From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id 1A2076B0003 for ; Wed, 8 Aug 2018 06:59:13 -0400 (EDT) Received: by mail-pf1-f197.google.com with SMTP id u8-v6so1186652pfn.18 for ; Wed, 08 Aug 2018 03:59:13 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id c125-v6si3471151pga.534.2018.08.08.03.59.11 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 08 Aug 2018 03:59:12 -0700 (PDT) Date: Wed, 8 Aug 2018 12:59:09 +0200 From: Michal Hocko Subject: Re: [PATCH 0/3] introduce memory.oom.group Message-ID: <20180808105909.GJ27972@dhcp22.suse.cz> References: <20180730180100.25079-1-guro@fb.com> <20180731235135.GA23436@castle.DHCP.thefacebook.com> <20180801224706.GA32269@castle.DHCP.thefacebook.com> <20180807003020.GA21483@castle.DHCP.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Roman Gushchin , linux-mm@kvack.org, Johannes Weiner , Tetsuo Handa , Tejun Heo , kernel-team@fb.com, linux-kernel@vger.kernel.org On Tue 07-08-18 15:34:58, David Rientjes wrote: > On Mon, 6 Aug 2018, Roman Gushchin wrote: > > > > In a cgroup-aware oom killer world, yes, we need the ability to specify > > > that the usage of the entire subtree should be compared as a single > > > entity with other cgroups. That is necessary for user subtrees but may > > > not be necessary for top-level cgroups depending on how you structure your > > > unified cgroup hierarchy. So it needs to be configurable, as you suggest, > > > and you are correct it can be different than oom.group. > > > > > > That's not the only thing we need though, as I'm sure you were expecting > > > me to say :) > > > > > > We need the ability to preserve existing behavior, i.e. process based and > > > not cgroup aware, for subtrees so that our users who have clear > > > expectations and tune their oom_score_adj accordingly based on how the oom > > > killer has always chosen processes for oom kill do not suddenly regress. > > > > Isn't the combination of oom.group=0 and oom.evaluate_together=1 describing > > this case? This basically means that if memcg is selected as target, > > the process inside will be selected using traditional per-process approach. > > > > No, that would overload the policy and mechanism. We want the ability to > consider user-controlled subtrees as a single entity for comparison with > other user subtrees to select which subtree to target. This does not > imply that users want their entire subtree oom killed. Yeah, that's why oom.group == 0, no? Anyway, can we separate this discussion from the current series please? We are getting more and more tangent. Or do you still see the current state to be not mergeable? -- Michal Hocko SUSE Labs