Jrcmd Command 'heap_diagnostics' didn't Calculate Free Heap-Memory Exactly (Doc ID 1429143.1)

Last updated on NOVEMBER 05, 2016

Applies to:

Oracle JRockit - Version R27.6 and later
Information in this document applies to any platform.

Symptoms

In the output of command 'jrcmd <pid> heap_diagnostics', the free heap memory displays as below:

Total memory in system: 541168795648 bytes
Available physical memory in system: 506851618816 bytes
-Xmx (maximal heap size) is 2147483648 bytes
Heapsize: 2147483648 bytes
Free heap-memory: 737277624 bytes

... ...

--------- Detailed Heap Statistics: ---------

... ...

585722kB total ---
--------- End of Detailed Heap Statistics ---


It shows that free memory is 737M, objects 580M, the sum is 1.3G, but heapsize is 2G (nursery size unknown)

Cause

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