hwloc-gather-cpuid - Man Page

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


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


-c <idx>

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

-q --quiet -s --silent

Do not show verbose messages.


Report version and exit.

-h --help

Display help message and exit.


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) overview page before reading this man page.


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 ./hwloc-x86-cpuid/pu0 ...
       Gathering CPUID of PU P#1 in path ./hwloc-x86-cpuid/pu1 ...
       Gathering CPUID of PU P#2 in path ./hwloc-x86-cpuid/pu2 ...
       Gathering CPUID of PU P#3 in path ./hwloc-x86-cpuid/pu3 ...
       Summary written to ./cpuid/hwloc-cpuid-info

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

hwloc(7), hwloc-gather-topology(1), lstopo(1)

Referenced By

hwloc-gather-topology(1), lstopo(1).

Dec 04, 2023 2.10.0 hwloc