From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751996AbcAEJQu (ORCPT ); Tue, 5 Jan 2016 04:16:50 -0500 Received: from LGEAMRELO11.lge.com ([156.147.23.51]:36515 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751936AbcAEJQo (ORCPT ); Tue, 5 Jan 2016 04:16:44 -0500 X-Original-SENDERIP: 156.147.1.151 X-Original-MAILFROM: byungchul.park@lge.com X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com From: Byungchul Park To: stable@vger.kernel.org Cc: peterz@infradead.org, linux-kernel@vger.kernel.org, ktkhai@parallels.com, rostedt@goodmis.org, juri.lelli@gmail.com, pang.xunlei@linaro.org, oleg@redhat.com, wanpeng.li@linux.intel.com, umgwanakikbuti@gmail.com, Thomas Gleixner Subject: [PATCH for v3.14.58 6/7] sched,dl: Remove return value from pull_dl_task() Date: Tue, 5 Jan 2016 18:16:27 +0900 Message-Id: <1451985388-19492-6-git-send-email-byungchul.park@lge.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1451985388-19492-1-git-send-email-byungchul.park@lge.com> References: <20160105085211.GB3621@X58A-UD3R> <1451985388-19492-1-git-send-email-byungchul.park@lge.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra 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 Conflicts: kernel/sched/deadline.c --- kernel/sched/deadline.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index aaefe1b..ec1f21d 100644 --- 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_rq) 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) -- 1.9.1