From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752286AbcFWMoY (ORCPT ); Thu, 23 Jun 2016 08:44:24 -0400 Received: from mail-wm0-f50.google.com ([74.125.82.50]:38700 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751691AbcFWMoX (ORCPT ); Thu, 23 Jun 2016 08:44:23 -0400 Date: Thu, 23 Jun 2016 14:44:21 +0200 From: Michal Hocko To: Mel Gorman Cc: Andrew Morton , Linux-MM , Rik van Riel , Vlastimil Babka , Johannes Weiner , LKML Subject: Re: [PATCH 00/27] Move LRU page reclaim from zones to nodes v7 Message-ID: <20160623124420.GI30077@dhcp22.suse.cz> References: <1466518566-30034-1-git-send-email-mgorman@techsingularity.net> <20160623102648.GP1868@techsingularity.net> <20160623112714.GF30077@dhcp22.suse.cz> <20160623123347.GV1868@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160623123347.GV1868@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 Thu 23-06-16 13:33:47, Mel Gorman wrote: > On Thu, Jun 23, 2016 at 01:27:14PM +0200, Michal Hocko wrote: > > On Thu 23-06-16 11:26:48, Mel Gorman wrote: > > > On Tue, Jun 21, 2016 at 03:15:39PM +0100, Mel Gorman wrote: > > > > The bulk of the updates are in response to review from Vlastimil Babka > > > > and received a lot more testing than v6. > > > > > > > > > > Hi Andrew, > > > > > > Please drop these patches again from mmotm. > > > > > > There has been a number of odd conflicts resulting in at least one major > > > bug where a node-counter is used on a zone that will result in random > > > behaviour. Some of the additional feedback is non-trivial and all of it > > > will need to be resolved against the OOM detection rework and the huge > > > tmpfs implementation. > > > > FWIW I haven't spotted any obvious misbehaving wrt. the OOM detection > > rework. You have kept the per-zone counters which are used for the retry > > logic so I think we should be safe. I am still reading through the > > series though. > > > > The main snag is NR_FILE_DIRTY and NR_WRITEBACK in should_reclaim_retry. > It currently is a random number generator if it reads a zone stat > instead of the node one. In some configurations, it even reads values > after the stats array. OK, I haven't spotted that. As I've said I haven't seen the whole series yet. I have just seen that the counters are there and assumed they are used properly where appropriate. -- Michal Hocko SUSE Labs