From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760412AbYEWXrG (ORCPT ); Fri, 23 May 2008 19:47:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751799AbYEWXqy (ORCPT ); Fri, 23 May 2008 19:46:54 -0400 Received: from mail.gmx.net ([213.165.64.20]:38966 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750787AbYEWXqx (ORCPT ); Fri, 23 May 2008 19:46:53 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1+bWI4GHBGbiKZqu694ZYsbqYBgzUkYTXehQDjd3T +Ck1jQ0VQABWMI Subject: Re: PostgreSQL pgbench performance regression in 2.6.23+ From: Mike Galbraith To: Greg Smith Cc: Ingo Molnar , Peter Zijlstra , Dhaval Giani , lkml , Srivatsa Vaddagiri In-Reply-To: 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> Content-Type: text/plain Date: Sat, 24 May 2008 01:46:47 +0200 Message-Id: <1211586407.4786.5.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 Fri, 2008-05-23 at 19:18 -0400, Greg Smith wrote: > On Fri, 23 May 2008, Mike Galbraith wrote: > > > It was running SCHED_BATCH, features=0...it needed features=0 as well to > > achieve O(1) batch performance. > > I figured out how to run pgbench with chrt in order to get SCHED_BATCH > behavior, but I don't understand what you mean by features=0 here. Since > I didn't see the same magnitude of different just using batch that seems > important, where does that get set at? /proc/sys/kernel/sched_features. You need CONFIG_SCHED_DEBUG to have accsess to the scheduler tweakables. > I'm also curious what hardware your results are coming from, to fit them > into my larger pgbench results context space. A grocery store Q6600 box. > Got my 4-core system back on-line again today (found some bad RAM) and > wanted to try another round of tests on that. Looks like you've defined 5 > test sets I should replicate: > > 2.6.22 > 2.6.22, batch > 2.6.26.git > 2.6.26.git, batch > 2.6.26.git, batch + se.load.weight patch > > Should I still be trying Peter's se.waker patch as well in this mix > somewhere? Yeah. -Mike