FULL PRODUCT VERSION :
java version "1.7.0_04-ea"
Java(TM) SE Runtime Environment (build 1.7.0_04-ea-b18)
Java HotSpot(TM) 64-Bit Server VM (build 23.0-b19, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Darwin macbook.lan 11.3.0 Darwin Kernel Version 11.3.0: Thu Jan 12 18:47:41 PST 2012; root:xnu-1699.24.23~1/RELEASE_X86_64 x86_64

A DESCRIPTION OF THE PROBLEM :
On the VM Summary tab I see this reported:

  Total physical memory: 6,291,456 kbytes
Free physical memory: 131,072 kbytes

the total value sometimes shows as 31,457,280 kbytes.

The free memory is alway 131,072 kbytes independent of the currently used memory.



REGRESSION. Last worked in version 6u31

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Start jconsole.
Select a local process e.g. sun.tools.jconsole.JConsole
Click on connect
Click onto the VM Summary tab
Observe the values

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
JDK 6 correctly shows my 8GB RAM and a free value which corresponds to the actual situation.

  Total physical memory: 8,388,608 kbytes
Free physical memory: 4,296,112 kbytes

Of course the free memory value changes depending on what applications are running on my computer.
ACTUAL -
  Total physical memory: 6,291,456 kbytes
Free physical memory: 131,072 kbytes

the total value sometimes shows as 31,457,280 kbytes.

REPRODUCIBILITY :
This bug can be reproduced always.