{
{   The purpose of this request is to advise the OS of intended
{ access to a portion of a segment.  This request is intended to
{ allow a user to assist memory manager in managing memory.  If the
{ system load is high, memory manager may ignore this request.
{
{   This request is equivalent to a "buffered page fault" for the
{ portion of a segment defined by <pointer> to <pointer> + <length>.
{ For each page containing addresses in the above range, memory
{ manager does the following:
{ - if the page is already in the Job Working Set (JWS), the page
{   age is reset to zero.
{ - if the page is in memory but has been aged out of the JWS,
{   the page is moved back to JWS and the page age is set to zero.
{ - if the page is on disk, an IO request is issued to read the
{   page into memory and add it to the JWS.
{ - if the page is not on disk (never referenced or above eoi),
{   then an available page frame is assigned, initialized, and
{   added to the JWS.
{
{   Although not stated above, memory manager will attempt to issue
{ IO requests in units of 1 transfer unit.  It should be noted
{ that the above algorithm is subject to change as a result of
{ system performance studies.
{
{       MMP$ADVISE_IN (PVA, LENGTH, STATUS)
{
{ PVA: (input) This parameter specifies the start of the range
{       of memory to be advised in.
{
{ LENGTH: (input) This parameter specifies the number of bytes to
{       be advised in.
{
{ STATUS: (output) This parameter specifies the request status.
{       The possible error codes are:
{             mme$file_server_terminated
{             mme$invalid_pva
{             mme$read_beyond_eoi
{             mme$read_write_beyond_msl
{             mme$ref_to_unrecovered_file
{             mme$write_beyond_eoi_no_append
{
