Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757770AbXIREad (ORCPT ); Tue, 18 Sep 2007 00:30:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756077AbXIREaJ (ORCPT ); Tue, 18 Sep 2007 00:30:09 -0400 Received: from wa-out-1112.google.com ([209.85.146.183]:50877 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754985AbXIREaG (ORCPT ); Tue, 18 Sep 2007 00:30:06 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=bTNEsxlc1KQUQbx2D1B19TvJqKm9kwRRr/0A3nJHldOnRsJ+UZS1oIEJKlKOU2+icsIbfZ4lghrkCTSj8uT5mePtmq+sXFCRrAz6xxeZlQDfNRWTASgLkA1DtRm6nZOnLS7EYyqKnTgexhPVdWzejFd1akPAX6hNB1FhQXIIF20= Message-ID: <6b8cef970709172130v317a6c48h814ef5a1488f798e@mail.gmail.com> Date: Tue, 18 Sep 2007 00:30:05 -0400 From: "Rob Hussey" To: "Ingo Molnar" Subject: Re: Scheduler benchmarks - a follow-up Cc: linux-kernel@vger.kernel.org, ck@vds.kolivas.org In-Reply-To: <20070917203607.GA20564@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <6b8cef970709170221s4301e896x2ee123a149c05c3a@mail.gmail.com> <20070917130524.GA10707@elte.hu> <20070917203607.GA20564@elte.hu> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2354 Lines: 85 On 9/17/07, Ingo Molnar wrote: > > * Ingo Molnar wrote: > > > i've meanwhile tested hackbench 90 and the performance difference > > between -ck and -cfs-devel seems to be mostly down to the more precise > > (but slower) sched_clock() introduced in v2.6.23 and to the startup > > penalty of freshly created tasks. > > Rob, another thing i just noticed in your .configs: you have > CONFIG_PREEMPT=y enabled. Would it be possible to get a testrun with > that disabled? That gives the best throughput and context-switch latency > numbers. (CONFIG_PREEMPT might also have preemption artifacts - there's > one report of it having _worse_ desktop latencies on certain hardware > than !CONFIG_PREEMPT.) I reverted the patch from before since it didn't seem to help. Do you think it may have to do with my system having Hyper-Threading enabled? I should have pointed out before that I don't really have a dual-core system, just a P4 with Hyper-Threading (I loosely used core to refer to processor). Some new numbers for 2.6.23-rc6-cfs-devel (!CONFIG_PREEMPT and bound to single processor) lat_ctx: 15 2.73 16 2.74 17 2.81 18 2.74 19 2.74 20 2.73 21 2.60 22 2.74 23 2.72 24 2.74 25 2.74 hackbench: 80 11.578 81 11.991 82 11.914 83 12.026 84 12.226 85 12.347 86 12.552 87 12.655 88 13.011 89 12.941 90 13.237 pipe-test: 1 9.58 2 9.58 3 9.58 4 9.58 5 9.58 6 9.58 7 9.58 8 9.58 9 9.58 10 9.58 The obligatory graphs: http://www.healthcarelinen.com/misc/benchmarks/BOUND_NOPREEMPT_lat_ctx_benchmark.png http://www.healthcarelinen.com/misc/benchmarks/BOUND_NOPREEMPT_hackbench_benchmark.png http://www.healthcarelinen.com/misc/benchmarks/BOUND_NOPREEMPT_pipe-test_benchmark.png A cursory glance suggests that performance wrt lat_ctx and hackbench has increased (lower numbers), but degraded quite a lot for pipe-test. The numbers for pipe-test are extremely stable though, while the numbers for hackbench are more erratic (which isn't saying much since the original numbers gave nearly a straight line). I'm still willing to try out any more ideas. Regards, Rob - 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/