on the following commit (thanks Frank van der Linden, Steve Woodford
and Alistair G. Crooks for english correction of HISTORY section):
date: 1999/08/05 18:08:10; author: thorpej; state: Exp; lines: +3 -2
Change the semantics of splsoftclock() to be like other spl*() functions,
that is priority is rasied. Add a new spllowersoftclock() to provide the
atomic drop-to-softclock semantics that the old splsoftclock() provided,
and update calls accordingly.
This fixes a problem with using the "rnd" pseudo-device from within
interrupt context to extract random data (e.g. from within the softnet
interrupt) where doing so would incorrectly unblock interrupts (causing
all sorts of lossage).
