Operating system support for parallel programming on RP3

RP3, the Research Parallel Processing Prototype, was a research vehicle for exploring the hardware and software aspects of highly parallel computation. RP3 was a shared-memory machine that was designed to be scalable to 512 processors; a 64-processor machine was in operation from October 1988 through March 1991. A parallel-programming environment based on the Mach operating system was developed, and a variety of programming models were tested on the machine. To help user programs realize the full potential of parallelism on RP3, the RP3 operating system was extended to support such RP3 architectural features as noncoherent caches, local and interleaved storage, and a hardware performance monitor. The system included explicit job-scheduling and processor-allocation facilities, facilities for exploiting the RP3 memory hierarchy, and performance-data collection and logging facilities. This paper describes these components of the RP3 operating system, provides the rationale for the design decisions that were made, and discusses the implementation of these operating system facilities.