[cfarm-users] Fixing CPU/core/threads count

[Baptiste Jonglez]

On 04-04-20, Brice Goglin wrote:
> Old POWER machines (e.g. gcc110 POWER7) are known to report strange or
> invalid topology information, for instance by reporting one CPU package
> per core. I don't remember the reason but IBM developers didn't want to
> fix their firmware because it would break something else. Things are
> reported correctly on modern POWER8/9 afaik.
> 
> Some ARM platforms (gcc117,118) have a similar issue but things are
> improving now that vendors are implementing the PPTT ACPI table (once
> you use a recent Linux kernel).
> 
> Using NUMA nodes for CPU sockets is indeed unreliable these days. Most
> vendors can expose multiple NUMA nodes per CPU package.

Ok, thanks.  Does this also apply to x86?

Also, do you know if it's possible to obtain all information (number of
nodes, packages, cores, pu) in a single call to hwloc-*, ideally with an
easily-parsable output?

Baptiste
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