[LinuxPPS] hardpps: PPSJITTER: jitter=80945, limit=67744

[Udo van den Heuvel]

Alexander,

On 2010-12-24 03:00, Alexander Gordeev wrote:
> Udo van den Heuvel <udovdh at xs4all.nl> пишет:
> 
>> I see messages like
>>
>> hardpps: PPSJITTER: jitter=80945, limit=67744
>>
>> every few minutes in my messages file. How come? How to fix?
> 
> I suspect that you have CONFIG_NO_HZ enabled.

There is no software fix to make NO_HZ behave like e.g. 100HZ?

>> Do I need RT kernel?
> 
> Should not be necessary.

Well, I would like to combine the power saving of NO_HZ with good
timekeeping. I know that they can be hard to combine, but this is just
catching an interrupt every now and then?

> Can you please try the latest patchset:
> https://github.com/downloads/ago/linux-2.6/patch-2.6.37-rc6-ts22.bz2
> 
> Kconfig magic in it ensures that users never select both CONFIG_NO_HZ
> and CONFIG_NTP_PPS at the same time. Please note that CONFIG_NTP_PPS is
> not selected automatically now so you may have to select it manually.

As soon as 2.6.37 hits post-rc status I will give it a go!
(firewall is ntp server, needs stable kernel)

Kind regards,
Udo