Re: Linux 2.6.29-rc6

From: Jesper Krogh
Date: Wed Mar 04 2009 - 13:37:21 EST


Jesper Krogh wrote:
john stultz wrote:
I guess something to test my idea above (that the drift is bad enough
that NTPd isn't making slew adjustments via adjtimex offset) is to
remove NTPd from the init.d startup.

Then after rebooting (into 2.6.29), run the attached python script for
10 minutes or so to get an idea of the ppm drift. Then repeat with
2.6.26.

To run: ./drift-test.py <ntp server>

It will give some wild ppm numbers, but after a few minutes it should
settle down to the "natural drift" of the system.

Ok. I removed ntpd from the system... heres is from "non-working

Updated. I think I has NTPd running in the former "non-working" test. I just tried to reproduce the numbers, and they look like this (reproducible on 2.6.29-rc6).

jk@quad12:~$ python drift-test.py 10.192.96.19
04 Mar 19:27:10 offset: -0.157696 drift: -693.0 ppm
04 Mar 19:28:10 offset: -0.195134 drift: -625.098360656 ppm
04 Mar 19:29:10 offset: -0.232579 drift: -624.595041322 ppm
04 Mar 19:30:10 offset: -0.270021 drift: -624.408839779 ppm
04 Mar 19:31:11 offset: -0.307461 drift: -621.727272727 ppm
04 Mar 19:32:11 offset: -0.344903 drift: -622.185430464 ppm
04 Mar 19:33:11 offset: -0.382345 drift: -622.491712707 ppm
04 Mar 19:34:11 offset: -0.419794 drift: -622.727488152 ppm
04 Mar 19:35:11 offset: -0.457239 drift: -622.89626556 ppm

Still the same.

And from working 2.6.27.19 kernel.

jk@quad12:~$ python drift-test.py 10.192.96.19
04 Mar 16:17:23 offset: -0.006929 drift: -62.0 ppm
04 Mar 16:18:24 offset: -0.010252 drift: -54.5967741935 ppm
04 Mar 16:19:24 offset: -0.013574 drift: -54.9754098361 ppm
04 Mar 16:20:24 offset: -0.016897 drift: -55.1098901099 ppm
04 Mar 16:21:24 offset: -0.020233 drift: -55.2314049587 ppm
04 Mar 16:22:24 offset: -0.023566 drift: -55.2947019868 ppm
04 Mar 16:23:24 offset: -0.026895 drift: -55.3259668508 ppm
04 Mar 16:24:24 offset: -0.030217 drift: -55.3317535545 ppm
04 Mar 16:25:24 offset: -0.033539 drift: -55.3360995851 ppm
04 Mar 16:26:24 offset: -0.036865 drift: -55.3468634686 ppm
04 Mar 16:27:25 offset: -0.038266 drift: -52.0713101161 ppm
04 Mar 16:28:25 offset: -0.039747 drift: -49.592760181 ppm
04 Mar 16:29:25 offset: -0.041331 drift: -47.6680497925 ppm



--
Jesper
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