Mirage: a coherent distributed shared memory design

Abstract

Shared memory is an effective and efficient paradigm for interprocess communication. We are concerned with software that makes use of shared memory in a single site system and its extension to a multimachine environment. Here we describe the design of a distributed shared memory (DSM) system called Mirage developed at UCLA. Mirage provides a form of network transparency to make network boundaries invisible for shared memory and is upward compatible with an existing interface to shared memory. We present the rationale behind our design decisions and important details of the implementation. Mirage's basic performance is examined by component timings, a worst case application, and a “representative” application. In some instances of page contention, the tuning parameter in our design improves application throughput. In other cases, thrashing is reduced and overall system performance improved using our tuning parameter.