[gclist] Fast-allocating non-copying GC's

[David Gadbois]

    Date: Thu, 14 Mar 1996 09:45-0600
    From: David Chase <chase@centerline.com>

[DC explains his statistical freelist allocator (you should give it a
catchy name) and wonders about allocation in long-running Smalltalk
systems.]

Don't know about Smalltalk, but I imagine long-running Lisp systems are
similar.  Allocations are mostly smallish, and mostly of a limited
number of sizes (lots cons cellsm class wrappers, and common structures
and slot vectors.)

One things that might come into play is that most systems allocate only
integral multiples of words.

For dealing with long-running systems, I'd add a special freelist
deletion scheme -- you may need lots of 520-byte objects on Monday, but
213-bytes objects are all the rage on Thursday.

How fundamental are the differences w.r.t. allocation and GC between
systems that run for seconds or minutes versus ones that are expected to
remain up and running indefinitely?

--David Gadbois