BRASS Research Group

Dynamic Runtime Scheduler Support for SCORE

Masters thesis by Michael Chu, University of California, Berkeley (December 2000).

Abstract: Reconfigurable computing devices offer substantial improvements in functional density and yield versus traditional microprocessors, yet remain out of generalpurpose use due in part to their difficulty of programming and lack of cross-device compatibility. In [CASPI00] a stream-based compute model called SCORE (Stream Computations Organized for Reconfigurable Execution) was introduced with a goal to provide a programming model for easily exploiting the computational density of reconfigurable devices. SCORE virtualizes reconfigurable resources (compute, storage, and communication) by dividing a computation up into fixed-size ``pages'' and time-multiplexing the virtual pages on available physical hardware. Consequently, SCORE applications can scale up or down automatically to efficiently run on a wide range of hardware. In this project we implement a dynamic runtime scheduler for SCORE that virtualizes the reconfigurable computation fabric and automatically manages the execution of SCORE applications in hardware. Initial performance scaling experiments show that a dynamic scheduler is able to automatically scale applications on reduced hardware and exploit hardware under-utilization to achieve reasonable area-time curves. In this paper, we present the basic scheduler details and runtime system flow along with key implementation highlights, such as scheduling heuristics, memory management, and deadlock detection.