At 14/06/00 17:48 -0700, Ken Forbus wrote:
>In an application we are building, several global GC's occur at an 
>inconvenient time, e.g., while the user is waiting for something to 
>happen.   What are the appropriate parameters to tune to (a) ramp up the 
>total space available, and (b) make global GC's less frequent, by doing 
>more growth when each one occurs?  I've looked over the documentation and 
>wasn't able to figure this out from what was there, but of course I could 
>have overlooked something.  Thanks in advance for any insights you can share.

Attached 2 recent posts from COMP.LANG.Lisp that should help you. 
Especially interesting is the description of new GC features that will be 
available in ACL6.
Two more things :
- you could trigger global GC at some well chosen time (e.g. after a long 
computation).
- with the appropriate settings the efficiency of a generational GC should 
be greater than 95% like in the following:
   scavenging...done eff: 99%, copy new: 2931064 + old: 528688 = 3459752