The advent of computers with 64-bit virtual address
spaces and giga-bytes of physical memory will provide
applications with many more orders of magnitude of
memory than is possible today. However, to tap the
potential of this new hardware, we need to re-examine
how virtual memory is traditionally managed. We con-
centrate in this note on two aspects of virtual memory:
software support for multiple page sizes, and memory
management policies tuned to large amounts of physical
memory. We argue for the need to examine these areas,
and we identify several questions that need to be
answered. In particular, we show that providing support
for multiple page sizes is not as straightforward as may
initially appear.