[PATCH 2/5] arm_pmu: have armpmu_alloc() take GFP flags

[Zhangshaokun]

Hi Mark,

We (HiSilicon) also met this issue and it works happily with this patch,
but it is still not in 4.15 version, any special reasons?

Thanks,
Shaokun

On 2017/11/1 22:12, Mark Rutland wrote:
> In ACPI systems, we don't know the makeup of CPUs until we hotplug them
> on, and thus have to allocate the PMU datastrcutures at hotplug time.
> Thus, we must use GFP_ATOMIC allocations.
> 
> Reorganise the PMU allocators to take a GFP argument so that we can
> permit this.
> 
> Signed-off-by: Mark Rutland <mark.rutland at arm.com>
> Cc: Will Deacon <will.deacon at arm.com>
> ---
>  drivers/perf/arm_pmu.c          | 6 +++---
>  drivers/perf/arm_pmu_acpi.c     | 2 +-
>  drivers/perf/arm_pmu_platform.c | 2 +-
>  include/linux/perf/arm_pmu.h    | 2 +-
>  4 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
> index 57df8dce8e19..3d6d4c5f2356 100644
> --- a/drivers/perf/arm_pmu.c
> +++ b/drivers/perf/arm_pmu.c
> @@ -779,18 +779,18 @@ static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
>  					    &cpu_pmu->node);
>  }
>  
> -struct arm_pmu *armpmu_alloc(void)
> +struct arm_pmu *armpmu_alloc(gfp_t flags)
>  {
>  	struct arm_pmu *pmu;
>  	int cpu;
>  
> -	pmu = kzalloc(sizeof(*pmu), GFP_KERNEL);
> +	pmu = kzalloc(sizeof(*pmu), flags);
>  	if (!pmu) {
>  		pr_info("failed to allocate PMU device!\n");
>  		goto out;
>  	}
>  
> -	pmu->hw_events = alloc_percpu(struct pmu_hw_events);
> +	pmu->hw_events = alloc_percpu_gfp(struct pmu_hw_events, flags);
>  	if (!pmu->hw_events) {
>  		pr_info("failed to allocate per-cpu PMU data.\n");
>  		goto out_free_pmu;
> diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
> index 705f1a390e31..a52f5b673a15 100644
> --- a/drivers/perf/arm_pmu_acpi.c
> +++ b/drivers/perf/arm_pmu_acpi.c
> @@ -127,7 +127,7 @@ static struct arm_pmu *arm_pmu_acpi_find_alloc_pmu(void)
>  		return pmu;
>  	}
>  
> -	pmu = armpmu_alloc();
> +	pmu = armpmu_alloc(GFP_ATOMIC);
>  	if (!pmu) {
>  		pr_warn("Unable to allocate PMU for CPU%d\n",
>  			smp_processor_id());
> diff --git a/drivers/perf/arm_pmu_platform.c b/drivers/perf/arm_pmu_platform.c
> index db863f14c406..686b3f28c5d1 100644
> --- a/drivers/perf/arm_pmu_platform.c
> +++ b/drivers/perf/arm_pmu_platform.c
> @@ -203,7 +203,7 @@ int arm_pmu_device_probe(struct platform_device *pdev,
>  	struct arm_pmu *pmu;
>  	int ret = -ENODEV;
>  
> -	pmu = armpmu_alloc();
> +	pmu = armpmu_alloc(GFP_KERNEL);
>  	if (!pmu)
>  		return -ENOMEM;
>  
> diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
> index 97426407904d..52e6d56a6a4e 100644
> --- a/include/linux/perf/arm_pmu.h
> +++ b/include/linux/perf/arm_pmu.h
> @@ -173,7 +173,7 @@ static inline int arm_pmu_acpi_probe(armpmu_init_fn init_fn) { return 0; }
>  #endif
>  
>  /* Internal functions only for core arm_pmu code */
> -struct arm_pmu *armpmu_alloc(void);
> +struct arm_pmu *armpmu_alloc(gfp_t flags);
>  void armpmu_free(struct arm_pmu *pmu);
>  int armpmu_register(struct arm_pmu *pmu);
>  int armpmu_request_irq(struct arm_pmu *armpmu, int cpu);
>