Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760145AbZD2RsZ (ORCPT ); Wed, 29 Apr 2009 13:48:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752369AbZD2RsP (ORCPT ); Wed, 29 Apr 2009 13:48:15 -0400 Received: from rcsinet11.oracle.com ([148.87.113.123]:38857 "EHLO rgminet11.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754025AbZD2RsO (ORCPT ); Wed, 29 Apr 2009 13:48:14 -0400 Subject: Re: Mainline kernel OLTP performance update From: Chris Mason To: Peter Zijlstra Cc: Andrew Morton , "Styner, Douglas W" , "linux-kernel@vger.kernel.org" , "Tripathi, Sharad C" , "arjan@linux.intel.com" , "Wilcox, Matthew R" , "Kleen, Andi" , "Siddha, Suresh B" , "Ma, Chinang" , "Wang, Peter Xihong" , "Nueckel, Hubert" , "Recalde, Luis F" , "Nelson, Doug" , "Cheng, Wu-sun" , "Prickett, Terry O" , "Shunmuganathan, Rajalakshmi" , "Garg, Anil K" , "Chilukuri, Harita" , Ingo Molnar In-Reply-To: <1241022336.8021.573.camel@laptop> References: <20090429002930.b786348b.akpm@linux-foundation.org> <20090429090706.bc5f462f.akpm@linux-foundation.org> <1241022336.8021.573.camel@laptop> Content-Type: text/plain Date: Wed, 29 Apr 2009 13:46:36 -0400 Message-Id: <1241027196.20099.42.camel@think.oraclecorp.com> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 Content-Transfer-Encoding: 7bit X-Source-IP: acsmt704.oracle.com [141.146.40.82] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A010207.49F89289.001F:SCFMA4539814,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2846 Lines: 64 On Wed, 2009-04-29 at 18:25 +0200, Peter Zijlstra wrote: > On Wed, 2009-04-29 at 09:07 -0700, Andrew Morton wrote: > > On Wed, 29 Apr 2009 08:48:19 -0700 "Styner, Douglas W" wrote: > > > > > >-----Original Message----- > > > >From: Andrew Morton [mailto:akpm@linux-foundation.org] > > > >Sent: Wednesday, April 29, 2009 12:30 AM > > > >To: Styner, Douglas W > > > >Cc: linux-kernel@vger.kernel.org; Tripathi, Sharad C; > > > >arjan@linux.intel.com; Wilcox, Matthew R; Kleen, Andi; Siddha, Suresh B; > > > >Ma, Chinang; Wang, Peter Xihong; Nueckel, Hubert; Recalde, Luis F; Nelson, > > > >Doug; Cheng, Wu-sun; Prickett, Terry O; Shunmuganathan, Rajalakshmi; Garg, > > > >Anil K; Chilukuri, Harita; chris.mason@oracle.com > > > >Subject: Re: Mainline kernel OLTP performance update > > > > > > > >On Tue, 28 Apr 2009 10:08:22 -0700 "Styner, Douglas W" > > > > wrote: > > > > > > > >> Summary: Measured the mainline kernel from kernel.org (2.6.30-rc3). > > > >> > > > >> The regression for 2.6.30-rc3 against the baseline, 2.6.24.2 is 1.91%. > > > >Oprofile reports 71.1626% user, 28.8295% system. > > > >> > > > >> Linux OLTP Performance summary > > > >> Kernel# Speedup(x) Intr/s CtxSw/s us% sys% idle% > > > >iowait% > > > >> 2.6.24.2 1.000 22106 43709 75 24 0 0 > > > >> 2.6.30-rc3 0.981 30645 43027 75 25 0 0 > > > > > > > >The main difference there is the interrupt frequency. Do we know which > > > >interrupt source(s) caused this? > > > > > > Our analysis of the interrupts shows that rescheduling interrupts are > > > up 2.2x from 2.6.24.2 --> 2.6.30-rc3. Qla2xxx interrupts are roughly > > > the same. > > > > (top-posting repaired) > > > > OK, thanks. Seems odd that the rescheduling interrupt rate increased > > while the context-switch rate actually fell a couple of percent. > > > > This came up a few weeks ago and iirc Peter was mainly involved, and I > > don't believe that anything conclusive ended up happening. Peter, > > could you please remind us of (and summarise) the story here? > > I've had several reports about the resched-ipi going in overdrive, but > nobody bothered to bisect it, nor have I yet done so -- no clear ideas > on why it is doing so. > > I'll put it somewhere higher on the todo list. > One cause of them in the past was the ondemand cpufreq module. It got fixed up for my laptop workload at least starting w/2.6.29, but it might make sense to try without ondemand if you're running it. -chris -- 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/