Five macros are provided for locking pages into a working set.
    These macros reside in SYS$LIBRARY:LIB.MLB. For a description
    of how to use these macros, see the VSI OpenVMS MACRO Compiler
    Porting and User's Guide.

    Three macros are used for image initialization-time lockdown, and
    two macros are used for on-the-fly lockdown.

                                   NOTE

       If the code is being locked because the IPL will be raised
       above 2, where page faults cannot occur, make sure that
       the delimited code does not call run-time library or other
       procedures. The VAX MACRO compiler generates calls to
       routines to emulate certain VAX instructions. An image that
       uses these macros must link against the system base image so
       that references to these routines are resolved by code in a
       nonpageable executive image.

       For OpenVMS I64 systems, these macros are still under
       development and additional OpenVMS routines are being
       provided to lock working sets. See the OpenVMS I64 Release
       Notes for more information.