1HWLOC-INFO(1)                        hwloc                       HWLOC-INFO(1)
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NAME

6       hwloc-info - Show some information about some objects or about a topol‐
7       ogy or about support features
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SYNOPSIS

10       hwloc-info [ options ]...  <object>...
11
12       hwloc-info [ options ]...
13
14       Note that hwloc(7) provides a detailed explanation of the hwloc  system
15       and  of  valid  <object> formats; it should be read before reading this
16       man page.
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OPTIONS

19       --objects
20              Report information specific objects.  This  is  the  default  if
21              some objects are given on the command-line.
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23       --topology
24              Report  a summary of the topology instead of about some specific
25              objects.  This is the default if no object is given on the  com‐
26              mand-line.
27
28       --support
29              Report the features that are supported by hwloc on the topology.
30              The  features  are  those  available  through  the  hwloc_topol‐
31              ogy_get_support()  function.  This is useful for verifying which
32              CPU or memory binding options are supported by the current hwloc
33              installation.
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35       -i <file>, --input <file>
36              Read  topology  from XML file <file> (instead of discovering the
37              topology on the local machine).  If <file> is "-", the  standard
38              input  is used.  XML support must have been compiled in to hwloc
39              for this option to be usable.
40
41       -i <directory>, --input <directory>
42              Read topology from <directory> instead of discovering the topol‐
43              ogy  of  the local machine.  On Linux, the directory may contain
44              the topology files gathered from another machine  topology  with
45              hwloc-gather-topology.   On  x86,  the  directory  may contain a
46              cpuid dump gathered with hwloc-gather-cpuid.
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48       -i <specification>, --input <specification>
49              Simulate a fake hierarchy (instead of discovering  the  topology
50              on  the local machine). If <specification> is "node:2 pu:3", the
51              topology will contain two NUMA nodes with 3 processing units  in
52              each of them.  The <specification> string must end with a number
53              of PUs.
54
55       --if <format>, --input-format <format>
56              Enforce the input in the given format, among xml, fsroot,  cpuid
57              and synthetic.
58
59       -v --verbose
60              Include additional detail.
61
62       -s --silent
63              Reduce the amount of details to show.  A single summary line per
64              object is displayed.
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66       --ancestors
67              Display information about the object as well as  about  all  its
68              ancestors up to the root of the topology.
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70       --ancestor <type>
71              Only display the object ancestors that match the given type.
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73       --children
74              Display information about the object children.
75
76       --descendants <type>
77              Display  information about the object descendants that match the
78              given type.
79
80       --local-memory
81              Display information about the NUMA nodes that are local  to  the
82              given object.
83
84       --local-memory-flags
85              Change  the flags used to select local NUMA nodes.  Flags may be
86              given as numeric values or as a  comma-separated  list  of  flag
87              names that are passed to hwloc_get_local_numanode_objs().  Those
88              names may be substrings of actual flag names as long as a single
89              one  matches.   The default is 3 (or smaller,larger) which means
90              NUMA nodes are displayed if their locality either contains or is
91              contained in the locality of the given object.
92
93              This option enables --local-memory.
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95       --best-memattr <name>
96              Enable  the  listing local memory nodes with --local-memory, but
97              only display the local node that has the best value for the mem‐
98              ory  attribute  given by <name> (or as an index).  If the memory
99              attribute values depend on the initiator, the  object  given  to
100              hwloc-info is used as the initiator.
101
102       -n     When  outputting  object  information, prefix each line with the
103              index of the considered object within the input.  For  instance,
104              if  three  cores  were  given in input, the output lines will be
105              prefixed with "0: ", "1: " or "2:  ".   If  --ancestor  is  also
106              used,  the  prefix  will  be "X.Y: " where X is the index of the
107              considered object within the input, and Y is the parent index (0
108              for the object itself, increasing towards the root of the topol‐
109              ogy).
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111       --disallowed
112              Include objects disallowed by administrative limitations.
113
114       --restrict <cpuset>
115              Restrict the topology to the given cpuset.
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117       --restrict nodeset=<nodeset>
118              Restrict  the  topology  to  the  given  nodeset,  unless  --re‐
119              strict-flags specifies something different.
120
121       --restrict binding
122              Restrict  the topology to the current process binding.  This op‐
123              tion requires the use of the actual current machine topology (or
124              any  other  topology  with --thissystem or with HWLOC_THISSYSTEM
125              set to 1 in the environment).
126
127       --restrict-flags <flags>
128              Enforce flags when restricting the topology.  Flags may be given
129              as  numeric  values  or  as a comma-separated list of flag names
130              that are passed to hwloc_topology_restrict().  Those  names  may
131              be  substrings  of  actual  flag  names  as long as a single one
132              matches, for instance bynodeset,memless.  The default is  0  (or
133              none).
134
135       --filter <type>:<kind>, --filter <type>
136              Filter  objects  of  type  <type>,  or  of any type if <type> is
137              "all".  "io", "cache" and "icache" are also supported.
138
139              <kind> specifies the filtering behavior.  If "none" or not spec‐
140              ified, all objects of the given type are removed.  If "all", all
141              objects are kept as usual.  If  "structure",  objects  are  kept
142              when they bring structure to the topology.  If "important" (only
143              applicable to I/O and Misc), only important  objects  are  kept.
144              See hwloc_topology_set_type_filter() for more details.
145
146       --no-icaches
147              Do not show Instruction caches, only Data and Unified caches are
148              considered.  This is identical to --filter icache:none.
149
150       --no-io
151              Do not show any I/O device or  bridge.   This  is  identical  to
152              --filter io:none.  By default, common devices (GPUs, NICs, block
153              devices, ...) and interesting bridges are shown.
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155       --no-bridges
156              Do not show any I/O bridge except hostbridges.  This is  identi‐
157              cal  to --filter bridge:none.  By default, common devices (GPUs,
158              NICs, block devices, ...) and interesting bridges are shown.
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160       --whole-io
161              Show all I/O devices and bridges.  This is identical to --filter
162              io:all.   By default, only common devices (GPUs, NICs, block de‐
163              vices, ...) and interesting bridges are shown.
164
165       --thissystem
166              Assume that the selected backend provides the topology  for  the
167              system on which we are running.  This is useful when using --re‐
168              strict binding and loading a custom  topology  such  as  an  XML
169              file.
170
171       --pid <pid>
172              Detect  topology  as  seen  by process <pid>, i.e. as if process
173              <pid> did the discovery itself.  Note that this can for instance
174              change  the  set  of allowed processors.  Also show this process
175              current CPU binding by marking the corresponding PUs  (in  Green
176              in the graphical output, see the COLORS section below, or by ap‐
177              pending (binding) to the verbose text output).  If 0 is given as
178              pid, the current binding for the lstopo process will be shown.
179
180       -p --physical
181              Use OS/physical indexes instead of logical indexes for input.
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183       -l --logical
184              Use  logical  indexes  instead  of physical/OS indexes for input
185              (default).
186
187       --version
188              Report version and exit.
189
190       -h --help
191              Display help message and exit.
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DESCRIPTION

