sched: rt-bandwidth accounting fix

It fixes an accounting bug where we would continue accumulating runtime
even though the bandwidth control is disabled. This would lead to very long
throttle periods once bandwidth control gets turned on again.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 07d9b33..5523107 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -440,9 +440,6 @@
 {
 	u64 runtime = sched_rt_runtime(rt_rq);
 
-	if (runtime == RUNTIME_INF)
-		return 0;
-
 	if (rt_rq->rt_throttled)
 		return rt_rq_throttled(rt_rq);
 
@@ -493,9 +490,11 @@
 		rt_rq = rt_rq_of_se(rt_se);
 
 		spin_lock(&rt_rq->rt_runtime_lock);
-		rt_rq->rt_time += delta_exec;
-		if (sched_rt_runtime_exceeded(rt_rq))
-			resched_task(curr);
+		if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
+			rt_rq->rt_time += delta_exec;
+			if (sched_rt_runtime_exceeded(rt_rq))
+				resched_task(curr);
+		}
 		spin_unlock(&rt_rq->rt_runtime_lock);
 	}
 }