Dear Michal,
Thank you for your reply.
Am 14.02.22 um 10:43 schrieb Michal Suchánek:
On Mon, Feb 14, 2022 at 07:08:07AM +0100, Paul Menzel wrote:
Dear PPC folks,
On the POWER8 server IBM S822LC running `ppc64_cpu --smt=off` or `ppc64_cpu
--smt=8`, Linux 5.17-rc4 does not log anything. I would have expected a
message about the change in number of processing units.
IIRC it was considered too noisy for systems with many CPUs and the
message was dropped. You can always check the resulting state with
ppc64_cpu or examining sysfs.
Yes, simple `nproc` suffice, but I was more thinking about, that the
Linux log is often used for debugging and the changes of amount of
processing units might be good to have. `ppc64_cpu --smt=off` or `=8`
seems to block for quite some time, and each thread/processing unit
seems to powered down/on sequentially, so it takes quite some time and
it blocks. So 140 messages would indeed be quite noise. No idea how
`ppc64_cpu` works, and if it could log a message at the beginning and end.
Kind regards,
Paul
