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 07d9b33079071445e742c227c4a8281525d787a1..552310798dadf13e3b2059d5f84e050f7e0926e2 100644 (file)
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -440,9 +440,6 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
 {
        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 @@ static void update_curr_rt(struct rq *rq)
                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);
        }
 }