From: Eric Sandeen Subject: Re: delalloc fragmenting files? Date: Thu, 01 Nov 2007 14:05:40 -0500 Message-ID: <472A2384.2010001@redhat.com> References: <47225B1E.2060708@redhat.com> <20071026221938.GV3042@webber.adilger.int> <4728ED3B.1060407@redhat.com> <47291F62.3000008@gmail.com> <4729EEB2.9090406@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Alex Tomas , Andreas Dilger , ext4 development To: Eric Sandeen Return-path: Received: from mx1.redhat.com ([66.187.233.31]:46021 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753678AbXKATFq (ORCPT ); Thu, 1 Nov 2007 15:05:46 -0400 In-Reply-To: <4729EEB2.9090406@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Eric Sandeen wrote: > Alex Tomas wrote: >> please, try the patch attached. > > Looks quite a bit better: > > http://people.redhat.com/esandeen/seekwatcher/ext4-alex.png > http://people.redhat.com/esandeen/seekwatcher/ext4-alex-ext4-dd-write.png > http://people.redhat.com/esandeen/seekwatcher/ext4-alex-ext4-xfs-dd-write.png > > It is much less fragmented, although still not exactly the nice linear > allocation I'd expect from a single threaded large write on a fresh fs... Note, we're still getting out-of-order extents, too: First block: 122880 Last block: 2694143 Discontinuity: Block 7424 is at 101376 (was 130303) Discontinuity: Block 28160 is at 133120 (was 122111) Discontinuity: Block 58368 is at 188416 (was 163327) Discontinuity: Block 66304 is at 180224 (was 196351) Discontinuity: Block 73984 is at 172032 (was 187903) Discontinuity: Block 81664 is at 167936 (was 179711) Discontinuity: Block 84736 is at 221184 (was 171007) Discontinuity: Block 92416 is at 212992 (was 228863) Discontinuity: Block 100096 is at 204800 (was 220671) Discontinuity: Block 107776 is at 198656 (was 212479) ... I'm trying to find time to look into this but other things are knocking at my door so no promises... -Eric