From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752677Ab3KTNO0 (ORCPT ); Wed, 20 Nov 2013 08:14:26 -0500 Received: from service87.mimecast.com ([91.220.42.44]:41918 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751133Ab3KTNOZ convert rfc822-to-8bit (ORCPT ); Wed, 20 Nov 2013 08:14:25 -0500 Message-ID: <528CB5AC.5080007@arm.com> Date: Wed, 20 Nov 2013 13:14:20 +0000 From: Marc Zyngier User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130330 Thunderbird/17.0.5 MIME-Version: 1.0 To: Vinayak Kale CC: "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Will Deacon , "jcm@redhat.com" , "tglx@linutronix.de" , Tuan Phan Subject: Re: [PATCH V4 2/2] arm64: perf: add support for percpu pmu interrupt References: <1384946021-22100-1-git-send-email-vkale@apm.com> <1384946021-22100-3-git-send-email-vkale@apm.com> In-Reply-To: <1384946021-22100-3-git-send-email-vkale@apm.com> X-Enigmail-Version: 1.4.6 X-OriginalArrivalTime: 20 Nov 2013 13:14:21.0634 (UTC) FILETIME=[6D257220:01CEE5F2] X-MC-Unique: 113112013142204401 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [dropped patches@apm.com] Vinayak, Please keep reviewers on CC, as it makes easier to track the changes. On 20/11/13 11:13, Vinayak Kale wrote: > Add support for irq registration when pmu interrupt is percpu. > > Signed-off-by: Vinayak Kale > Signed-off-by: Tuan Phan > --- > arch/arm64/kernel/perf_event.c | 108 ++++++++++++++++++++++++++++++---------- > 1 file changed, 81 insertions(+), 27 deletions(-) > > diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c > index cea1594..de12ba8 100644 > --- a/arch/arm64/kernel/perf_event.c > +++ b/arch/arm64/kernel/perf_event.c > @@ -22,6 +22,7 @@ > > #include > #include > +#include > #include > #include > #include > @@ -363,22 +364,55 @@ 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()); > + if (irqs < 1) > + return; > > - 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); > + irq = platform_get_irq(pmu_device, 0); > + if (irq < 0) So I'm going to sound like a stuck record: irq == 0 is not a valid IRQ number, full stop. This is how we express the fact that there is no IRQ. If you're touching that code, you might as well fix this buglet. > + return; > + > + if (irq_is_percpu(irq)) { > + on_each_cpu(armpmu_disable_percpu_irq, armpmu, 1); > + free_percpu_irq(irq, &cpu_hw_events); > + } else { > + 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) Same here. > + free_irq(irq, armpmu); > + } > } > } > > +static void > +armpmu_enable_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); > + > + enable_percpu_irq(irq, 0); > + cpumask_set_cpu(smp_processor_id(), &armpmu->active_irqs); > +} > + > static int > armpmu_reserve_hardware(struct arm_pmu *armpmu) > { > @@ -396,34 +430,54 @@ armpmu_reserve_hardware(struct arm_pmu *armpmu) > return -ENODEV; > } > > - for (i = 0; i < irqs; ++i) { > - err = 0; > - irq = platform_get_irq(pmu_device, i); > - if (irq < 0) > - continue; > + irq = platform_get_irq(pmu_device, 0); > + if (irq < 0) { And here. > + pr_err("failed to get an irq for PMU device\n"); > + return -ENODEV; > + } > > - /* > - * If we have a single PMU interrupt that we can't shift, > - * assume that we're running on a uniprocessor machine and > - * continue. Otherwise, continue without this interrupt. > - */ > - if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) { > - pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n", > - irq, i); > - continue; > - } > + if (irq_is_percpu(irq)) { > + err = request_percpu_irq(irq, armpmu->handle_irq, > + "arm-pmu", &cpu_hw_events); > > - err = request_irq(irq, armpmu->handle_irq, > - IRQF_NOBALANCING, > - "arm-pmu", armpmu); > if (err) { > - pr_err("unable to request IRQ%d for ARM PMU counters\n", > - irq); > + pr_err("unable to request percpu IRQ%d for ARM PMU counters\n", > + irq); > armpmu_release_hardware(armpmu); > return err; > } > > - cpumask_set_cpu(i, &armpmu->active_irqs); > + on_each_cpu(armpmu_enable_percpu_irq, armpmu, 1); > + } else { > + for (i = 0; i < irqs; ++i) { > + err = 0; > + irq = platform_get_irq(pmu_device, i); > + if (irq < 0) And here. > + continue; > + > + /* > + * If we have a single PMU interrupt that we can't shift, > + * assume that we're running on a uniprocessor machine and > + * continue. Otherwise, continue without this interrupt. > + */ > + if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) { > + pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n", > + irq, i); > + continue; > + } > + > + err = request_irq(irq, armpmu->handle_irq, > + IRQF_NOBALANCING, > + "arm-pmu", armpmu); > + if (err) { > + pr_err("unable to request IRQ%d for ARM PMU counters\n", > + irq); > + armpmu_release_hardware(armpmu); > + return err; > + } > + > + cpumask_set_cpu(i, &armpmu->active_irqs); > + } > } > > return 0; > M. -- Jazz is not dead. It just smells funny...