[M3devel] user threads

[Jay]

User threads seem to work on on FreeBSD/x86 7.0.
Mika can you report back the perf cm3 vs. pm3?
Still, kernel threads have been around a long time and imho should be strongly favored..
 
 
Kernel threads should be a /little/ faster than they were -- PushEFrame removed from successful heap allocations. And should be further improvable via __thread where it is supported -- probably not FreeBSD 4.x, sometimes older is not better. :)
 
 
I've temporarily switched FreeBSD/x86 to userthreads by default but I think that's just an experiment and should be undone shortly, maybe work out some other story for easily switching between them, or just keep the existing story of "you get to rebuild everything".
 
 
Tony, can you look into GetGCRatio? I removed the call to it. The "fatal" pragma invokes PushEFrame apparently.
 
 
We should now "fix" Win32 and pthreads to not have GetActivation initialize on-demand, just leave Init to initialize always. This should shave a few more cycles from PushEFrame.
 
 
 - Jay