LSTOPO(1) hwloc LSTOPO(1)
lstopo, lstopo-no-graphics - Show the topology of the system
lstopo [ options ]... [ filename ]
lstopo-no-graphics [ options ]... [ filename ]
Note that hwloc(7) provides a detailed explanation of the hwloc system; it should be read before reading this man page
--of <format>, --output-format <format>
Enforce the output in the given format. See the OUTPUT FORMATS section below.
-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
--if <format>, --input-format <format>
Enforce the input in the given format, among xml, fsroot and synthetic.
Include additional detail. The hwloc-info tool may be used to display even more information about specific objects.
Reduce the amount of details to show.
Display hwloc logical indexes instead of physical/OS indexes (default for console output). These indexes are prefixed with "L#".
The physical indexes of some objects (PU and Node by default, all objects if verbose) will appear as object attribute "P#...".
Display OS/physical indexes instead of hwloc logical indexes (default for graphical output). These indexes are prefixed with "P#"
instead of "L#" in the console output.
Display the cpuset of each object.
Only display the cpuset of each object; do not display anything else about the object.
Show CPU set strings in the format recognized by the taskset command-line program instead of hwloc-specific CPU set string format.
This option should be combined with --cpuset or --cpuset-only, otherwise it will imply --cpuset.
Only show objects of the given type in the textual output.
Ignore all objects of type <type> in the topology. hwloc supports ignoring any type except PUs and I/O devices. However lstopo
still offers PU ignoring by hiding PU objects in the graphical and textual outputs. Note that PU may not be ignored in the XML out-
Do not show caches.
Do not show caches which do not have a hierarchical impact.
Do not show Instruction caches, only Data and Unified caches are displayed.
Do not consider administration limitations.
Do not show levels that do not have a hierarchical impact.
Restrict the topology to the given cpuset.
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).
Do not show any I/O device or bridge. By default, common devices (GPUs, NICs, block devices, ...) and interesting bridges are
Do not show any I/O bridge except hostbridges. By default, common devices (GPUs, NICs, block devices, ...) and interesting bridges
Show all I/O devices and bridges. By default, only common devices (GPUs, NICs, block devices, ...) and interesting bridges are
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.
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 graphi-
cal 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.
Show existing processes as misc objects in the output. To avoid uselessly cluttering the output, only processes that are restricted
to some part of the machine are shown. On Linux, kernel threads are not shown. If many processes appear, the output may become
hard to read anyway, making the hwloc-ps program more practical.
Set size of text font.
Set size of margin between elements.
Horizontal graphical layout instead of nearly 4/3 ratio. If a comma-separated list of types is given, the layout only applies to
the corresponding containers.
Vertical graphical layout instead of nearly 4/3 ratio. If a comma-separated list of types is given, the layout only applies to the
Remove the text legend at the bottom.
Report version and exit.
lstopo and lstopo-no-graphics are capable of displaying a topological map of the system in a variety of different output formats. The only
difference between lstopo and lstopo-no-graphics is that graphical outputs are only supported by lstopo, to reduce dependencies on external
If no filename is specified and the DISPLAY environment variable is set, lstopo displays the map in a graphical window. If no filename is
specified and the DISPLAY environment variable is not set, a text summary is displayed.
The filename specified directly implies the output format that will be used; see the OUTPUT FORMATS section, below. Output formats that
support color will indicate specific characteristics about individual CPUs by their color; see the COLORS section, below.
The filename on the command line usually determines the format of the output. There are a few filenames that indicate specific output for-
mats and devices (e.g., a filename of "-" will output a text summary to stdout), but most filenames indicate the desired output format by
their suffix (e.g., "topo.png" will output a PNG-format file).
The format of the output may also be changed with "--of". For instance, "--of pdf" will generate a PDF-format file on the standard output,
while "--of fig toto" will output a Xfig-format file named "toto".
The list of currently supported formats is given below. Any of them may be used with "--of" or as a filename suffix.
Send the output to a window or to the console depending on the environment.
