Software based distributed shared memory (DSM) model using shared variables between multiprocessors

A Distributed shared memory systems represent a successful hybrid of two parallel computer classes: distributed computer systems and shared memory multiprocessors. They provide the shared memory abstraction in systems with physically distributed memories, and consequently combine the advantages of both approaches. Distributed shared memory is the abstraction that supports the shared memory in a physically non-shared (distributed) architecture. Shared memory is a simple yet powerful paradigm for structuring systems. Recently, there has been an interest in extending this paradigm to non-shared memory architectures as well. For example, the virtual address spaces for all variables in a distributed variable-based system could be viewed as constituting a global distributed shared memory. The Distributed shared memory system is designed on the basis of page-based, shared-variable-based or object-based access. There are certain advantages and disadvantages of each access methodology. We propose a shared variable based DSM model for managing distributed shared memory. These paper also present implementation levels with its several issues require to be consider. We have presented an implementation of this model in the context of a linux operating system.