GC is slow. (repair_reference)

[diiq]

Calls to repair_reference make up more than 1/5 of total load time for eight at the moment. GC in general can probably be sped up, but repair_reference is apparently a major offender.

[diiq]

I've fudged this; GC still takes up almost 1/2 of the total time spent by eight, but it now happens a little less frequently; load-time is significantly reduced. (Which is to say, it will use more memory now than it did before, because it won't collect until more than 10mb are used AND the amount used is more than twice the amount of memory left after the last collection.)

Are there more effective methods for deciding when to garbage collect?

[diiq]

Aaaand GC is back over 50% of my profiling run:
% cumulative self self total
time seconds seconds calls s/call s/call name
30.18 6.53 6.53 6401 0.00 0.00 collectify
29.05 12.82 6.29 773679948 0.00 0.00 repair_reference
8.23 14.60 1.78 5729077 0.00 0.00 rectify_closing_i
6.38 15.98 1.38 222093785 0.00 0.00 allocatery
4.41 16.93 0.96 67468405 0.00 0.00 cheap_cons

Memory management is taking up 66% of my time. That's not cool.