I\'ve read a few articles, and I understood the following (please correct me and/or edit the question if I\'m wrong):
The java heap is segmented like this:
If you are working with Java EE application it's probably a classloader leak.
you might find the following additional links to be useful:
http://www.zeroturnaround.com/blog/rjc201/
http://www.ibm.com/developerworks/java/library/j-dclp3/index.html