't need it to be useful, and that there is nothing preventing anyone from adding configurability later on. David subsequently nacked the series as he considers it incomplete. Neither Michal nor I see technical merit in David's nack. Michal acked the implementation, but on the condition that the new behavior be opt-in, to not surprise existing users. I *think* we agree that respecting the cgroup topography during global OOM is what we should have been doing when cgroups were initially introduced; where we disagree is that I think users shouldn't have to opt in to improvements. We have done much more invasive changes to the victim selection without actual regressions in the past. Further, this change only applies to mounts of the new cgroup2. Tejun also wasn't convinced of the risk for regression, and too would prefer cgroup-awareness to be the default in cgroup2. I would ask for patch 5/6 to be dropped. Thanks