ts_globpri() returns the global scheduling priority

ts_tick() is called every 1/HZ seconds to check how much time slice is left

ts_update() is called every second to bump priorities

ts_cpupri	System-controlled priority (bouncing via ts_dptbl)
ts_uprilim	The most ts_upri could be
ts_upri		Current user-controlled priority (nice value)
ts_boost	IA class priority boost

Possibly useful values:

	t->t_pctcpu:	%cpu at last clock_tick(), binary point at
			right of high-order bit