From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932341AbWFCAKQ (ORCPT ); Fri, 2 Jun 2006 20:10:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932590AbWFCAKQ (ORCPT ); Fri, 2 Jun 2006 20:10:16 -0400 Received: from mail03.syd.optusnet.com.au ([211.29.132.184]:39107 "EHLO mail03.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S932341AbWFCAKP (ORCPT ); Fri, 2 Jun 2006 20:10:15 -0400 From: Con Kolivas To: linux-kernel@vger.kernel.org Subject: Re: [patch] cfq: ioprio inherit rt class Date: Sat, 3 Jun 2006 10:10:08 +1000 User-Agent: KMail/1.9.3 Cc: Jens Axboe , ck list References: <200605271150.41924.kernel@kolivas.org> <20060602171215.GM4400@suse.de> In-Reply-To: <20060602171215.GM4400@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200606031010.08794.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Saturday 03 June 2006 03:12, Jens Axboe wrote: > On Sat, May 27 2006, Con Kolivas wrote: > > Jens, ml > > > > I was wondering if cfq io priorities should be explicitly set to the > > realtime class when no io priority is specified from realtime tasks as in > > the following patch? (rt_task() will need to be modified to suit the PI > > changes in -mm) > > Not sure. RT io needs to be considered carefully, but I guess so does RT > CPU scheduling. For now I'd prefer to play it a little safer, and only > inheric the priority value and not the class. The problem I envisioned with that was that realtime tasks, if they don't specify an io priority (as most current code doesn't), would basically get io priority 4 and have the same proportion as any nice 0 SCHED_NORMAL task whereas -nice tasks automatically are getting better io priority. How about givent them normal class but best priority so they are at least getting the same as nice -20? -- -ck