Commit 0fdcccfa authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

tick/nohz: Call tick_nohz_task_switch() with interrupts disabled 



Call tick_nohz_task_switch() slightly earlier after the context switch
to benefit from disabled IRQs. This way the function doesn't need to
disable them once more.

Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210512232924.150322-10-frederic@kernel.org
parent a1dfb631

kernel/sched/core.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -4212,6 +4212,7 @@ static struct rq *finish_task_switch(struct task_struct *prev) 
	vtime_task_switch(prev);

	vtime_task_switch(prev);

	perf_event_task_sched_in(prev, current);

	perf_event_task_sched_in(prev, current);

	finish_task(prev);

	finish_task(prev);

	tick_nohz_task_switch();

	finish_lock_switch(rq);

	finish_lock_switch(rq);

	finish_arch_post_lock_switch();

	finish_arch_post_lock_switch();

	kcov_finish_switch(current);

	kcov_finish_switch(current);
@@ -4257,7 +4258,6 @@ static struct rq *finish_task_switch(struct task_struct *prev) 
		put_task_struct_rcu_user(prev);

		put_task_struct_rcu_user(prev);

	}

	}





	tick_nohz_task_switch();

	return rq;

	return rq;

}

}

kernel/time/tick-sched.c

+1 −6
Original line number Original line Diff line number Diff line
@@ -487,13 +487,10 @@ void tick_nohz_dep_clear_signal(struct signal_struct *sig, enum tick_dep_bits bi 
 */

 */

void __tick_nohz_task_switch(void)

void __tick_nohz_task_switch(void)

{

{

	unsigned long flags;

	struct tick_sched *ts;

	struct tick_sched *ts;





	local_irq_save(flags);



	if (!tick_nohz_full_cpu(smp_processor_id()))

	if (!tick_nohz_full_cpu(smp_processor_id()))

		goto out;

		return;





	ts = this_cpu_ptr(&tick_cpu_sched);

	ts = this_cpu_ptr(&tick_cpu_sched);
@@ -502,8 +499,6 @@ void __tick_nohz_task_switch(void) 
		    atomic_read(&current->signal->tick_dep_mask))

		    atomic_read(&current->signal->tick_dep_mask))

			tick_nohz_full_kick();

			tick_nohz_full_kick();

	}

	}

out:

	local_irq_restore(flags);

}

}





/* Get the boot-time nohz CPU list from the kernel parameters. */

/* Get the boot-time nohz CPU list from the kernel parameters. */