From: Peter Zijlstra Subject: Re: regression: 100% io-wait with 2.6.24-rcX Date: Mon, 14 Jan 2008 12:41:26 +0100 Message-ID: <1200310886.15103.1.camel@twins> References: <200801071151.11200.lists@naasa.net> <20080114035439.GA7330@mail.ustc.edu.cn> <400304530.01514@ustc.edu.cn> <200801141230.13694.jplatte@naasa.net> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Fengguang Wu , Ingo Molnar , linux-kernel@vger.kernel.org, "linux-ext4@vger.kernel.org" To: jplatte@naasa.net Return-path: Received: from pentafluge.infradead.org ([213.146.154.40]:42595 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754817AbYANLlf (ORCPT ); Mon, 14 Jan 2008 06:41:35 -0500 In-Reply-To: <200801141230.13694.jplatte@naasa.net> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, 2008-01-14 at 12:30 +0100, Joerg Platte wrote: > Am Montag, 14. Januar 2008 schrieb Fengguang Wu: > > > Joerg, this patch fixed the bug for me :-) > > Fengguang, congratulations, I can confirm that your patch fixed the bug! With > previous kernels the bug showed up after each reboot. Now, when booting the > patched kernel everything is fine and there is no longer any suspicious > iowait! > > Do you have an idea why this problem appeared in 2.6.24? Did somebody change > the ext2 code or is it related to the changes in the scheduler? It was Fengguang who changed the inode writeback code, and I guess the new and improved code was less able do deal with these funny corner cases. But he has been very good in tracking them down and solving them, kudos to him for that work!