Commit 7995888f authored by Ingo Molnar's avatar Ingo Molnar
Browse files

perfcounters: tweak group scheduling 



Impact: schedule in groups atomically

If there are multiple groups in a task, make sure they are scheduled
in and out atomically.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 8fb93313

kernel/perf_counter.c

+13 −3
Original line number Diff line number Diff line
@@ -367,21 +367,26 @@ counter_sched_in(struct perf_counter *counter, 
	ctx->nr_active++;

}



static void

static int

group_sched_in(struct perf_counter *group_counter,

	       struct perf_cpu_context *cpuctx,

	       struct perf_counter_context *ctx,

	       int cpu)

{

	struct perf_counter *counter;

	int was_group = 0;



	counter_sched_in(group_counter, cpuctx, ctx, cpu);



	/*

	 * Schedule in siblings as one group (if any):

	 */

	list_for_each_entry(counter, &group_counter->sibling_list, list_entry)

	list_for_each_entry(counter, &group_counter->sibling_list, list_entry) {

		counter_sched_in(counter, cpuctx, ctx, cpu);

		was_group = 1;

	}



	return was_group;

}



/*
@@ -416,7 +421,12 @@ void perf_counter_task_sched_in(struct task_struct *task, int cpu) 
		if (counter->cpu != -1 && counter->cpu != cpu)

			continue;



		group_sched_in(counter, cpuctx, ctx, cpu);

		/*

		 * If we scheduled in a group atomically and

		 * exclusively, break out:

		 */

		if (group_sched_in(counter, cpuctx, ctx, cpu))

			break;

	}

	spin_unlock(&ctx->lock);