Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261695AbTHTEUZ (ORCPT ); Wed, 20 Aug 2003 00:20:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261700AbTHTEUZ (ORCPT ); Wed, 20 Aug 2003 00:20:25 -0400 Received: from tmr-02.dsl.thebiz.net ([216.238.38.204]:13075 "EHLO gatekeeper.tmr.com") by vger.kernel.org with ESMTP id S261695AbTHTEUX (ORCPT ); Wed, 20 Aug 2003 00:20:23 -0400 Date: Wed, 20 Aug 2003 00:11:26 -0400 (EDT) From: Bill Davidsen To: William Lee Irwin III cc: David Lang , Eric St-Laurent , linux-kernel@vger.kernel.org Subject: Re: scheduler interactivity: timeslice calculation seem wrong In-Reply-To: <20030820004851.GD4306@holomorphy.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1486 Lines: 39 On Tue, 19 Aug 2003, William Lee Irwin III wrote: > On Tue, Aug 19, 2003 at 05:32:04PM -0700, David Lang wrote: > > while thinking about scaling based on CPU speed remember systems with > > variable CPU clocks (or even just variable performance like the transmeta > > CPU's) > > This and/or mixed cpu speeds could make load balancing interesting on > SMP. I wonder who's tried. jejb? Hum, I *guess* that if you are using some "mean time between dispatches" to tune time slice you could apply a CPU speed correction, but mixed speed SMP is too corner a case for me. I think if you were tuning time slice by mean time between dispatches (or similar) you could either apply a correction, set affinity low to keep jobs changing CPUs, or just ignore it. The thing I like about the idea is that if the CPU speed changes the MTBD will change and the timeslice will compensate. You could use median MTBD, or pick some percentile to tune for response or throughput. I thought I was just thinking out loud, but it does sound interesting to try, since it would not prevent using some priorities as well. > > > -- wli > -- bill davidsen CTO, TMR Associates, Inc Doing interesting things with little computers since 1979. - 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/