Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753173Ab2E3LlH (ORCPT ); Wed, 30 May 2012 07:41:07 -0400 Received: from merlin.infradead.org ([205.233.59.134]:58178 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753085Ab2E3LlF convert rfc822-to-8bit (ORCPT ); Wed, 30 May 2012 07:41:05 -0400 Message-ID: <1338378051.26856.267.camel@twins> Subject: Re: [PATCH v3 4/6] add a new scheduler hook for context switch From: Peter Zijlstra To: Glauber Costa Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, devel@openvz.org, Paul Turner , Tejun Heo , "Eric W. Biederman" , handai.szj@gmail.com, Andrew.Phillips@lmax.com, Serge Hallyn Date: Wed, 30 May 2012 13:40:51 +0200 In-Reply-To: <1338376851.26856.260.camel@twins> References: <1338371317-5980-1-git-send-email-glommer@parallels.com> <1338371317-5980-5-git-send-email-glommer@parallels.com> <1338376851.26856.260.camel@twins> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 812 Lines: 21 On Wed, 2012-05-30 at 13:20 +0200, Peter Zijlstra wrote: > > $ perf stat -e cycles --repeat 100 perf bench sched messaging -p -g 100 > > 48,826,146,710 cycles # 2.470 GHz ( +- 0.17% ) > 2.149005270 seconds time elapsed ( +- 0.12% ) A repeat count of 250 dropped it down to: 2.144582157 seconds time elapsed ( +- 0.08% ) Also, if you're poking at the context switch path, something like: $ taskset 1 perf stat -e cycles --repeat 10 perf bench sched pipe -l 100000 gives a good number and is usually more stable than hackbench. -- 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/