Instruction-throughput regulation in computer processors with data-center applications

Abstract

This paper tests a recently-proposed technique for regulating output performance of Discrete Event Dynamic Systems and Stochastic Hybrid Systems. The controller is based on an integrator with a variable gain, adjusted so as to guarantee wide stability margins of the closed-loop system. The gain is adjusted by estimating, in real time, the derivative of the plant function via approximations to its IPA derivative. The technique is robust to computational errors in the loop, and hence these approximations are designed for fast computation rather than precision. The development of the regulation technique has been motivated by applications in computer processors, and extensively tested in the past on a cycle-level, full system simulator. In this paper we describe implementations of the regulator on an Intel machine based on the Haswell processor, and apply it to control the instructions’ throughput of various industry program-benchmarks as well as data-center applications.