Commit 42c62a58 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched/rt: Keep period timer ticking when rt throttling is active 



When a runqueue is throttled we cannot disable the period timer
because that timer is the only way to undo the throttling.

We got stale throttling entries when a rq was throttled and then the
global sysctl was disabled, which stopped the timer.

Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
[ Added changelog ]
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/n/tip-nuj34q52p6ro7szapuz84i0v@git.kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 7e4d9609

kernel/sched/rt.c

+8 −5
Original line number Diff line number Diff line
@@ -778,12 +778,9 @@ static inline int balance_runtime(struct rt_rq *rt_rq) 


static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)

{

	int i, idle = 1;

	int i, idle = 1, throttled = 0;

	const struct cpumask *span;



	if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)

		return 1;



	span = sched_rt_period_mask();

	for_each_cpu(i, span) {

		int enqueue = 0;
@@ -818,12 +815,17 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) 
			if (!rt_rq_throttled(rt_rq))

				enqueue = 1;

		}

		if (rt_rq->rt_throttled)

			throttled = 1;



		if (enqueue)

			sched_rt_rq_enqueue(rt_rq);

		raw_spin_unlock(&rq->lock);

	}



	if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF))

		return 1;



	return idle;

}
@@ -884,7 +886,8 @@ static void update_curr_rt(struct rq *rq) 
	if (unlikely((s64)delta_exec < 0))

		delta_exec = 0;



	schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec));

	schedstat_set(curr->se.statistics.exec_max,

		      max(curr->se.statistics.exec_max, delta_exec));



	curr->se.sum_exec_runtime += delta_exec;

	account_group_exec_runtime(curr, delta_exec);

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