From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750839AbWDQAIa (ORCPT ); Sun, 16 Apr 2006 20:08:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750847AbWDQAIa (ORCPT ); Sun, 16 Apr 2006 20:08:30 -0400 Received: from mail14.syd.optusnet.com.au ([211.29.132.195]:26852 "EHLO mail14.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S1750857AbWDQAI3 (ORCPT ); Sun, 16 Apr 2006 20:08:29 -0400 From: Con Kolivas To: Andreas Mohr Subject: Re: [ck] Re: [patch][rfc] quell interactive feeding frenzy Date: Mon, 17 Apr 2006 10:08:08 +1000 User-Agent: KMail/1.9.1 Cc: Al Boldi , ck list , Mike Galbraith , linux-kernel@vger.kernel.org References: <200604112100.28725.kernel@kolivas.org> <200604160923.00047.kernel@kolivas.org> <20060416184426.GA15642@rhlx01.fht-esslingen.de> In-Reply-To: <20060416184426.GA15642@rhlx01.fht-esslingen.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200604171008.10067.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Monday 17 April 2006 04:44, Andreas Mohr wrote: > Hi, > > On Sun, Apr 16, 2006 at 09:22:59AM +1000, Con Kolivas wrote: > > The current value, 6ms at 1000HZ, is chosen because it's the largest > > value that can schedule a task in less than normal human perceptible > > range when two competing heavily cpu bound tasks are the same priority. > > At 250HZ it works out to 7.5ms and 10ms at 100HZ. Ironically in my > > experimenting I found the cpu cache improvements become much less > > significant above 7ms so I'm very happy with this compromise. > > Heh, this part is *EXACTLY* a fully sufficient explanation of what I was > wondering about myself just these days ;) > (I'm experimenting with different timeslice values on my P3/450 to verify > what performance impact exactly it has) > However with a measly 256kB cache it probably doesn't matter too much, > I think. > > But I think it's still important to mention that your perception might be > twisted by your P4 limitation (no testing with slower and really slow > machines). You underestimate me. Those cpu cache effects were performance effects measured down to a PII 233, but all were i386 architecture. As for "perception" this isn't my testing I'm talking about; these are neuropsychiatric tests that have nothing to do with pcs or what processor you use ;) -- -ck