perf: Complete software pmu grouping (b04243ef) · Commits · 戴 / test

include/linux/perf_event.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -804,12 +804,18 @@ struct perf_event {
		#endif /* CONFIG_PERF_EVENTS */
		};

		enum perf_event_context_type {
		task_context,
		cpu_context,
		};

		/**
		* struct perf_event_context - event context structure
		*
		* Used as a container for task events and CPU events as well:
		*/
		struct perf_event_context {
		enum perf_event_context_type type;
		struct pmu *pmu;
		/*
		* Protect the states of the events in the list,

kernel/perf_event.c

+60 −5

Original line number	Diff line number	Diff line
		@@ -5184,6 +5184,7 @@ int perf_pmu_register(struct pmu *pmu)

		cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
		__perf_event_init_context(&cpuctx->ctx);
		cpuctx->ctx.type = cpu_context;
		cpuctx->ctx.pmu = pmu;
		cpuctx->timer_interval = TICK_NSEC;
		hrtimer_init(&cpuctx->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
		@@ -5517,7 +5518,8 @@ SYSCALL_DEFINE5(perf_event_open,
		struct perf_event_attr __user *, attr_uptr,
		pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
		{
		struct perf_event event, group_leader = NULL, *output_event = NULL;
		struct perf_event group_leader = NULL, output_event = NULL;
		struct perf_event event, sibling;
		struct perf_event_attr attr;
		struct perf_event_context *ctx;
		struct file *event_file = NULL;
		@@ -5525,6 +5527,7 @@ SYSCALL_DEFINE5(perf_event_open,
		struct task_struct *task = NULL;
		struct pmu *pmu;
		int event_fd;
		int move_group = 0;
		int fput_needed = 0;
		int err;

		@@ -5574,8 +5577,29 @@ SYSCALL_DEFINE5(perf_event_open,
		* any hardware group.
		*/
		pmu = event->pmu;
		if ((pmu->task_ctx_nr == perf_sw_context) && group_leader)

		if (group_leader &&
		(is_software_event(event) != is_software_event(group_leader))) {
		if (is_software_event(event)) {
		/*
		* If event and group_leader are not both a software
		* event, and event is, then group leader is not.
		*
		* Allow the addition of software events to !software
		* groups, this is safe because software events never
		* fail to schedule.
		*/
		pmu = group_leader->pmu;
		} else if (is_software_event(group_leader) &&
		(group_leader->group_flags & PERF_GROUP_SOFTWARE)) {
		/*
		* In case the group is a pure software group, and we
		* try to add a hardware event, move the whole group to
		* the hardware context.
		*/
		move_group = 1;
		}
		}

		if (pid != -1)
		task = find_lively_task_by_vpid(pid);
		@@ -5605,8 +5629,14 @@ SYSCALL_DEFINE5(perf_event_open,
		* Do not allow to attach to a group in a different
		* task or CPU context:
		*/
		if (move_group) {
		if (group_leader->ctx->type != ctx->type)
		goto err_context;
		} else {
		if (group_leader->ctx != ctx)
		goto err_context;
		}

		/*
		* Only a group leader can be exclusive or pinned
		*/
		@@ -5626,9 +5656,34 @@ SYSCALL_DEFINE5(perf_event_open,
		goto err_context;
		}

		if (move_group) {
		struct perf_event_context *gctx = group_leader->ctx;

		mutex_lock(&gctx->mutex);
		perf_event_remove_from_context(group_leader);
		list_for_each_entry(sibling, &group_leader->sibling_list,
		group_entry) {
		perf_event_remove_from_context(sibling);
		put_ctx(gctx);
		}
		mutex_unlock(&gctx->mutex);
		put_ctx(gctx);
		}

		event->filp = event_file;
		WARN_ON_ONCE(ctx->parent_ctx);
		mutex_lock(&ctx->mutex);

		if (move_group) {
		perf_install_in_context(ctx, group_leader, cpu);
		get_ctx(ctx);
		list_for_each_entry(sibling, &group_leader->sibling_list,
		group_entry) {
		perf_install_in_context(ctx, sibling, cpu);
		get_ctx(ctx);
		}
		}

		perf_install_in_context(ctx, event, cpu);
		++ctx->generation;
		mutex_unlock(&ctx->mutex);

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