Ubuntu Manpage: hwloc-info - Show some information about some objects, a topology or supported features

NAME

       hwloc-info - Show some information about some objects, a topology or supported features

SYNOPSIS

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

       hwloc-info [ options ] root hwloc-info [ options ] [ topology | levels | support ]

       <object>...  may  be  a  space-separated  list  of  target  objects  to  query.   The program reports all
       information about one object before looking at the next one:

           $ hwloc-info core:2 package:1 pu:all
           Core L#2
            type = Core
            ...
           Package L#1
            ...
           PU L#0
            ...
           PU L#1
            ...

       The list may also contain special keywords such as:

           root for the topology root object.

           levels for information about topology levels (default if no target  object  is  given,  identical  to
       --topology).

           topology  for  topology  info  attributes  stored  in the root object (for forward compatibility with
       topology info attrs in hwloc 3.0).

           support for information about supported features (identical to --support).

       Real targets and special keywords may be combined:

           $ hwloc-info core:2 topology pu:3 levels

       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 equivalent to
passing levels as a target object on the command-line. 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. This is equivalent to
passing support as a target object on the command-line.

-i <path>, --input <path>
Read the topology from <path> instead of discovering the topology of the local machine.

If <path> is a file, it may be a XML file exported by a previous hwloc program. If <path> is "-",
the standard input may be used as a XML file.

On Linux, <path> may be a directory containing the topology files gathered from another machine
topology with hwloc-gather-topology.

On x86, <path> may be a directory containing a cpuid dump gathered with hwloc-gather-cpuid.

When the archivemount program is available, <path> may also be a tarball containing such Linux or
x86 topology files.

-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, cpuid and synthetic.

-v --verbose
Include additional detail.

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

--get-attr <name>
Only report the attribute of name <name> for each object (instead of all attributes). The name
must exactly match what is usually reported by the program, for instance "complete cpuset" in
"0.1: complete cpuset = %0x00ffff00".

Only the value is reported, any other prefix or object name is ignored, so that the output may
easily be used by other tools.

This option also works on topology information but it is ignored for levels and support keywords.

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

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

Some special values matching multiple types may also be given: kind=normal (CPU objects, including
caches), kind=cpu (CPU objects, excluding caches), kind=cache (all caches, including memory-side
caches), kind=memory (NUMA nodes or memory-side caches), kind=io (IO objects), kind=all (all
objects). See also Object Kind in Terms and Definitions in the documentation. The prefix kind=
may be omitted if there is no ambiguity.

If multiple ancestors match, they are reported from the deepest to the highest in the topology.
Adding --first will only show the first one.

--children
Display information about the object children.

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

If multiple objects match, they are reported in a depth-first order (first child, then its
children, etc., then second child, etc.). Adding --first will only show the first one.

--local-memory
Display information about the NUMA nodes that are local to the given object.

--local-memory-flags
Change the flags used to select local NUMA nodes. Flags may be given as numeric values or as a
comma-separated list of flag names that are passed to hwloc_get_local_numanode_objs(). Those
names may be substrings of actual flag names as long as a single one matches. The default is 3
(or smaller,larger) which means NUMA nodes are displayed if their locality either contains or is
contained in the locality of the given object.

This option enables --local-memory.

--best-memattr <name>
Enable the listing of local memory nodes with --local-memory, but only display the local nodes
that have the best value for the memory attribute given by <name> (or as an index). If the memory
attribute values depend on the initiator, the object given to hwloc-info is used as the initiator.

<name> may be suffixed with flags to tune the selection of best nodes, for instance as
bandwidth,strict,default. default means that all local nodes are reported if no best could be
found. strict means that nodes are selected only if their performance is the best for all the
input CPUs. On a dual-socket machine with HBM in each socket, both HBMs are the best for their
local socket, but not for the remote socket. Hence both HBM are also considered best for the
entire machine by default, but none if strict.

