From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762916AbYEVHKY (ORCPT ); Thu, 22 May 2008 03:10:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757291AbYEVHKM (ORCPT ); Thu, 22 May 2008 03:10:12 -0400 Received: from mail.gmx.net ([213.165.64.20]:50403 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755569AbYEVHKL (ORCPT ); Thu, 22 May 2008 03:10:11 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1/pvDdOJKnpCOOlsmkdMzTMYhIUbSCMQ/V7kPFiLl JWaQ10GrALh4d1 Subject: Re: PostgreSQL pgbench performance regression in 2.6.23+ From: Mike Galbraith To: Greg Smith Cc: lkml , Peter Zijlstra , Ingo Molnar In-Reply-To: References: Content-Type: text/plain Date: Thu, 22 May 2008 09:10:07 +0200 Message-Id: <1211440207.5733.8.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 On Wed, 2008-05-21 at 13:34 -0400, Greg Smith wrote: > PostgreSQL ships with a simple database benchmarking tool named pgbench, > in what's labeled the contrib section (in many distributions it's a > separate package from the main server/client ones). I see there's been > some work done already improving how the PostgreSQL server works under the > new scheduler (the "Poor PostgreSQL scaling on Linux 2.6.25-rc5" thread). > I wanted to provide you a different test case using pgbench that has taken > a sharp dive starting with 2.6.23, and the server improvement changes in > 2.6.25 actually made this problem worse. > > I think it will be easy for someone else to replicate my results and I'll > go over the exact procedure below. Yup, I can reproduce. Running the test with 2.6.25.4, everything is waking/running on one CPU, leaving my box 75% idle. Not good. -Mike