Kernel clock issue "Clocksource tsc unstable"

[Rashkae]

Hal Burgiss wrote:

> 
> On the older system I get:
> 
> cat /sys/devices/system/clocksource/clocksource0/available_clocksource
>  tsc acpi_pm jiffies 
> 
> and its using tsc ATM. On the other, newer system:
> 
> cat /sys/devices/system/clocksource/clocksource0/available_clocksource
>   acpi_pm jiffies tsc 
> 
> and its *now* using acpi_pm, but I don't know what it was before
> resetting it today. Its possible, that there had been a kernel update
> somewhere and it did not kick in until the reboot and the clocksource
> might be different. I had no log data at all on that system since
> yesterday at 6:05, so I am in the dark on that one.
> 
> 
>> You can specify one of the available clocksources by editing your grub
>> menu.lst file and appending a clocksource= option to the kernel you
>> boot.  For example, you can try clocksource=acpi_pm and test if acpi
>> works if you boot with it rather than switch to it.  If acpi_pm doesn't
>> work reliably on your systems, I would then try hpet or pit if those are
>> available.
> 
> Thanks for the info! Very helpful.
> 


wow,, your hardware is a bit limited, with no hpet timer and no pic
timer.. (pic was the old standard timer).   Jiffies, as I understand,
should be avoided like the plague and is only included for special
cases.  (Jiffies is basically the software counting time based on cpu
clock frequency or some such.)

I would try adding clocksource=acpi_pm to the boot of both your systems
and see if that solves the problem.