[RFC][PATCH 1/5] sched/fair: Update the rq clock before detaching tasks

From: Matt Fleming <matt@codeblueprint.co.uk>
To: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org,
	Byungchul Park <byungchul.park@lge.com>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Luca Abeni <luca.abeni@unitn.it>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	Rik van Riel <riel@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Wanpeng Li <wanpeng.li@hotmail.com>,
	Yuyang Du <yuyang.du@intel.com>,
	Mel Gorman <mgorman@techsingularity.net>,
	Mike Galbraith <umgwanakikbuti@gmail.com>,
	Matt Fleming <matt@codeblueprint.co.uk>
Subject: [RFC][PATCH 1/5] sched/fair: Update the rq clock before detaching tasks
Date: Thu, 12 May 2016 20:49:49 +0100	[thread overview]
Message-ID: <1463082593-27777-2-git-send-email-matt@codeblueprint.co.uk> (raw)
In-Reply-To: <1463082593-27777-1-git-send-email-matt@codeblueprint.co.uk>

detach_task_cfs_rq() may indirectly call rq_clock() to inform the
cpufreq code that the rq utilisation has changed. In which case, we
need to update the rq clock.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Yuyang Du <yuyang.du@intel.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
---
 kernel/sched/fair.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 218f8e83db73..02856647339d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8378,6 +8378,8 @@ static void detach_task_cfs_rq(struct task_struct *p)
 	struct sched_entity *se = &p->se;
 	struct cfs_rq *cfs_rq = cfs_rq_of(se);
 
+	update_rq_clock(task_rq(p));
+
 	if (!vruntime_normalized(p)) {
 		/*
 		 * Fix up our vruntime so that the current sleep doesn't
-- 
2.7.3
