Program modelling via inter-reference gaps and applications

Locality of reference in program behavior has been studied and modelled extensively because of its application to CPU, cache and virtual memory design, code optimization, multiprogramming etc. In this paper we propose a scheme based on Markov chains for modelling the time interval between successive references to the same address in a program execution. Using this technique and trace driven simulations, it is shown that memory references are predictable and repetitive. This is used to improve miss ratios of memory replacement algorithms. Using trace driven simulations over a wide range of traces we get improvements up to 35% over the least recently used (LRU) replacement algorithm