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Commit 5f5092e7 authored by Will Deacon's avatar Will Deacon
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ARM: perf: hook up perf_sample_event_took around pmu irq handling 



Since we indirect all of our PMU IRQ handling through a dispatcher, it's
trivial to hook up perf_sample_event_took to prevent applications such
as oprofile from generating interrupt storms due to an unrealisticly
low sample period.

Reported-by: default avatarRobert Richter <rric@kernel.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent d84c4783

arch/arm/kernel/perf_event.c

+9 −2
Original line number Diff line number Diff line
@@ -302,6 +302,8 @@ static irqreturn_t armpmu_dispatch_irq(int irq, void *dev) 
	struct arm_pmu *armpmu;

	struct platform_device *plat_device;

	struct arm_pmu_platdata *plat;

	int ret;

	u64 start_clock, finish_clock;



	if (irq_is_percpu(irq))

		dev = *(void **)dev;
@@ -309,10 +311,15 @@ static irqreturn_t armpmu_dispatch_irq(int irq, void *dev) 
	plat_device = armpmu->plat_device;

	plat = dev_get_platdata(&plat_device->dev);



	start_clock = sched_clock();

	if (plat && plat->handle_irq)

		return plat->handle_irq(irq, dev, armpmu->handle_irq);

		ret = plat->handle_irq(irq, dev, armpmu->handle_irq);

	else

		return armpmu->handle_irq(irq, dev);

		ret = armpmu->handle_irq(irq, dev);

	finish_clock = sched_clock();



	perf_sample_event_took(finish_clock - start_clock);

	return ret;

}



static void