Clocksource tsc unstable

punt · 07-12-2007, 11:03 PM

My server keeps hanging and when I see the last event that occurred before the system lags in /var/log/messages, it is the following:

Code:

Jul 12 21:00:05 server kernel: Clocksource tsc unstable (delta = 4685968956 ns)
Jul 12 21:00:05 server kernel: Time: acpi_pm clocksource has been installed.

I asked someone about this and he suspected that my CMOS battery was dying. I replaced it. The problem remains.

This only started after I upgraded to Fedora 7. I didn't have this problem prior to that.

Has anyone else experienced the issue and/or knows of a fix or what this problem truly is?

TIA.

{BBI}Nexus{BBI} · 07-12-2007, 11:19 PM

TSC=Time Stamp Counter. Processors have dynamically changed clock speed (ofc to save power). The TSC is supposed to tick at the CPU rate (unless it's a constant_tsc, see /proc/cpuinfo flags, so on frequency change, this ought to happen. The kernel will automatically switch to something else. There's acpi_pm <-(this is what yours has switched to) and, IIRC, pit. This message seems to appear with the newer kernel upgrades.

punt · 07-12-2007, 11:28 PM

Thanks for the information. How do I remove it? Can I add constant_tsc to the flags on /proc/cpuinfo?

punt · 07-13-2007, 07:54 AM

Bump - just don't want to do the wrong thing and have kernel panic.

punt · 07-13-2007, 04:47 PM

Okay, I can't edit /proc/cpuinfo anyway. What can I do to avoid this problem? My server is dying nearly every 24-36 hours.

{BBI}Nexus{BBI} · 07-13-2007, 10:35 PM

Quote:

Originally Posted by punt

Okay, I can't edit /proc/cpuinfo anyway. What can I do to avoid this problem? My server is dying nearly every 24-36 hours.

Roll back to your previous kernel or see if there is a patch you can apply to your current kernel.

punt · 07-14-2007, 08:16 PM

I think all the previous kernels work for FC6. This problem only existed when I upgraded to FC7. I'm not familiar with how to go about this.

punt · 07-15-2007, 11:04 AM

bump for anyone specifically familiar with this for FC7. I'm about to reboot my machine again because of this problem.

{BBI}Nexus{BBI} · 07-15-2007, 02:50 PM

You could try disabling the acpi in the bios, other than that there seems to be various fixes around for the tsc problem. I don't know if any of them will help you. To see a few put this in google: Fix TSC timer selection

punt · 07-15-2007, 04:28 PM

I'm going to take the route to disable ACPI in the BIOS. We'll see what happens. Thanks.

punt · 07-20-2007, 06:10 PM

Just wanted to be fair to update this thread and say that it appears disabling the ACPI in the BIOS in fact did the trick. Thanks

saavik · 12-29-2008, 03:16 AM

that also helped me.

Thanks everybody.