perf tools: Add support for PERF_RECORD_ITRACE_START

Add support for the PERF_RECORD_ITRACE_START event type.  This event can
be used to determine the pid and tid that are running when Instruction
Tracing starts.  Generally that information would come from a
sched_switch event but, at the start, no sched_switch events may yet
have been recorded.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1430404667-10593-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index a7ad511..2f47110 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -494,6 +494,14 @@
 	return 0;
 }
 
+int machine__process_itrace_start_event(struct machine *machine __maybe_unused,
+					union perf_event *event)
+{
+	if (dump_trace)
+		perf_event__fprintf_itrace_start(event, stdout);
+	return 0;
+}
+
 struct map *machine__new_module(struct machine *machine, u64 start,
 				const char *filename)
 {
@@ -1341,6 +1349,9 @@
 		ret = machine__process_lost_event(machine, event, sample); break;
 	case PERF_RECORD_AUX:
 		ret = machine__process_aux_event(machine, event); break;
+	case PERF_RECORD_ITRACE_START:
+		ret = machine__process_itrace_start_event(machine, event);
+		break;
 	default:
 		ret = -1;
 		break;