The Shared-Thread Multiprocessor

This paper describes initial results for an architecture called the Shared-Thread Multiprocessor (STMP). The STMP combines features of a multithreaded processor and a chip multiprocessor; specifically, it enables distinct cores on a chip multiprocessor to share thread state. This shared thread state allows the system to schedule threads from a shared pool onto individual cores, allowing for rapid movement of threads between cores. This paper demonstrates and evaluates three benefits of this architecture: (1) By providing more thread state storage than available in the cores themselves, the architecture enjoys the ILP benefits of many threads, but carries the in-core complexity of supporting just a few. (2) Threads can move between cores fast enough to hide long-latency events such as memory accesses.