Jake Burkholder is porting the BSD/OS mutexes. I don't expect there to be much of a difference in regards to your heavy-weight interrupt work. I'm going to take a look at Jake's patchset tonight. I think the only operational item we need to research is the sti/cli stuff in the BSDI mutexes... we should be able to remove them at some point (my interrupt code is already using the ipending mechanism to deal with the scheduler mutex being active on the current cpu).

If Jake's removed that, then we'll want to put it back in at some point since it saves a significant amount of overhead ('sti' and 'cli' are expensive instructions).