From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754789Ab0E2Cwg (ORCPT ); Fri, 28 May 2010 22:52:36 -0400 Received: from bosmailout19.eigbox.net ([66.96.184.19]:47454 "EHLO bosmailout19.eigbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751264Ab0E2Cwc (ORCPT ); Fri, 28 May 2010 22:52:32 -0400 X-Greylist: delayed 1876 seconds by postgrey-1.27 at vger.kernel.org; Fri, 28 May 2010 22:52:32 EDT X-EN-OrigOutIP: 10.20.18.11 X-EN-IMPSID: PEMD1e0010EKspE01EMD48 Message-ID: <4C007A0F.6020304@jaysonking.com> Date: Fri, 28 May 2010 21:21:03 -0500 From: "Jayson R. King" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100301 Fedora/3.0.3-1.fc11 Thunderbird/3.0.3 MIME-Version: 1.0 To: tytso@mit.edu CC: "Jayson R. King" , Stable team , LKML , Greg Kroah-Hartman , "Aneesh Kumar K.V" , Dave Chinner , Ext4 Developers List , Kay Diederichs Subject: Re: [PATCH 2.6.27.y 1/3] ext4: Use our own write_cache_pages() References: <4C001888.8020006@jaysonking.com> <4C0018E1.5060007@jaysonking.com> <20100529004913.GL26177@thunk.org> <4C0070D8.8060500@jaysonking.com> In-Reply-To: <4C0070D8.8060500@jaysonking.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-EN-UserInfo: 06af1bc540adb20c3d2d7097199478a6:08dd1976e651f6e3791fbe97eaa5f898 X-EN-AuthUser: jaysonking@jaysonking.com X-EN-OrigIP: 68.93.139.172 X-EN-OrigHost: unknown Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/28/2010 08:41 PM, Jayson R. King wrote: > On 05/28/2010 07:49 PM, tytso@mit.edu wrote: >> This doesn't fix a bug; it's to make it easy for Dave Chinner to make >> some changes to fix XFS's performance and to undo some ext4-specific >> changes to write_cache_pages(). I'm not sure there's a good reason to >> backport this to 2.6.27.y.... > > The difference is that, 2.6.27's write_cache_pages() in page-writeback.c > still updates wbc->nr_to_write, since the patch which changed that > behavior was dropped from .27-rc2 due to the XFS regression it causes on > mainline. I meant, it was dropped from .27.47-rc2 stable. Sorry for any confusion. > ext4 appears to want the behavior of write_cache_pages which > does not update wbc->nr_to_write. This write_cache_pages_da() does what > ext4 wants, without introducing the XFS regression. So I believe it is > needed. > > Did I mis-judge? > > Rgds, > > Jayson >