Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757473AbYCKBfO (ORCPT ); Mon, 10 Mar 2008 21:35:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757092AbYCKBe6 (ORCPT ); Mon, 10 Mar 2008 21:34:58 -0400 Received: from mga02.intel.com ([134.134.136.20]:15396 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756956AbYCKBe5 (ORCPT ); Mon, 10 Mar 2008 21:34:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.25,477,1199692800"; d="scan'208";a="261807428" Date: Mon, 10 Mar 2008 18:34:56 -0700 From: Suresh Siddha To: Andrew Morton Cc: Gregory Haskins , suresh.b.siddha@intel.com, ego@in.ibm.com, rjw@sisk.pl, dmitry.adamushko@gmail.com, mingo@elte.hu, oleg@sign.ru, yi.y.yang@intel.com, linux-kernel@vger.kernel.org, tglx@linutronix.de Subject: Re: [PATCH v2] keep rd->online and cpu_online_map in sync Message-ID: <20080311013456.GD15909@linux-os.sc.intel.com> References: <20080310221014.GB27329@linux-os.sc.intel.com> <20080310215813.10968.960.stgit@novell1.haskins.net> <20080310163613.65a7313c.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080310163613.65a7313c.akpm@linux-foundation.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1956 Lines: 58 On Mon, Mar 10, 2008 at 04:36:13PM -0700, Andrew Morton wrote: > > --- a/kernel/sched.c > > +++ b/kernel/sched.c > > @@ -5881,7 +5881,8 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) > > spin_unlock_irq(&rq->lock); > > break; > > > > - case CPU_DOWN_PREPARE: > > + case CPU_DYING: > > + case CPU_DYING_FROZEN: > > /* Update our root-domain */ > > rq = cpu_rq(cpu); > > spin_lock_irqsave(&rq->lock, flags); > > Does this make > cpu-hotplug-register-update_sched_domains-notifier-with-higher-prio.patch > (below) obsolete, Yes. I would like to Ack for the keep-rd-online-and-cpu_online_map-in-sync.patch, as it is more cleaner. > or do we want both? No. I don't think so. Gautham, do you agree? thanks, suresh > > --- a/kernel/sched.c~cpu-hotplug-register-update_sched_domains-notifier-with-higher-prio > +++ a/kernel/sched.c > @@ -7096,8 +7096,16 @@ void __init sched_init_smp(void) > if (cpus_empty(non_isolated_cpus)) > cpu_set(smp_processor_id(), non_isolated_cpus); > put_online_cpus(); > - /* XXX: Theoretical race here - CPU may be hotplugged now */ > - hotcpu_notifier(update_sched_domains, 0); > + /* > + * XXX: Theoretical race here - CPU may be hotplugged now > + * > + * We register the notifier with priority 11, which means that > + * update_sched_domains() will be called just before migration_call(). > + * > + * This is necessary to ensure that the rt wake up logic works fine > + * and the rq->rd->online_map remains in sync with the cpu_online_map. > + */ > + hotcpu_notifier(update_sched_domains, 11); > > /* Move init over to a non-isolated CPU */ > if (set_cpus_allowed(current, non_isolated_cpus) < 0) > _ > -- 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/