Re: [PATCH v2 15/25] genirq: Update request_percpu_nmi() to take an affinity
From: Jonathan Cameron <jonathan.cameron@huawei.com>
Date: 2025-09-16 16:19:47
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On Mon, 15 Sep 2025 09:56:52 +0100 Marc Zyngier [off-list ref] wrote:
Continue spreading the notion of affinity to the percpu interrupt request code by updating the call sites that use request_percpu_nmi() (all two of them) to take an affinity pointer. This pointer is firmly NULL for now. Signed-off-by: Marc Zyngier <maz@kernel.org>
A few fussy reviewer comments inline.
quoted hunk ↗ jump to hunk
--- arch/arm64/kernel/smp.c | 2 +- drivers/perf/arm_pmu.c | 4 +++- include/linux/interrupt.h | 4 ++-- kernel/irq/manage.c | 11 +++++++---- 4 files changed, 13 insertions(+), 8 deletions(-)diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 68cea3a4a35ca..6fb838eee2e7d 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c@@ -1094,7 +1094,7 @@ static void ipi_setup_sgi(int ipi) irq = ipi_irq_base + ipi; if (ipi_should_be_nmi(ipi)) { - err = request_percpu_nmi(irq, ipi_handler, "IPI", &irq_stat); + err = request_percpu_nmi(irq, ipi_handler, "IPI", NULL, &irq_stat); WARN(err, "Could not request IRQ %d as NMI, err=%d\n", irq, err); } else { err = request_percpu_irq(irq, ipi_handler, "IPI", &irq_stat);diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index 5c310e803dd78..de9eca2290a97 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c@@ -659,7 +659,9 @@ int armpmu_request_irq(int irq, int cpu) irq_ops = &pmunmi_ops; } } else if (armpmu_count_irq_users(irq) == 0) { - err = request_percpu_nmi(irq, handler, "arm-pmu", &cpu_armpmu); + err = request_percpu_nmi(irq, handler, "arm-pmu", + NULL,
I was assuming this odd formatting was to help reduce churn in a later patch, but nope this whole block get replaced in patch 18. So might as well move NULL up a line an have a cleaner intermediate state.
quoted hunk ↗ jump to hunk
+ &cpu_armpmu); /* If cannot get an NMI, get a normal interrupt */ if (err) {diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 52147d5f432b3..2134e7c08c169 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h@@ -197,8 +197,8 @@ request_percpu_irq(unsigned int irq, irq_handler_t handler, } extern int __must_check -request_percpu_nmi(unsigned int irq, irq_handler_t handler, - const char *devname, void __percpu *dev); +request_percpu_nmi(unsigned int irq, irq_handler_t handler, const char *devname,
Odd inconsistency in parameter naming devname/name Perhaps worth tidying that up whilst here. I only noticed because of the wrap comment below.
quoted hunk ↗ jump to hunk
+ const struct cpumask *affinity, void __percpu *dev_id); extern const void *free_irq(unsigned int, void *); extern void free_percpu_irq(unsigned int, void __percpu *);diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 5f4c651677436..49c237aca2a70 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c@@ -2527,6 +2527,7 @@ EXPORT_SYMBOL_GPL(__request_percpu_irq); * @irq: Interrupt line to allocate * @handler: Function to be called when the IRQ occurs. * @name: An ascii name for the claiming device + * @affinity: A cpumask describing the target CPUs for this interrupt * @dev_id: A percpu cookie passed back to the handler function * * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs@@ -2544,7 +2545,8 @@ EXPORT_SYMBOL_GPL(__request_percpu_irq); * will fail returning a negative value. */ int request_percpu_nmi(unsigned int irq, irq_handler_t handler, - const char *name, void __percpu *dev_id) + const char *name, + const struct cpumask *affinity, void __percpu *dev_id)
This seems like an odd wrap and I can't immediately see it making more sense in later patches.
{