Optimization of One-to-Many Communication Primitives for Dragonfly Topologies

Collective communication primitives (CCPs), such as multicast and broadcast, are essential for many parallel and distributed applications. In response, this study compares a topology-oblivious algorithm underlying the implementation of CCPs in standard instances of MPI with two topology-aware implementations, based on the LLF and GLF algorithms, and an ideal hardware-assisted approach. By using real scientific applications, instead of synthetic traffic, our study reveals workload-dependent performance variations among CCP implementations; and highlights the importance of CCP algorithm selection in optimizing application performance in supercomputing environments.