Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932340Ab3GCIwP (ORCPT ); Wed, 3 Jul 2013 04:52:15 -0400 Received: from merlin.infradead.org ([205.233.59.134]:34136 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755005Ab3GCIuh (ORCPT ); Wed, 3 Jul 2013 04:50:37 -0400 Date: Wed, 3 Jul 2013 10:50:25 +0200 From: Peter Zijlstra To: Michael Wang Cc: LKML , Ingo Molnar , Mike Galbraith , Alex Shi , Namhyung Kim , Paul Turner , Andrew Morton , "Nikunj A. Dadhania" , Ram Pai Subject: Re: [PATCH v2] sched: smart wake-affine Message-ID: <20130703085025.GG23916@twins.programming.kicks-ass.net> References: <51A43B16.9080801@linux.vnet.ibm.com> <51D25A80.8090406@linux.vnet.ibm.com> <51D3C058.3020601@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51D3C058.3020601@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2637 Lines: 86 On Wed, Jul 03, 2013 at 02:10:32PM +0800, Michael Wang wrote: > +static int wake_wide(struct task_struct *p) > +{ > + int factor = nr_cpus_node(cpu_to_node(smp_processor_id())); That's still a cpumask_weight() in there... we should avoid that. How about something like the below: > + > + /* > + * Yeah, it's the switching-frequency, could means many wakee or > + * rapidly switch, use factor here will just help to automatically > + * adjust the loose-degree, so bigger node will lead to more pull. > + */ > + if (p->nr_wakee_switch > factor) { > + /* > + * wakee is somewhat hot, it needs certain amount of cpu > + * resource, so if waker is far more hot, prefer to leave > + * it alone. > + */ > + if (current->nr_wakee_switch > (factor * p->nr_wakee_switch)) > + return 1; > + } > + > + return 0; > +} --- diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9b1f2e5..166ab9b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5081,18 +5083,23 @@ static void destroy_sched_domains(struct sched_domain *sd, int cpu) * two cpus are in the same cache domain, see cpus_share_cache(). */ DEFINE_PER_CPU(struct sched_domain *, sd_llc); +DEFINE_PER_CPU(int, sd_llc_size); DEFINE_PER_CPU(int, sd_llc_id); static void update_top_cache_domain(int cpu) { struct sched_domain *sd; int id = cpu; + int size = 1; sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES); - if (sd) + if (sd) { id = cpumask_first(sched_domain_span(sd)); + size = cpumask_weight(sched_domain_span(sd)); + } rcu_assign_pointer(per_cpu(sd_llc, cpu), sd); + per_cpu(sd_llc_size, cpu) = size; per_cpu(sd_llc_id, cpu) = id; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index ef0a7b2..c992f58 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -595,6 +595,7 @@ static inline struct sched_domain *highest_flag_domain(int cpu, int flag) } DECLARE_PER_CPU(struct sched_domain *, sd_llc); +DECLARE_PER_CPU(int, sd_llc_size); DECLARE_PER_CPU(int, sd_llc_id); struct sched_group_power { --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3175,7 +3175,7 @@ static inline unsigned long effective_lo static int wake_wide(struct task_struct *p) { - int factor = nr_cpus_node(cpu_to_node(smp_processor_id())); + int factor = this_cpu_read(sd_llc_size); /* * Yeah, it's the switching-frequency, could means many wakee or -- 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/