From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932108AbaKDQL4 (ORCPT ); Tue, 4 Nov 2014 11:11:56 -0500 Received: from terminus.zytor.com ([198.137.202.10]:59515 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752698AbaKDQLx (ORCPT ); Tue, 4 Nov 2014 11:11:53 -0500 Date: Tue, 4 Nov 2014 08:10:51 -0800 From: tip-bot for Wanpeng Li Message-ID: Cc: ktkhai@parallels.com, juri.lelli@arm.com, tglx@linutronix.de, rostedt@goodmis.org, mingo@kernel.org, wanpeng.li@linux.intel.com, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, peterz@infradead.org, hpa@zytor.com Reply-To: hpa@zytor.com, peterz@infradead.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, wanpeng.li@linux.intel.com, mingo@kernel.org, rostedt@goodmis.org, juri.lelli@arm.com, tglx@linutronix.de, ktkhai@parallels.com In-Reply-To: <1414708776-124078-1-git-send-email-wanpeng.li@linux.intel.com> References: <1414708776-124078-1-git-send-email-wanpeng.li@linux.intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/rt: Clean up check_preempt_equal_prio() Git-Commit-ID: 308a623a40ce168eb234ea82c2bd13ff85a098d9 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: 308a623a40ce168eb234ea82c2bd13ff85a098d9 Gitweb: http://git.kernel.org/tip/308a623a40ce168eb234ea82c2bd13ff85a098d9 Author: Wanpeng Li AuthorDate: Fri, 31 Oct 2014 06:39:31 +0800 Committer: Ingo Molnar CommitDate: Tue, 4 Nov 2014 07:17:52 +0100 sched/rt: Clean up check_preempt_equal_prio() This patch checks if current can be pushed/pulled somewhere else in advance to make logic clear, the same behavior as dl class. - If current can't be migrated, useless to reschedule, let's hope task can move out. - If task is migratable, so let's not schedule it and see if it can be pushed or pulled somewhere else. Signed-off-by: Wanpeng Li Signed-off-by: Peter Zijlstra (Intel) Cc: Juri Lelli Cc: Kirill Tkhai Cc: Steven Rostedt Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1414708776-124078-1-git-send-email-wanpeng.li@linux.intel.com Signed-off-by: Ingo Molnar --- kernel/sched/rt.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index d024e6c..3d14312 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1351,16 +1351,22 @@ out: static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) { - if (rq->curr->nr_cpus_allowed == 1) + /* + * Current can't be migrated, useless to reschedule, + * let's hope p can move out. + */ + if (rq->curr->nr_cpus_allowed == 1 || + !cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) return; + /* + * p is migratable, so let's not schedule it and + * see if it is pushed or pulled somewhere else. + */ if (p->nr_cpus_allowed != 1 && cpupri_find(&rq->rd->cpupri, p, NULL)) return; - if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) - return; - /* * There appears to be other cpus that can accept * current and none to run 'p', so lets reschedule