Powerd and est / eist functionality

[Ian Smith]

On Fri, 26 Mar 2010, Jeremy Chadwick wrote:

[ leaving the MB monitoring stuff alone for your expert attention :-]

 > > It jumped up in vcore a little there with powerd. C1E and C2E which
 > > include P-states are what I am really after and I think that the
 > > bios by itself provides those changes better than any other changes
 > > in these settings.
 > 
 > ...and this would fall under the est(4) subset driver for cpufreq(4).

Just checking, I know nothing about these so far, but are you suggesting 
that John having C1E and C2E enabled in BIOS may be affecting ACPI/EST 
detection, and that things may be different were these disabled?

If that's not what you meant, could you expand a little?

John: you may want to explore where this comes together in kern_cpu.c 
where you'll see those cpufreq debugging messages you quoted.  Some of 
the more gritty documentation may be found browsing with something like: 
% less /sys/{sys,kern,amd64/include}/*cpu*.[ch]

cheers, Ian