Evaluating Spatial Computation For Whole Program Execution using the Tartan Architecture

Tuesday March 21, 2006
Hamerschlag Hall D-210
4:30 pm

Mahim Mishra
Carnegie Mellon University

Spatial Computing (SC) has been shown to be an energy-efficient scaling-tolerant model for implementing kernels. In this talk I explore the feasibility of building a general-purpose processing system based on the SC model: I describe Tartan, an architecture which integrates a general-purpose processor with a reconfigurable fabric (RF), and evaluate its performance and energy efficiency when executing entire (large) applications. I also present Tartan's compilation toolflow, which can automatically partition an application and generate a processor instruction stream and an RF configuration. The results indicate that a hierarchical RF architecture, designed around a scalable interconnect, is instrumental in harnessing the benefits of spatial computation in such a hybrid system. The interconnect uses static configuration and routing at the lower levels, and a packet-switched, dynamically-routed network at the top level. Tartan is most energy-efficient when almost all of the application is mapped to the RF, indicating the need for the RF to support most general-purpose programming constructs. Initial investigations reveal that such a system can provide, on average, an order of magnitude increase in energy efficiency compared to an aggressive superscalar core on single-threaded workloads, while delivering acceptable performance.

Mahim is a PhD candidate in the Computer Science Department at CMU, where he is part of the Phoenix project led by Prof. Seth Goldstein. His current research focuses on the architecture of the Tartan reconfigurable fabric, with particular emphasis on the design of the compute units and memory hierarchy, and on the fabric's defect tolerance aspects. His other research interests include processor architecture, high-level synthesis, CAD algorithms, VLSI test methods, and simulation and modeling. When not chained to his desk in the interior of Wean Hall, Mahim likes to play tennis, listen to classic rock and drink beer. Before joining CMU, Mahim obtained a BS in Computer Science and Engineering from the Indian Institute of Technology, Kanpur.