man: convert some URLs to https

branches: 1.36.8;
Normalize some machine dependent CPU frequenct sysctl variables.

This moves machdep.*.frequency.* to machdep.cpu.frequency.*.

This was proposed on tech-kern some time ago. The intention is to allow
third-party tools such as estd and conky to more easily and reliably
fetch or modify the current CPU frequency without iterating through
various machine-dependent variables to check their presence.

Pp before Bl

branches: 1.34.34; 1.34.40; 1.34.42;
Finally, add missing %D.

One more.

Add few papers to SEE ALSO. Particularly the first one demonstrates
the diminishing value of P-states compared to C-states on new CPUs.

Fix SYNOPSIS.

Add missing period.

Xref x86/tsc(9).

Add one bug to the list. (Neither acpicpu(4) nor est(4) or powernow(4)
handle possible skew in timers and counters such as TSC.)

Finally remove COMPATIBILITY entirely. Xref odcm(4).

Update compatibility notes.

Fix powernow section in xref.

Remove the last reference to #ifdef a.k.a. options(4) POWERNOW_K8.

Update.

Update compatibility notes.

branches: 1.21.2;
Update.

Fix typos.

Remove C1E from CAVEATS, as it is now handled by acpicpu(4).

Note that all relatively new x86 systems should prefer acpicpu(4).

Also mention that the legacy ENHANCED_SPEEDSTEP and POWERNOW_K8 are known to
be problematic or entirely dysfunctional with new processors.

Grammar fix.

Fix PR kern/43765 from Scott Ellis.

Note that the solution is not optimal. If ichlpcib(4) provides SpeedStep
support, possible I/O resource conflicts may occur with acpicpu(4). Ideally,
as noted for instance in Windows design documents, ichlpcib(4) should never
expose SpeedStep when ACPI is being used. The probability for potential race
conditions is however very small, being limited to few P4-era machines and
being dependent on user actions.

Add native support for AMD family 0Fh processors. This is the furthest we
will go backwards; K7 will not be supported already due doubts about
availability and reliability of ACPI during that era. Some unfortunate code
duplication is present (but not overly much). Thanks to cegger@ and jakllsch@
for patiently testing this.

Add COMPATIBILITY.

Update.

branches: 1.12.2;
After a second thought, remove the references, clarify wording, fix acronym.

Add some basic references that were used to write acpicpu(4).

Use capitals in a subtitle.

Document T-states. One less item in CAVEATS.

Document the sysctl(8) controls with a note that these may be removed in
future versions without further notice.

Call a flag flag, not argument.

Note the gathered statistics. One CAVEAT down.

Fix a typo. Sypported indeed.

Group hyphens differently.

Fix typo.

Document P-states. Update notes about C-states. Shorten CAVEATS.

Add acpicpu(4). Describes the basic functionality (will be adjusted as the
functionality grows). Contains a big list of caveats as a TODO.