Dynamic Partitioning of Shared Cache Memory

Abstract

This paper proposes dynamic cache partitioning amongst simultaneously executing processes/threads. We present a general partitioning scheme that can be applied to set-associative caches. Since memory reference characteristics of processes/threads can change over time, our method collects the cache miss characteristics of processes/threads at run-time. Also, the workload is determined at run-time by the operating system scheduler. Our scheme combines the information, and partitions the cache amongst the executing processes/threads. Partition sizes are varied dynamically to reduce the total number of misses. The partitioning scheme has been evaluated using a processor simulator modeling a two-processor CMP system. The results show that the scheme can improve the total IPC significantly over the standard least recently used (LRU) replacement policy. In a certain case, partitioning doubles the total IPC over standard LRU. Our results show that smart cache management and scheduling is essential to achieve high performance with shared cache memory.