Improving Communication and Load Balancing with Thread Mapping in Manycore Systems

Communication and load balancing have a significant impact on the performance of parallel applications and have been the subject of extensive research in multicore architectures. Thread mapping has been one of the solutions adopted in multicore architectures to address both communication and load balancing. However, the impact of such issues on more recently introduced manycore architectures is still unknown. Most related work on manycore architectures focus on execution time and idleness information for scheduling decisions. In this paper, we improve the state of the art by performing a very detailed analysis of the impact of thread mapping on communication and load balancing in two manycore systems from Intel, namely Knights Corner and Knights Landing. We observed that the widely used metric of CPU time provides very inaccurate information for load balancing. We also evaluated the usage of thread mapping based on the communication and load information of the applications to improve the performance of manycore systems.