setpriority
if (setpriority (PRIO_PROCESS, 0, 0) < 0)
(void) setpriority(PRIO_PROCESS, 0, t->t_nice);
(void) setpriority(PRIO_PROCESS,
(void) setpriority(PRIO_PROCESS, 0, nval);
if (setpriority(which, who, prio) < 0) {
(void) setpriority(PRIO_PROCESS, 0, PRIO_MIN);
extern int setpriority(int, int, int);
extern int setpriority();
if (setpriority(PRIO_PROCESS, 0, prio + incr) == -1)
extern int setpriority(int, id_t, int);