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I've a problem on one of my Gentoo server. After some time, the clock starts running very very slow. It takes about one minute for one second to go. The major problem is that not only the clock is impacted but the system is running slow as well. If I run top, it takes more than 10 seconds to open. A sleep 1 takes about a minute.

There is no load on the system, almost nothing is running. I'm running the kernel 4.0.5. The hardware clock is running fine.

What could be the source of such problem ?

Here is the clocksource information: 

# cat /sys/devices/system/clocksource/clocksource0/available_clocksource
refined-jiffies jiffies tsc
# cat /sys/devices/system/clocksource/clocksource0/current_clocksource
refined-jiffies
Baptiste Wicht
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    Check the current clock source. (This may be failing hardware). – Konrad Gajewski Jul 10 '15 at 11:31
  • Reboot into `knoppix` to compare. If `knoppix` runs without a clock problem, then there's a problem with your kernel or a hardware problem. If `knoppix` has the same clock issue, then it's a hardware issue. – CIA Jul 10 '15 at 13:20
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    @KonradGajewski I added information about the clocksource. It is using refined-jiffies. Could that be an issue since I'm running a system with "dynticks idle" ? – Baptiste Wicht Jul 10 '15 at 15:28
  • Try using jiffies and tsc and see what happens. – Konrad Gajewski Jul 10 '15 at 15:31
  • Did you compile your own kernel (I am not really good with Gentoo). – Konrad Gajewski Jul 10 '15 at 15:49
  • Take a look at the known issues with dynticks_idle, you could try changing the interrupt handling strategy to rule that out: https://www.kernel.org/doc/Documentation/timers/NO_HZ.txt – ErikE Jul 10 '15 at 23:09

1 Answers1

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Changing the clocksource to tsc fixed the problem.

Baptiste Wicht
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