文档介绍：Memory Coherence in Shared Virtual
Memory Systems
KAI Ll
Princeton University
and
PAUL HUDAK
Yale University
The memory coherence problem in designing and implementing a shared virtual memory on loosely
coupled multiprocessors is studied in depth. Two classes of algorithms, centralized and distributed,
for solving the problem are presented. A prototype shared virtual memory on an Apollo ring based
on these algorithms has been implemented. Both theoretical and practical results show that the
memory coherence problem can indeed be solved efficiently on a loosely coupled multiprocessor.
Categories and Subject Descriptors: [works]: Network Ar-
chitecture and Design--munications; [works]:
Distributed work operating systems; [Operating Systems]: Storage Manage-
ment-distributed memories; uirtuol memory; [Operating Systems]: Organization and
Design-distributed systems
General Terms: Algorithms, Design, Experimentation, Measurement, Performance
Additional Key Words and Phrases: Loosely coupled multiprocessors, memory coherence, parallel
programming, shared virtual memory
1. INTRODUCTION
The benefits of a virtual memory go without saying; almost every high perfor-
mance puter in existence today has one. In fact, it is hard to
believe that loosely coupled multiprocessors would not also benefit from virtual
memory. One can easily imagine how virtual memory would be incorporated into
a shared-memory parallel machine because the memory hierarchy need not be
much different from that of a sequential machine. On a multiprocessor in which
the physical memory is distributed, however, the implementation is not obvious.
This research was supported in part by National Science Foundation grants MCS-8302018, DCR-
8106181, R-8814265. A preliminary version of this paper appeared in the Proceedings of the
5th Annual ACM Symposium on Principles of puting [36].
Authors’ addresses: K. Li, Department puter S