From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263336AbVGOQyU (ORCPT ); Fri, 15 Jul 2005 12:54:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263337AbVGOQyU (ORCPT ); Fri, 15 Jul 2005 12:54:20 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:65458 "EHLO parcelfarce.linux.theplanet.co.uk") by vger.kernel.org with ESMTP id S263336AbVGOQyS (ORCPT ); Fri, 15 Jul 2005 12:54:18 -0400 Date: Fri, 15 Jul 2005 17:56:16 +0100 From: Joel Becker To: Badari Pulavarty Cc: Tejun Heo , Daniel McNeil , "linux-aio@kvack.org" , Linux Kernel Mailing List Subject: Re: [rfc patch 2/2] direct-io: remove address alignment check Message-ID: <20050715165616.GH16877@parcelfarce.linux.theplanet.co.uk> Mail-Followup-To: Joel Becker , Badari Pulavarty , Tejun Heo , Daniel McNeil , "linux-aio@kvack.org" , Linux Kernel Mailing List References: <1121298112.6025.21.camel@ibm-c.pdx.osdl.net> <42D70318.1000304@gmail.com> <42D74724.8000703@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <42D74724.8000703@us.ibm.com> User-Agent: Mutt/1.4.1i X-Burt-Line: Trees are cool. X-Red-Smith: Ninety feet between bases is perhaps as close as man has ever come to perfection. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 14, 2005 at 10:18:28PM -0700, Badari Pulavarty wrote: > I can imagine a reason for relaxing the alignment. I keep getting asked > whether we can do "O_DIRECT mount option". Database folks wants to > make sure all the access to files in a given filesystem are O_DIRECT All currently existing "O_DIRECT mount option" implementations that I know of do: if (not-512-aligned) bounce_buffer() That is, no one attempts to support the wacky variations in DMA engines. Joel -- Brain: I shall pollute the water supply with this DNAdefibuliser, turning everyone into mindless slaves. Pinky: What about the people who drink bottled water? Brain: Pinky, people who pay 5 dollars for a bottle of water are already mindless slaves. http://www.jlbec.org/ jlbec@evilplan.org