194       hwloc-info displays information about the specified object.  It is  in‐
195       tended  to be used with tools such as grep for filtering certain attri‐
196       bute lines.  When no object is specified, or when --topology is passed,
197       hwloc-info prints a summary of the topology.  When --support is passed,
198       hwloc-info lists the supported features for the topology.
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200       Objects may be specified as location tuples, as explained in  hwloc(7).
201       However hexadecimal bitmasks are not accepted since they may correspond
202       to multiple objects.
203
204       NOTE: It is highly recommended that you read the hwloc(7) overview page
205       before  reading  this  man  page.   Most  of  the concepts described in
206       hwloc(7) directly apply to the hwloc-calc utility.
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EXAMPLES

209       To display information about each package:
210
211           $ hwloc-info package:all
212           Package L#0
213            logical index = 0
214           ...
215
216       To display information about the core whose physical index is 2:
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218           $ hwloc-info -p core:2
219           Core L#1
220            logical index = 1
221            os index = 2
222           ...
223
224       To list the NUMA nodes that are local a PU:
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226           $ hwloc-info --local-memory pu:25
227           NUMANode L#6 = local memory #0 of PU L#25
228            type = NUMANode
229           ...
230           NUMANode L#7 = local memory #1 of PU L#25
231            type = NUMANode
232           ...
233
234       To show the best-bandwidth node among NUMA nodes local to a PU:
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236           $ hwloc-info --local-memory --best-memattr bandwidth pu:25
237           NUMANode L#7 = local memory #1 of PU L#25
238            type = NUMANode
239           ...
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SEE ALSO

243       hwloc(7), lstopo(1), hwloc-calc(1), hwloc-bind(1), hwloc-ps(1)
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2482.5.0                            Jun 14, 2021                    HWLOC-INFO(1)
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