"--" at the beginning of a end-collection line and best region count when it's not 2048

[Ron Reynolds]

-- 59G->59G(59G), 2.0932801 secs]
^^ this "--" is entirely undocumented as far as i can tell; i believe it
indicates that the young collection (or any collection?) was cancelled
(i've always seen these in the last-ditch-attempt young-collections before
a full-GC).  is that correct?

also the various docs recommend 2048 regions but if you MUST have more or
less which should you choose and what are reasonable limits?  e.g., i have
a 59G heap with default 16MB regions (which means there should be 3832 of
them); in what cases (if any) would it make sense to use 32MB regions
instead?
most docs say to size your regions based on max-heap size rather than
starting-heap size, which would seem to indicate <2048 regions is better
than >2048, since at the start that hypothetical JVM would certainly have
fewer than 2048 regions until it grew into its max-heap size.

thanks :)
.....................ron.
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