Steven M. Bellovin wrote:

>On Fri, 09 Jun 2006 13:34:42 +0200, Frank Kardel <kardel@NetBSD.org> wrote:
>
>
>  
>
>>Yes, this is something I expected to happen.
>>Background: The implementation of TSC is
>>different for different CPUs. Older CPUs use the clock
>>frequency to drive TSC and are thus dependent on selected
>>frequency. Newer CPUs are said to count at a fixed frequency
>>regardless of the selected frequency (possibly using bigger
>>increments).
>>FreeBSD did disable TSC when some kind of Powermanagement
>>is detected.
>>Instead of TSC try using i8254:
>>     sysctl  -w kern.timecounter.hardware=i8254
>>
>>    
>>
>
>Is it safe to put that into /etc/sysctl.conf unconditionally?
>
Yes.

>  I use estd,
>which changes the frequency quite frequently when I'm running on battery.
>  
>
Sensible thing to do for now until we have more counters and
better defaulting in place.

>		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb
>
>  
>
Frank