From: Maurizio Lombardi Subject: Re: [PATCH 2/2] ext4: fix bug in ext4_mb_normalize_request() Date: Wed, 11 Jun 2014 10:47:19 +0200 Message-ID: <20140611084719.GA6931@dhcp-27-189.brq.redhat.com> References: <1393855228-13592-1-git-send-email-mlombard@redhat.com> <1393855228-13592-3-git-send-email-mlombard@redhat.com> <20140306154407.GA28226@thunk.org> <20140306165416.GA2182@dhcp-27-189.brq.redhat.com> <20140526165010.GN22284@thunk.org> <20140603203639.GB25483@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: =?utf-8?B?THVrw6HFoQ==?= Czerner , adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org To: "Theodore Ts'o" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:10271 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750958AbaFKIr0 (ORCPT ); Wed, 11 Jun 2014 04:47:26 -0400 Content-Disposition: inline In-Reply-To: <20140603203639.GB25483@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Jun 03, 2014 at 04:36:39PM -0400, Theodore Ts'o wrote: > On Tue, Jun 03, 2014 at 08:43:40PM +0200, Luk=C3=A1=C5=A1 Czerner wro= te: > >=20 > > I think that leaving the alignment of the start offset for the smal= l > > files/allocation is not good idea. We might end up with suboptimal > > file layout for smaller files. While this is not a big deal for > > bigger files, with smaller ones it might cause some troubles. >=20 > I thought we were only aligning the start offset for files > 2MB? > That's true. With my patch the behaviour changes slightly because it doesn't depend only from the file size but also from the number of blocks per group. So, if you create a filesystem with blocksize=3D=3D1Kb and 1024 blocks = per group, we will start aligning the start offset for files with size > 1Mb (1Kb * 1024) The alignment is not performed on small files unless you have a very low number of blocks per group. Maurizio Lombardi -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html