I'd be curious to see the rest of the benchmarks.
Edit: Remembered based on ice799's comment below that in 1.9 the threads still won't be allowed to operate in parallel, which neuters most of the aforementioned benefits to using native threads.
It's not likely they will remain so for very long
In case of this patch, even the author himself says that Ruby 1.9 doesn't do stack copying. He's not "explaining as if he discovered it himself".
It seems that the techniques these bloggers are discovering have already been figured out, or at least equalled (in this case bettered, apparently) by the 1.9 team. I'd say fewer people should be working on enhancing 1.8 if they could just back-port the enhancements that already exist from 1.9. Instead, if they actually want to optimize something, start with the codebase that doesn't have huge, obvious, already-solved(!) performance flaws to begin with, and then backport the new optimizations you find.
Ruby 1.9 uses libpthread which creates stacks for its threads in a similar way (mmap and a guard page).
