1HWLOC-INFO(1) hwloc HWLOC-INFO(1)
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6 hwloc-info - Show some information about some objects or about a topol‐
7 ogy or about support features
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10 hwloc-info [ options ]... <object>...
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12 hwloc-info [ options ]...
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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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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.
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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.
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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.
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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.
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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.
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76 --descendants <type>
77 Display information about the object descendants that match the
78 given type.
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80 --local-memory
81 Display information about the NUMA nodes that are local to the
82 given object.
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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.
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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.
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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).
110
111 --disallowed
112 Include objects disallowed by administrative limitations.
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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.
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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).
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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.
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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.
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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.
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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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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.
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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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209 To display information about each package:
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211 $ hwloc-info package:all
212 Package L#0
213 logical index = 0
214 ...
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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 ...
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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 ...
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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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243 hwloc(7), lstopo(1), hwloc-calc(1), hwloc-bind(1), hwloc-ps(1)
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2482.4.1 Feb 11, 2021 HWLOC-INFO(1)