Java native memory usage

Question

Is there any tool to know how many native memory has been used from my java application ? I\'ve experienced outofmemory from my application : Current setting is : -Xmx900m

Answer 1

For those that come after, VMMap will give you your answer. It will show native memory allocations. In my experience, the -Xss is ignored at minimum amount of 124K I believe within the OS allocation chunks. The OS allocations come in ever doubling chunks until it gets to 1GB(and then you're done.) If you can't reduce your threads, then try reducing your max heap and max permgen settings or try the /3GB switch.