Transactional Coherence & Consistency

Tuesday September 21, 2004
Hamerschlag Hall D-210
4:00 pm

Christos Kozyrakis
Stanford University

With uniprocessor systems running into ILP limits and fundamental VLSI constraints, parallel architectures provide a realistic path towards scalable performance. Nevertheless, shared memory multiprocessors are neither simple to design nor easy to program. Transactional Coherence and Consistency (TCC) is a new model for shared memory systems with the potential to address both issues. TCC relies on user-defined, light-weight transactions as the basic unit of parallel work, communication, memory coherence, memory consistency, and error recovery. TCC simplifies shared memory hardware design by eliminating the need for cache line ownership tracking in the cache coherence protocol. It also replaces the need for small, low latency messages for cache coherence. TCC simplifies parallel programming by eliminating the need for manual orchestration of parallelism using locks. The use of a single abstraction for parallelism, communication, and synchronization makes it easy for the programmer to identify and remove performance bottlenecks. This talk will introduce the hardware and software aspects of TCC and provide an initial evaluation of its potential as a shared memory model.

Christos Kozyrakis is an assistant professor of Electrical Engineering and Computer Science at Stanford University. He holds a B.S. from the University of Crete in Greece and a Ph.D. from the University of California at Berkeley. Christos' research focuses on architectures, compilers, and programming models for parallel computer systems.