Multicore Programming Models and their Implementation Challenges

Abstract – The computer industry is at a major inflection point in its hardware roadmap due to the end of a decades-long trend of exponentially increasing clock frequencies. It is widely agreed that spatial parallelism in the form of multiple power-efficient cores must be exploited to compensate for this lack of frequency scaling. Unlike previous generations of hardware evolution, this shift towards multicore and manycore computing will have a profound impact on software. These software challenges are further compounded by the need to enable parallelism in workloads and application domains that have traditionally not had to worry about multiprocessor parallelism in the past. In this talk we will focus on the programming problem for tightly coupled homogeneous and heterogeneous multicore processors. We present early experiences with the Habanero Multicore Software Research project at Rice University (http://habanero.rice.edu) that encompasses work on programming models, compilers, runtimes, and concurrency libraries so as to enable portable software to run unchanged on a range of homogeneous and heterogeneous multicore systems. The Habanero project takes a two-level approach to programming models, with a high-level model based on Intel Concurrent Collections for parallelism-oblivious domain experts, and a lower-level model based on the high productivity X10 language for parallelism-aware developers. We discuss compiler and runtime implementation challenges that must be overcome to enable mainstream applications to use these models on multicore systems.

Biography – Vivek Sarkar conducts research in multiple aspects of parallel software including programming languages, program analysis, compiler optimizations and runtimes for parallel and high performance computer systems. He currently leads the Habanero Multicore Software Research project at Rice University, serves as Associate Director of the NSF-funded Center for Domain-Specific Computing, and as co-PI on the DARPA-funded project on Platform-Aware Compilation Environment (PACE). Prior to joining Rice in July 2007, Vivek was Senior Manager of Programming Technologies at IBM Research. His responsibilities at IBM included leading IBM’s research efforts in programming model, tools, and productivity in the PERCS project during 2002- 2007 as part of the DARPA High Productivity Computing System program. His past projects include the X10 programming language, the Jikes Research Virtual Machine for the Java language, the ASTI optimizer used in IBM’s XL Fortran product compilers, the PTRAN automatic parallelization system, and profile-directed partitioning and scheduling of Sisal programs. Vivek became a member of the IBM Academy of Technology in 1995, the E.D. Butcher Professor of Computer Science at Rice University in 2007, and was inducted as an ACM Fellow in 2008. He holds a B.Tech. degree from the Indian Institute of Technology, Kanpur, an M.S. degree from University of Wisconsin-Madison, and a Ph.D. from Stanford University. In 1997, he was on sabbatical as a visiting associate professor at MIT, where he was a founding member of the MIT RAW multicore project.