libpmc: Add pmc.perf.3 manpage

[anascime_amd.com]

Summary

Document the AMD APERF/MPERF PMC events added in the preceding
change, describing their semantics and how to use them via pmc(3)
and pmcstat(8).

Signed-off-by: Anderson Nascimento <[e-mail]>
Sponsored by: AMD

[ziaee]

Why did you spin this off into it's own revision? I left feedback on your previous review, which was the appropriate place for it, and none of it is addressed here.

[anascime_amd.com]

In D58649#1345757, @ziaee wrote:

Why did you spin this off into it's own revision? I left feedback on your previous review, which was the appropriate place for it, and none of it is addressed here.

That was the intention at first, but as this is my first submission, I ended up putting it all together. I was instructed to do it that way because it would be better for reviewing. I only saw your comments after I created this differential. I'll apply the corrections you suggested and update this revision. Thank you very much!

[ziaee]

Siloing off docs is a classic mistake that results in poor docs. I would greatly prefer if you abandoned this revision and put them back together. Thank you for your consideration.

[anascime_amd.com]

In D58649#1345762, @ziaee wrote:

Siloing off docs is a classic mistake that results in poor docs. I would greatly prefer if you abandoned this revision and put them back together. Thank you for your consideration.

Done! I've put everything together in one revision and marked this one as abandoned. Sorry for the mistake.

hwpmc: add APERF/MPERF MSR support for AMD CPUs
https://reviews.freebsd.org/D58647

[ziaee]

Done! I've put everything together in one revision and marked this one as abandoned.

Thank you so much, review feedback left there

Sorry for the mistake.

Please, no need to apologize. This is a widespread issue in our profession.