[PATCH 10/10] sched: rt: dont stop the period timer when there are tasks wanting to run

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

[-- Attachment #1: sched-rt-fix-timer-idle.patch --]
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When a runnable group failed to get any runtime within a period it would be
found idle and the period timer would be stopped.

So if the group ever gets throttled, it will never wake up again.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: "Daniel K." <dk@uw.no>
---
 kernel/sched_rt.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Index: linux-2.6/kernel/sched_rt.c
===================================================================
--- linux-2.6.orig/kernel/sched_rt.c
+++ linux-2.6/kernel/sched_rt.c
@@ -408,7 +408,8 @@ static int do_sched_rt_period_timer(stru
 			if (rt_rq->rt_time || rt_rq->rt_nr_running)
 				idle = 0;
 			spin_unlock(&rt_rq->rt_runtime_lock);
-		}
+		} else if (rt_rq->rt_nr_running)
+			idle = 0;
 
 		if (enqueue)
 			sched_rt_rq_enqueue(rt_rq);

--