From: Will Deacon Date: Tue, 11 Feb 2014 18:08:41 +0000 (+0000) Subject: ARM: perf: hook up perf_sample_event_took around pmu irq handling X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=5f5092e72cc25a6a5785308270e0085b2b2772cc;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git 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: Robert Richter Signed-off-by: Will Deacon --- diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 361a1aaee7c8..a6bc431cde70 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -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