Red Hat Bugzilla – Bug 236611
Kernel 2.6.20-1.2944.fc6 - ntp now correcting time by +1s approx every 15 mins
Last modified: 2008-08-02 19:40:36 EDT
Description of problem:
Since using the 2944 kernel, ntp is now reporting a time reset of +1.05 seconds
approximately every 15 minutes.
Version-Release number of selected component (if applicable):
Happens constantly with kernel 2.6.20-1.2944.fc6 when using ntp-4.2.4p0-1.fc6
Steps to Reproduce:
1. Boot with kernel shown above
2. Look in /var/log/messages for ntp output
3. Find "time reset" messages from ntpd
time reset +1.0xxxxs from ntpd in /var/log/messages
These messages did not exist with any previous FC6 kernel test, so 2798, 2925,
Please post contents of the file /var/log/dmesg after booting
both the working and non-working kernels.
Created attachment 152772 [details]
dmesg for 2.6.20-1.2944.fc6 - this being the broken kernel
Created attachment 152773 [details]
dmesg for working kernel 2.6.20-1.2933.fc6
Please try the kernel parameter "clocksource=acpi_pm" or
clocksource=acpi_pm has removed the time reset messages.
Would a test with clocksource=pit be useful? If so I'll do it later today and
add the result here.
BTW, I can't find a succinct explanation of how these different clock sources
differ. Is there anything that describes it, or is is a "read the source" job?
Unfortunately the clocksource parameter isn't very well documented.
After booting you can look in
(This is a mass-update to all current FC6 kernel bugs in NEW state)
I'm reviewing this bug list as part of the kernel bug triage project, an attempt
to isolate current bugs in the Fedora kernel.
I am CC'ing myself to this bug, however this version of Fedora is no longer
Please attempt to reproduce this bug with a current version of Fedora (presently
Fedora 8). If the bug no longer exists, please close the bug or I'll do so in a
few days if there is no further information lodged.
Thanks for using Fedora!
No longer seeing this problem, currently using Fedora 7 with latest kernel
18.104.22.168-52.fc7, I do not have any Fedora 8 systems at present.
Note that I no longer have the hardware that triggered this bug (failed
motherboard that is no longer bootable).