Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755499Ab0HDEiQ (ORCPT ); Wed, 4 Aug 2010 00:38:16 -0400 Received: from fafnir.cs.unc.edu ([152.2.129.90]:40912 "EHLO fafnir.cs.unc.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754131Ab0HDEiP (ORCPT ); Wed, 4 Aug 2010 00:38:15 -0400 X-Greylist: delayed 2687 seconds by postgrey-1.27 at vger.kernel.org; Wed, 04 Aug 2010 00:38:15 EDT Message-ID: <4C58E42B.40000@cs.unc.edu> Date: Tue, 03 Aug 2010 23:53:15 -0400 From: Andrea Bastoni User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.10) Gecko/20100619 Icedove/3.0.5 MIME-Version: 1.0 To: Peter Zijlstra CC: Bjoern Brandenburg , Raistlin , linux-kernel , Song Yuan , Dmitry Adamushko , Thomas Gleixner , Nicola Manica , Luca Abeni , Claudio Scordino , Harald Gustafsson , Giuseppe Lipari Subject: Re: periods and deadlines in SCHED_DEADLINE References: <1278682707.6083.227.camel@Palantir> <1278685133.1900.201.camel@laptop> <51F8E441-58D7-45E1-B7A0-7A717EDF08B5@email.unc.edu> <1278693304.1900.266.camel@laptop> <1278752489.4390.97.camel@Palantir> <1280828775.1923.447.camel@laptop> In-Reply-To: <1280828775.1923.447.camel@laptop> X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1435 Lines: 32 On 08/03/2010 05:46 AM, Peter Zijlstra wrote: > On Sun, 2010-07-11 at 08:42 +0200, Bjoern Brandenburg wrote: >> If you want to do G-EDF with limited and different budgets on each CPU >> (e.g., G-EDF tasks may only run for 100 out of 1000 ms on CPU 0, but >> for 400 out of 1000 ms on CPU 1), then you are entering the domain of >> restricted-supply scheduling, which is significantly more complicated >> to analyze (see [1,2]). > > Would making the thing homogenious by assuming the worst for all cpus > make the analysis easier? That is, in the above example, only allow the > G-EDF scheduler to run for 100 out of 1000 ms on both cpus. Both [1,2] (and also [4]) assumes a more general model than the one based on the worst for all CPUs, therefore the analysis (based on these papers) will likely be more pessimistic, but not necessarily easier. - Andrea [4] E. Bini, M. Bertogna, S. Baruah, Virtual Multiprocessor Platforms: Specification and Use. In Proceedings of the 2009 30th IEEE Real-Time Systems Symposium, 437-446, 2009. -- Andrea Bastoni Visiting Ph.D. Student Dept. of Computer Science University of North Carolina at Chapel Hill http://www.sprg.uniroma2.it/home/bastoni/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/