From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755149AbZELK1z (ORCPT ); Tue, 12 May 2009 06:27:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752097AbZELK1p (ORCPT ); Tue, 12 May 2009 06:27:45 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:50899 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751013AbZELK1o (ORCPT ); Tue, 12 May 2009 06:27:44 -0400 Date: Tue, 12 May 2009 12:27:22 +0200 From: Ingo Molnar To: KOSAKI Motohiro Cc: Peter Zijlstra , mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, schwidefsky@de.ibm.com, balajirrao@gmail.com, dhaval@linux.vnet.ibm.com, balbir@linux.vnet.ibm.com, bharata@linux.vnet.ibm.com, tglx@linutronix.de, kamezawa.hiroyu@jp.fujitsu.com, linux-tip-commits@vger.kernel.org Subject: Re: [tip:sched/core] sched: cpuacct: Use bigger percpu counter batch values for stats counters Message-ID: <20090512102722.GA11714@elte.hu> References: <1242122579.11251.325.camel@twins> <20090512190346.D638.A69D9226@jp.fujitsu.com> <20090512191650.D63E.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090512191650.D63E.A69D9226@jp.fujitsu.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * KOSAKI Motohiro wrote: > > > On Tue, 2009-05-12 at 19:01 +0900, KOSAKI Motohiro wrote: > > > > +#ifdef CONFIGCONFIG_SMP > > > > > > typo ? > > > > yes, this week is my memorial stupid one ;) > > ok, assemble list indicate current patch have no typo ;) > > ffffffff814ae920: 48 c7 40 30 10 eb 2a movq $0xffffffff812aeb10,0x30(%rax) > ffffffff814ae927: 81 > ffffffff814ae928: c7 05 3e 37 fe ff 01 movl $0x1,-0x1c8c2(%rip) # ffffffff81492070 > ffffffff814ae92f: 00 00 00 > ffffffff814ae932: 8b 05 28 52 fe ff mov -0x1add8(%rip),%eax # ffffffff81493b60 > ffffffff814ae938: 89 05 36 37 fe ff mov %eax,-0x1c8ca(%rip) # ffffffff81492074 > ffffffff814ae93e: 41 5c pop %r12 > > > > --------------------------------------------------------- > Subject: [PATCH] cpuacct: Use bigger percpu counter batch values for stats counters on archs that have VIRT_CPU_ACCOUNTING=y > > percpu counters used to accumulate statistics in cpuacct controller use > the default batch value [max(2*nr_cpus, 32)] which can be too small for > archs that define VIRT_CPU_ACCOUNTING. In such archs, a tick could result in > cputime updates in the range of thousands. As a result, cpuacct_update_stats() > would end up acquiring the percpu counter spinlock on every tick which > is not good for performance. > > Let those architectures to have a bigger batch threshold so that percpu counter > spinlock isn't taken on every tick. This change doesn't affect the archs which > don't define VIRT_CPU_ACCOUNTING and they continue to have the default > percpu counter batch value. > > Cc: Balaji Rao > Cc: Dhaval Giani > Cc: KAMEZAWA Hiroyuki > Cc: Peter Zijlstra > Cc: Balbir Singh > Cc: Ingo Molnar > Cc: Martin Schwidefsky > Signed-off-by: Bharata B Rao > Signed-off-by: KOSAKI Motohiro > --- > kernel/sched.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) Please reuse the commit log formatting fixes i did when i applied your patch. (you should still have that commit notification email) Ingo