From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id 9ED006B004D for ; Mon, 16 Nov 2009 12:57:47 -0500 (EST) Date: Mon, 16 Nov 2009 17:57:39 +0000 From: Mel Gorman Subject: Re: [PATCH 0/5] Reduce GFP_ATOMIC allocation failures, candidate fix V3 Message-ID: <20091116175739.GW29804@csn.ul.ie> References: <1258054235-3208-1-git-send-email-mel@csn.ul.ie> <200911131004.25293.elendil@planet.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <200911131004.25293.elendil@planet.nl> Sender: owner-linux-mm@kvack.org To: Frans Pop Cc: Andrew Morton , Jiri Kosina , Sven Geggus , Karol Lewandowski , Tobias Oetiker , linux-kernel@vger.kernel.org, "linux-mm@kvack.org" , KOSAKI Motohiro , Pekka Enberg , Rik van Riel , Christoph Lameter , Stephan von Krawczynski , "Rafael J. Wysocki" , Kernel Testers List , Chris Mason List-ID: On Fri, Nov 13, 2009 at 10:04:21AM +0100, Frans Pop wrote: > On Thursday 12 November 2009, Mel Gorman wrote: > > Changelog since V2 > > o Dropped the kswapd-quickly-notice-high-order patch. In more detailed > > testing, it made latencies even worse as kswapd slept more on > > high-order congestion causing order-0 direct reclaims. > > o Added changes to how congestion_wait() works > > o Added a number of new patches altering the behaviour of reclaim > > I have tested this series on top of .32-rc7. First impression is that it > does seem to improve my test case, but does not yet completely solve it. > > My last gitk instance now loads more smoothly for most of the time it takes > to complete, but I still see a choke point where things freeze for a while > and where I get SKB allocation errors from my wireless. > However, that choke point does seem to happen later and to be shorter than > without the patches. > I haven't fully figured out why this makes a difference yet, but with .32-rc7 and these patches, could you retry the test except beforehand do cd /sys for SYS in `find -name low_latency`; do echo 0 > $SYS done I believe the low_latency logic might be interfering with the number of clean pages available for kswapd to reclaim. Thanks -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org