Messages in this thread | | | Date | Mon, 18 Nov 2013 20:26:15 +0530 | Subject | Re: [PATCH V3 2/2] arm64: perf: add support for percpu pmu interrupt | From | Vinayak Kale <> |
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On Mon, Nov 18, 2013 at 8:10 PM, Marc Zyngier <marc.zyngier@arm.com> wrote: > On 2013-11-18 14:18, Vinayak Kale wrote: >> >> On Mon, Nov 18, 2013 at 7:16 PM, Marc Zyngier <marc.zyngier@arm.com> >> wrote: >>> >>> Vinayak, >>> >>> >>> On 2013-11-18 13:22, Vinayak Kale wrote: >>>> >>>> >>>> Add support for irq registration when pmu interrupt is percpu. >>>> >>>> Signed-off-by: Vinayak Kale <vkale@apm.com> >>>> Signed-off-by: Tuan Phan <tphan@apm.com> >>>> --- >>>> arch/arm64/kernel/perf_event.c | 102 >>>> +++++++++++++++++++++++++++++----------- >>>> 1 file changed, 74 insertions(+), 28 deletions(-) >>>> >>>> diff --git a/arch/arm64/kernel/perf_event.c >>>> b/arch/arm64/kernel/perf_event.c >>>> index cea1594..23475f6 100644 >>>> --- a/arch/arm64/kernel/perf_event.c >>>> +++ b/arch/arm64/kernel/perf_event.c >>>> @@ -22,6 +22,7 @@ >>>> >>>> #include <linux/bitmap.h> >>>> #include <linux/interrupt.h> >>>> +#include <linux/irq.h> >>>> #include <linux/kernel.h> >>>> #include <linux/export.h> >>>> #include <linux/perf_event.h> >>>> @@ -363,22 +364,51 @@ validate_group(struct perf_event *event) >>>> } >>>> >>>> static void >>>> +armpmu_disable_percpu_irq(void *data) >>>> +{ >>>> + struct arm_pmu *armpmu = data; >>>> + struct platform_device *pmu_device = armpmu->plat_device; >>>> + int irq = platform_get_irq(pmu_device, 0); >>>> + >>>> + cpumask_test_and_clear_cpu(smp_processor_id(), >>>> &armpmu->active_irqs); >>>> + disable_percpu_irq(irq); >>>> +} >>>> + >>>> +static void >>>> armpmu_release_hardware(struct arm_pmu *armpmu) >>>> { >>>> int i, irq, irqs; >>>> struct platform_device *pmu_device = armpmu->plat_device; >>>> >>>> - irqs = min(pmu_device->num_resources, num_possible_cpus()); >>>> + irq = platform_get_irq(pmu_device, 0); >>>> >>>> - for (i = 0; i < irqs; ++i) { >>>> - if (!cpumask_test_and_clear_cpu(i, >>>> &armpmu->active_irqs)) >>>> - continue; >>>> - irq = platform_get_irq(pmu_device, i); >>>> - if (irq >= 0) >>>> - free_irq(irq, armpmu); >>>> + if (irq_to_desc(irq) && irq_is_percpu(irq)) { >>> >>> >>> >>> Why do you need to check the irq_desc here? It really looks like a misuse >>> of >>> the API. >> >> I don't think it's being misused. In case of invalid irq number, the >> API would return null. > > > And feeding an error code to irq_to_desc() doesn't disturb you? Since the API handles the error condition and returns null, so it won't break stuff. But I think your earlier suggestion of checking invalid irq number beforehand is better, since it would help to avoid wasting time in searching the irq desc. > Do you call that a normal use of the API? Humfff.... > > M. > > -- > Fast, cheap, reliable. Pick two. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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