diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
index 32b8b5178f01..25a08d640d81 100644
--- a/tools/perf/util/cpumap.h
+++ b/tools/perf/util/cpumap.h
@@ -24,16 +24,18 @@ struct aggr_cpu_id {
 	int core;
 };
 
+/** A collection of aggr_cpu_id values, the "built" version is sorted and uniqued. */
 struct cpu_aggr_map {
 	refcount_t refcnt;
+	/** Number of valid entries. */
 	int nr;
+	/** The entries. */
 	struct aggr_cpu_id map[];
 };
 
 struct perf_record_cpu_map_data;
 
 struct perf_cpu_map *perf_cpu_map__empty_new(int nr);
-struct cpu_aggr_map *cpu_aggr_map__empty_new(int nr);
 
 struct perf_cpu_map *cpu_map__new_data(struct perf_record_cpu_map_data *data);
 size_t cpu_map__snprint(struct perf_cpu_map *map, char *buf, size_t size);
@@ -67,6 +69,12 @@ int cpu__get_die_id(int cpu);
  */
 int cpu__get_core_id(int cpu);
 
+/**
+ * cpu_aggr_map__empty_new - Create a cpu_aggr_map of size nr with every entry
+ * being empty.
+ */
+struct cpu_aggr_map *cpu_aggr_map__empty_new(int nr);
+
 typedef struct aggr_cpu_id (*aggr_cpu_id_get_t)(int cpu, void *data);
 
 /**