Re: System clock speed too high - 2.6.3 kernel

Bill Davidsen
2004-05-27T13:33:04Z

Joris van Rantwijk wrote:
> On Tue, 25 May 2004, john stultz wrote:
>
>>On Tue, 2004-05-25 at 02:22, Joris van Rantwijk wrote:
>>
>>>If there are many systems with this problem, then calibrating the PM timer
>>>against the PIT timer at boot time (possibly rejecting invalid rates)
>>>might be an option.
>
>
>>I'll put it on my todo list, but if you'd like to take a swing at ti and
>>beat me to the implementation, I wouldn't complain.
>
>
> Sounds fair. I tried something and it even seems to work here.
> My dmesg now says:
> PM-Timer running at invalid rate: 199% of normal - aborting.
> Detected 400.816 MHz processor.
> Using tsc for high-res timesource
>
> Hmm, I think I'm enjoying this :-)
> My patch is included below and also submitted at the Kernel Bugzilla
> thing. I would appreciate it if someone else could also test it a bit.
>
> Yesterday, I ran into a (hopefully) completely seperate issue with the
> timer. This happened before I even started messing with the kernel and
> while running with "clock=tsc". The kernel suddenly logged:
> Losing too many ticks!
> TSC cannot be used as a timesource
> ...
> Falling back to a sane timesource now.
>

Have to say that since adding clock=tsc my test systems are all keeping
perfect time (ntpd running) which has not been the case since I started
using test kernels about 2.5.38.

You do seem to have an issue with the pit.

--
-bill davidsen (davidsen@tmr.com)
"The secret to procrastination is to put things off until the
last possible moment - but no longer" -me