Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753297Ab2E3MKn (ORCPT ); Wed, 30 May 2012 08:10:43 -0400 Received: from mx2.parallels.com ([64.131.90.16]:54729 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753124Ab2E3MKm (ORCPT ); Wed, 30 May 2012 08:10:42 -0400 Message-ID: <4FC60DB8.70405@parallels.com> Date: Wed, 30 May 2012 16:08:24 +0400 From: Glauber Costa User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Peter Zijlstra CC: , , , Paul Turner , Tejun Heo , "Eric W. Biederman" , , , Serge Hallyn Subject: Re: [PATCH v3 4/6] add a new scheduler hook for context switch References: <1338371317-5980-1-git-send-email-glommer@parallels.com> <1338371317-5980-5-git-send-email-glommer@parallels.com> <1338376851.26856.260.camel@twins> <1338378051.26856.267.camel@twins> In-Reply-To: <1338378051.26856.267.camel@twins> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 905 Lines: 24 On 05/30/2012 03:40 PM, Peter Zijlstra wrote: > 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. thanks for the pointers -- 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/