Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753524AbZLBLcl (ORCPT ); Wed, 2 Dec 2009 06:32:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753486AbZLBLck (ORCPT ); Wed, 2 Dec 2009 06:32:40 -0500 Received: from gir.skynet.ie ([193.1.99.77]:38997 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753267AbZLBLcj (ORCPT ); Wed, 2 Dec 2009 06:32:39 -0500 Date: Wed, 2 Dec 2009 11:32:41 +0000 From: Mel Gorman To: Tobi Oetiker Cc: Andrew Morton , KOSAKI Motohiro , Frans Pop , Jiri Kosina , Sven Geggus , Karol Lewandowski , linux-kernel@vger.kernel.org, "linux-mm@kvack.org" , Pekka Enberg , Rik van Riel , Christoph Lameter , Stephan von Krawczynski , "Rafael J. Wysocki" , Kernel Testers List Subject: Re: still getting allocation failures (was Re: [PATCH] vmscan: Stop kswapd waiting on congestion when the min watermark is not being met V2) Message-ID: <20091202113241.GC1457@csn.ul.ie> References: <20091113142608.33B9.A69D9226@jp.fujitsu.com> <20091113135443.GF29804@csn.ul.ie> <20091114023138.3DA5.A69D9226@jp.fujitsu.com> <20091113181557.GM29804@csn.ul.ie> <2f11576a0911131033w4a9e6042k3349f0be290a167e@mail.gmail.com> <20091113200357.GO29804@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2944 Lines: 68 On Sun, Nov 29, 2009 at 08:42:09AM +0100, Tobi Oetiker wrote: > Hi Mel, > > Thursday Tobias Oetiker wrote: > > Hi Mel, > > > > Nov 13 Mel Gorman wrote: > > > > > The last version has a stupid bug in it. Sorry. > > > > > > Changelog since V1 > > > o Fix incorrect negation > > > o Rename kswapd_no_congestion_wait to kswapd_skip_congestion_wait as > > > suggested by Rik > > > > > > If reclaim fails to make sufficient progress, the priority is raised. > > > Once the priority is higher, kswapd starts waiting on congestion. However, > > > if the zone is below the min watermark then kswapd needs to continue working > > > without delay as there is a danger of an increased rate of GFP_ATOMIC > > > allocation failure. > > > > > > This patch changes the conditions under which kswapd waits on > > > congestion by only going to sleep if the min watermarks are being met. > > > > I finally got around to test this together with the whole series on > > 2.6.31.6. after running it for a day I have not yet seen a single > > order:5 allocation problem ... (while I had several an hour before) > > > for the record, my kernel is now running with the following > > patches: > > > > patch1:Date: Thu, 12 Nov 2009 19:30:31 +0000 > > patch1:Subject: [PATCH 1/5] page allocator: Always wake kswapd when restarting an allocation attempt after direct reclaim failed > > > > patch2:Date: Thu, 12 Nov 2009 19:30:32 +0000 > > patch2:Subject: [PATCH 2/5] page allocator: Do not allow interrupts to use ALLOC_HARDER > > > > patch3:Date: Thu, 12 Nov 2009 19:30:33 +0000 > > patch3:Subject: [PATCH 3/5] page allocator: Wait on both sync and async congestion after direct reclaim > > > > patch4:Date: Thu, 12 Nov 2009 19:30:34 +0000 > > patch4:Subject: [PATCH 4/5] vmscan: Have kswapd sleep for a short interval and double check it should be asleep > > > > patch5:Date: Fri, 13 Nov 2009 20:03:57 +0000 > > patch5:Subject: [PATCH] vmscan: Stop kswapd waiting on congestion when the min watermark is not being met V2 > > > > patch6:Date: Tue, 17 Nov 2009 10:34:21 +0000 > > patch6:Subject: [PATCH] vmscan: Have kswapd sleep for a short interval and double check it should be asleep fix 1 > > > I have now been running the new kernel for a few days and I am > sorry to report that about a day after booting the allocation > failures started showing again. More order:4 instead of order:5 ... > Why has the order changed? Also, what allocator were you using in 2.6.30 and 2.6.31.6, SLAB or SLUB? Did you happen to change them when upgrading the kernel? -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/