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hwloc_distances_s(3)       Library Functions Manual       hwloc_distances_s(3)


NAME

       hwloc_distances_s


SYNOPSIS

       #include <distances.h>

   Data Fields
       unsigned nbobjs
       hwloc_obj_t * objs
       unsigned long kind
       hwloc_uint64_t * values


Detailed Description

       Matrix of distances between a set of objects.

       The most common matrix contains latencies between NUMA nodes (as
       reported in the System Locality Distance Information Table (SLIT) in
       the ACPI specification), which may or may not be physically accurate.
       It corresponds to the latency for accessing the memory of one node from
       a core in another node. The corresponding kind is
       HWLOC_DISTANCES_KIND_MEANS_LATENCY | HWLOC_DISTANCES_KIND_FROM_USER.
       The name of this distances structure is 'NUMALatency'.

       The matrix may also contain bandwidths between random sets of objects,
       possibly provided by the user, as specified in the kind attribute.
       Others common distance structures include and 'XGMIBandwidth',
       'XGMIHops', 'XeLinkBandwidth' and 'NVLinkBandwidth'.

       Pointers objs and values should not be replaced, reallocated, freed,
       etc. However callers are allowed to modify kind as well as the contents
       of objs and values arrays. For instance, if there is a single NUMA node
       per Package, hwloc_get_obj_with_same_locality() may be used to convert
       between them and replace NUMA nodes in the objs array with the
       corresponding Packages. See also hwloc_distances_transform() for
       applying some transformations to the structure.


Field Documentation

   unsigned long hwloc_distances_s::kind
       OR'ed set of hwloc_distances_kind_e.

   unsigned hwloc_distances_s::nbobjs
       Number of objects described by the distance matrix.

   hwloc_obj_t* hwloc_distances_s::objs
       Array of objects described by the distance matrix. These objects are
       not in any particular order, see hwloc_distances_obj_index() and
       hwloc_distances_obj_pair_values() for easy ways to find objects in this
       array and their corresponding values.

   hwloc_uint64_t* hwloc_distances_s::values
       Matrix of distances between objects, stored as a one-dimension array.
       Distance from i-th to j-th object is stored in slot i*nbobjs+j. The
       meaning of the value depends on the kind attribute.



Author

       Generated automatically by Doxygen for Hardware Locality (hwloc) from
       the source code.

Hardware Locality (hwloc)       Version 2.11.0            hwloc_distances_s(3)

hwloc 2.11.0 - Generated Fri Jun 28 07:38:17 CDT 2024
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