PS_ISPWAIT
if (kp->p_psflags & PS_ISPWAIT)
atomic_clearbits_int(&pr->ps_pptr->ps_flags, PS_ISPWAIT);
PS_ISPWAIT);
atomic_setbits_int(&curpr->ps_flags, PS_ISPWAIT);
while (curpr->ps_flags & PS_ISPWAIT)