KN_BUSY
KASSERT((kn->kn_status & KN_BUSY) == 0);
kn->kn_status |= KN_BUSY;
kn->kn_status &= ~KN_BUSY;
kn->kn_status &= ~KN_BUSY;
kn->kn_status &= ~(KN_ACTIVE|KN_BUSY);
kn->kn_status &= ~KN_BUSY;
kn->kn_status &= ~(KN_ACTIVE|KN_BUSY);
kn->kn_status &= ~(KN_ACTIVE|KN_BUSY);
kn->kn_status &= ~KN_BUSY;
} else if (kn->kn_status & KN_BUSY) {