From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966154AbbBDOgs (ORCPT ); Wed, 4 Feb 2015 09:36:48 -0500 Received: from terminus.zytor.com ([198.137.202.10]:38751 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932943AbbBDOgo (ORCPT ); Wed, 4 Feb 2015 09:36:44 -0500 Date: Wed, 4 Feb 2015 06:36:10 -0800 From: tip-bot for Xunlei Pang Message-ID: Cc: peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org, mingo@kernel.org, pang.xunlei@linaro.org, juri.lelli@gmail.com, hpa@zytor.com, linux-kernel@vger.kernel.org Reply-To: peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org, pang.xunlei@linaro.org, juri.lelli@gmail.com, mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org In-Reply-To: <1421642980-10045-2-git-send-email-pang.xunlei@linaro.org> References: <1421642980-10045-2-git-send-email-pang.xunlei@linaro.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/deadline: Remove cpu_active_mask from cpudl_find() Git-Commit-ID: 9659e1eeee28f7025b6545934d644d19e9c6e603 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 9659e1eeee28f7025b6545934d644d19e9c6e603 Gitweb: http://git.kernel.org/tip/9659e1eeee28f7025b6545934d644d19e9c6e603 Author: Xunlei Pang AuthorDate: Mon, 19 Jan 2015 04:49:37 +0000 Committer: Ingo Molnar CommitDate: Wed, 4 Feb 2015 07:52:29 +0100 sched/deadline: Remove cpu_active_mask from cpudl_find() cpu_active_mask is rarely changed (only on hotplug), so remove this operation to gain a little performance. If there is a change in cpu_active_mask, rq_online_dl() and rq_offline_dl() should take care of it normally, so cpudl::free_cpus carries enough information for us. For the rare case when a task is put onto a dying cpu (which rq_offline_dl() can't handle in a timely fashion), it will be handled through _cpu_down()->...->multi_cpu_stop()->migration_call() ->migrate_tasks(), preventing the task from hanging on the dead cpu. Cc: Juri Lelli Signed-off-by: Xunlei Pang [peterz: changelog] Signed-off-by: Peter Zijlstra (Intel) Link: http://lkml.kernel.org/r/1421642980-10045-2-git-send-email-pang.xunlei@linaro.org Cc: Linus Torvalds Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- kernel/sched/cpudeadline.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c index fd9d3fb..c6acb07 100644 --- a/kernel/sched/cpudeadline.c +++ b/kernel/sched/cpudeadline.c @@ -108,8 +108,7 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p, const struct sched_dl_entity *dl_se = &p->dl; if (later_mask && - cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed) && - cpumask_and(later_mask, later_mask, cpu_active_mask)) { + cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed)) { best_cpu = cpumask_any(later_mask); goto out; } else if (cpumask_test_cpu(cpudl_maximum(cp), &p->cpus_allowed) &&