The Portable Hardware Locality (hwloc) software package provides a portable abstraction (across OS, versions, architectures, ...) of the hierarchical topology of modern architectures, including as follows: - NUMA memory nodes; - sockets; - shared caches; - cores and simultaneous multithreading. It also gathers various system attributes such as cache and memory information as well as the locality of I/O devices (such as network interfaces, InfiniBand HCAs or GPUs). It primarily aims at helping applications with gathering information about modern computing hardware so as to exploit it accordingly and efficiently [1]. [1] Portable Hardware Locality (hwloc) WWW. WWW: https://www.open-mpi.org/projects/hwloc/