Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755054AbYJGNhp (ORCPT ); Tue, 7 Oct 2008 09:37:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753736AbYJGNhR (ORCPT ); Tue, 7 Oct 2008 09:37:17 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:48833 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753618AbYJGNhP (ORCPT ); Tue, 7 Oct 2008 09:37:15 -0400 Date: Tue, 7 Oct 2008 09:36:51 -0400 From: Christoph Hellwig To: Theodore Tso , "Aneesh Kumar K.V" , Christoph Hellwig , Chris Mason , Dave Chinner , Andrew Morton , linux-kernel , linux-fsdevel , ext4 Subject: Re: [PATCH] Improve buffered streaming write ordering Message-ID: <20081007133651.GA19895@infradead.org> References: <1222950054.6745.18.camel@think.oraclecorp.com> <20081002181856.GB29613@skywalker> <20081002234309.GH30001@disturbed> <1223063155.13375.64.camel@think.oraclecorp.com> <20081006101605.GA15881@skywalker> <1223302903.16546.58.camel@think.oraclecorp.com> <20081007084531.GB15881@skywalker> <20081007090554.GA23811@infradead.org> <20081007100257.GA30745@skywalker> <20081007132911.GA6905@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081007132911.GA6905@mit.edu> User-Agent: Mutt/1.5.18 (2008-05-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1299 Lines: 24 On Tue, Oct 07, 2008 at 09:29:11AM -0400, Theodore Tso wrote: > That's true, but there is a lot of code duplication, which means that > bugs or changes in write_cache_pages() would need to be fixed in > ext4_write_cache_pages(). So another approach that might be better > from a long-term code maintenance point of view is to add a flag in > struct writeback_control that tells write_cache_pages() not to update > those fields, and avoid duplicating approximately 95 lines of code. > It means a change in a core mm function, though, so if folks thinks > its too ugly, we can make our own copy in fs/ext4. > > Opinions? Andrew, as someone who often weighs in on fs and mm issues, > what do you think? My preference would be to make the change to > mm/page-writeback.c, controlled by a flag which ext4 would set be set > by fs/ext4 before it calls write_cache_pages(). I agree. But I'm still not quite sure if that requirement is unique to ext4 anyway. Give me some time to dive into the writeback code again, haven't been there for quite a while. -- 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/