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hwloc-gather-cpuid - 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>.
-s --silent
Do not show verbose messages.
-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


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.


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

February 11, 2021 2.4.1