driver concurrency

[David Holland <dholland-tech%netbsd.org@localhost>]

How many drivers are there (hardware-level drivers, not things like
raidframe) where it really matters for more than one lwp to be able to
be running (not stopped) in the driver at once?

I'm thinking probably network cards but not much else.

(This question is supposed to provoke a discussion; I have a reason
for asking, which I don't want to state to avoid skewing things.)
-- 
David A. Holland
dholland%netbsd.org@localhost