[PATCH 5/8] arm: arm64: pmu: Assign platform PMU CPU affinity

Jeremy Linton [off-list ref] writes:

|-----Original Message-----
|From: Punit Agrawal [mailto:punit.agrawal at arm.com]
|Sent: Monday, June 20, 2016 11:41 AM
|To: Jeremy Linton
|Cc: linux-arm-kernel at lists.infradead.org; Mark Rutland; Lorenzo Pieralisi;
|mlangsdorf at redhat.com; peterz at infradead.org; Catalin Marinas; Will
|Deacon; acme at kernel.org; linux-acpi at vger.kernel.org;
|alexander.shishkin at linux.intel.com; mingo at redhat.com
|Subject: Re: [PATCH 5/8] arm: arm64: pmu: Assign platform PMU CPU affinity
|
|Jeremy Linton [off-list ref] writes:
|
|> On systems with multiple PMU types the PMU to CPU affinity needs to be
|> detected and set. The CPU to interrupt affinity should also be set.
|>
|
|One comment below.
|
|> Signed-off-by: Jeremy Linton [off-list ref]
|> ---
|>  drivers/perf/arm_pmu.c | 52
|++++++++++++++++++++++++++++++++++++++++----------
|>  1 file changed, 42 insertions(+), 10 deletions(-)
|>
|> diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
|> index fee4be0e8..865a9db 100644
|> --- a/drivers/perf/arm_pmu.c
|> +++ b/drivers/perf/arm_pmu.c
|
|[...]
|
|> @@ -872,25 +874,56 @@ static void cpu_pmu_destroy(struct arm_pmu
|*cpu_pmu)
|>  }
|>
|>  /*
|> - * CPU PMU identification and probing.
|> + * CPU PMU identification and probing. Its possible to have
|> + * multiple CPU types in an ARM machine. Assure that we are
|> + * picking the right PMU types based on the CPU in question
|>   */
|> -static int probe_current_pmu(struct arm_pmu *pmu,
|> -     const struct pmu_probe_info *info)
|> +static int probe_plat_pmu(struct arm_pmu *pmu,
|> +     const struct pmu_probe_info *info,
|> +     unsigned int pmuid)
|>  {
|> -int cpu = get_cpu();
|> -unsigned int cpuid = read_cpuid_id();
|>  int ret = -ENODEV;
|> +int cpu;
|> +int aff_ctr = 0;
|> +struct platform_device *pdev = pmu->plat_device;
|> +int irq = platform_get_irq(pdev, 0);
|>
|> -pr_info("probing PMU on CPU %d\n", cpu);
|> +if (irq >= 0 && !irq_is_percpu(irq)) {
|> +pmu->irq_affinity = kcalloc(pdev->num_resources,
|sizeof(int),
|> +    GFP_KERNEL);
|> +if (!pmu->irq_affinity)
|> +return -ENOMEM;
|> +}
|> +
|> +for_each_possible_cpu(cpu) {
|> +unsigned int cpuid = read_specific_cpuid(cpu);
|> +
|> +if (cpuid == pmuid) {
|> +cpumask_set_cpu(cpu, &pmu->supported_cpus);
|> +pr_devel("enable pmu on cpu %d\n", cpu);
|> +if (pmu->irq_affinity) {
|
|The check for irq_affinity can be dropped as you already do that earlier.

There isn't an irq_affinity structure for machines with PMU's using
PPI's, that is why the check is there...

You're right. I missed the PPIs case. Apologies for the noise.

Thanks,

IMPORTANT NOTICE: The contents of this email and any attachments are
confidential and may also be privileged. If you are not the intended
recipient, please notify the sender immediately and do not disclose
the contents to any other person, use it for any purpose, or store or
copy the information in any medium. Thank you.


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel at lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel