> Processes that are in the busy wait state (ie waiting at a priority
> above PZERO) are usually waiting for "fast" I/O.

This was the way it worked at some time.  The (un)interruptability of a sleep
is now indicated by a separate bit in the priority field (PCATCH), so even
lower priority sleeps can wait without being interrupted by signals.
--
ws@TooLs.DE     (Wolfgang Solfrank, TooLs GmbH) 	+49-228-985800