From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756482Ab3ILXVG (ORCPT ); Thu, 12 Sep 2013 19:21:06 -0400 Received: from ozlabs.org ([203.10.76.45]:56404 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755450Ab3ILXVE (ORCPT ); Thu, 12 Sep 2013 19:21:04 -0400 From: Michael Neuling To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, peterz@infradead.org, tglx@linutronix.de, tip-bot for Peter Zijlstra cc: linux-tip-commits@vger.kernel.org Subject: Re: [tip:sched/core] sched/fair: Fix group power_orig computation In-reply-to: References: Comments: In-reply-to tip-bot for Peter Zijlstra message dated "Thu, 12 Sep 2013 11:05:45 -0700." X-Mailer: MH-E 8.2; nmh 1.5; GNU Emacs 23.4.1 Date: Fri, 13 Sep 2013 09:21:03 +1000 Message-ID: <18117.1379028063@ale.ozlabs.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org tip-bot for Peter Zijlstra wrote: > Commit-ID: 863bffc80898b8df295ebac111af2335ec05f85d > Gitweb: http://git.kernel.org/tip/863bffc80898b8df295ebac111af2335ec05f85d > Author: Peter Zijlstra > AuthorDate: Wed, 28 Aug 2013 11:44:39 +0200 > Committer: Ingo Molnar > CommitDate: Thu, 12 Sep 2013 19:14:43 +0200 > > sched/fair: Fix group power_orig computation > > When looking at the code I noticed we don't actually compute > sgp->power_orig correctly for groups, fix that. > > Currently the only consumer of that value is fix_small_capacity() > which is only used on POWER7+ and that code excludes this case by > being limited to SD_SHARE_CPUPOWER which is only ever set on the SMT > domain which must be the lowest domain and this has singleton groups. > > So nothing should be affected by this change. > > Cc: Michael Neuling > Signed-off-by: Peter Zijlstra > Link: http://lkml.kernel.org/n/tip-db2pe0vxwunv37plc7onnugj@git.kernel.org > Signed-off-by: Ingo Molnar FWIW, this doesn't seem to break POWER7. Thanks! Mikey > --- > kernel/sched/fair.c | 16 +++++++++++----- > 1 file changed, 11 insertions(+), 5 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index f9f4385..baba313 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -4450,7 +4450,7 @@ void update_group_power(struct sched_domain *sd, int cpu) > { > struct sched_domain *child = sd->child; > struct sched_group *group, *sdg = sd->groups; > - unsigned long power; > + unsigned long power, power_orig; > unsigned long interval; > > interval = msecs_to_jiffies(sd->balance_interval); > @@ -4462,7 +4462,7 @@ void update_group_power(struct sched_domain *sd, int cpu) > return; > } > > - power = 0; > + power_orig = power = 0; > > if (child->flags & SD_OVERLAP) { > /* > @@ -4470,8 +4470,12 @@ void update_group_power(struct sched_domain *sd, int cpu) > * span the current group. > */ > > - for_each_cpu(cpu, sched_group_cpus(sdg)) > - power += power_of(cpu); > + for_each_cpu(cpu, sched_group_cpus(sdg)) { > + struct sched_group *sg = cpu_rq(cpu)->sd->groups; > + > + power_orig += sg->sgp->power_orig; > + power += sg->sgp->power; > + } > } else { > /* > * !SD_OVERLAP domains can assume that child groups > @@ -4480,12 +4484,14 @@ void update_group_power(struct sched_domain *sd, int cpu) > > group = child->groups; > do { > + power_orig += group->sgp->power_orig; > power += group->sgp->power; > group = group->next; > } while (group != child->groups); > } > > - sdg->sgp->power_orig = sdg->sgp->power = power; > + sdg->sgp->power_orig = power_orig; > + sdg->sgp->power = power; > } > > /* >