Commit 96c1c0cf authored by Abel Wu's avatar Abel Wu Committed by Peter Zijlstra
Browse files

sched/fair: Cleanup for SIS_PROP 



The sched-domain of this cpu is only used for some heuristics when
SIS_PROP is enabled, and it should be irrelevant whether the local
sd_llc is valid or not, since all we care about is target sd_llc
if !SIS_PROP.

Access the local domain only when there is a need.

Signed-off-by: default avatarAbel Wu <wuyun.abel@bytedance.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarMel Gorman <mgorman@suse.de>
Link: https://lore.kernel.org/r/20220907112000.1854-6-wuyun.abel@bytedance.com
parent 398ba2b0

kernel/sched/fair.c

+6 −6
Original line number Original line Diff line number Diff line
@@ -6396,19 +6396,19 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool 
	struct sched_domain_shared *sd_share;

	struct sched_domain_shared *sd_share;

	struct rq *this_rq = this_rq();

	struct rq *this_rq = this_rq();

	int this = smp_processor_id();

	int this = smp_processor_id();

	struct sched_domain *this_sd;

	struct sched_domain *this_sd = NULL;

	u64 time = 0;

	u64 time = 0;





	this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc));

	if (!this_sd)

		return -1;



	cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);

	cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);





	if (sched_feat(SIS_PROP) && !has_idle_core) {

	if (sched_feat(SIS_PROP) && !has_idle_core) {

		u64 avg_cost, avg_idle, span_avg;

		u64 avg_cost, avg_idle, span_avg;

		unsigned long now = jiffies;

		unsigned long now = jiffies;





		this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc));

		if (!this_sd)

			return -1;



		/*

		/*

		 * If we're busy, the assumption that the last idle period

		 * If we're busy, the assumption that the last idle period

		 * predicts the future is flawed; age away the remaining

		 * predicts the future is flawed; age away the remaining
@@ -6462,7 +6462,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool 
	if (has_idle_core)

	if (has_idle_core)

		set_idle_cores(target, false);

		set_idle_cores(target, false);





	if (sched_feat(SIS_PROP) && !has_idle_core) {

	if (sched_feat(SIS_PROP) && this_sd && !has_idle_core) {

		time = cpu_clock(this) - time;

		time = cpu_clock(this) - time;





		/*

		/*