perf session: Add storage for seperating event types in report

This patch adds the structures necessary to count each event
type independently in perf report.

Signed-off-by: Eric B Munson <ebmunson@us.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1267804269-22660-4-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 31950fc..5c33417 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -20,6 +20,7 @@
 	struct thread		*last_match;
 	struct map		*vmlinux_maps[MAP__NR_TYPES];
 	struct events_stats	events_stats;
+	struct rb_root		stats_by_id;
 	unsigned long		event_total[PERF_RECORD_MAX];
 	unsigned long		unknown_events;
 	struct rb_root		hists;