From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932170AbWEGQZt (ORCPT ); Sun, 7 May 2006 12:25:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932192AbWEGQZt (ORCPT ); Sun, 7 May 2006 12:25:49 -0400 Received: from viper.oldcity.dca.net ([216.158.38.4]:25062 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S932170AbWEGQZs (ORCPT ); Sun, 7 May 2006 12:25:48 -0400 Subject: Re: [PATCH] Direct I/O bio size regression From: Lee Revell To: David Chinner Cc: Jens Axboe , linux-kernel@vger.kernel.org In-Reply-To: <20060426023031.GH611708@melbourne.sgi.com> References: <20060424061403.GF611708@melbourne.sgi.com> <20060424070236.GD22614@suse.de> <20060424090508.GI22614@suse.de> <20060424145635.GH611485@melbourne.sgi.com> <20060424184730.GH29724@suse.de> <20060426023031.GH611708@melbourne.sgi.com> Content-Type: text/plain Date: Sun, 07 May 2006 12:25:45 -0400 Message-Id: <1147019145.15364.236.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2006-04-26 at 12:30 +1000, David Chinner wrote: > Got any data that you can share with us? > The thread was from July 2004 and was called: Re: [linux-audio-dev] Re: [announce] [patch] Voluntary Kernel Preemption Patch Also some info in thread: Re: [patch] voluntary-preempt-2.6.8-rc2-M5 > Wrt latency, is the problem to do with large requests causing short > term latency? I thought that latency minimisation is the job of the > I/O scheduler, so if this is the case, doesn't this indicate a > deficiency of the I/O scheduler? e.g. the I/o scheduler could split > large requests to reduce latency, just like you merge adjacent > requests to reduce the number of I/Os and keep overall latency > low... > I think you are talking past each other - Jens is referring to scheduler latency, not IO latency. Lee