From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751481AbdAYME2 (ORCPT ); Wed, 25 Jan 2017 07:04:28 -0500 Received: from mx2.suse.de ([195.135.220.15]:39734 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751370AbdAYME1 (ORCPT ); Wed, 25 Jan 2017 07:04:27 -0500 Date: Wed, 25 Jan 2017 13:04:20 +0100 From: Michal Hocko To: Trevor Cordes Cc: Mel Gorman , linux-kernel@vger.kernel.org, Joonsoo Kim , Minchan Kim , Rik van Riel , Srikar Dronamraju Subject: Re: mm, vmscan: commit makes PAE kernel crash nightly (bisected) Message-ID: <20170125120420.GM32377@dhcp22.suse.cz> References: <20170117142114.r7abr3x2bbik47sd@techsingularity.net> <20170117145450.GQ19699@dhcp22.suse.cz> <20170119034850.0b7d504c@pog.tecnopolis.ca> <20170119113757.GP30786@dhcp22.suse.cz> <20170120003544.7e6e34d1@pog.tecnopolis.ca> <20170120110232.y7xd4b7wtwqslgnw@techsingularity.net> <20170120155553.gjv2x5eycvdudnil@techsingularity.net> <20170122184559.0b5c0fd8@pog.tecnopolis.ca> <20170123104858.gpjy25y2ogju3gkg@techsingularity.net> <20170125040246.5b211135@pog.tecnopolis.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170125040246.5b211135@pog.tecnopolis.ca> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 25-01-17 04:02:46, Trevor Cordes wrote: > On 2017-01-23 Mel Gorman wrote: > > On Sun, Jan 22, 2017 at 06:45:59PM -0600, Trevor Cordes wrote: > > > On 2017-01-20 Mel Gorman wrote: > > > > > > > > > > Thanks for the OOM report. I was expecting it to be a particular > > > > > shape and my expectations were not matched so it took time to > > > > > consider it further. Can you try the cumulative patch below? It > > > > > combines three patches that > > > > > > > > > > 1. Allow slab shrinking even if the LRU patches are > > > > > unreclaimable in direct reclaim > > > > > 2. Shrinks slab based once based on the contents of all memcgs > > > > > instead of shrinking one at a time > > > > > 3. Tries to shrink slabs if the lowmem usage is too high > > > > > > > > > > Unfortunately it's only boot tested on x86-64 as I didn't get > > > > > the chance to setup an i386 test bed. > > > > > > > > > > > > > There was one major flaw in that patch. This version fixes it and > > > > addresses other minor issues. It may still be too agressive > > > > shrinking slab but worth trying out. Thanks. > > > > > > I ran with your patch below and it oom'd on the first night. It was > > > weird, it didn't hang the system, and my rebooter script started a > > > reboot but the system never got more than half down before it just > > > sat there in a weird state where a local console user could still > > > login but not much was working. So the patches don't seem to solve > > > the problem. > > > > > > For the above compile I applied your patches to 4.10.0-rc4+, I hope > > > that's ok. > > > > > > > It would be strongly preferred to run them on top of Michal's other > > fixes. The main reason it's preferred is because this OOM differs from > > earlier ones in that it OOM killed from GFP_NOFS|__GFP_NOFAIL context. > > That meant that the slab shrinking could not happen from direct > > reclaim so the balancing from my patches would not occur. As > > Michal's other patches affect how kswapd behaves, it's important. > > OK, I patched & compiled mhocko's git tree from the other day 4.9.0+. > (To confirm, weird, but mhocko's git tree I'm using from a couple of > weeks ago shows the newest commit (git log) is > 69973b830859bc6529a7a0468ba0d80ee5117826 "Linux 4.9"? Let me know if > I'm doing something wrong, see below.) My fault. I should have noted that you should use since-4.9 branch. -- Michal Hocko SUSE Labs