advice for parrot vm gc

[Mitchell N Charity <address@hidden>]

The parrot vm folks are currently puzzling over garbage collection, so
perhaps someone who as "been there and done that" might contribute an
insightful word.

http://archive.develooper.com/perl6-internals%40perl.org/msg14240.html
>From Steve Fink <steve@fink.com>, To: P6I <perl6-internals@perl.org>.

   Many of our tinderbox failures result from architecture-specific
   shortcomings in our current root set scanning code. The whole
   stackwalk/register scan is also rather slow, as Peter Gibbs showed a
   few decades back. (Okay, so it was probably only about a year ago.) In
   pondering the problem, I found myself reinventing several solutions
   that have already been proposed, and in many cases implemented, by
   other people. So I decided to summarize the various approaches in
   hopes that something will jump out at someone. I would be grateful if
   interested people could check this over and

     (1) tell me what I have wrong or am overlooking (especially with
	 respect to longjmp() -- I have the feeling that it's a bigger
	 problem than I realize),

     (2) point out what's wrong with my "variant 5: generational
	 stack",

      and/or

     (3) propose something else that solves the whole problem neatly.

  [...]

Re vocabulary - "PMC", "Perl Magic Cookie", is simply a unit of allocation.

Mitchell Charity