higher speed mutexes

[Petri Helenius]

Hi,

I have some low-contention mutexes which I'm trying to make perform 
better and I'm wondering if the current threading library does have some 
primitives I could use or if I'm better off using atomic_cmpset_* and 
pthread_yield() if the thread hit's contention (which should be about 
1:10000 of the lock/unlock operation).

Any scheduling caveats from above, except obviously it would spin while 
waiting for the lock. Most systems I plan on running this on have 
dual-hypethreading CPU's.

I remember there were some discussion about dropping i386 compatible 
support for mutexes and using atomic operations instead. Is there 
code/compile time options for this on a branch I could check out and 
give it a spin?

Pete