From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751179AbdAQNw7 (ORCPT ); Tue, 17 Jan 2017 08:52:59 -0500 Received: from mx2.suse.de ([195.135.220.15]:37587 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751146AbdAQNwy (ORCPT ); Tue, 17 Jan 2017 08:52:54 -0500 Date: Tue, 17 Jan 2017 14:52:28 +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: <20170117135228.GN19699@dhcp22.suse.cz> References: <20170111103243.GA27795@pog.tecnopolis.ca> <20170111121146.i53jyerxont7b74i@techsingularity.net> <20170111121428.4sswbkzyqz7vf6so@techsingularity.net> <20170111165232.0b7abe18@pog.tecnopolis.ca> <20170112093613.GF2264@dhcp22.suse.cz> <20170115002752.4559f668@pog.tecnopolis.ca> <20170116110934.7zopy3ecg2lfadkd@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170116110934.7zopy3ecg2lfadkd@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 16-01-17 11:09:34, Mel Gorman wrote: [...] > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 532a2a750952..46aac487b89a 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2684,6 +2684,7 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) > continue; > > if (sc->priority != DEF_PRIORITY && > + !buffer_heads_over_limit && > !pgdat_reclaimable(zone->zone_pgdat)) > continue; /* Let kswapd poll it */ I think we should rather remove pgdat_reclaimable here. This sounds like a wrong layer to decide whether we want to reclaim and how much. But even that won't help very much I am afraid. As I've noted in the other response as long as we will scale the slab shrinking based on nr_scanned we will have a problem with situations where slab outnumbers lru lists too much. I do not have a good idea how to fix that though... -- Michal Hocko SUSE Labs