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Commit b04243ef authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf: Complete software pmu grouping 



Aside from allowing software events into a !software group,
allow adding !software events to pure software groups.

Once we've moved the software group and attached the first
!software event, the group will no longer be a pure software
group and hence no longer be eligible for movement, at which
point the straight ctx comparison is correct again.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20100917093009.410784731@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent d14b12d7

include/linux/perf_event.h

+6 −0
Original line number Original line Diff line number Diff line
@@ -804,12 +804,18 @@ struct perf_event { 
#endif /* CONFIG_PERF_EVENTS */

#endif /* CONFIG_PERF_EVENTS */

};

};





enum perf_event_context_type {

	task_context,

	cpu_context,

};



/**

/**

 * struct perf_event_context - event context structure

 * struct perf_event_context - event context structure

 *

 *

 * Used as a container for task events and CPU events as well:

 * Used as a container for task events and CPU events as well:

 */

 */

struct perf_event_context {

struct perf_event_context {

	enum perf_event_context_type	type;

	struct pmu			*pmu;

	struct pmu			*pmu;

	/*

	/*

	 * Protect the states of the events in the list,

	 * Protect the states of the events in the list,

kernel/perf_event.c

+60 −5
Original line number Original line 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);

		cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);

		__perf_event_init_context(&cpuctx->ctx);

		__perf_event_init_context(&cpuctx->ctx);

		cpuctx->ctx.type = cpu_context;

		cpuctx->ctx.pmu = pmu;

		cpuctx->ctx.pmu = pmu;

		cpuctx->timer_interval = TICK_NSEC;

		cpuctx->timer_interval = TICK_NSEC;

		hrtimer_init(&cpuctx->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);

		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,

		struct perf_event_attr __user *, attr_uptr,

		pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)

		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_attr attr;

	struct perf_event_context *ctx;

	struct perf_event_context *ctx;

	struct file *event_file = NULL;

	struct file *event_file = NULL;
@@ -5525,6 +5527,7 @@ SYSCALL_DEFINE5(perf_event_open, 
	struct task_struct *task = NULL;

	struct task_struct *task = NULL;

	struct pmu *pmu;

	struct pmu *pmu;

	int event_fd;

	int event_fd;

	int move_group = 0;

	int fput_needed = 0;

	int fput_needed = 0;

	int err;

	int err;
@@ -5574,8 +5577,29 @@ SYSCALL_DEFINE5(perf_event_open, 
	 * any hardware group.

	 * any hardware group.

	 */

	 */

	pmu = event->pmu;

	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;

			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)

	if (pid != -1)

		task = find_lively_task_by_vpid(pid);

		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

		 * Do not allow to attach to a group in a different

		 * task or CPU context:

		 * task or CPU context:

		 */

		 */

		if (move_group) {

			if (group_leader->ctx->type != ctx->type)

				goto err_context;

		} else {

			if (group_leader->ctx != ctx)

			if (group_leader->ctx != ctx)

				goto err_context;

				goto err_context;

		}



		/*

		/*

		 * Only a group leader can be exclusive or pinned

		 * Only a group leader can be exclusive or pinned

		 */

		 */
@@ -5626,9 +5656,34 @@ SYSCALL_DEFINE5(perf_event_open, 
		goto err_context;

		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;

	event->filp = event_file;

	WARN_ON_ONCE(ctx->parent_ctx);

	WARN_ON_ONCE(ctx->parent_ctx);

	mutex_lock(&ctx->mutex);

	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);

	perf_install_in_context(ctx, event, cpu);

	++ctx->generation;

	++ctx->generation;

	mutex_unlock(&ctx->mutex);

	mutex_unlock(&ctx->mutex);