I have a JavaFX app which is consuming far more memory than the heap allocates... even when I set Xmx. For example, with java -Xmx64m I can see that the app runs just fine, but it still consumes over 200MB according to the OS (checked with htop and with Mac's System Monitor). Does anyone know a tool to help find out why the JVM is holding on to so much memory beyond the heap, or how to make the JVM use less native memory?
I've found out that vmmap (as shown here[1]) is only a little helpful, as it has so much info I can't really make sense of it... and I also found this[2] answer on StackOverflow that was very helpful as it lets me see the native memory allocation by the JVM... but all I know now is that less than half of my JVM memory consumption is the actual heap: the rest is thread stacks (huge for JavaFX - around 50MB for my app), GC-allocated memory and around 25MB of class definitions!
[1] https://plumbr.io/blog/memory-leaks/why-does-my-java-process...