Commit a480adde authored by Josh Don's avatar Josh Don Committed by Peter Zijlstra
Browse files

sched: Account number of SCHED_IDLE entities on each cfs_rq 



Adds cfs_rq->idle_nr_running, which accounts the number of idle entities
directly enqueued on the cfs_rq.

Signed-off-by: default avatarJosh Don <joshdon@google.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20210820010403.946838-3-joshdon@google.com
parent a130e8fb

kernel/sched/debug.c

+2 −0
Original line number Diff line number Diff line
@@ -614,6 +614,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) 
			cfs_rq->nr_spread_over);

	SEQ_printf(m, "  .%-30s: %d\n", "nr_running", cfs_rq->nr_running);

	SEQ_printf(m, "  .%-30s: %d\n", "h_nr_running", cfs_rq->h_nr_running);

	SEQ_printf(m, "  .%-30s: %d\n", "idle_nr_running",

			cfs_rq->idle_nr_running);

	SEQ_printf(m, "  .%-30s: %d\n", "idle_h_nr_running",

			cfs_rq->idle_h_nr_running);

	SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);

kernel/sched/fair.c

+24 −1
Original line number Diff line number Diff line
@@ -2995,6 +2995,8 @@ account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) 
	}

#endif

	cfs_rq->nr_running++;

	if (se_is_idle(se))

		cfs_rq->idle_nr_running++;

}



static void
@@ -3008,6 +3010,8 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) 
	}

#endif

	cfs_rq->nr_running--;

	if (se_is_idle(se))

		cfs_rq->idle_nr_running--;

}



/*
@@ -5577,6 +5581,17 @@ static int sched_idle_rq(struct rq *rq) 
			rq->nr_running);

}



/*

 * Returns true if cfs_rq only has SCHED_IDLE entities enqueued. Note the use

 * of idle_nr_running, which does not consider idle descendants of normal

 * entities.

 */

static bool sched_idle_cfs_rq(struct cfs_rq *cfs_rq)

{

	return cfs_rq->nr_running &&

		cfs_rq->nr_running == cfs_rq->idle_nr_running;

}



#ifdef CONFIG_SMP

static int sched_idle_cpu(int cpu)

{
@@ -11575,7 +11590,7 @@ int sched_group_set_idle(struct task_group *tg, long idle) 
	for_each_possible_cpu(i) {

		struct rq *rq = cpu_rq(i);

		struct sched_entity *se = tg->se[i];

		struct cfs_rq *grp_cfs_rq = tg->cfs_rq[i];

		struct cfs_rq *parent_cfs_rq, *grp_cfs_rq = tg->cfs_rq[i];

		bool was_idle = cfs_rq_is_idle(grp_cfs_rq);

		long idle_task_delta;

		struct rq_flags rf;
@@ -11586,6 +11601,14 @@ int sched_group_set_idle(struct task_group *tg, long idle) 
		if (WARN_ON_ONCE(was_idle == cfs_rq_is_idle(grp_cfs_rq)))

			goto next_cpu;



		if (se->on_rq) {

			parent_cfs_rq = cfs_rq_of(se);

			if (cfs_rq_is_idle(grp_cfs_rq))

				parent_cfs_rq->idle_nr_running++;

			else

				parent_cfs_rq->idle_nr_running--;

		}



		idle_task_delta = grp_cfs_rq->h_nr_running -

				  grp_cfs_rq->idle_h_nr_running;

		if (!cfs_rq_is_idle(grp_cfs_rq))

kernel/sched/sched.h

+1 −0
Original line number Diff line number Diff line
@@ -530,6 +530,7 @@ struct cfs_rq { 
	struct load_weight	load;

	unsigned int		nr_running;

	unsigned int		h_nr_running;      /* SCHED_{NORMAL,BATCH,IDLE} */

	unsigned int		idle_nr_running;   /* SCHED_IDLE */

	unsigned int		idle_h_nr_running; /* SCHED_IDLE */



	u64			exec_clock;