No. 9302
issued in March, 1993
Title:
A Distributed Single Address-Space Operating System Supporting Persistence

Author(s):
Gernot Heiser, Kevin Elphinstone, Stephen Russell, Graham R. Hellestrand

Abstract:
Persistence has long been difficult to integrate into operating systems.
The main problem is that pointers lose their meaning once they are taken
out of their address-space. We present a distributed system which has a
single address-space encompassing all virtual memory of every node in
the system. This design has become possible (and practicable) with the
advent of 64-bit microprocessors.

In our system, every pointer retains its meaning independent of its
location, even across nodes or on secondary storage. No restrictions are
imposed on the use of pointers by application programs. Hence
persistence is naturally and elegantly integrated into the system.
Further features are uniform addressing and unlimited sharing of data,
and memory protection based on password capabilities, making the system
easy to use. A reliable paging protocol ensures that the impact of node
crashes on other parts of the system is minimised.