[LinuxPPS] 100hz versus 250hz kernel

[Udo van den Heuvel]

clemens at dwf.com wrote:
>> Folkert van Heusden wrote:
>>> Has anyone measured the stability for a 100hz and a non-100-hz kernel
>>> (eg 250hz)?
>> Please add the NO_HZ thingie for 2.6.28 since that could help with the 
>> 'slowness' of 100 Hz?
>>
> This was discussed, at least slightly, several months ago when I was
> having problems.
> 
> The net result was that the TIMEKEEPING KERNEL code needs different time constants
> for different frequencies.  It would seem that FreeBSD (may) have these
> time constants built in, but Linux definately doesnt.

At 2.6.28 this is still the fact?
If so, do we know the right values for 250Hz?
Then we could propose a kernel patch?

> I sent a email to the person listed as taking care of this code in Linux,
> but as far as I know, nothing has been done.

Hmmm.. Time for action?

Udo