papi_counter_t counter_data;
int event_set;
};
-extern std::map</* computation unit name */ std::string, papi_process_data> units2papi_setup;
+extern std::map</* computation unit name */ std::string, papi_process_data, std::less<>> units2papi_setup;
extern std::unordered_map<std::string, double> location2speedup;