From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f43.google.com (mail-ee0-f43.google.com [74.125.83.43]) by kanga.kvack.org (Postfix) with ESMTP id 61CAE6B0031 for ; Thu, 12 Dec 2013 07:11:43 -0500 (EST) Received: by mail-ee0-f43.google.com with SMTP id c13so180799eek.16 for ; Thu, 12 Dec 2013 04:11:42 -0800 (PST) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTP id m44si23380256eeo.142.2013.12.12.04.11.42 for ; Thu, 12 Dec 2013 04:11:42 -0800 (PST) Date: Thu, 12 Dec 2013 13:11:40 +0100 From: Michal Hocko Subject: Re: [patch 1/2] mm, memcg: avoid oom notification when current needs access to memory reserves Message-ID: <20131212121140.GD2630@dhcp22.suse.cz> References: <20131204111318.GE8410@dhcp22.suse.cz> <20131209124840.GC3597@dhcp22.suse.cz> <20131210103827.GB20242@dhcp22.suse.cz> <20131211095549.GA18741@dhcp22.suse.cz> <20131212103159.GB2630@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131212103159.GB2630@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Johannes Weiner , Andrew Morton , KAMEZAWA Hiroyuki , linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org On Thu 12-12-13 11:31:59, Michal Hocko wrote: [...] > The semantic would be as simple as "notification is sent only when > an action is due". It will be still racy as nothing prevents a task > which is not under OOM to exit and release some memory but there is no > sensible way to address that. On the other hand such a semantic would be > sensible for oom_control listeners because they will know that an action > has to be or will be taken (the line was drawn). > > Can we agree on this, Johannes? Or you see the line drawn when > mem_cgroup_oom_synchronize has been reached already no matter whether > the action is to be done or not? Something like the following: