Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758191Ab0KOTnZ (ORCPT ); Mon, 15 Nov 2010 14:43:25 -0500 Received: from mail3.unitn.it ([193.205.206.70]:43484 "EHLO mail3.unitn.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758012Ab0KOTnY (ORCPT ); Mon, 15 Nov 2010 14:43:24 -0500 Message-ID: <4CE18C7E.2060202@unitn.it> Date: Mon, 15 Nov 2010 20:39:42 +0100 From: Luca Abeni User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.15) Gecko/20101027 Fedora/3.0.10-1.fc12 Thunderbird/3.0.10 MIME-Version: 1.0 To: "James H. Anderson" CC: Raistlin , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , Steven Rostedt , Chris Friesen , oleg@redhat.com, Frederic Weisbecker , Darren Hart , Johan Eker , "p.faure" , linux-kernel , Claudio Scordino , michael trimarchi , Fabio Checconi , Tommaso Cucinotta , Juri Lelli , Nicola Manica , Dhaval Giani , Harald Gustafsson , paulmck , Bjoern Brandenburg Subject: Re: [RFC][PATCH 18/22] sched: add reclaiming logic to -deadline tasks References: <1289588215.6525.697.camel@Palantir> <80992760-24F2-42AE-AF2D-15727F6A1C81@email.unc.edu> <4CE17DD2.3060807@cs.unc.edu> In-Reply-To: <4CE17DD2.3060807@cs.unc.edu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1123 Lines: 27 On 15/11/10 19:37, James H. Anderson wrote: [...] > If you're talking about our most recent "stochastic" paper, it is about > supporting > soft real-time task systems on a multiprocessor where resource > reservations are > used. The main result of the paper is that if you provision the > reservation for a > task slightly higher than it's average-case execution time [...] BTW, I think we are aligned on this. I was a little bit surprised when Peter mentioned allocating a runtime equal to the average execution time (because of the meta-stability considerations that Tommaso also mentioned), but I fully agree that if the allocated runtime is higher than the average execution time then the queue is stable and it's possible to find a bound for the expected tardiness (or even its probability distribution... This is similar to my "probabilistic deadlines"). Luca -- 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/