From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965278Ab1GMKkd (ORCPT ); Wed, 13 Jul 2011 06:40:33 -0400 Received: from cantor2.suse.de ([195.135.220.15]:43924 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965209Ab1GMKkc (ORCPT ); Wed, 13 Jul 2011 06:40:32 -0400 Date: Wed, 13 Jul 2011 11:40:25 +0100 From: Mel Gorman To: Christoph Lameter Cc: Minchan Kim , KOSAKI Motohiro , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] mm: vmscan: Do use use PF_SWAPWRITE from zone_reclaim Message-ID: <20110713104025.GE7529@suse.de> References: <1310389274-13995-1-git-send-email-mgorman@suse.de> <1310389274-13995-2-git-send-email-mgorman@suse.de> <4E1C1684.4090706@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 12, 2011 at 10:43:47AM -0500, Christoph Lameter wrote: > On Tue, 12 Jul 2011, Minchan Kim wrote: > > > If I am not against this patch, at least, we need agreement of > > Christoph and others and if we agree this change, we changes vm.txt, > > too. > > I think PF_SWAPWRITE should only be set if may_write was set earlier in > __zone_reclaim. If zone reclaim is not configured to do writeback then it > makes no sense to set the bit. > That would effectively make the patch a no-op as the check for PF_SWAPWRITE only happens if may_write is set. The point of the patch is that zone reclaim differs from direct reclaim in that zone reclaim obeys congestion where as zone reclaim does not. If you're saying that this is the way it's meant to be, then fine, I'll drop the patch. While I think it's a bad idea, I also didn't specifically test for problems related to it and I think the other two patches in the series are more important. -- Mel Gorman SUSE Labs