| From | Luis Henriques <> | Subject | [PATCH 3.11 093/138] ARM: perf: hook up perf_sample_event_took around pmu irq handling | Date | Tue, 3 Jun 2014 12:38:59 +0100 |
| |
3.11.10.11 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Will Deacon <will.deacon@arm.com>
commit 5f5092e72cc25a6a5785308270e0085b2b2772cc upstream.
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 <rric@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Weng Meiling <wengmeiling.weng@huawei.com> [ luis: backported to 3.11: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- arch/arm/kernel/perf_event.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index e186ee1e63f6..de5cd767e4df 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -303,11 +303,18 @@ static irqreturn_t armpmu_dispatch_irq(int irq, void *dev) struct arm_pmu *armpmu = (struct arm_pmu *) dev; struct platform_device *plat_device = armpmu->plat_device; struct arm_pmu_platdata *plat = dev_get_platdata(&plat_device->dev); + int ret; + u64 start_clock, finish_clock; + 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 -- 1.9.1
|