From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752335Ab0CFIgv (ORCPT ); Sat, 6 Mar 2010 03:36:51 -0500 Received: from mail.gmx.net ([213.165.64.20]:53469 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752104Ab0CFIgu (ORCPT ); Sat, 6 Mar 2010 03:36:50 -0500 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1+zh0wBf+KzLyFvmMj7ODa8JiVxBLefnf9hFyGLqH DwS3ZkWGRAYKO+ Subject: Re: [patch 2/2] sched: fix select_idle_sibling() logic in select_task_rq_fair() From: Mike Galbraith To: Suresh Siddha Cc: Peter Zijlstra , Ingo Molnar , Arjan van de Ven , linux-kernel@vger.kernel.org, Vaidyanathan Srinivasan , Yanmin Zhang , Gautham R Shenoy In-Reply-To: <20100305184213.922106492@sbs-t61.sc.intel.com> References: <20100305184213.829832580@sbs-t61.sc.intel.com> <20100305184213.922106492@sbs-t61.sc.intel.com> Content-Type: text/plain Date: Sat, 06 Mar 2010 09:36:45 +0100 Message-Id: <1267864605.22645.20.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1.1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 X-FuHaFi: 0.63 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2010-03-05 at 10:39 -0800, Suresh Siddha wrote: > plain text document attachment (fix_lat_ctx.patch) > Performance improvements with this patch: > "lat_ctx -s 0 2" ~22usec (before-this-patch) ~5usec (after-this-patch) BTW, is your cpu governor kicking into high gear? That unpatched number looks like a throttled down cpu to me. I know on my box, when there are micro idles, sometimes cores do not throttle up, making for some fairly crappy numbers. Q6600 doesn't throttle down far enough to make such a _huge_ difference though. -Mike