Commit 39b6a429 authored by Vincent Guittot's avatar Vincent Guittot Committed by Ingo Molnar
Browse files

sched/fair: Reduce the window for duplicated update 



Start to update last_blocked_load_update_tick to reduce the possibility
of another cpu starting the update one more time

Signed-off-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarValentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210224133007.28644-8-vincent.guittot@linaro.org
parent c6f88654

kernel/sched/fair.c

+8 −3
Original line number Diff line number Diff line
@@ -7852,16 +7852,20 @@ static inline bool others_have_blocked(struct rq *rq) 
	return false;

}



static inline void update_blocked_load_status(struct rq *rq, bool has_blocked)

static inline void update_blocked_load_tick(struct rq *rq)

{

	rq->last_blocked_load_update_tick = jiffies;

	WRITE_ONCE(rq->last_blocked_load_update_tick, jiffies);

}



static inline void update_blocked_load_status(struct rq *rq, bool has_blocked)

{

	if (!has_blocked)

		rq->has_blocked_load = 0;

}

#else

static inline bool cfs_rq_has_blocked(struct cfs_rq *cfs_rq) { return false; }

static inline bool others_have_blocked(struct rq *rq) { return false; }

static inline void update_blocked_load_tick(struct rq *rq) {}

static inline void update_blocked_load_status(struct rq *rq, bool has_blocked) {}

#endif
@@ -8022,6 +8026,7 @@ static void update_blocked_averages(int cpu) 
	struct rq_flags rf;



	rq_lock_irqsave(rq, &rf);

	update_blocked_load_tick(rq);

	update_rq_clock(rq);



	decayed |= __update_blocked_others(rq, &done);
@@ -8363,7 +8368,7 @@ static bool update_nohz_stats(struct rq *rq) 
	if (!cpumask_test_cpu(cpu, nohz.idle_cpus_mask))

		return false;



	if (!time_after(jiffies, rq->last_blocked_load_update_tick))

	if (!time_after(jiffies, READ_ONCE(rq->last_blocked_load_update_tick)))

		return true;



	update_blocked_averages(cpu);