options		CALLWHEEL		# use callwheel (scheme 6) for callouts
options		MRITIMER		# enable ITIMER_MULTIREAL extension
options		MRIT_USE_SETCALLOUT	# make ITIMER_MULTIREAL use
					# setcallout() instead of timeout()
options		MAX_SOFTCLOCK_STEPS=100 # max steps softclock() may take before
					# reenabling interrupts
options		CALLOUTS_PER_PROC=8	# used only if MRITIMER is set