Optimisation and performance evaluation of mechanisms for latency tolerance in remote memory access communication on clusters

摘要

This paper describes the design and performance evaluation of the mechanisms for latency tolerance in the remote memory access communication on clusters equipped with high-performance networks such as Myrinet. It discusses strategies that bridge the gap between user-level requirements and network-specific communication interfaces while attempting to increase opportunities for latency hiding. Mechanisms for overlapping communication with computation and coalescing small messages (trading latency for bandwidth) are explored. The effectiveness of these techniques is evaluated using microbenchmarks and application kernels including the NAS parallel benchmark suite. The microbenchmark results showed a much better degree of overlap for non-blocking operations in ARMCI when compared with MPI. Application results showed up to 30-45% improvement over MPI on using non-blocking operations. The aggregation of small messages yielded performance improvement of up to 78% over non-aggregated communication.