Performance assessment of contents management in multilevel on-chip caches

This paper deals with two level on-chip cache memories. We show the impact of three different relationships between the contents of these levels on the system performance. In addition to the classical Inclusion contents management, we propose two alternatives, namely Exclusion and Demand, developing for them the necessary coherence support and quantifying their relative performance in a design space (sizes, latencies, ...) in agreement with the constraints imposed by integration. Two performance metrics are considered: the second-level cache miss ratio and the system CPI. The experiments have been carried out running a set of integer and floating point SPEC'92 benchmarks. We conclude showing the superiority of our improved version of Exclusion throughout all the sizing and workload spectrum studied.