From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751113AbWFDBiH (ORCPT ); Sat, 3 Jun 2006 21:38:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751185AbWFDBiH (ORCPT ); Sat, 3 Jun 2006 21:38:07 -0400 Received: from mail20.syd.optusnet.com.au ([211.29.132.201]:45984 "EHLO mail20.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S1751113AbWFDBiG (ORCPT ); Sat, 3 Jun 2006 21:38:06 -0400 From: Con Kolivas To: Lee Revell Subject: Re: [patch] cfq: ioprio inherit rt class Date: Sun, 4 Jun 2006 11:37:45 +1000 User-Agent: KMail/1.9.3 Cc: linux-kernel@vger.kernel.org, Jens Axboe , ck list References: <200605271150.41924.kernel@kolivas.org> <200606031010.08794.kernel@kolivas.org> <1149356428.28744.27.camel@mindpipe> In-Reply-To: <1149356428.28744.27.camel@mindpipe> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200606041137.46601.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sunday 04 June 2006 03:40, Lee Revell wrote: > On Sat, 2006-06-03 at 10:10 +1000, Con Kolivas wrote: > > On Saturday 03 June 2006 03:12, Jens Axboe wrote: > > > 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? > > Con, > > Have you seen RT threads trying to disk IO 'in the wild' or is this a > theoretical concern? I don't know of any such apps. > Yeah, cd burning software comes to mind. -- -ck