perf_counter: Add counter->id to the throttle event

So as to be able to distuinguish between multiple counters.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/perf_counter.h

@@ -286,6 +286,7 @@ enum perf_event_type {
 	 * struct {
 	 *	struct perf_event_header	header;
 	 *	u64				time;
+	 *	u64				id;
 	 * };
 	 */
 	PERF_EVENT_THROTTLE		= 5,

kernel/perf_counter.c

@@ -2950,13 +2950,15 @@ static void perf_log_throttle(struct perf_counter *counter, int enable)
 	struct {
 		struct perf_event_header	header;
 		u64				time;
+		u64				id;
 	} throttle_event = {
 		.header = {
 			.type = PERF_EVENT_THROTTLE + 1,
 			.misc = 0,
 			.size = sizeof(throttle_event),
 		},
-		.time = sched_clock(),
+		.time	= sched_clock(),
+		.id	= counter->id,
 	};
 
 	ret = perf_output_begin(&handle, counter, sizeof(throttle_event), 1, 0);