perf evsel: Cache associated event_format

We already lookup the associated event_format when reading the perf.data
header, so that we can cache the tracepoint name in evsel->name, so do
it a little further and save the event_format itself, so that we can
avoid relookups in tools that need to access it.

Change the tools to take the most obvious advantage, when they were
using pevent_find_event directly. More work is needed for further
removing the need of a pointer to pevent, such as when asking for event
field values ("common_pid" and the other common fields and per
event_format fields).

This is something that was planned but only got actually done when
Andrey Wagin needed to do this lookup at perf_tool->sample() time, when
we don't have access to pevent (session->pevent) to use with
pevent_find_event().

Cc: Andrey Wagin <avagin@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/n/tip-txkvew2ckko0b594ae8fbnyk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 0715c84..1208834 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -167,20 +167,11 @@
 	return pevent_read_number(pevent, ptr, size);
 }
 
-void print_trace_event(struct pevent *pevent, int cpu, void *data, int size)
+void event_format__print(struct event_format *event,
+			 int cpu, void *data, int size)
 {
-	struct event_format *event;
 	struct pevent_record record;
 	struct trace_seq s;
-	int type;
-
-	type = trace_parse_common_type(pevent, data);
-
-	event = pevent_find_event(pevent, type);
-	if (!event) {
-		warning("ug! no event found for type %d", type);
-		return;
-	}
 
 	memset(&record, 0, sizeof(record));
 	record.cpu = cpu;
@@ -192,6 +183,19 @@
 	trace_seq_do_printf(&s);
 }
 
+void print_trace_event(struct pevent *pevent, int cpu, void *data, int size)
+{
+	int type = trace_parse_common_type(pevent, data);
+	struct event_format *event = pevent_find_event(pevent, type);
+
+	if (!event) {
+		warning("ug! no event found for type %d", type);
+		return;
+	}
+
+	event_format__print(event, cpu, data, size);
+}
+
 void print_event(struct pevent *pevent, int cpu, void *data, int size,
 		 unsigned long long nsecs, char *comm)
 {