Impact of Multiprogramming on Cache Performance

This chapter discusses both the performance of virtual caches for multiprogramming workloads, and the validity of the earlier schemes to model multiprogramming effects. After outlining our cache analysis methods for multiprogramming workloads, we compare cache performance data at different levels of multiprogramming to motivate a study of this nature. We evaluate various techniques that have been proposed for improving multitasking in caches, such as cache flushing and PIDs. After initially considering only user references, we then include system references and discuss the impact of system references on cache performance in a multiprogramming environment. We contrast our experimental findings with various synthetic models of multiprogrammed caches used by earlier researchers and examine the validity of assumptions made by earlier studies. We end this chapter by examining various techniques to improve cache performance for multiprogramming.