Cooperative Data Sharing: a layered approach to an architecture-independent Message-Passing Interface

Abstract

When MPI began to take form as a rather high-level interface with extensive features, it became somewhat less attractive to some benchmarkers and tool builders who required a very efficient low-level portable interjflace and did not need extensive features targeted toward application development. As a result, the Message Passing Kernel (MPK) project began at NAS. The name changed to the Cooperative Data Sharing (CDS) System when it became clear that the semantics we desired did not require copying (as message-passing does). This document describes the design and implementation of the kernel level of COS, called CDSl, and some directions we are taking on a highel; MPI-level interface built upon it, called CDS2. The semantics of communication in CDSl are similar to shared memory in that no copying is required and data sharing and one-sided communication is supported, and similar to message-passing in that regions of contiguous data can be passed from one process to another through queues. A prototype of CDSl has been demonstrated on an SGI Power Challenge Array and a network of Sun workstations running Solaris.

Shared-memory communication approaches for an MPI message-passing library

“…Such messages have to be transferred with double copying in a similar way to that of the mixed shared-memory management scheme. We are not aware of any implementations of such a purely dynamic shared-memory management scheme as described above, although a similar approach was considered in [14].…”