Hi Chris,

On Fri, Oct 19, 2012 at 8:46 AM, Chris Muller <asqueaker@gmail.com> wrote:
I have an image which needed to allocate 500MB of memory for a large
operation.  Now that operation is done and all objects have been
reclaimed.  According to VM I am now only using 200MB.

  (Smalltalk vmParameterAt: 2) max: (Smalltalk vmParameter at: 1)    "221923374"

However, when I look at my VM process in "top" or the System Monitor,
it still says its >500MB.

How does this work?

Depends on the platform.  On Mac OS X memory is not returned. On Windows memory is allocated and freed via VirtualAlloc and VirtualFree.  On Unix memory is allocated and returned via mmap and munmap by default.  What OS are you on?  Looks like the unix code could be ported to the Mac easily.