Scheduling Multiple Multithreaded Applications on Asymmetric and Symmetric Chip Multiprocessors

This paper evaluates new techniques to improve performance, fairness and jitter of workloads consisting of multiple multithreaded applications running on Chip MultiProcessors (CMP). Current thread assignment techniques which are tailored for single-thread applications result in sub-optimal usage of the multiprocessor resources, unfairness between applications and jitter in execution runtimes when dealing with multiple multithreaded applications running in parallel. Multithreaded applications contain serial phases (single thread) and parallel phases (many threads). In this paper, we propose a new thread assignment mechanism that takes into account the different requirements of each phase, granting higher priority to applications during their critical-serial phases. Analytic and experimental evaluation of the proposed thread assignment mechanism on both symmetric and asymmetric multiprocessors show throughput improvements by as much as 16%, improved fairness by as much as 26% and reduced jitter by as much as 88%.