Commit 984ffb6a authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

sched/fair: Remove SIS_PROP 



SIS_UTIL seems to work well, lets remove the old thing.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20231020134337.GD33965@noisy.programming.kicks-ass.net
parent 22165f61

include/linux/sched/topology.h

+0 −2
Original line number Diff line number Diff line
@@ -109,8 +109,6 @@ struct sched_domain { 
	u64 max_newidle_lb_cost;

	unsigned long last_decay_max_lb_cost;



	u64 avg_scan_cost;		/* select_idle_sibling */



#ifdef CONFIG_SCHEDSTATS

	/* load_balance() stats */

	unsigned int lb_count[CPU_MAX_IDLE_TYPES];

kernel/sched/core.c

+0 −5
Original line number Diff line number Diff line
@@ -3792,9 +3792,6 @@ ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags, 
		if (rq->avg_idle > max)

			rq->avg_idle = max;



		rq->wake_stamp = jiffies;

		rq->wake_avg_idle = rq->avg_idle / 2;



		rq->idle_stamp = 0;

	}

#endif
@@ -9953,8 +9950,6 @@ void __init sched_init(void) 
		rq->online = 0;

		rq->idle_stamp = 0;

		rq->avg_idle = 2*sysctl_sched_migration_cost;

		rq->wake_stamp = jiffies;

		rq->wake_avg_idle = rq->avg_idle;

		rq->max_idle_balance_cost = sysctl_sched_migration_cost;



		INIT_LIST_HEAD(&rq->cfs_tasks);

kernel/sched/fair.c

+0 −48
Original line number Diff line number Diff line
@@ -7209,45 +7209,9 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool 
	struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_rq_mask);

	int i, cpu, idle_cpu = -1, nr = INT_MAX;

	struct sched_domain_shared *sd_share;

	struct rq *this_rq = this_rq();

	int this = smp_processor_id();

	struct sched_domain *this_sd = NULL;

	u64 time = 0;



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



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

		u64 avg_cost, avg_idle, span_avg;

		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

		 * predicts the future is flawed; age away the remaining

		 * predicted idle time.

		 */

		if (unlikely(this_rq->wake_stamp < now)) {

			while (this_rq->wake_stamp < now && this_rq->wake_avg_idle) {

				this_rq->wake_stamp++;

				this_rq->wake_avg_idle >>= 1;

			}

		}



		avg_idle = this_rq->wake_avg_idle;

		avg_cost = this_sd->avg_scan_cost + 1;



		span_avg = sd->span_weight * avg_idle;

		if (span_avg > 4*avg_cost)

			nr = div_u64(span_avg, avg_cost);

		else

			nr = 4;



		time = cpu_clock(this);

	}



	if (sched_feat(SIS_UTIL)) {

		sd_share = rcu_dereference(per_cpu(sd_llc_shared, target));

		if (sd_share) {
@@ -7301,18 +7265,6 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool 
	if (has_idle_core)

		set_idle_cores(target, false);



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

		time = cpu_clock(this) - time;



		/*

		 * Account for the scan cost of wakeups against the average

		 * idle time.

		 */

		this_rq->wake_avg_idle -= min(this_rq->wake_avg_idle, time);



		update_avg(&this_sd->avg_scan_cost, time);

	}



	return idle_cpu;

}

kernel/sched/features.h

+0 −1
Original line number Diff line number Diff line
@@ -49,7 +49,6 @@ SCHED_FEAT(TTWU_QUEUE, true) 
/*

 * When doing wakeups, attempt to limit superfluous scans of the LLC domain.

 */

SCHED_FEAT(SIS_PROP, false)

SCHED_FEAT(SIS_UTIL, true)



/*

kernel/sched/sched.h

+0 −3
Original line number Diff line number Diff line
@@ -1059,9 +1059,6 @@ struct rq { 
	u64			idle_stamp;

	u64			avg_idle;



	unsigned long		wake_stamp;

	u64			wake_avg_idle;



	/* This is used to determine avg_idle's max value */

	u64			max_idle_balance_cost;