HWLOC-DISTANCES(1)						       hwloc							HWLOC-DISTANCES(1)

NAME

       hwloc-distances - Displays distance matrices

SYNOPSIS

       hwloc-distances [options]

OPTIONS

       -l --logical
	      Display hwloc logical indexes (default) instead of physical/OS indexes.

       -p --physical
	      Display OS/physical indexes instead of hwloc logical indexes.

       -i <file>, --input <file>
	      Read topology from XML file <file> (instead of discovering the topology on the local machine).  If <file> is "-", the standard input
	      is used.	XML support must have been compiled in to hwloc for this option to be usable.

       -i <directory>, --input <directory>
	      Read topology from the chroot specified by <directory> (instead of discovering the topology on the local machine).  This	option	is
	      generally only available on Linux.  The chroot was usually created by gathering another machine topology with hwloc-gather-topology.

       -i <specification>, --input <specification>
	      Simulate	a  fake  hierarchy  (instead  of  discovering the topology on the local machine). If <specification> is "node:2 pu:3", the
	      topology will contain two NUMA nodes with 3 processing units in each of them.  The <specification> string must end with a number	of
	      PUs.

       --if <format>, --input-format <format>
	      Enforce the input in the given format, among xml, fsroot and synthetic.

       --restrict <cpuset>
	      Restrict the topology to the given cpuset.

       -v     Verbose messages.

       --version
	      Report version and exit.

DESCRIPTION

       hwloc-distances	displays also distance matrices attached to the topology.  A breadth-first 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 hwloc-distances also displays matrices that ignore part of the topology.

EXAMPLES

       On a quad-socket opteron machine:

	   $ hwloc-distances
	   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 VALUE

       Upon successful execution, hwloc-distances returns 0.

       hwloc-distances will return nonzero if any kind of error occurs, such as (but not limited to) failure to parse the command line.

SEE ALSO

       hwloc(7), lstopo(1)

1.4.1								   Feb 27, 2012 						HWLOC-DISTANCES(1)