SHMSEG_WIRED
if (cmd == SHM_LOCK && (shmseg->shm_perm.mode & SHMSEG_WIRED) == 0) {
shmseg->shm_perm.mode |= SHMSEG_WIRED;
(shmseg->shm_perm.mode & SHMSEG_WIRED) != 0) {
shmseg->shm_perm.mode &= ~SHMSEG_WIRED;
SHMSEG_ALLOCATED | (lockmem ? SHMSEG_WIRED : 0);