> I ran some benchmarks as well... JRuby's threaded enumerators spin up
> 5-20x times slower than 1.9's, but nowhere near as slow as 1.8.7.
> 1.8.7 seems to be broken it's so bad, and it shoots up to 400-500MB
> during this benchmark:

Doesn't 1.8.x use continuations to create enumerators?  If so that
might explain the immense slowdown.

> So lightweight enumeration in JRuby is nearly 4x faster than 100% native Fiber-based enumeration in 1.9.

Yeah I think that's the case in 1.9, as well--if they ripped out the
fiber based enumeration it would be much faster.  Wonder if there's a
way to get the best of both worlds...

-r