NMT (Native Memory Tracking) is very powerful tool. It would help greatly to Hotspot developers to show how much memory is used by different VM parts without using additional applications (jcmd, JFR) to access collected data. It could use already existing in Hotspot VM mechanism to dump collected statistic during VM exit. See print_statistics() method in src/share/vm/runtime/java.cpp which is called from before_exit() method.
Add new flag -XX:+PrintNMTStatistics with which the output is produced. NMT statistic output could show how much memory is used per memory type and total. Also it could print methods (from collected call stack) which are main users of native memory.