A Control Theory Approach to Improve the Real-Time Capability of Multi-Threaded Microprocessors

Our aim is to investigate if it is possible to control the throughput (IPC rate) of a thread running on a simultaneous multi-threaded microprocessor by a closed feedback loop. We showed in previous experimental studies that the proposed approach works. In this paper we discuss the control theory approach from a theoretical point of view. We develop a mathematical model of a general purpose multi-threaded microprocessor enhanced with a closed feedback controller and use control theory methods to investigate properties like stability and settling time.