Dynamic Cache Partitioning for Simultaneous Multithreading Systems

This paper proposes a dynamic cache partitioning method for simultaneous multithreading systems. We present a general partitioning scheme that can be applied to setassociative caches at any partition granularity. Furthermore, in our scheme threads can have overlapping partitions, which provides more degrees of freedom when partitioning caches with low associativity. Since memory reference characteristics of threads can change very quickly, our method collects the miss-rate characteristics of simultaneously executing threads at runtime, and partitions the cache among the executing threads. Partition sizes are varied dynamically to improve hit rates. Trace-driven simulation results show a relative improvement in the L2 hit-rate of up to 40.5% over those generated by the standard least recently used replacement policy, and IPC improvements of up to 17%. Our results show that smart cache management and scheduling is important for SMT systems to achieve high performance.