Resource efficiency and equity in chip Multithreading architecture

For Chip Multithreading (CMT) architecture, the inter-thread competition for resources has some uncontrollable and unwanted impacts on both any designated thread and the overall performance. A crucial reason lies in the absence of all-sided approaches to evaluate, predict and further control thread performance and resource utilization. In this paper, we take Rename-Register-File (RRF), a representative storage resource that is critical in regulating resource allocation and therein thread performance, for instance to study the efficiency and equity of resource allocation. For in-depth comparison, we devise two ideal allocation strategies, i.e. Maximizing Performance (MP) and Maximizing Fairness (MF). Then we propose three complementary metrics called Relative Fairness (RF), Efficiency Index (EI), and Effective Utilization (EU), respectively, and carry out a series of evaluations on MP, MF and various classical strategies. The results show that these metrics are objective and instructive, and thus meaningful for further improving thread scheduling and resource allocation.