Performance and Fairness Improvement on CMPs Considering Bandwidth and Cache Utilization

Abstract

Chip multiprocessors (CMPs) have become dominant both in server and embedded domain as they accommodate an increasing amount of cores in order to satisfy the workload demands. However, when applications run concurrently, they compete for shared resources, such as Last Level Cache (LLC) and main memory bandwidth. Applications are affected in various ways by contention, and uneven degradation makes the system unreliable and the overall performance unpredictable. The goal of this work is to improve performance by sophisticated grouping that balances bandwidth and LLC requirements, while at the same time providing a fair execution environment by prioritizing applications that experience the least accumulated progress. The proposed scheduler achieves an average performance gain of 16 percent over the Linux scheduler and 6.3 percent over another performance-oriented scheduler. Additionally, it keeps unfairness very close to two fairness-oriented schedulers.