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New Malloc Trace
The new malloc trace allows to track all native memory allocations in the JVM process on _Linux _and MacOSX. To be able to use the trace, the VM has to be started with the -XX:+UseMallocHooks flag. Then the malloc trace can be enabled via the following jcmd (<pid> is the process id of the VM process):
jcmd <pid> MallocTrace.enable
Now every call to malloc, calloc and so on is intercepted and a stack trace is taken. To view current statistic about the tracked allocations, the following jcmd can be used:
jcmd <pid> MallocTrace.dump
This returns the 10 stacks with the biggest total allocation size. To get more than the top 10 stacks, the '-max-entries' option can be used:
jcmd <pid> MallocTrace.dump -max-entries=50
The malloc trace can be disabled via:
jcmd <pid> MallocTrace.disable
If you only want to see the memory currently still in use, you must enable the malloc trace with the -track-free flag. Note that this uses more additional memory and costs some additional performance.
To get a list of all the jcmd options supported by the VM use
jcmd <pid> help MallocTrace.enable.
jcmd <pid> help MallocTrace.dump.
For more information see this page.