On Alpha and Integrity server systems, locks a range of virtual
    addresses in the working set. If the pages are not already in
    the working set, the service brings them in and locks them. A
    page locked in the working set does not become a candidate for
    replacement.

    This service accepts 64-bit addresses.

    Format

      SYS$LKWSET_64  start_va_64 ,length_64 ,acmode ,return_va_64

                     ,return_length_64

    C Prototype

      int sys$lkwset_64  (void *start_va_64, unsigned __int64

                         length_64, unsigned int acmode, void

                         *(*(return_va_64)), unsigned __int64

                         *return_length_64);