Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756019AbcCBCDH (ORCPT ); Tue, 1 Mar 2016 21:03:07 -0500 Received: from mail333.us4.mandrillapp.com ([205.201.137.77]:42851 "EHLO mail333.us4.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754480AbcCAXv1 (ORCPT ); Tue, 1 Mar 2016 18:51:27 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; q=dns; s=mandrill; d=linuxfoundation.org; b=ZYD61RN4tBgZofOqsAIkS3yEFVg1mOmH0uwbP/NSnnU8NyRtoTLi/y/5JXq9NEcSDPlAoLatyzKX zlUr0pBHU9g4XTB5VbzaRJYjmQVbEhOkr5vTze6yS9hgZmjTlpk7O8hhnW3nAXKZHBr3x8waq1XA JYqxVgTXAmdk/RVc5kM=; From: Greg Kroah-Hartman Subject: [PATCH 3.14 047/130] sched,dl: Remove return value from pull_dl_task() X-Mailer: git-send-email 2.7.2 To: Cc: Greg Kroah-Hartman , , "Peter Zijlstra (Intel)" , , , , , , , , Thomas Gleixner , Byungchul Park Message-Id: <20160301234501.418682242@linuxfoundation.org> In-Reply-To: <20160301234459.768886030@linuxfoundation.org> References: <20160301234459.768886030@linuxfoundation.org> X-Report-Abuse: Please forward a copy of this message, including all headers, to abuse@mandrill.com X-Report-Abuse: You can also report abuse here: http://mandrillapp.com/contact/abuse?id=30481620.f8ca25cf11734d4a992995caacc20381 X-Mandrill-User: md_30481620 Date: Tue, 01 Mar 2016 23:51:05 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2122 Lines: 75 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Zijlstra commit 0ea60c2054fc3b0c3eb68ac4f6884f3ee78d9925 upstream. In order to be able to use pull_dl_task() from a callback, we need to do away with the return value. Since the return value indicates if we should reschedule, do this inside the function. Since not all callers currently do this, this can increase the number of reschedules due rt balancing. Too many reschedules is not a correctness issues, too few are. Signed-off-by: Peter Zijlstra (Intel) Cc: ktkhai@parallels.com Cc: rostedt@goodmis.org Cc: juri.lelli@gmail.com Cc: pang.xunlei@linaro.org Cc: oleg@redhat.com Cc: wanpeng.li@linux.intel.com Cc: umgwanakikbuti@gmail.com Link: http://lkml.kernel.org/r/20150611124742.859398977@infradead.org Signed-off-by: Thomas Gleixner Signed-off-by: Byungchul Park Signed-off-by: Greg Kroah-Hartman --- kernel/sched/deadline.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1351,15 +1351,16 @@ static void push_dl_tasks(struct rq *rq) ; } -static int pull_dl_task(struct rq *this_rq) +static void pull_dl_task(struct rq *this_rq) { - int this_cpu = this_rq->cpu, ret = 0, cpu; + int this_cpu = this_rq->cpu, cpu; struct task_struct *p; + bool resched = false; struct rq *src_rq; u64 dmin = LONG_MAX; if (likely(!dl_overloaded(this_rq))) - return 0; + return; /* * Match the barrier from dl_set_overloaded; this guarantees that if we @@ -1414,7 +1415,7 @@ static int pull_dl_task(struct rq *this_ src_rq->curr->dl.deadline)) goto skip; - ret = 1; + resched = true; deactivate_task(src_rq, p, 0); set_task_cpu(p, this_cpu); @@ -1427,7 +1428,8 @@ skip: double_unlock_balance(this_rq, src_rq); } - return ret; + if (resched) + resched_task(this_rq->curr); } static void pre_schedule_dl(struct rq *rq, struct task_struct *prev)