diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 6772d256dfdf..a16f60da06ab 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -95,7 +95,7 @@ struct egroup {
 static struct evsel *find_evsel_group(struct evlist *perf_evlist,
 				      struct expr_parse_ctx *pctx,
 				      struct evsel **metric_events,
-				      bool *evlist_used)
+				      unsigned long *evlist_used)
 {
 	struct evsel *ev;
 	bool leader_found;
@@ -105,7 +105,7 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist,
 	double *val_ptr;
 
 	evlist__for_each_entry (perf_evlist, ev) {
-		if (evlist_used[j++])
+		if (test_bit(j++, evlist_used))
 			continue;
 		if (hashmap__find(&pctx->ids, ev->name, (void **)&val_ptr)) {
 			if (!metric_events[i])
@@ -141,7 +141,7 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist,
 			j++;
 		}
 		ev = metric_events[i];
-		evlist_used[ev->idx] = true;
+		set_bit(ev->idx, evlist_used);
 	}
 
 	return metric_events[0];
@@ -157,13 +157,11 @@ static int metricgroup__setup_events(struct list_head *groups,
 	int ret = 0;
 	struct egroup *eg;
 	struct evsel *evsel;
-	bool *evlist_used;
+	unsigned long *evlist_used;
 
-	evlist_used = calloc(perf_evlist->core.nr_entries, sizeof(bool));
-	if (!evlist_used) {
-		ret = -ENOMEM;
-		return ret;
-	}
+	evlist_used = bitmap_alloc(perf_evlist->core.nr_entries);
+	if (!evlist_used)
+		return -ENOMEM;
 
 	list_for_each_entry (eg, groups, nd) {
 		struct evsel **metric_events;
@@ -201,7 +199,7 @@ static int metricgroup__setup_events(struct list_head *groups,
 		list_add(&expr->nd, &me->head);
 	}
 
-	free(evlist_used);
+	bitmap_free(evlist_used);
 
 	return ret;
 }