Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755487AbZCEBL2 (ORCPT ); Wed, 4 Mar 2009 20:11:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751653AbZCEBLS (ORCPT ); Wed, 4 Mar 2009 20:11:18 -0500 Received: from mga03.intel.com ([143.182.124.21]:24206 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751077AbZCEBLR (ORCPT ); Wed, 4 Mar 2009 20:11:17 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.38,304,1233561600"; d="scan'208";a="116884340" Date: Thu, 5 Mar 2009 09:09:20 +0800 From: Wu Fengguang To: "Rafael J. Wysocki" Cc: Linux Kernel Mailing List , Kernel Testers List , Andrew Morton , "Lin, Ming M" , Linus Torvalds , Nick Piggin , Peter Zijlstra Subject: Re: [Bug #12809] iozone regression with 2.6.29-rc6 Message-ID: <20090305010920.GB11575@localhost> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1497 Lines: 36 On Tue, Mar 03, 2009 at 09:25:59PM +0200, Rafael J. Wysocki wrote: > This message has been generated automatically as a part of a report > of recent regressions. > > The following bug entry is on the current list of known regressions > from 2.6.28. Please verify if it still should be listed and let me know > (either way). > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=12809 > Subject : iozone regression with 2.6.29-rc6 > Submitter : Lin Ming > Date : 2009-02-27 9:13 (5 days old) > First-Bad-Commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1cf6e7d83bf334cc5916137862c920a97aabc018 > References : http://marc.info/?l=linux-kernel&m=123572630504360&w=4 > Handled-By : Wu Fengguang Following Peter's idea of relaxing writeback throttling, Lin Ming and I tried the idea of totally disabling writeback throttling by doing benchmarks with the following parameters: echo 60 > /proc/sys/vm/dirty_ratio echo 50 > /proc/sys/vm/dirty_background_ratio The result is encouraging: the iozone performance is restored to the level of 2.6.29-rc5! We'll continue to evaluate the dirty/throttling numbers with Nick's patch. Thanks, Fengguang -- 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/