EM2: Execution Migration Machine
Speaker: Srini Devadas, MIT
Series: Topical Seminars
Location: Engineering Quadrangle B205
Date/Time: Monday, March 21, 2011, 4:30 p.m. - 5:30 p.m.
We introduce the Execution Migration Machine (EM2) a computation-migration-based multicore architecture that provides speedy access to on-chip distributed cache data by either migrating execution or via remote memory operations. Since only one copy of data is stored on-chip, cache coherence and sequential consistency are trivially ensured without the need for coherence logic or large directories. We develop a one-step migration protocol that is deadlock-free based on the concept of cores native to a thread, and present on-line decision algorithms under this protocol that decide when to migrate or otherwise perform a remote access. Simulation results indicate that the best on-line decision algorithm in our directoryless 256-core architecture is superior in performance to a directory-based cache-coherent baseline on a range of Splash-2 benchmarks, and further has lower energy consumption. Finally, we introduce the notion of library cache coherence and describe how it can be integrated into EM2 to further improve performance.
Srini Devadas is a Professor of Electrical Engineering and Computer Science at the Massachusetts Institute of Technology (MIT), and has been on the faculty of MIT since 1988. He currently serves as the Associate Head with responsibility for Computer Science. Devadas has worked in the areas of Computer-Aided Design, testing, formal verification, compilers for embedded processors, computer architecture, computer security, and computational biology and has co-authored numerous papers and books in these areas. Devadas was elected a Fellow of the IEEE in 1998.