Commit 6dafc713 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

sched: Simplify sched_tick_remote() 



Use guards to reduce gotos and simplify control flow.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarValentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20230801211812.236247952@infradead.org
parent 4bdada79

kernel/sched/core.c

+16 −23
Original line number Diff line number Diff line
@@ -5721,9 +5721,6 @@ static void sched_tick_remote(struct work_struct *work) 
	struct tick_work *twork = container_of(dwork, struct tick_work, work);

	int cpu = twork->cpu;

	struct rq *rq = cpu_rq(cpu);

	struct task_struct *curr;

	struct rq_flags rf;

	u64 delta;

	int os;



	/*
@@ -5733,30 +5730,26 @@ static void sched_tick_remote(struct work_struct *work) 
	 * statistics and checks timeslices in a time-independent way, regardless

	 * of when exactly it is running.

	 */

	if (!tick_nohz_tick_stopped_cpu(cpu))

		goto out_requeue;



	rq_lock_irq(rq, &rf);

	curr = rq->curr;

	if (cpu_is_offline(cpu))

		goto out_unlock;

	if (tick_nohz_tick_stopped_cpu(cpu)) {

		guard(rq_lock_irq)(rq);

		struct task_struct *curr = rq->curr;



		if (cpu_online(cpu)) {

			update_rq_clock(rq);



			if (!is_idle_task(curr)) {

				/*

		 * Make sure the next tick runs within a reasonable

		 * amount of time.

				 * Make sure the next tick runs within a

				 * reasonable amount of time.

				 */

		delta = rq_clock_task(rq) - curr->se.exec_start;

				u64 delta = rq_clock_task(rq) - curr->se.exec_start;

				WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3);

			}

			curr->sched_class->task_tick(rq, curr, 0);



			calc_load_nohz_remote(rq);

out_unlock:

	rq_unlock_irq(rq, &rf);

out_requeue:

		}

	}



	/*

	 * Run the remote tick once per second (1Hz). This arbitrary