Coarrays in the Context of XcalableMP

Abstract

AbstractCoarray features have been implemented on the Omni XcalableMP compiler with a source-to-source translator and layered runtime libraries. Three memory allocation methods for coarrays were implemented for the GASNet and MPI-3 communication libraries and the native interface of Fujitsu. For the coarray PUT/GET communication, algorithms using DMA (zero-copy) and buffering were introduced. Important techniques for achieving high performance were the non-blocking PUT communication implemented in the runtime library and the optimization for the GET communication in the translator. Using the ping-pong benchmark and the modified version, the fundamental performance was evaluated and analyzed. The MPI version of the Himeno benchmark was ported to the coarray version and modified for fully using the non-blocking PUT. As a result of the evaluation, the non-blocking coarray version clearly outperformed the original and non-blocking MPI versions.