sched: Update shares on idle_balance

Since shares updates are no longer expensive and effectively local, update them
at idle_balance().  This allows us to more quickly redistribute shares to
another cpu when our load becomes idle.

Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234938.204191702@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/sched_fair.c

@@ -3343,6 +3343,7 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
 	 */
 	raw_spin_unlock(&this_rq->lock);
 
+	update_shares(this_cpu);
 	for_each_domain(this_cpu, sd) {
 		unsigned long interval;
 		int balance = 1;