Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261885AbVDFAIu (ORCPT ); Tue, 5 Apr 2005 20:08:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262013AbVDFAIt (ORCPT ); Tue, 5 Apr 2005 20:08:49 -0400 Received: from fmr24.intel.com ([143.183.121.16]:55997 "EHLO scsfmr004.sc.intel.com") by vger.kernel.org with ESMTP id S261885AbVDFAIr (ORCPT ); Tue, 5 Apr 2005 20:08:47 -0400 Message-Id: <200504060008.j3608Zg22021@unix-os.sc.intel.com> From: "Chen, Kenneth W" To: "'Ingo Molnar'" Cc: "Paul Jackson" , , , , Subject: RE: [patch] sched: auto-tune migration costs [was: Re: Industry db benchmark result on recent 2.6 kernels] Date: Tue, 5 Apr 2005 17:08:34 -0700 X-Mailer: Microsoft Office Outlook, Build 11.0.6353 Thread-Index: AcU43vtCQO5COAU3Rbej+It5BdScZQBW4Wvg In-Reply-To: <20050404062414.GA22664@elte.hu> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1152 Lines: 32 Ingo Molnar wrote on Sunday, April 03, 2005 11:24 PM > great! How long does the benchmark take (hours?), and is there any way > to speed up the benchmarking (without hurting accuracy), so that > multiple migration-cost settings could be tried? Would it be possible to > try a few other values via the migration_factor boot option, in 0.5 msec > steps or so, to find the current sweet spot? It used to be at 11 msec > previously, correct? It take days, each experiment is 5 hours. Previous experiments on 2.6.8 shows that the sweet spot was 12.5ms. This time on 2.6.11, it got pushed into 16 ms. Results comparing to 10ms: 8 ms -0.3% 10 ms -- 12 ms +0.11% 16 ms +0.14% 20 ms +0.06% 12ms and up all has about 1.5% idle time. We are not anywhere near the limits on what the disk storage can deliver. So there is a potential to to tune/optimize the scheduler and reap these extra idle time. - Ken - 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/