From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267350AbUHECNI (ORCPT ); Wed, 4 Aug 2004 22:13:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267361AbUHECNI (ORCPT ); Wed, 4 Aug 2004 22:13:08 -0400 Received: from gizmo04ps.bigpond.com ([144.140.71.14]:34003 "HELO gizmo04ps.bigpond.com") by vger.kernel.org with SMTP id S267350AbUHECNF (ORCPT ); Wed, 4 Aug 2004 22:13:05 -0400 Message-ID: <411197AB.8060809@bigpond.net.au> Date: Thu, 05 Aug 2004 12:12:59 +1000 From: Peter Williams User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 X-Accept-Language: en-us, en MIME-Version: 1.0 To: William Lee Irwin III CC: Linux Kernel Mailing List , Michal Kaczmarski , Shane Shrybman Subject: Re: [PATCH] V-3.0 Single Priority Array O(1) CPU Scheduler Evaluation References: <20040803020345.GU2334@holomorphy.com> <410F08D6.5050200@bigpond.net.au> <20040803104912.GW2334@holomorphy.com> <41102FE5.9010507@bigpond.net.au> <20040804005034.GE2334@holomorphy.com> <41103DBB.6090100@bigpond.net.au> <20040804015115.GF2334@holomorphy.com> <41104C8F.9080603@bigpond.net.au> <20040804074440.GL2334@holomorphy.com> <4111882B.9090504@bigpond.net.au> <20040805020041.GQ2334@holomorphy.com> In-Reply-To: <20040805020041.GQ2334@holomorphy.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org William Lee Irwin III wrote: > William Lee Irwin III wrote: > >>>Software constructs are less of a concern. This also presumes that >>>taking timer interrupts when cpu-intensive workloads voluntarily >>>yield often enough is necessary or desirable. > > > On Thu, Aug 05, 2004 at 11:06:51AM +1000, Peter Williams wrote: > >>Voluntary yielding can't be relied upon. Writing a program that never >>gives up the CPU voluntarily is trivial. Some have been known to do it >>without even trying :-) > > > No reliance is implied. In such a scenario, the timers for timeslice > expiry are always cancelled because userspace voluntarily yields first, > so no timer interrupts are delivered. Should userspace fail to do so, > timer interrupts programmed for timeslice expiry would not be cancelled. OK. My misunderstanding. Peter -- Peter Williams pwil3058@bigpond.net.au "Learning, n. The kind of ignorance distinguishing the studious." -- Ambrose Bierce