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Commit 8537bb95 authored by Frederic Weisbecker's avatar Frederic Weisbecker
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nohz: Implement wide kick on top of irq work 



It simplifies it and allows wide kick to be performed, even when IRQs
are disabled, without an asynchronous level in the middle.

This comes at a cost of some more overhead on features like perf and
posix cpu timers slow-paths, which is probably not much important
for nohz full users.

Requested-by: default avatarPeter Zijlstra <peterz@infradead.org>
Reviewed-by: default avatarChris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent 5fd7a09c

kernel/time/tick-sched.c

+4 −8
Original line number Diff line number Diff line
@@ -234,24 +234,20 @@ void tick_nohz_full_kick_cpu(int cpu) 
	irq_work_queue_on(&per_cpu(nohz_full_kick_work, cpu), cpu);

}



static void nohz_full_kick_ipi(void *info)

{

	/* Empty, the tick restart happens on tick_nohz_irq_exit() */

}



/*

 * Kick all full dynticks CPUs in order to force these to re-evaluate

 * their dependency on the tick and restart it if necessary.

 */

void tick_nohz_full_kick_all(void)

{

	int cpu;



	if (!tick_nohz_full_running)

		return;



	preempt_disable();

	smp_call_function_many(tick_nohz_full_mask,

			       nohz_full_kick_ipi, NULL, false);

	tick_nohz_full_kick();

	for_each_cpu_and(cpu, tick_nohz_full_mask, cpu_online_mask)

		tick_nohz_full_kick_cpu(cpu);

	preempt_enable();

}