# Clocksource is unstable [unsolved]

## jonfr

I am have a bit of a odd problem. This message happens regularly.

```
Clocksource tsc unstable (delta = 62500223 ns)

```

Here are info on the system.

```
uname -a

Linux jupiter 2.6.32.9 #1 SMP PREEMPT Tue Mar 16 01:42:44 GMT 2010 x86_64 AMD Athlon(tm) 64 X2 Dual Core Processor 5200+ AuthenticAMD GNU/Linux

```

Any suggestion on how to fix this ? This appeared after I added 2GB memory to this pc, from 1GB to 3GB.

Thanks for the help.

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## aCOSwt

I would understand it is not the best idea however, did you try disabling the acpi in the bios ?

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## Rexilion

That mostly happens when you use cpufreq, I have it too:

 *Quote:*   

> Marking TSC unstable due to cpufreq changes

 

It's nothing bad. Unless you are experiencing something weird with your clock.

Furthermore, yes ACPI might 'fix' it. But that could cause a lot of stuff to stop working (sound, network, audio etc etc)

What you are basically doing is disabling cpufreq when you disable ACPI. But ACPI is important in computers these days.

What I try to say, is that marking something unstable doesn't imply it's 'bad'   :Very Happy: 

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## jonfr

I never use cpufreq option as this is not a laptop. I do not know why I get this error, and I don't know how to fix them.

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## Rexilion

It's *not* an error. It's just to acknowledge you that a certain clocksource has been marked unstable. That does not say your hardware/kernel is bad. Unless you are experiencing trouble (which I doubt).

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## Sadako

You could always just switch to another clocksource if this really bothers you, "/sys/devices/system/clocksource/clocksource0/available_clocksource" should list the currently available sources, and you can simply echo whatever value you want to "/sys/devices/system/clocksource/clocksource0/current_clocksource" upon boot via /etc/conf.d/local (or local.start with baselayout 1).

Of course, this depends on what you have available in terms of hardware and enabled in the kernel, acpi_pm appears to have been developed precisely for what you're seeing.

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## jonfr

What command do I add to local.start to change about clock source ?

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## s4e8

This is non error, so no fix.

AMD multi-core CPU has a mis-feature, the TSC between 2 core is UNSYNC, this message just say it and won't use unsync TSC as clocksource (TSC is fastest clocksource). Just like the /usepmtimer in BOOT.INI.

Other reason TSC can't be clocksource is TSC stopped in deep sleepping mode. Many Intel CPU has this problem.

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## Hupf

 *jonfr wrote:*   

> What command do I add to local.start to change about clock source ?

 

In /boot/grub/grub.conf, add clocksource=hpet (e.g.) to your kernel=... line. See also /usr/src/linux/Documentation/kernel-parameters.txt for further reference.

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