Send a text summary to stdout. Binding, unallowed or offline processors are only annotated in this mode if verbose; see the COLORS
txt Output an ASCII art representation of the map. If outputting to stdout and if colors are supported on the terminal, the output will
fig Output a representation of the map that can be loaded in Xfig.
pdf If lstopo was compiled with the proper support, lstopo outputs a PDF representation of the map.
ps If lstopo was compiled with the proper support, lstopo outputs a Postscript representation of the map.
png If lstopo was compiled with the proper support, lstopo outputs a PNG representation of the map.
svg If lstopo was compiled with the proper support, lstopo outputs an SVG representation of the map.
If the topology is symmetric (which requires that the root object has its symmetric_subtree field set), lstopo outputs a synthetic
description string. This output may be reused as an input synthetic topology description later. Note that I/O devices often cause
topology asymmetry. Adding --no-io may then be useful when the synthetic export fails. See also the Synthetic topologies section
in the documentation.
xml If lstopo was compiled with the proper support, lstopo outputs an XML representation of the map. It may be reused later, even on
another machine, with lstopo --input, the HWLOC_XMLFILE environment variable, or the hwloc_topology_set_xml() function.
The following special names may be used:
- Send a text summary to stdout.
Send a text summary to stdout. It is effectively the same as specifying "-".
If the entire filename is "-.<format>", lstopo behaves as if "--of <format> -" was given, which means a file of the given format is
sent to the standard output.
See the output of "lstopo --help" for a specific list of what graphical output formats are supported in your hwloc installation.
Individual CPUs are colored in the semi-graphical and graphical output formats to indicate different characteristics:
Green The topology is reported as seen by a specific process (see --pid), and the given CPU is in this process CPU binding mask.
White The CPU is in the allowed set (see below). If the topology is reported as seen by a specific process (see --pid), the given CPU is
also not in this process CPU binding mask.
Red The CPU is not in the allowed set (see below).
Black The CPU is offline (not all OS's support displaying offline CPUs).
The "allowed set" is the set of CPUs to which the current process is allowed to bind. The allowed set is usually either inherited from the
parent process or set by administrative qpolicies on the system. Linux cpusets are one example of limiting the allowed set for a process
and its children to be less than the full set of CPUs on the system.
Different processes may therefore have different CPUs in the allowed set. Hence, invoking lstopo in different contexts and/or as different
users may display different colors for the same individual CPUs (e.g., running lstopo in one context may show a specific CPU as red, but
running lstopo in a different context may show the same CPU as white).
Some lstopo output modes, e.g. the console mode (default non-graphical output), do not support colors at all. The console mode displays
the above characteristics by appending text to each PU line if verbose messages are enabled.
In its graphical output, lstopo uses simple rectangular heuristics to try to achieve a 4/3 ratio between width and height. However, in the
particular case of NUMA nodes, the layout is always a flat rectangle, to avoid letting the user believe any particular NUMA topology
(lstopo is not able to render that yet).
To display the machine topology in textual mode:
To display the machine topology in pseudo-graphical mode:
To display in graphical mode (assuming that the DISPLAY environment variable is set to a relevant value):
To export the topology to a PNG file:
To export an XML file on a machine and later display the corresponding graphical output on another machine:
machine1$ lstopo file.xml
<transfer file.xml from machine1 to machine2>
machine2$ lstopo --input file.xml
To save the current machine topology to XML and later reload it faster while still considering it as the current machine:
$ lstopo file.xml
$ lstopo --input file.xml --thissystem
To restrict an XML topology to only physical processors 0, 1, 4 and 5:
lstopo --input file.xml --restrict 0x33 newfile.xml
To restrict an XML topology to only numa node whose logical index is 1:
lstopo --input file.xml --restrict $(hwloc-calc --input file.xml node:1) newfile.xml
To display a summary of the topology:
To get more details about the topology:
To only show cores:
lstopo --only core
To show cpusets:
To only show the cpusets of sockets:
lstopo --only socket --cpuset-only
Simulate a fake hierarchy; this example shows with 2 NUMA nodes of 2 processor units:
lstopo --input "n:2 2"
To count the number of logical processors in the system
lstopo --only pu | wc -l
hwloc(7), hwloc-info(1), hwloc-bind(1), hwloc-ps(1), hwloc-gather-topology(1)
1.7 Apr 07, 2013 LSTOPO(1)