On Fri, 09 Jun 2006, Frank Kardel wrote:
> Resolution options:
>    - Find a way to detect whether TSC frequency follows cpu
>      frequency if yes: no TSC for timekeeping as default that platform
>    - no TSC as default when powermanagement is present
>    - use other more suitable time counters (e. g. ACPI timer)

If you had a log of the history of recent CPU speed changes (with old
speed, new speed, and timestamp for each change) then it should be
possible to do the right arithmetic.  Add a hook to the timecounters
framework so that the speedstep code can report "I am now changing the
speed from X to Y", and let the timecounters code do the bookkeeping.

--apb (Alan Barrett)