Abstract:

Scalable systems employing a mix of GPUs with CPUs are becoming increasingly prevalent in high-performance computing (HPC). The presence of such accelerators introduces significant challenges and complexities to both language developers and end users. This paper provides a close study of efficient coordination mechanisms to handle parallel requests from multiple hosts of control to a GPU under hybrid programming. Using a set of microbenchmarks and applications on a GPU cluster, we show that thread- and process-based context hosting have different tradeoffs. Experimental results on application benchmarks suggest that both thread-based context funneling and process-based context switching natively perform similarly on the latest Fermi GPU, while manually guided context funneling is currently the best way to achieve optimal performance.

Paper available at ACM.