[PATCH 17/24] sched: Update rq clock before idle balancing

[Frederic Weisbecker <fweisbec@gmail.com>]

idle_balance() is called from schedule() right before we schedule the
idle task. It needs to record the idle timestamp at that time and for
this the rq clock must be accurate. If the CPU is running tickless
we need to update the rq clock manually.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/sched/fair.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 347dd3f..291e225 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5013,6 +5013,7 @@ void idle_balance(int this_cpu, struct rq *this_rq)
 	int pulled_task = 0;
 	unsigned long next_balance = jiffies + HZ;
 
+	update_nohz_rq_clock(this_rq);
 	this_rq->idle_stamp = this_rq->clock;
 
 	if (this_rq->avg_idle < sysctl_sched_migration_cost)
-- 
1.7.5.4