> I imagine
> full GC is going to take quite a while to run. And, at times I imagine
> you'd want to collect more than the incremental GC, but without waiting
> on a lengthy full GC. Would it be useful in a 64 bit object memory to
> introduce more generations?
>
> - Stephen


Nope, you forget as I did (and Tim then reminded me) that you just fall  
back to a reference counting GC.

a) you've got quite a few more bits around for making the header bigger  
(32bits would be enough)
b) 64bit machines usually have quite a few extra integer execution  
engines and you can hide the
reference counting math in the regular execution of the reference  
update, so there is no cost.

c) Mmm I wonder if you forget to do GC compaction how long you could  
run?  You just keep allocating new
pages from OS virtual memory.

PS This does raise the question would reference counting work better on  
high end 32bit CPU today? Wonder if anyone has  gone back to try this?

--
======================================================================== 
===
John M. McIntosh <johnmci at smalltalkconsulting.com> 1-800-477-2659
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
======================================================================== 
===