FUTEX_WAITERS
mval = (uval & FUTEX_WAITERS) | FUTEX_OWNER_DIED;
if (!pi && (uval & FUTEX_WAITERS)) {
newval |= FUTEX_WAITERS;
newval = uval | FUTEX_WAITERS;
newval = FUTEX_WAITERS | task_pid_vnr(new_owner);
newtid = task_pid_vnr(newowner) | FUTEX_WAITERS;
tid |= FUTEX_WAITERS;