perf evsel: Introduce perf_evsel__is_group_event() helper

The perf_evsel__is_group_event function is for checking whether given
evsel needs event group view support or not.  Please note that it's
different to the existing perf_evsel__is_group_leader() which checks
only the given evsel is a leader or a standalone (i.e. non-group) event
regardless of event group feature.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1362462812-30885-7-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 52021c3087df..bf758e53c929 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -9,6 +9,7 @@
 #include "xyarray.h"
 #include "cgroup.h"
 #include "hist.h"
+#include "symbol.h"
  
 struct perf_counts_values {
 	union {
@@ -246,11 +247,34 @@ static inline struct perf_evsel *perf_evsel__next(struct perf_evsel *evsel)
 	return list_entry(evsel->node.next, struct perf_evsel, node);
 }
 
+/**
+ * perf_evsel__is_group_leader - Return whether given evsel is a leader event
+ *
+ * @evsel - evsel selector to be tested
+ *
+ * Return %true if @evsel is a group leader or a stand-alone event
+ */
 static inline bool perf_evsel__is_group_leader(const struct perf_evsel *evsel)
 {
 	return evsel->leader == evsel;
 }
 
+/**
+ * perf_evsel__is_group_event - Return whether given evsel is a group event
+ *
+ * @evsel - evsel selector to be tested
+ *
+ * Return %true iff event group view is enabled and @evsel is a actual group
+ * leader which has other members in the group
+ */
+static inline bool perf_evsel__is_group_event(struct perf_evsel *evsel)
+{
+	if (!symbol_conf.event_group)
+		return false;
+
+	return perf_evsel__is_group_leader(evsel) && evsel->nr_members > 1;
+}
+
 struct perf_attr_details {
 	bool freq;
 	bool verbose;