From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270456AbTGMX4a (ORCPT ); Sun, 13 Jul 2003 19:56:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270460AbTGMX4a (ORCPT ); Sun, 13 Jul 2003 19:56:30 -0400 Received: from c17870.thoms1.vic.optusnet.com.au ([210.49.248.224]:51145 "EHLO mail.kolivas.org") by vger.kernel.org with ESMTP id S270456AbTGMX43 (ORCPT ); Sun, 13 Jul 2003 19:56:29 -0400 From: Con Kolivas To: Daniel Phillips , William Lee Irwin III Subject: Re: [RFC][PATCH] SCHED_ISO for interactivity Date: Mon, 14 Jul 2003 10:13:12 +1000 User-Agent: KMail/1.5.2 Cc: linux kernel mailing list References: <200307112053.55880.kernel@kolivas.org> <20030712154924.GC15452@holomorphy.com> <200307132203.55414.phillips@arcor.de> In-Reply-To: <200307132203.55414.phillips@arcor.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200307141013.12202.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 14 Jul 2003 06:03, Daniel Phillips wrote: > On Saturday 12 July 2003 17:49, William Lee Irwin III wrote: > > On Fri, Jul 11, 2003 at 08:53:38PM +1000, Con Kolivas wrote: > > > Wli coined the term "isochronous" (greek for same time) for a real time > > > task that was limited in it's timeslice but still guaranteed to run. > > > I've decided to abuse this term and use it to name this new policy in > > > this patch. This is neither real time, nor guaranteed. > > > > I didn't coin it; I know of it from elsewhere. > > Right, for example, USB has an isochronous transfer facility intended to > support media applications, e.g., cameras, that require realtime > bandwidth/latency guarantees. The thing is, such guarantees have to be > end-to-end in the media pipeline. Sound is just one of the applications > that needs the kind of realtime support we (or more properly, Davide) just > proposed. I'm not looking at creating a true realtime policy of any sort. Mine is more a dynamic policy change to an interactive state that is sustained, which gives no more capabilities to a normal user process than they can currently get on SCHED_NORMAL tasks. Audio will definitely get priority... along with any other interactive task, but not in a real time fashion. Basically they effectively get a nice -5 unless they do the wrong thing. Con