Using Mixed-Radix Decomposition to Enumerate Computational Resources of Deeply Hierarchical Architectures
Philippe Swartvagher, Sascha Hunold, Jesper Larsson Träff, Ioannis Vardas · 2023
Current HPC architectures are deeply hierarchical (racks, nodes, sockets, NUMA domains, caches,...), and the mapping of MPI processes to cores can significantly influence application performance. To study hierarchy effects on MPI application performance, we propose a procedure for expressing mappings by enumerating cores in the hierarchy in different orders. We explore two use cases: MPI rank reordering for applications using subcommunicators, and core selection for applications not using all cores on a node.