Time to reconsider m:n or green threading options?

[Charles Oliver Nutter]

Seems to me lately all the super-scaling languages and runtimes getting 
attention are based on m:n or green threads across multiple processes. 
Given that kernel threads obviously can't scale up to the tens of 
thousands of concurrent processes e.g. Erlang can handle, is it possibly 
a good time to consider adding an m:n threading model back into JVM?

Forgive my ignorance about the history of threading in JVM...what I 
remember is that green threads used to be the only threading model, at 
least on platforms I used. I thought I'd heard that it was m:n at some 
point as well. And I thought I'd heard that Solaris was actually m:n 
internally at some point too. Too much noise floating around in this brain.

Thoughts? Here's another framework trying to solve the threading issue 
with bytecode postprocessing, similar to how Rife already supports 
continuations. Seems like there's definitely demand for this, eh?

http://www.malhar.net/sriram/kilim/

- Charlie