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>
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 0955cff..f080cc4 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -649,9 +649,7 @@
 
 		next = disasm__get_next_ip_line(&notes->src->source, dl);
 
-		if (symbol_conf.event_group &&
-		    perf_evsel__is_group_leader(evsel) &&
-		    evsel->nr_members > 1) {
+		if (perf_evsel__is_group_event(evsel)) {
 			nr_percent = evsel->nr_members;
 			ppercents = calloc(nr_percent, sizeof(double));
 			if (ppercents == NULL)
@@ -721,8 +719,7 @@
 		if (queue)
 			return -1;
 
-		if (symbol_conf.event_group &&
-		    perf_evsel__is_group_leader(evsel))
+		if (perf_evsel__is_group_event(evsel))
 			width *= evsel->nr_members;
 
 		if (!*dl->line)
@@ -1126,7 +1123,7 @@
 	len = symbol__size(sym);
 	namelen = strlen(d_filename);
 
-	if (symbol_conf.event_group && perf_evsel__is_group_leader(evsel))
+	if (perf_evsel__is_group_event(evsel))
 		width *= evsel->nr_members;
 
 	printf(" %-*.*s|	Source code & Disassembly of %s\n",