From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262907AbTJGWUT (ORCPT ); Tue, 7 Oct 2003 18:20:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262930AbTJGWUT (ORCPT ); Tue, 7 Oct 2003 18:20:19 -0400 Received: from gateway-1237.mvista.com ([12.44.186.158]:25077 "EHLO av.mvista.com") by vger.kernel.org with ESMTP id S262907AbTJGWUP (ORCPT ); Tue, 7 Oct 2003 18:20:15 -0400 Message-ID: <3F833C06.7000802@mvista.com> Date: Tue, 07 Oct 2003 15:19:50 -0700 From: George Anzinger Organization: MontaVista Software User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2) Gecko/20021202 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Clayton Weaver CC: linux-kernel@vger.kernel.org Subject: Re: Circular Convolution scheduler References: <20031006161733.24441.qmail@email.com> In-Reply-To: <20031006161733.24441.qmail@email.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 Ok, I'll admit my ignorance. What is circular convolution? Where can I learn more? -g Clayton Weaver wrote: > Though the mechanism is doubtless familiar > to signal processing and graphics implementers, > it's probably not thought of much in a > process scheduling contex (although there was > the Evolution Scheduler of a few years ago, > whose implementer may have had something like > circular convolution in mind). It just seems to me > (intuition) that the concept of what circular convolution does is akin to what we've been > feeling around for with these ad hoc heuristic > tweaks to the scheduler to adjust for interactivity > and batch behavior, searching for an incremental self-adjusting mechanism that favors interactivity > on demand. > > I've never implemented a circular convolver in > any context, so I was wondering if anyone who > has thinks scheduler prioritization would be > simpler if implemented directly as a circular convolution. > > (If nothing else, it seems to me that the abstract model of what the schedule prioritizer is doing > would be more coherent than it is with ad hoc > code. This perhaps reduces the risk of unexpected side-effects of incremental tweaks to the scheduler. The behavior of an optimizer that implements > an integer approximation of a known mathematical transform when you change its inputs is fairly predictable.) > > Regards, > > Clayton Weaver > > > -- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/ Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml