perf: Clean up pmu specific data (bd2da08d) · Commits · git / linux-net

include/linux/perf_event.h

+0 −12

Original line number	Diff line number	Diff line
		@@ -501,16 +501,6 @@ struct pmu {
		*/
		struct kmem_cache *task_ctx_cache;

		/*
		* PMU specific parts of task perf event context (i.e. ctx->task_ctx_data)
		* can be synchronized using this function. See Intel LBR callstack support
		* implementation and Perf core context switch handling callbacks for usage
		* examples.
		*/
		void (swap_task_ctx) (struct perf_event_pmu_context prev_epc,
		struct perf_event_pmu_context *next_epc);
		/* optional */

		/*
		* Set up pmu-private data structures for an AUX area
		*/
		@@ -933,7 +923,6 @@ struct perf_event_pmu_context {
		atomic_t refcount; /* event <-> epc */
		struct rcu_head rcu_head;

		void task_ctx_data; / pmu specific data */
		/*
		* Set when one or more (plausibly active) event can't be scheduled
		* due to pmu overcommit or pmu constraints, except tolerant to
		@@ -981,7 +970,6 @@ struct perf_event_context {
		int nr_user;
		int is_active;

		int nr_task_data;
		int nr_stat;
		int nr_freq;
		int rotate_disable;

kernel/events/core.c

+3 −73

Original line number	Diff line number	Diff line
		@@ -1254,20 +1254,6 @@ static void get_ctx(struct perf_event_context *ctx)
		refcount_inc(&ctx->refcount);
		}

		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 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);
		}

		static void free_ctx(struct rcu_head *head)
		{
		struct perf_event_context *ctx;
		@@ -3577,42 +3563,6 @@ static void perf_event_sync_stat(struct perf_event_context *ctx,
		}
		}

		#define double_list_for_each_entry(pos1, pos2, head1, head2, member) \
		for (pos1 = list_first_entry(head1, typeof(*pos1), member), \
		pos2 = list_first_entry(head2, typeof(*pos2), member); \
		!list_entry_is_head(pos1, head1, member) && \
		!list_entry_is_head(pos2, head2, member); \
		pos1 = list_next_entry(pos1, member), \
		pos2 = list_next_entry(pos2, member))

		static void perf_event_swap_task_ctx_data(struct perf_event_context *prev_ctx,
		struct perf_event_context *next_ctx)
		{
		struct perf_event_pmu_context prev_epc, next_epc;

		if (!prev_ctx->nr_task_data)
		return;

		double_list_for_each_entry(prev_epc, next_epc,
		&prev_ctx->pmu_ctx_list, &next_ctx->pmu_ctx_list,
		pmu_ctx_entry) {

		if (WARN_ON_ONCE(prev_epc->pmu != next_epc->pmu))
		continue;

		/*
		* PMU specific parts of task perf context can require
		* additional synchronization. As an example of such
		* synchronization see implementation details of Intel
		* LBR call stack data profiling;
		*/
		if (prev_epc->pmu->swap_task_ctx)
		prev_epc->pmu->swap_task_ctx(prev_epc, next_epc);
		else
		swap(prev_epc->task_ctx_data, next_epc->task_ctx_data);
		}
		}

		static void perf_ctx_sched_task_cb(struct perf_event_context *ctx,
		struct task_struct *task, bool sched_in)
		{
		@@ -3687,16 +3637,15 @@ perf_event_context_sched_out(struct task_struct task, struct task_struct next)
		WRITE_ONCE(next_ctx->task, task);

		perf_ctx_sched_task_cb(ctx, task, false);
		perf_event_swap_task_ctx_data(ctx, next_ctx);

		perf_ctx_enable(ctx, false);

		/*
		* RCU_INIT_POINTER here is safe because we've not
		* modified the ctx and the above modification of
		* ctx->task and ctx->task_ctx_data are immaterial
		* since those values are always verified under
		* ctx->lock which we're now holding.
		* ctx->task is immaterial since this value is
		* always verified under ctx->lock which we're now
		* holding.
		*/
		RCU_INIT_POINTER(task->perf_event_ctxp, next_ctx);
		RCU_INIT_POINTER(next->perf_event_ctxp, ctx);
		@@ -5005,7 +4954,6 @@ find_get_pmu_context(struct pmu pmu, struct perf_event_context ctx,
		struct perf_event *event)
		{
		struct perf_event_pmu_context new = NULL, pos = NULL, *epc;
		void *task_ctx_data = NULL;

		if (!ctx->task) {
		/*
		@@ -5038,14 +4986,6 @@ find_get_pmu_context(struct pmu pmu, struct perf_event_context ctx,
		if (!new)
		return ERR_PTR(-ENOMEM);

		if (event->attach_state & PERF_ATTACH_TASK_DATA) {
		task_ctx_data = alloc_task_ctx_data(pmu);
		if (!task_ctx_data) {
		kfree(new);
		return ERR_PTR(-ENOMEM);
		}
		}

		__perf_init_event_pmu_context(new, pmu);

		/*
		@@ -5080,14 +5020,7 @@ find_get_pmu_context(struct pmu pmu, struct perf_event_context ctx,
		epc->ctx = ctx;

		found_epc:
		if (task_ctx_data && !epc->task_ctx_data) {
		epc->task_ctx_data = task_ctx_data;
		task_ctx_data = NULL;
		ctx->nr_task_data++;
		}
		raw_spin_unlock_irq(&ctx->lock);

		free_task_ctx_data(pmu, task_ctx_data);
		kfree(new);

		return epc;
		@@ -5103,7 +5036,6 @@ static void free_cpc_rcu(struct rcu_head *head)
		struct perf_cpu_pmu_context *cpc =
		container_of(head, typeof(*cpc), epc.rcu_head);

		kfree(cpc->epc.task_ctx_data);
		kfree(cpc);
		}

		@@ -5111,7 +5043,6 @@ static void free_epc_rcu(struct rcu_head *head)
		{
		struct perf_event_pmu_context epc = container_of(head, typeof(epc), rcu_head);

		kfree(epc->task_ctx_data);
		kfree(epc);
		}

		@@ -14103,7 +14034,6 @@ inherit_event(struct perf_event *parent_event,
		if (is_orphaned_event(parent_event) \|\|
		!atomic_long_inc_not_zero(&parent_event->refcount)) {
		mutex_unlock(&parent_event->child_mutex);
		/* task_ctx_data is freed with child_ctx */
		free_event(child_event);
		return NULL;
		}