--first
For each input object, only report the first matching output object (first ancestor, first child,
etc.).

-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).

--disallowed
Include objects disallowed by administrative limitations.

--restrict <cpuset>
Restrict the topology to the given cpuset. This removes some PUs and their now-child-less
parents.

Beware that restricting the PUs in a topology may change the logical indexes of many objects,
including NUMA nodes.

--restrict nodeset=<nodeset>
Restrict the topology to the given nodeset (unless --restrict-flags specifies something
different). This removes some NUMA nodes and their now-child-less parents.

Beware that restricting the NUMA nodes in a topology may change the logical indexes of many
objects, including PUs.

--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).

Beware that restricting the topology may change the logical indexes of many objects, including PUs
and NUMA nodes.

--restrict-flags <flags>
Enforce flags when restricting the topology. Flags may be given as numeric values or as a comma-
separated list of flag names that are passed to hwloc_topology_restrict(). Those names may be
substrings of actual flag names as long as a single one matches, for instance bynodeset,memless.
The default is 0 (or none).

--filter <type>:<kind>, --filter <type>
Filter objects of type <type>, or of any type if <type> is "all". "io", "cache" and "icache" are
also supported.

<kind> specifies the filtering behavior. If "none" or not specified, all objects of the given
type are removed. If "all", all objects are kept as usual. If "structure", objects are kept when
they bring structure to the topology. If "important" (only applicable to I/O and Misc), only
important objects are kept. See hwloc_topology_set_type_filter() for more details.

--no-icaches
Do not show Instruction caches, only Data and Unified caches are considered. This is identical to
--filter icache:none.

--no-io
Do not show any I/O device or bridge. This is identical to --filter io:none. By default, common
devices (GPUs, NICs, block devices, ...) and interesting bridges are shown.

--no-bridges
Do not show any I/O bridge except hostbridges. This is identical to --filter bridge:none. By
default, common devices (GPUs, NICs, block devices, ...) and interesting bridges are shown.

--whole-io
Show all I/O devices and bridges. This is identical to --filter io:all. 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.

-h --help
Display help message and exit.

DESCRIPTION

       hwloc-info displays information about the specified objects.  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:

           $ hwloc-info -p core:2
           Core L#1
            logical index = 1
            os index = 2
           ...

       To list the OS devices that are of subtype OpenCL:

           $ hwloc-info -s "os[OpenCL]:all"
           CoProc:6
           CoProc:8

       To find the PCI bus ID of PCI devices containing OpenCL devices:

           $ hwloc-info --ancestor PCI --get-attr "attr PCI bus id" 'os[opencl]:all'
           0000:05:00.0
           0000:42:00.0

       To list the NUMA nodes that are local a PU:

           $ hwloc-info --local-memory pu:25
           NUMANode L#6 = local memory #0 of PU L#25
            type = NUMANode
           ...
           NUMANode L#7 = local memory #1 of PU L#25
            type = NUMANode
           ...

       To show the best-bandwidth node(s) among NUMA nodes local to a PU:

           $ hwloc-info --local-memory --best-memattr bandwidth pu:25
           NUMANode L#7 = local memory #1 of PU L#25
            type = NUMANode
           ...

       to find where a NUMA node is attached in the hierarchy of CPU cores:

           $ hwloc-info --ancestor kind=normal --first -s numa:1
           Package:0

       To see levels and topology info attributes stored in the root object:

           $ hwloc-info levels topology
           depth 0:           1 Machine (type #0)
            depth 1:          1 Package (type #1)
             depth 2:         2 Core (type #2)
              depth 3:        4 PU (type #3)
           Special depth -3:  1 NUMANode (type #13)
           info Backend = Linux
           info LinuxCgroup = /user/622
           info Architecture = x86_64
           info hwlocVersion = 3.0.0a1-git

NAME

SYNOPSIS

OPTIONS

DESCRIPTION

EXAMPLES

SEE ALSO