hwloc-dump-hwdata - Man Page

Dump topology and locality information from hardware tables


hwloc-dump-hwdata [options]


-o <dir>

save output files to directory <dir> instead of the default /run/hwloc/ that was specified at configure time.

You may want to set the HWLOC_DUMPED_HWDATA_DIR environment variable as well so that the hwloc library looks for dumped files in that same directory.

-h --help

Display help message and exit.


hwloc may benefit from some locality and topology information from SMBIOS or ACPI tables. They are accessible from raw hardware files under directories such /sys/firmware/dmi/ or /sys/firmware/acpi/ on Linux. These files are usually only accessible to root, and they only exist when there is dmi-sysfs support in the Linux kernel.

The hwloc-dump-hwdata tool dumps the useful contents of such files into human-readable and world-accessible files. The intent is to run the tool once during boot and have the main (non-privileged) hwloc library gather information from these human-readable files.

hwloc-dump-hwdata is currently only useful for Intel Xeon Phi processors (Knights Landing and Knights Mill).

The current list of dumped information is:

Intel Xeon Phi processor memory, cache and clustering configuration

gathered from specific SMBIOS entries such as /sys/firmware/dmi/entries/14-* and /sys/firmware/dmi/entries/160-*, and saved in file knl_memoryside_cache.

See Also

hwloc(7), lstopo(1)


Mar 30, 2020 2.2.0 hwloc