From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750849AbdAXM73 (ORCPT ); Tue, 24 Jan 2017 07:59:29 -0500 Received: from mx2.suse.de ([195.135.220.15]:41406 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753AbdAXM72 (ORCPT ); Tue, 24 Jan 2017 07:59:28 -0500 Date: Tue, 24 Jan 2017 13:59:21 +0100 From: Michal Hocko To: Mel Gorman Cc: Trevor Cordes , 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: <20170124125921.GI6867@dhcp22.suse.cz> References: <20170117135228.GN19699@dhcp22.suse.cz> <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170123104858.gpjy25y2ogju3gkg@techsingularity.net> 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 Mon 23-01-17 10:48:58, Mel Gorman wrote: [...] > Unfortunately, even that will be race prone for GFP_NOFS callers as > they'll effectively be racing to see if kswapd or another direct > reclaimer can reclaim before the OOM conditions are hit. It is by > design, but it's apparent that a __GFP_NOFAIL request can trigger OOM > relatively easily as it's not necessarily throttled or waiting on kswapd > to complete any work. I'll keep thinking about it. Yes, we shouldn't trigger the OOM for GFP_NOFS as the memory reclaim is really weaker. And that might really matter here. So the mmomt tree will behave differently in this regards as we have [1] [1] http://lkml.kernel.org/r/20161220134904.21023-3-mhocko@kernel.org -- Michal Hocko SUSE Labs