Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6e82a3be authored by Ingo Molnar's avatar Ingo Molnar
Browse files

sched: optimize update_rq_clock() calls in the load-balancer 



optimize update_rq_clock() calls in the load-balancer: update them
right after locking the runqueue(s) so that the pull functions do
not have to call it.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 2daa3577

kernel/sched.c

+8 −6
Original line number Original line Diff line number Diff line
@@ -2017,6 +2017,8 @@ static void double_rq_lock(struct rq *rq1, struct rq *rq2) 
			spin_lock(&rq1->lock);

			spin_lock(&rq1->lock);

		}

		}

	}

	}

	update_rq_clock(rq1);

	update_rq_clock(rq2);

}

}





/*

/*
@@ -2113,10 +2115,8 @@ void sched_exec(void) 
static void pull_task(struct rq *src_rq, struct task_struct *p,

static void pull_task(struct rq *src_rq, struct task_struct *p,

		      struct rq *this_rq, int this_cpu)

		      struct rq *this_rq, int this_cpu)

{

{

	update_rq_clock(src_rq);

	deactivate_task(src_rq, p, 0);

	deactivate_task(src_rq, p, 0);

	set_task_cpu(p, this_cpu);

	set_task_cpu(p, this_cpu);

	__update_rq_clock(this_rq);

	activate_task(this_rq, p, 0);

	activate_task(this_rq, p, 0);

	/*

	/*

	 * Note that idle threads have a prio of MAX_PRIO, for this test

	 * Note that idle threads have a prio of MAX_PRIO, for this test
@@ -2798,6 +2798,8 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd) 
	if (busiest->nr_running > 1) {

	if (busiest->nr_running > 1) {

		/* Attempt to move tasks */

		/* Attempt to move tasks */

		double_lock_balance(this_rq, busiest);

		double_lock_balance(this_rq, busiest);

		/* this_rq->clock is already updated */

		update_rq_clock(busiest);

		ld_moved = move_tasks(this_rq, this_cpu, busiest,

		ld_moved = move_tasks(this_rq, this_cpu, busiest,

					imbalance, sd, CPU_NEWLY_IDLE,

					imbalance, sd, CPU_NEWLY_IDLE,

					&all_pinned);

					&all_pinned);
@@ -2895,6 +2897,8 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) 




	/* move a task from busiest_rq to target_rq */

	/* move a task from busiest_rq to target_rq */

	double_lock_balance(busiest_rq, target_rq);

	double_lock_balance(busiest_rq, target_rq);

	update_rq_clock(busiest_rq);

	update_rq_clock(target_rq);





	/* Search for an sd spanning us and the target CPU. */

	/* Search for an sd spanning us and the target CPU. */

	for_each_domain(target_cpu, sd) {

	for_each_domain(target_cpu, sd) {
@@ -4962,13 +4966,11 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) 
		goto out;

		goto out;





	on_rq = p->se.on_rq;

	on_rq = p->se.on_rq;

	if (on_rq) {

	if (on_rq)

		update_rq_clock(rq_src);

		deactivate_task(rq_src, p, 0);

		deactivate_task(rq_src, p, 0);

	}



	set_task_cpu(p, dest_cpu);

	set_task_cpu(p, dest_cpu);

	if (on_rq) {

	if (on_rq) {

		update_rq_clock(rq_dest);

		activate_task(rq_dest, p, 0);

		activate_task(rq_dest, p, 0);

		check_preempt_curr(rq_dest, p);

		check_preempt_curr(rq_dest, p);

	}

	}