Re: [NTP 0/9] NTP patches

From: Roman Zippel
Date: Thu Aug 17 2006 - 06:38:23 EST


Hi,

On Wed, 16 Aug 2006, john stultz wrote:

> How much real-world testing have you done with these patches? I've been
> running w/ this set of patches for a few days and I've been noticing my
> system is having difficulties synching up w/ the NTP server.

I tested it on a few machines of course.

> I haven't been logging anything, so its currently uncertain data, but
> normally I've seen NTP sync the time within 1-2ms in just an hour or so,
> however since this morning (~6 hours ago) I'm seeing it still 10ms off.
>
> I'm going to let it run for the rest of the day then try to bisect the
> patches to see where things went wrong. I'll let you know as soon as I
> find anything.

I would need the loopstats over a few days to really say something about
this. It may also depend on the stability of your remote NTP serer. The
new code adjusts a little a slower, but should be overall a little more
stable.
The ntpd does basically "if (!pll_nano) ntv.constant = sys_poll - 4;" to
adjust for the difference in behaviour of the two models, but this causes
rather fast adjustments. In the NTP4 patch I undo this adjustment for the
new model.

> I'm going to let it run for the rest of the day then try to bisect the
> patches to see where things went wrong. I'll let you know as soon as I
> find anything.

Well, upto the NTP4 patch the behaviour should be mostly unchanged.

bye, Roman
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