Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763524AbYFGR4e (ORCPT ); Sat, 7 Jun 2008 13:56:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761267AbYFGR40 (ORCPT ); Sat, 7 Jun 2008 13:56:26 -0400 Received: from mail.gmx.net ([213.165.64.20]:34947 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1761146AbYFGR40 (ORCPT ); Sat, 7 Jun 2008 13:56:26 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1+3NZxNkl+3sddaYq3MdhxTUs7MhwTu1zA+PFydQU Db96eLgnM+R7as Subject: Re: [patch] Re: PostgreSQL pgbench performance regression in 2.6.23+ From: Mike Galbraith To: Peter Zijlstra Cc: Ingo Molnar , Greg Smith , Dhaval Giani , lkml , Srivatsa Vaddagiri In-Reply-To: <1212855380.19205.96.camel@lappy.programming.kicks-ass.net> References: <1211440207.5733.8.camel@marge.simson.net> <20080522082814.GA4499@linux.vnet.ibm.com> <1211447105.4823.7.camel@marge.simson.net> <1211452465.7606.8.camel@marge.simson.net> <1211455553.4381.9.camel@marge.simson.net> <1211456659.29104.20.camel@twins> <1211458176.5693.6.camel@marge.simson.net> <1211459081.29104.40.camel@twins> <1211536814.5851.18.camel@marge.simson.net> <20080523101000.GA13964@elte.hu> <1211537717.5851.22.camel@marge.simson.net> <1211586407.4786.5.camel@marge.simson.net> <1211867950.5505.47.camel@marge.simson.net> <1212732780.13981.43.camel@marge.simson.net> <1212838682.5571.6.camel@marge.simson.net> <1212843008.4934.16.camel@marge.simson.net> <1212844027.19205.82.camel@lappy.programming.kicks-ass.net> <1212848179.4668.3.camel@marge.simson.net> <1212855380.19205.96.camel@lappy.programming.kicks-ass.net> Content-Type: text/plain Date: Sat, 07 Jun 2008 19:56:21 +0200 Message-Id: <1212861381.4953.8.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 791 Lines: 21 On Sat, 2008-06-07 at 18:16 +0200, Peter Zijlstra wrote: > The idea was to dynamically detect sync wakeups, who's defining property > is that the waker will sleep after waking the wakee. And who's effect is > pulling tasks together on wakeups - so that we might have the most > benefit of cache sharing. > > So if we were to exclude cross cpu wakeups from this measurement we'd > handicap the whole scheme, because then we'd never measure that its > actually a sync wakeup and wants to run on the same cpu. Ah, I get it now, thanks. -Mike -- 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/