Re: [tip:perf/urgent] perf/x86: Set pmu->module in Intel PMU modules

[Peter Zijlstra <peterz@infradead.org>]

On Thu, Jan 05, 2017 at 07:07:05AM -0800, tip-bot for David Carrillo-Cisneros wrote:
> --- a/arch/x86/events/intel/cstate.c
> +++ b/arch/x86/events/intel/cstate.c
> @@ -434,6 +434,7 @@ static struct pmu cstate_core_pmu = {
>  	.stop		= cstate_pmu_event_stop,
>  	.read		= cstate_pmu_event_update,
>  	.capabilities	= PERF_PMU_CAP_NO_INTERRUPT,
> +	.module		= THIS_MODULE,
>  };
>  
>  static struct pmu cstate_pkg_pmu = {
> @@ -447,6 +448,7 @@ static struct pmu cstate_pkg_pmu = {
>  	.stop		= cstate_pmu_event_stop,
>  	.read		= cstate_pmu_event_update,
>  	.capabilities	= PERF_PMU_CAP_NO_INTERRUPT,
> +	.module		= THIS_MODULE,
>  };
>  
>  static const struct cstate_model nhm_cstates __initconst = {
> diff --git a/arch/x86/events/intel/rapl.c b/arch/x86/events/intel/rapl.c
> index bd34124..17c3564 100644
> --- a/arch/x86/events/intel/rapl.c
> +++ b/arch/x86/events/intel/rapl.c
> @@ -697,6 +697,7 @@ static int __init init_rapl_pmus(void)
>  	rapl_pmus->pmu.start		= rapl_pmu_event_start;
>  	rapl_pmus->pmu.stop		= rapl_pmu_event_stop;
>  	rapl_pmus->pmu.read		= rapl_pmu_event_read;
> +	rapl_pmus->pmu.module		= THIS_MODULE;
>  	return 0;
>  }
>  
> diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
> index 97c246f..8c4ccdc 100644
> --- a/arch/x86/events/intel/uncore.c
> +++ b/arch/x86/events/intel/uncore.c
> @@ -733,6 +733,7 @@ static int uncore_pmu_register(struct intel_uncore_pmu *pmu)
>  			.start		= uncore_pmu_event_start,
>  			.stop		= uncore_pmu_event_stop,
>  			.read		= uncore_pmu_event_read,
> +			.module		= THIS_MODULE,
>  		};
>  	} else {
>  		pmu->pmu = *pmu->type->pmu;


Ah, forgot about this, thanks for picking it up.

The first time I saw this I thought about doing something like the
below, but never got around to testing if that works and subsequently
forgot about things again.

Does this make sense and or work?

---

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 4741ecdb9817..70f8a5a2e224 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -852,7 +852,14 @@ extern int perf_aux_output_skip(struct perf_output_handle *handle,
 				unsigned long size);
 extern void *perf_get_aux(struct perf_output_handle *handle);
 
-extern int perf_pmu_register(struct pmu *pmu, const char *name, int type);
+extern int __perf_pmu_register(struct pmu *pmu, const char *name, int type);
+
+#define perf_pmu_register(_pmu, _name, _type)			\
+({								\
+ 	(_pmu)->module = THIS_MODULE;				\
+ 	__perf_pmu_register((_pmu), (_name), (_type));		\
+})
+
 extern void perf_pmu_unregister(struct pmu *pmu);
 
 extern int perf_num_counters(void);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index faf073d0287f..cde2004d932d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8752,7 +8767,7 @@ static int pmu_dev_alloc(struct pmu *pmu)
 static struct lock_class_key cpuctx_mutex;
 static struct lock_class_key cpuctx_lock;
 
-int perf_pmu_register(struct pmu *pmu, const char *name, int type)
+int __perf_pmu_register(struct pmu *pmu, const char *name, int type)
 {
 	int cpu, ret;