Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933679Ab3GWQx1 (ORCPT ); Tue, 23 Jul 2013 12:53:27 -0400 Received: from merlin.infradead.org ([205.233.59.134]:46268 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933220Ab3GWQx0 (ORCPT ); Tue, 23 Jul 2013 12:53:26 -0400 Date: Tue, 23 Jul 2013 18:53:19 +0200 From: Peter Zijlstra To: Rakib Mullick Cc: mingo@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH, RFC] sched: update_top_cache_domain only at the times of building sched domain. Message-ID: <20130723165319.GC27075@twins.programming.kicks-ass.net> References: <1374594257.5382.5.camel@localhost.localdomain> <20130723154736.GB27075@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: 1010 Lines: 31 On Tue, Jul 23, 2013 at 10:20:20PM +0600, Rakib Mullick wrote: > You mean using sd == NULL rather than using update_cache_domain variable ? Yes, note how: @@ -6109,7 +6110,7 @@ static void detach_destroy_domains(const struct cpumask *cpu_map) rcu_read_lock(); for_each_cpu(i, cpu_map) - cpu_attach_domain(NULL, &def_root_domain, i); rcu_read_unlock(); } Always has NULL for sd? Which means you can do: @@ -5138,7 +5138,8 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) rcu_assign_pointer(rq->sd, sd); destroy_sched_domains(tmp, cpu); - update_top_cache_domain(cpu); + if (sd) + update_top_cache_domain(cpu); } /* cpus with isolated domains */ -- 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/