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| author | Will Deacon <will.deacon@arm.com> | 2014-02-11 18:08:41 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-11 12:03:27 -0700 |
| commit | c318d7b4db9b4f47e0e29c24f4cac6f5e0644dc1 (patch) | |
| tree | e12b1e6d87b36168dd1c56c0db569951fa0b634d | |
| parent | 02f98e3e36da106338b7c732fed516420fb20e2a (diff) | |
| download | lwn-c318d7b4db9b4f47e0e29c24f4cac6f5e0644dc1.tar.gz lwn-c318d7b4db9b4f47e0e29c24f4cac6f5e0644dc1.zip | |
ARM: perf: hook up perf_sample_event_took around pmu irq handling
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm/kernel/perf_event.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index e19edc6f2d15..ace0ce8f6641 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 |