A practical processor design for multithreading

High speed message handling is one of the most important problems for efficient multithread processing. We have proposed a processor architecture called Datarol-II, that promotes the efficient fine-grain multithreaded execution, by performing fast context switching among fine-grain concurrent processes. We are developing a prototype multithread machine KUMP/D (Kyushu University Multi-media Processor on Datarol-II). The processing element of KUMP/D is designed on the basis of a fine-grain message driven (FMD) execution model, in which fine-grain multithreaded executions are driven and controlled by simple fine-grain message communications. In the design of the KUMP/D, we used the off-the-shelf microprocessor Pentium for its processing element and designed a co-processor, called FMP (Fine grain Message Processor), for fine grained message handling and communication control. In this paper, we propose the FMD model and introduce the processing element construction. In the KUMP/D machine which is a practical implementation of the FMD using the Pentium and the FMP, then discuss the feasibility of the design from the viewpoint of cost/performance.