Hardware Locality

Hardware Locality (hwloc) is a software toolset that provides applications with a portable and abstracted view of the hierarchical topology of modern computing systems. It discovers and maps hardware components like NUMA memory nodes, processor cores, caches, and PCI devices, revealing their relationships and distances. This enables performance-critical software—including MPI and OpenMP applications—to make intelligent, architecture-aware decisions about thread and memory placement. By understanding the underlying hardware layout, developers and runtime systems can optimize data locality, reduce communication overhead, and significantly boost application performance across diverse platforms, from laptops to large-scale HPC clusters.