From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 8BB856B0098 for ; Thu, 30 Jul 2009 00:08:05 -0400 (EDT) Date: Thu, 30 Jul 2009 12:08:03 +0800 From: Wu Fengguang Subject: Re: Bug in kernel 2.6.31, Slow wb_kupdate writeout Message-ID: <20090730040803.GA20652@localhost> References: <1786ab030907281211x6e432ba6ha6afe9de73f24e0c@mail.gmail.com> <33307c790907281449k5e8d4f6cib2c93848f5ec2661@mail.gmail.com> <33307c790907290015m1e6b5666x9c0014cdaf5ed08@mail.gmail.com> <20090729114322.GA9335@localhost> <33307c790907290711s320607b0i79c939104d4c2d61@mail.gmail.com> <20090730010630.GA7326@localhost> <33307c790907291812j40146a96tc2e9c5e097a33615@mail.gmail.com> <20090730015754.GC7326@localhost> <33307c790907291959r47b1bd3ap7cfa06fd5154aaad@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <33307c790907291959r47b1bd3ap7cfa06fd5154aaad@mail.gmail.com> Sender: owner-linux-mm@kvack.org To: Martin Bligh Cc: Chad Talbott , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Michael Rubin , Andrew Morton , "sandeen@redhat.com" , Michael Davidson List-ID: On Thu, Jul 30, 2009 at 10:59:09AM +0800, Martin Bligh wrote: > On Wed, Jul 29, 2009 at 6:57 PM, Wu Fengguang wrote: > > On Thu, Jul 30, 2009 at 09:12:26AM +0800, Martin Bligh wrote: > >> > I agree on the unification of kupdate and sync paths. In fact I had a > >> > patch for doing this. And I'd recommend to do it in two patches: > >> > one to fix the congestion case, another to do the code unification. > >> > > >> > The sync path don't care whether requeue_io() or redirty_tail() is > >> > used, because they disregard the time stamps totally - only order of > >> > inodes matters (ie. starvation), which is same for requeue_io()/redirty_tail(). > >> > >> But, as I understand it, both paths share the same lists, so we still have > >> to be consistent? > > > > Then let's first unify the code, then fix the congestion case? :) > > OK, I will send it out as separate patches. I am just finishing up the testing > first. Note that this is a simple fix that may have suboptimal write performance. Here is an old reasoning: http://lkml.org/lkml/2009/3/28/235 Thanks, Fengguang -- 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