Commit d0f5d3ce authored by Shrikanth Hegde's avatar Shrikanth Hegde Committed by Ingo Molnar
Browse files

sched/fair: Introduce is_rd_overutilized() helper function to access root_domain::overutilized 



The root_domain::overutilized field is READ_ONCE() accessed in
multiple places, which could be simplified with a helper function.

This might also make it more apparent that it needs to be used
only in case of EAS.

No change in functionality intended.

Signed-off-by: default avatarShrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarQais Yousef <qyousef@layalina.io>
Reviewed-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240307085725.444486-3-sshegde@linux.ibm.com
parent be3a51e6

kernel/sched/fair.c

+12 −3
Original line number Diff line number Diff line
@@ -6685,6 +6685,15 @@ static inline bool cpu_overutilized(int cpu) 
	return !util_fits_cpu(cpu_util_cfs(cpu), rq_util_min, rq_util_max, cpu);

}



/*

 * Ensure that caller can do EAS. overutilized value

 * make sense only if EAS is enabled

 */

static inline int is_rd_overutilized(struct root_domain *rd)

{

	return READ_ONCE(rd->overutilized);

}



static inline void set_rd_overutilized_status(struct root_domain *rd,

					      unsigned int status)

{
@@ -6704,7 +6713,7 @@ static inline void check_update_overutilized_status(struct rq *rq) 
	if (!sched_energy_enabled())

		return;



	if (!READ_ONCE(rq->rd->overutilized) && cpu_overutilized(rq->cpu))

	if (!is_rd_overutilized(rq->rd) && cpu_overutilized(rq->cpu))

		set_rd_overutilized_status(rq->rd, SG_OVERUTILIZED);

}

#else
@@ -7990,7 +7999,7 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) 


	rcu_read_lock();

	pd = rcu_dereference(rd->pd);

	if (!pd || READ_ONCE(rd->overutilized))

	if (!pd || is_rd_overutilized(rd))

		goto unlock;



	/*
@@ -10897,7 +10906,7 @@ static struct sched_group *sched_balance_find_src_group(struct lb_env *env) 
	if (sched_energy_enabled()) {

		struct root_domain *rd = env->dst_rq->rd;



		if (rcu_dereference(rd->pd) && !READ_ONCE(rd->overutilized))

		if (rcu_dereference(rd->pd) && !is_rd_overutilized(rd))

			goto out_balanced;

	}