From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262605AbUGIBqi (ORCPT ); Thu, 8 Jul 2004 21:46:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262730AbUGIBqi (ORCPT ); Thu, 8 Jul 2004 21:46:38 -0400 Received: from smtp011.mail.yahoo.com ([216.136.173.31]:53399 "HELO smtp011.mail.yahoo.com") by vger.kernel.org with SMTP id S262605AbUGIBqe (ORCPT ); Thu, 8 Jul 2004 21:46:34 -0400 Message-ID: <40EDF8F5.2060808@yahoo.com.au> Date: Fri, 09 Jul 2004 11:46:29 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040401 Debian/1.6-4 X-Accept-Language: en MIME-Version: 1.0 To: Peter Williams CC: "Povolotsky, Alexander" , "'linux-kernel@vger.kernel.org'" , "'Mike Galbraith'" , "'akpm@osdl.org'" , "'rml@tech9.net'" , "'Ingo Molnar'" , "'Con Kolivas'" , "'Elladan'" , "'Chris Siebenmann'" Subject: Re: Maximum frequency of re-scheduling (minimum time quantum ) que stio n References: <313680C9A886D511A06000204840E1CF08F42FE6@whq-msgusr-02.pit.comms.marconi.com> <40EDD980.4040608@bigpond.net.au> In-Reply-To: <40EDD980.4040608@bigpond.net.au> 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 Peter Williams wrote: > Povolotsky, Alexander wrote: > >> Hi Peter, >> >> >>> By freeing "time slice"s from their involvement in active/expired >>> priority array switching etc., the various single priority array >>> schedulers (e.g. Con Kolivas's staircase scheduler and my SPA "pb" >>> and "eb" schedulers) that are under development raise the possibility >>> of allowing the time slice for SCHED_RR tasks to be different to that >>> of ordinary tasks or even for it to be set separately for each >>> SCHED_RR task. Whether this is desirable or not is another question. >> >> >> >> IMHO (I am new in Linux),- if this functionality could be either >> optionally >> configured at compile time or be optionally invokable at run time (or >> combination of both) - why not to have it ? - this addition enhances >> choices >> of scheduling, >> which is good. >> >> Is there a chance such functionality will make into Linux 2.6 as a >> patch (at >> some later time) ? > > > Not until the current scheduler is replaced with a single priority array > scheduler. However, if there's enough interest, I could add this > functionality to the CPU scheduler evaluation patch so that people could > experiment with it (BUT it would be at the bottom of my to do list). You are mistaken. The current scheduler only uses a single array for realtime tasks. Functionality would be trivial to implement now. > >> >> By the way - what is the "mechanism" of decision making process (among >> Linux >> kernel developers) on such things ? > > > I'll leave this question to someone more knowledgeable. > I'd defer a final decision to others more knowlegeable of course (Ingo, Andrew, Linus?), however it would be almost out of the question to do a wholesale replacement in 2.6. However well tested your scheduler might be, it needs several orders of magnitude more testing ;) Maybe the best we can hope for is compile time selectable alternatives.