From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752088AbdFOWDV (ORCPT ); Thu, 15 Jun 2017 18:03:21 -0400 Received: from mail-pf0-f176.google.com ([209.85.192.176]:33595 "EHLO mail-pf0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751798AbdFOWDU (ORCPT ); Thu, 15 Jun 2017 18:03:20 -0400 Date: Thu, 15 Jun 2017 15:03:17 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Michal Hocko cc: Andrew Morton , Tetsuo Handa , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [patch] mm, oom: prevent additional oom kills before memory is freed In-Reply-To: <20170615214133.GB20321@dhcp22.suse.cz> Message-ID: References: <20170615103909.GG1486@dhcp22.suse.cz> <20170615214133.GB20321@dhcp22.suse.cz> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 15 Jun 2017, Michal Hocko wrote: > > Yes, quite a bit in testing. > > > > One oom kill shows the system to be oom: > > > > [22999.488705] Node 0 Normal free:90484kB min:90500kB ... > > [22999.488711] Node 1 Normal free:91536kB min:91948kB ... > > > > followed up by one or more unnecessary oom kills showing the oom killer > > racing with memory freeing of the victim: > > > > [22999.510329] Node 0 Normal free:229588kB min:90500kB ... > > [22999.510334] Node 1 Normal free:600036kB min:91948kB ... > > > > The patch is absolutely required for us to prevent continuous oom killing > > of processes after a single process has been oom killed and its memory is > > in the process of being freed. > > OK, could you play with the patch/idea suggested in > http://lkml.kernel.org/r/20170615122031.GL1486@dhcp22.suse.cz? > I cannot, I am trying to unblock a stable kernel release to my production that is obviously fixed with this patch and cannot experiment with uncompiled and untested patches that introduce otherwise unnecessary locking into the __mmput() path and is based on speculation rather than hard data that __mmput() for some reason stalls for the oom victim's mm. I was hoping that this fix could make it in time for 4.12 since 4.12 kills 1-4 processes unnecessarily for each oom condition and then can review any tested solution you may propose at a later time. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 318886B0279 for ; Thu, 15 Jun 2017 18:03:21 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id r70so22192127pfb.7 for ; Thu, 15 Jun 2017 15:03:21 -0700 (PDT) Received: from mail-pf0-x232.google.com (mail-pf0-x232.google.com. [2607:f8b0:400e:c00::232]) by mx.google.com with ESMTPS id b80si316432pfb.79.2017.06.15.15.03.19 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 15 Jun 2017 15:03:20 -0700 (PDT) Received: by mail-pf0-x232.google.com with SMTP id s66so13321810pfs.1 for ; Thu, 15 Jun 2017 15:03:19 -0700 (PDT) Date: Thu, 15 Jun 2017 15:03:17 -0700 (PDT) From: David Rientjes Subject: Re: [patch] mm, oom: prevent additional oom kills before memory is freed In-Reply-To: <20170615214133.GB20321@dhcp22.suse.cz> Message-ID: References: <20170615103909.GG1486@dhcp22.suse.cz> <20170615214133.GB20321@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Andrew Morton , Tetsuo Handa , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu, 15 Jun 2017, Michal Hocko wrote: > > Yes, quite a bit in testing. > > > > One oom kill shows the system to be oom: > > > > [22999.488705] Node 0 Normal free:90484kB min:90500kB ... > > [22999.488711] Node 1 Normal free:91536kB min:91948kB ... > > > > followed up by one or more unnecessary oom kills showing the oom killer > > racing with memory freeing of the victim: > > > > [22999.510329] Node 0 Normal free:229588kB min:90500kB ... > > [22999.510334] Node 1 Normal free:600036kB min:91948kB ... > > > > The patch is absolutely required for us to prevent continuous oom killing > > of processes after a single process has been oom killed and its memory is > > in the process of being freed. > > OK, could you play with the patch/idea suggested in > http://lkml.kernel.org/r/20170615122031.GL1486@dhcp22.suse.cz? > I cannot, I am trying to unblock a stable kernel release to my production that is obviously fixed with this patch and cannot experiment with uncompiled and untested patches that introduce otherwise unnecessary locking into the __mmput() path and is based on speculation rather than hard data that __mmput() for some reason stalls for the oom victim's mm. I was hoping that this fix could make it in time for 4.12 since 4.12 kills 1-4 processes unnecessarily for each oom condition and then can review any tested solution you may propose at a later time. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org