An operating system extension for a multiprocessor

In the last few years computer architectures based on multiple processors have massively crossed the border from the mere academic research systems domain to the real world of industrial and consumer applications. New operating systems (OSs) for these parallel machines are now readily available. Some are true multiprocessor or distributed OSs, others are simpler single processor multitasking OSs which have been extended to allow users to take advantage from parallel machines with a minimum cost. In this paper we present a practical development based on this last approach an extension for the Microware's OS9 operating system which we have developed for our bus-based multiprocessor. The OS extension adds basically a new interprocess communication (IPC) mechanism, which is built around the message model using channels and virtual circuits. Application processes residing on different processors communicate through messages in a transparent way. The IPC performance figures obtained match or exceed the ones reported for similar systems. The presentation highlights the problems faced and the solutions found in the implementation of well-known OS concepts. (C) 1998 Published by Elsevier Science B.V. All rights reserved.