Re: Enabling acpicpu(4) by default

[Jukka Ruohonen <jruohonen%iki.fi@localhost>]

On Thu, Dec 30, 2010 at 12:15:22PM -0500, Steven Bellovin wrote:
> What about pkgsrc/sysutils/estd -- will that work with acpicpu?

Yes, backwards compatibility is maintained; sysutils/estd or equivalent
solutions should work just fine. But it can be noted that the long-term
goal is to move towards a machine-independent in-kernel implementation, like
in most modern operating systems.

Generally there should be no visible changes to users. The machines that are
affected have been manufactured during the short period in which ACPI was not
yet widely used, but SpeedStep was moved to the "native", MSR-based, interface.
By assumption, this would correspond with Pentium 4 and AMD's Duron. The change
does not affect very old Pentiums that use ichlpcib(4) or even piixpcib(4) for
SpeedStep (largely due design mistakes done by Intel). On the bright side, it
is apparent that the different x86 processor power management facilities have
finally stabilized; presently both AMD and Intel use almost an identical
interface -- and ACPI is a central part of it.

- Jukka.