From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261271AbULMQrL (ORCPT ); Mon, 13 Dec 2004 11:47:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261274AbULMQrK (ORCPT ); Mon, 13 Dec 2004 11:47:10 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:38058 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S261271AbULMQrI (ORCPT ); Mon, 13 Dec 2004 11:47:08 -0500 Date: Mon, 13 Dec 2004 17:46:25 +0100 From: Jens Axboe To: Jeff Sipek Cc: Linux Kernel Mailing List , kernel@kolivas.org, nickpiggin@yahoo.com.au Subject: Re: IO Priorities Message-ID: <20041213164625.GX3033@suse.de> References: <20041213142217.GA22853@optonline.net> <20041213143809.GO3033@suse.de> <20041213164325.GA26031@optonline.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041213164325.GA26031@optonline.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 13 2004, Jeff Sipek wrote: > On Mon, Dec 13, 2004 at 03:38:10PM +0100, Jens Axboe wrote: > > On Mon, Dec 13 2004, Jeff Sipek wrote: > > > Hello all, > > > About a week ago, I said I would try to implement IO priorities. > > > I tried. I got the whole thing done, but there is one major problem - it > > > > I did too, did you see my patch? > > I did after I sent mine. I was reading it and I noticed: > > "Disable TCQ in the hardware/driver by default. Can be changed (as > always) with the max_depth setting. If you do that, don't expect > fairness or priorities to work as well." > > Would this cause my problem? Only if you test on SCSI with TCQ enabled. But I already outlined what your problems are even if you did. > > Additionally, you don't do anything with the priorities internally. > > Sure I do, I multiply the slice by cfq_prio_scale[ioprio]. It did seem > too simple. :-) Looking at your code right now, I kind of see some code > that should have been in my implementation as well. Back to coding... > :-) If you would base changes on what I already did with CFQ, that would be handy. You need the CFQ bits anyways. Updated patch here: http://www.kernel.org/pub/linux/kernel/people/axboe/patches/v2.6/2.6.10-rc3-mm1/cfq-time-slices-11-2.6.10-rc3-mm1.gz -- Jens Axboe