From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262777AbVGNXow (ORCPT ); Thu, 14 Jul 2005 19:44:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262769AbVGNXov (ORCPT ); Thu, 14 Jul 2005 19:44:51 -0400 Received: from smtp.osdl.org ([65.172.181.4]:19911 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S262777AbVGNXou (ORCPT ); Thu, 14 Jul 2005 19:44:50 -0400 Subject: Re: [rfc patch 2/2] direct-io: remove address alignment check From: Daniel McNeil To: Badari Pulavarty Cc: "linux-aio@kvack.org" , Linux Kernel Mailing List In-Reply-To: <1121382983.6755.87.camel@dyn9047017102.beaverton.ibm.com> References: <1121298112.6025.21.camel@ibm-c.pdx.osdl.net> <1121382983.6755.87.camel@dyn9047017102.beaverton.ibm.com> Content-Type: text/plain Message-Id: <1121384672.6025.81.camel@ibm-c.pdx.osdl.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Thu, 14 Jul 2005 16:44:33 -0700 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2005-07-14 at 16:16, Badari Pulavarty wrote: > How does your patch ensures that we meet the driver alignment > restrictions ? Like you said, you need atleast "even" byte alignment > for IDE etc.. > > And also, are there any restrictions on how much the "minimum" IO > size has to be ? I mean, can I read "1" byte ? I guess you are > not relaxing it (yet).. > This patch does not change the i/o size requirements -- they must be a multiple of device block size (usually 512). It only relaxes the address alignment restriction. I do not know what the driver alignment restrictions are. Without the 1st patch, it was impossible to relax the address space check and have direct-io generate the correct i/o's to submit. This 2nd patch, is just for testing and generating feedback to find out what the address alignment issues are. Then we can decide how to proceed. Did you look over the 1st patch? Comments? Thanks, Daniel