From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id E56196B0044 for ; Fri, 6 Nov 2009 04:51:43 -0500 (EST) From: Frans Pop Subject: Re: [Bug #14141] order 2 page allocation failures in iwlagn Date: Fri, 6 Nov 2009 10:51:37 +0100 References: <3onW63eFtRF.A.xXH.oMTxKB@chimera> <200910262206.13146.elendil@planet.nl> <200911052114.36718.elendil@planet.nl> In-Reply-To: <200911052114.36718.elendil@planet.nl> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200911061051.40443.elendil@planet.nl> Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: Chris Mason , David Rientjes , KOSAKI Motohiro , "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Pekka Enberg , Reinette Chatre , Bartlomiej Zolnierkiewicz , Karol Lewandowski , Mohamed Abbas , Jens Axboe , "John W. Linville" , linux-mm@kvack.org List-ID: On Thursday 05 November 2009, Frans Pop wrote: > On Monday 26 October 2009, Frans Pop wrote: > > On Tuesday 20 October 2009, Mel Gorman wrote: > > > I've attached a patch below that should allow us to cheat. When it's > > > applied, it outputs who called congestion_wait(), how long the > > > timeout was and how long it waited for. By comparing before and > > > after sleep times, we should be able to see which of the callers has > > > significantly changed and if it's something easily addressable. > > > > The results from this look fairly interesting (although I may be a bad > > judge as I don't really know what I'm looking at ;-). > > > > I've tested with two kernels: > > 1) 2.6.31.1: 1 test run > > 2) 2.6.31.1 + congestion_wait() reverts: 2 test runs > > I've taken another look at the data from this debug patch, resulting in > these graphs: http://people.debian.org/~fjp/tmp/kernel/congestion.pdf > > I think the graph may show the reason for the congestion_wait() > regression. Horizontal axis shows time, vertical axis shows number of > logged congestion_wait calls per type. I'm sorry. My initial version had a skewed time axis (showed occurrences instead of actual time). I've now uploaded a corrected version: http://people.debian.org/~fjp/tmp/kernel/congestion.pdf I've also uploaded a second version that shows cumulative delay per type, which probably gives a better insight: http://people.debian.org/~fjp/tmp/kernel/congestion2.pdf For both the top chart is without the revert, the bottom one after the revert. -- 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