HWLOC-INFO(1)

NAME
hwloc-info - Show some information about some objects or about a topology or about support features

SYNOPSIS

hwloc-info [ options ]... <object>...

hwloc-info [ options ]...

Note that hwloc(7) provides a detailed explanation of the hwloc system and of valid <object> formats; it should be read before reading this man page.

OPTIONS

--objects
    Report information specific objects. This is the default if some objects are given on the command-line.

--topology
    Report a summary of the topology instead of about some specific objects. This is the default if no object is given on the command-line.

--support
    Report the features that are supported by hwloc on the topology. The features are those available through the hwloc_topology_get_support() function. This is useful for verifying which CPU or memory binding options are supported by the current hwloc installation.

-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.

-v --verbose
    Include additional detail.

-s --silent
    Reduce the amount of details to show. A single summary line per object is displayed.

--ancestors
    Display information about the object as well as about all its ancestors up to the root of the topology.

--ancestor <type>
    Only display the object ancestors that match the given type.

--children
    Display information about the object children.

--descendants <type>
    Display information about the object descendants that match the given type.

-n  When outputting object information, prefix each line with the index of the considered object within the input. For instance, if three cores were given in input, the output lines will be prefixed with "0: ", "1: " or "2: ". If --ancestor is also used, the prefix will be "X.Y: " where X is the index of the considered object within the input, and Y is the parent index (0 for the object itself, increasing towards the root of the topology).

--whole-system
    Do not consider administration limitations.

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

--restrict binding
    Restrict the topology to the current process binding. This option requires the use of the actual current machine topology (or any other topology with --thissystem or with HWLOC_THISSYSTEM set to 1 in the environment).

--no-icaches
    Do not show Instruction caches, only Data and Unified caches are considered.

--no-io
    Do not show any I/O device or bridge. By default, common devices (GPUs, NICs, block devices, ...) and interesting bridges are shown.

--no-bridges
    Do not show any I/O bridge except hostbridges. By default, common devices (GPUs, NICs, block devices, ...) and interesting bridges are shown.

--whole-io
    Show all I/O devices and bridges. By default, only common devices (GPUs, NICs, block devices, ...) and interesting bridges are shown.

--thissystem
    Assume that the selected backend provides the topology for the system on which we are running. This is useful when using --restrict binding and loading a custom topology such as an XML file.

--pid <pid>
    Detect topology as seen by process <pid>, i.e. as if process <pid> did the discovery itself. Note that this can for instance change the set of allowed processors. Also show this process current CPU binding by marking the corresponding PUs (in Green in the graphical output, see the COLORS section below, or by appending (binding) to the verbose text output). If 0 is given as pid, the current binding for the lstopo process will be shown.

-p --physical
    Use OS/physical indexes instead of logical indexes for input.

-l --logical
    Use logical indexes instead of physical/OS indexes for input (default).

--version
    Report version and exit.

DESCRIPTION
hwloc-info displays information about the specified object. It is intended to be used with tools such as grep for filtering certain attribute lines. When no object is specified, or when --topology is passed, hwloc-info prints a summary of the topology. When --support is passed, hwloc-info lists the supported features for the topology.

Objects may be specified as location tuples, as explained in hwloc(7). However hexadecimal bitmasks are not accepted since they may correspond to multiple objects.

NOTE: It is highly recommended that you read the hwloc(7) overview page before reading this man page. Most of the concepts described in hwloc(7) directly apply to the hwloc-calc utility.

EXAMPLES

To display information about each package:
    $ hwloc-info package:all
    Package L#0
     logical index = 0
    ... To display information about the core whose physical index is 2:
    $ utils/hwloc-info -p core:2
    Core L#1
     logical index = 1
     os index = 2
   ...

SEE ALSO
hwloc(7), lstopo(1), hwloc-calc(1), hwloc-bind(1), hwloc-ps(1), hwloc-gather-topology(1)