perf/x86: Remove task_ctx_size

A new kmem_cache method has replaced the kzalloc() to allocate the PMU
specific data. The task_ctx_size is not required anymore.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1593780569-62993-19-git-send-email-kan.liang@linux.intel.com

arch/x86/events/core.c

@@ -2371,7 +2371,6 @@ static struct pmu pmu = {
 
 	.event_idx		= x86_pmu_event_idx,
 	.sched_task		= x86_pmu_sched_task,
-	.task_ctx_size          = sizeof(struct x86_perf_task_context),
 	.swap_task_ctx		= x86_pmu_swap_task_ctx,
 	.check_period		= x86_pmu_check_period,
 

arch/x86/events/intel/lbr.c

@@ -1672,7 +1672,6 @@ void __init intel_pmu_arch_lbr_init(void)
 
 	size = sizeof(struct x86_perf_task_context_arch_lbr) +
 	       lbr_nr * sizeof(struct lbr_entry);
-	x86_get_pmu()->task_ctx_size = size;
 	x86_get_pmu()->task_ctx_cache = create_lbr_kmem_cache(size, 0);
 
 	x86_pmu.lbr_from = MSR_ARCH_LBR_FROM_0;

include/linux/perf_event.h

@@ -419,10 +419,6 @@ struct pmu {
 	 */
 	void (*sched_task)		(struct perf_event_context *ctx,
 					bool sched_in);
-	/*
-	 * PMU specific data size
-	 */
-	size_t				task_ctx_size;
 
 	/*
 	 * Kmem cache of PMU specific data

kernel/events/core.c

@@ -1243,15 +1243,13 @@ static void *alloc_task_ctx_data(struct pmu *pmu)
 	if (pmu->task_ctx_cache)
 		return kmem_cache_zalloc(pmu->task_ctx_cache, GFP_KERNEL);
 
-	return kzalloc(pmu->task_ctx_size, GFP_KERNEL);
+	return NULL;
 }
 
 static void free_task_ctx_data(struct pmu *pmu, void *task_ctx_data)
 {
 	if (pmu->task_ctx_cache && task_ctx_data)
 		kmem_cache_free(pmu->task_ctx_cache, task_ctx_data);
-	else
-		kfree(task_ctx_data);
 }
 
 static void free_ctx(struct rcu_head *head)