Message-Driven Relaxed Consistency in a Software Distributed
Shared Memory
Povl T. Koch, Robert J. Fowler, Eric Jul
University of Copenhagen
Abstract
Message-passing and distributed shared memory have their respective
advantages and disadvantages in distributed parallel programming. We
approach the problem of integrating both mechanisms into a single
system by proposing a new message-driven coherency mechanism.
Messages carrying explicit causality annotations are exchanged to
trigger memory coherency actions. By adding annotations to standard
message-based protocols, it is easy to construct efficient
implementations of common synchronization and communication
mechanisms. Because these are user-level messages, the set of
available primitives is extended easily with language- or
application-specific mechanisms. CarlOS, an experimental prototype
for evaluating this approach, is derived from the lazy release
consistent memory of TreadMarks. We describe the message-driven
coherency memory model used in CarlOS, and we examine the performance
of several applications.
Download the full text of this paper in
POSTSCRIPT (142,290 bytes) form.
To Become a USENIX Member, please see our
Membership Information.