Messages in this thread | | | Date | Fri, 03 Aug 2007 09:47:17 +0200 | From | John Sigler <> | Subject | Re: System clock frequency offset changes drastically across reboots |
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> John Sigler wrote: > >> I'm using 2.6.20.7-rt8 on a P3. > > (But some ntpd users have reported the problem with mainline kernels and > different versions.) > >> I've noticed that the frequency offset of my system clock (computed >> either by ntpd, or by hand) changes drastically across reboots. >> >> By drastically, I mean +/- 60 ppm every time I reboot. >> >> Apparently this is caused by some imprecision in the frequency >> estimation done in calculate_cpu_khz() (arch/i386/kernel/tsc.c) >> >> My brutally crude work-around was to skip the computation altogether >> and hard-code the "correct" value for cpu_khz. >> >> http://linux.kernel.free.fr/cpu_khz.adlink >> >> Has this issue been investigated more thoroughly by other users?
Is there, perhaps, more appropriate a forum to discuss such matters?
Regards.
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