HWLOC-GATHER-CPUID(1) hwloc HWLOC-GATHER-CPUID(1)

# [NAME](#NAME)

hwloc-gather-cpuid - Dumps the relevant x86 cpuid values for later (possibly offline) usage

# [SYNOPSIS](#SYNOPSIS)

**hwloc-gather-cpuid \[*options*] \[*<outdir>*]**

# [OPTIONS](#OPTIONS)

[**-c <idx>**](#c)

Only gather cpuid values for logical processor whose OS/physical index is <idx>.

[**-q** **--quiet** **-s** **--silent**](#q)

Do not show verbose messages.

[**--version**](#version)

Report version and exit.

[**-h** **--help**](#h)

Display help message and exit.

# [DESCRIPTION](#DESCRIPTION)

**hwloc-gather-cpuid** dumps all the relevant x86 cpuid values into subdirectory *cpuid* of current directory, or in **<outdir>** if specified.

These files can be used later to explore the machine topology offline, for instance by setting the environment variable *HWLOC\_CPUID\_PATH* to the directory containing all output files, and by forcing the x86 backend with *HWLOC\_COMPONENTS=x86,stop*.

The directory contents may also be submitted to hwloc developers to debug issues remotely.

If **-** is used as <outdir>, the output is dumped to the standard output, but a unique logical processor must have been given with **-c**.

**hwloc-gather-cpuid** is a x86 specific tool, it cannot be used on other platforms.

**NOTE:** **hwloc-gather-cpuid** gathers many hardware details about the platform. Output files should not be posted on public lists or websites unless it is clear that they contain no sensitive information.

**NOTE:** The output of **hwloc-gather-cpuid** is included in the tarball saved by **hwloc-gather-topology** on Linux/x86.

**NOTE:** It is highly recommended that you read the [hwloc(7)](/man/enterprise-packages/hwloc-cuda-12.9/hwloc.7) overview page before reading this man page.

# [EXAMPLES](#EXAMPLES)

To store cpuid information of all logical processors of the current machine:

$ hwloc-gather-cpuid  
Gathering in directory ./cpuid ...  
Gathering CPUID of PU P#0 in path ./cpuid/pu0 ...  
Gathering CPUID of PU P#1 in path ./cpuid/pu1 ...  
Gathering CPUID of PU P#2 in path ./cpuid/pu2 ...  
Gathering CPUID of PU P#3 in path ./cpuid/pu3 ...  
Summary written to ./cpuid/hwloc-cpuid-info

# [RETURN VALUE](#RETURN_VALUE)

Upon successful execution, **hwloc-gather-cpuid** will exit with the code 0.

**hwloc-gather-cpuid** will return nonzero exit status if any kind of error occurs, such as (but not limited to) failure to create the output files.

# [SEE ALSO](#SEE_ALSO)

[hwloc(7)](/man/enterprise-packages/hwloc-cuda-12.9/hwloc.7), [hwloc-gather-topology(1)](/man/enterprise-packages/hwloc-cuda-12.9/hwloc-gather-topology.1), [lstopo(1)](/man/enterprise-packages/hwloc-cuda-12.9/lstopo.1)

Unreleased developer copy 2.15.0rc2-git

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Document: hwloc-gather-cpuid(1) from hwloc-cuda-12.9 2.15.0-r0 (Chainguard OS)
Source: https://github.com/open-mpi/hwloc