From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ted Ts'o Subject: Re: [PATCH] mballoc: allocate stripe-multiple IOs on stripe boundaries Date: Mon, 26 Jul 2010 18:52:23 -0400 Message-ID: <20100726225223.GB14072@thunk.org> References: <4C3E27BF.2000005@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: ext4 development , Mike Snitzer To: Eric Sandeen Return-path: Received: from thunk.org ([69.25.196.29]:36338 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754780Ab0GZWwZ (ORCPT ); Mon, 26 Jul 2010 18:52:25 -0400 Content-Disposition: inline In-Reply-To: <4C3E27BF.2000005@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, Jul 14, 2010 at 04:10:23PM -0500, Eric Sandeen wrote: > For some reason, today mballoc only allocates IOs which are exactly > stripe-sized on a stripe boundary. If you have a multiple (say, a > 128k IO on a 64k stripe) you may end up unaligned. > > It seems to me that a simple change to align stripe-multiple IOs > on stripe boundaries would be a very good idea, unless this breaks > some other mballoc heuristic for some reason... I've added this to the ext4 tree, thanks. - Ted