sched/fair: Reorder newidle_balance pulled_task tests

Reorder the tests and skip useless ones when no load balance has been
performed and rq lock has not been released.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210224133007.28644-6-vincent.guittot@linaro.org

kernel/sched/fair.c

@@ -10584,7 +10584,6 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
 	if (curr_cost > this_rq->max_idle_balance_cost)
 		this_rq->max_idle_balance_cost = curr_cost;
 
-out:
 	/*
 	 * While browsing the domains, we released the rq lock, a task could
 	 * have been enqueued in the meantime. Since we're not going idle,
@@ -10593,14 +10592,15 @@ out:
 	if (this_rq->cfs.h_nr_running && !pulled_task)
 		pulled_task = 1;
 
-	/* Move the next balance forward */
-	if (time_after(this_rq->next_balance, next_balance))
-		this_rq->next_balance = next_balance;
-
 	/* Is there a task of a high priority class? */
 	if (this_rq->nr_running != this_rq->cfs.h_nr_running)
 		pulled_task = -1;
 
+out:
+	/* Move the next balance forward */
+	if (time_after(this_rq->next_balance, next_balance))
+		this_rq->next_balance = next_balance;
+
 	if (pulled_task)
 		this_rq->idle_stamp = 0;
 	else