mutex_ceiling
*oceil = mp->mutex_ceiling;
mp->mutex_ceiling = ceil;
*ceiling = ((mutex_t *)mp)->mutex_ceiling;
((type & LOCK_PRIO_PROTECT) && mp->mutex_ceiling != ceil)) {
mp->mutex_ceiling = ceil;
ceil = mp->mutex_ceiling;
prio = mcp->mxchain_mx->mutex_ceiling;
si_p->si_prioceiling = generic_so.lock.mutex_ceiling;