This CR should be release-noted. Doc-writer, please use the following
text, suitably word-smithed to provide suitable verbage in release notes:-
The default out-of-the-box heap size and shape parameters for the
concurrent mark sweep collector (CMS) have been modified to take advantage of
the faster platforms since JDK 6 was released when these settings were
last changed. Like the other collectors in HotSpot, CMS will now use
the available physical memory on the platform to size its heap, while
attempting to shape that heap so as to keep pause times associated with
minor collections "reasonable". The specific shape of the heap may
be platform-dependent in other ways as well. Users can override all or
some of these default settings by means of explicitly sizing or shaping
the heap, aka "heap tuning", to suit their specific needs.
At this point, please point to the heap tuning guide which will also be
updated to describe the default settings for this and other collectors.