On Alpha and Integrity server systems, unlocks pages that were
    previously locked in memory by the Lock Pages in Memory ($LCKPAG_
    64) service.

    This service accepts 64-bit addresses.

    Format

      SYS$ULKPAG_64  start_va_64 ,length_64 ,acmode ,return_va_64

                     ,return_length_64

    C Prototype

      int sys$ulkpag_64  (void *start_va_64, unsigned __int64

                         length_64, unsigned int acmode, void

                         *(*(return_va_64)), unsigned __int64

                         *return_length_64);