Effective parallelization of loops in the presence of I/O operations

Software-based thread-level parallelization has been widely studied for exploiting data parallelism in purely computational loops to improve program performance on multiprocessors. However, none of the previous efforts deal with efficient parallelization of hybrid loops, i.e., loops that contain a mix of computation and I/O operations. In this paper, we propose a set of techniques for efficiently parallelizing hybrid loops. Our techniques apply DOALL parallelism to hybrid loops by breaking the cross-iteration dependences caused by I/O operations. We also support speculative execution of I/O operations to enable speculative parallelization of hybrid loops. Helper threading is used to reduce the I/O bus contention caused by the improved parallelism. We provide an easy-to-use programming model for exploiting parallelism in loops with I/O operations. Parallelizing hybrid loops using our model requires few modifications to the code. We have developed a prototype implementation of our pr...

• Type: Journal
• Year: 2012
• Where: PLDI
• Authors: Min Feng, Rajiv Gupta, Iulian Neamtiu
• Keywords: Bus Contention, Data Parallelism, Multi Player Game, PLDI 2012, Programming Languages