Non-uniform reference model in multiple bus multiprocessors

Abstract

Concurrent/distributed procesing is becoming increasingly popular for building high performance systems. In multiprocessors, system performance could be severely hampered when there is frequent access to a particular memory module resulting in hotspots. The conventional assumption of uniform reference model no longer holds in such cases. Multiprocessor systems exhibit non-uniform memory reference behavior. In this thesis, a multiple bus interconnection network is analyzed under non-uniform reference model in general and 'hotspot' reference in particular. Closed form expressions for bandwidth, probability of acceptance are developed using probability theory, combinatorics and Markov chains for three models viz. unbuffered requests, queued requests and resumbitted requests model. Theoretical results obtained were found to be in close agreement with simulation results proving the validity of the expressions.