一种具有QoS特性的同时多线程处理器取指策略

同时多线程处理器通过每时钟周期从多个运行的线程取指令执行，从而极大地提高了处理器的性能.建议了一种具有QoS特性的同时多线程处理器取指策略，并讨论了其在QoS管理方面的问题.该策略的核心思想是利用线程的优先级和流速来同时控制线程的取指过程，从而满足线程在执行速度上的QoS需求.与传统的基于纯优先级的取指策略相比，该策略不但具有QoS特性，同时还可以更加有效地分配取指带宽，从而能获得更高的处理器性能.该策略的物理实现非常简单.模拟实验的结果表明，该策略在提供QoS支持的基础上，可以在传统的基于优先级的取指策略ICOUNT的基础上提高15%的系统性能.

A QoS Capable Fetch Policy for SMT Processors

Simultaneous multithreaded(SMT)processors improve instruction throughput by allowing fetching and running instructions from several threads simultaneously at a single cycle.In this paper,a QoS capable fetch policy for SMT processors is proposed and the related issues about QoS management are discussed.The key idea of the policy is using a priority and a flow speed to control the fetching process of every running thread to fulfill the QoS requirement of it.Compared with the pure-priority-based fetch policy,this scheme not only has the QoS capability,but also utilizes the fetch bandwidth in a more efficient way.Thus it provides a better performance and a higher instruction throughput for SMT processors.The implementation of the fetch policy is simple.Execution-driven simulation results show that besides the QoS capability this policy improves the overall performance of the pure-priority-based fetch policy,ICOUNT,by 15% on average.