
NAMEhwlocdistances  Displays distance matricesSYNOPSIShwlocdistances [ options]OPTIONS
DESCRIPTIONhwlocdistances displays also distance matrices attached to the topology. The value in the ith row and jth column is the distance from object #i to object #j. Unless defined by the user, matrices currently always contain relative latencies between NUMA nodes (which may or may not be accurate). See the definition of struct hwloc_distances_s in include/hwloc.h or the documentation for details. These latencies are normalized to the latency of a local (nonNUMA) access. Hence 3.5 in row #i column #j means that the latency from cores in NUMA node #i to memory in NUMA node #j is 3.5 higher than the latency from cores to their local memory. A breadthfirst traversal of the topology is performed starting from the root to find all distance matrices. NOTE: lstopo may also display distance matrices in its verbose textual output. However lstopo only prints matrices that cover the entire topology while hwlocdistances also displays matrices that ignore part of the topology.EXAMPLESOn a quadpackage opteron machine:$ hwlocdistances Latency matrix between 4 NUMANodes (depth 2) by logical indexes: index 0 1 2 3 0 1.000 1.600 2.200 2.200 1 1.600 1.000 2.200 2.200 2 2.200 2.200 1.000 1.600 3 2.200 2.200 1.600 1.000 RETURN VALUEUpon successful execution, hwlocdistances returns 0. hwlocdistances will return nonzero if any kind of error occurs, such as (but not limited to) failure to parse the command line.SEE ALSOhwloc(7), lstopo(1)
Visit the GSP FreeBSD Man Page Interface. 