Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270930AbTHFTBs (ORCPT ); Wed, 6 Aug 2003 15:01:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270967AbTHFTBs (ORCPT ); Wed, 6 Aug 2003 15:01:48 -0400 Received: from adsl-63-194-239-202.dsl.lsan03.pacbell.net ([63.194.239.202]:4872 "EHLO mmp-linux.matchmail.com") by vger.kernel.org with ESMTP id S270930AbTHFTBq (ORCPT ); Wed, 6 Aug 2003 15:01:46 -0400 Date: Wed, 6 Aug 2003 12:01:42 -0700 From: Mike Fedyk To: Timothy Miller Cc: Nick Piggin , Con Kolivas , linux kernel mailing list , Andrew Morton , Ingo Molnar , Felipe Alfaro Solana Subject: Re: Interactivity improvements Message-ID: <20030806190142.GE21290@matchmail.com> Mail-Followup-To: Timothy Miller , Nick Piggin , Con Kolivas , linux kernel mailing list , Andrew Morton , Ingo Molnar , Felipe Alfaro Solana References: <200308050207.18096.kernel@kolivas.org> <200308051220.04779.kernel@kolivas.org> <3F2F149F.1020201@cyberone.com.au> <200308051306.38180.kernel@kolivas.org> <3F2F21DF.1050601@cyberone.com.au> <3F314D6B.9090302@techsource.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3F314D6B.9090302@techsource.com> User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1571 Lines: 30 On Wed, Aug 06, 2003 at 02:48:11PM -0400, Timothy Miller wrote: > The idea I'm proposing, however poorly formed, is that if we allow some > "excessive" oscillation early on in the life of a process, we may be > able to more quickly get processes to NEAR its correct priority, OR get > its CPU time over the course of three times being run for the > underdamped case to be about the same as it would be if we knew in > advance what the priority should be. But in the underdamped case, the > priority would continue to oscillate up and down around the correct > level, because we are intentionally overshooting the mark each time we > adjust priority. > > This may not be related, but something that pops into my mind is a > numerical method called Newton's Method. It's a way to solve for roots > of an equation, and it involved derivatives, and I don't quite remember > how it works. But in any event, the results are less accurate than, > say, bisection, but you get to the answer MUCH more quickly. Sounds interesting. Much like a decaying average, or average over the entire lifetime of the process which can be weighed into the short term interactivity calculations also. I think Con is working on something like this already, except that it's taking the short term into account more than the long term. - 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/