{   The purpose of this request is to lock one or more pages to prevent
{ the pages from being removed from the working set or written to backing
{ storage without an explicit request from the program. All pages that
{ are totally or partially contained within the specified portion of
{ the segment are locked.
{   If any of the pages in the specified portion of the segment are already
{ locked or are not in memory, this request will be rejected and no pages
{ are locked.
{
{       MMP$LOCK_PAGES (PVA, LENGTH, STATUS)
{
{ PVA: (input) This parameter specifies the start of the
{       range of memory to be locked.
{
{ LENGTH: (input) This parameter specifies the number of bytes
{       to be locked.
{
{ STATUS: (output) This parameter specifies the request status.
{       The possible error codes are:
{             mme$invalid_pva
{             mme$invalid_request
{             mme$lock_unlock_invalid_length
{             mme$not_valid_in_page_table
{             mme$page_already_locked
{             mme$page_not_in_page_table
{             mme$ref_to_unrecovered_file
{
