FUTEX_WAITERS
owner = owner & (FUTEX_WAITERS | FUTEX_OWNER_DIED);
owner | FUTEX_WAITERS);
new_owner = FUTEX_WAITERS;
mval = (uval & FUTEX_WAITERS) | FUTEX_OWNER_DIED;
if (!pi && (uval & FUTEX_WAITERS)) {
} else if (pi && (uval & FUTEX_WAITERS)) {