Subject: Re: HEADS UP: timecounters (branch simonb-timecounters) merged into
To: Steven M. Bellovin <email@example.com>
From: Frank Kardel <firstname.lastname@example.org>
Date: 06/09/2006 14:59:32
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
>>FreeBSD did disable TSC when some kind of Powermanagement
>>Instead of TSC try using i8254:
>> sysctl -w kern.timecounter.hardware=i8254
>Is it safe to put that into /etc/sysctl.conf unconditionally?
> 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