Co-Scheduling Threads in SMT Processors Fairly
Zhang Min-xuan · Dianzi xuebao · 2008
In Simultaneous Multithreading(SMT)processors,the instruction fetch policy determines the way of allocating shared resources among co-scheduled threads implicitly,and affects throughput and fairness consequently.However,prior work on fetch policies almost focuses on throughput optimization.The issue of fairness between threads in progress rates is studied rarely.In this paper,we purchase fairness as the main optimization goal and propose a novel fetch policy called FAIR.Results show that for all types of workloads,FAIR can achieve good fairness and RPRrange(a fairness metric defined in this paper)is less than 5%.Furthermore,FAIR does not sacrifice throughput severely.Compared to fetch policies orienting towards throughput maximization such as ICOUNT,degradation of FAIR in throughput is 3.8% on average.