Kernel clock issue "Clocksource tsc unstable"

[NoOp]

On 02/27/2009 02:21 PM, Hal Burgiss wrote:
> On Fri, Feb 27, 2009 at 03:18:29PM -0500, Rashkae wrote:
>> 
>> wow,, your hardware is a bit limited, with no hpet timer and no pic
> 
> The older one is dual P3's in an IBM server box. It ran fine for years
> on CentOS and probably Gentoo before that, so this is all curious.
> Either the hardware has gotten funky or something in the ubuntu server
> kernel is funky. The newer one is a brand new AMD Opteron. 

Don't feel bad... have an old Thinkpad A21M that doesn't have hpet either.

> 
>> 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.
> 
> Thanks. I'll give that a shot. 
> 

I wonder if your issue is related to this:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/221351
[TSC Clocksource can cause hangs and time jumps]

You might also want to have a look at:
https://launchpad.net/ubuntu/hardy/+source/linux/2.6.24-24.50
Note the TSC/clock issues.

Changelog

linux (2.6.24-24.50) hardy-proposed; urgency=low

  [Alok Kataria]

  * x86: add X86_FEATURE_HYPERVISOR feature bit
    - LP: #319945
  * x86: add a synthetic TSC_RELIABLE feature bit
    - LP: #319945
  * x86: vmware: look for DMI string in the product serial key
    - LP: #319945
  * x86: Hypervisor detection and get tsc_freq from hypervisor
    - LP: #319945
  * x86: Use the synthetic TSC_RELIABLE bit to workaround virtualization
    anomalies.
    - LP: #319945
  * x86: Skip verification by the watchdog for TSC clocksource.
    - LP: #319945
  * x86: Mark TSC synchronized on VMware.
    - LP: #319945

You can click on the bugs in the changelog to have a look. Also:
https://launchpad.net/+search?field.text=TSC+Clocksource
[messy, but sometimes turns up a place to start when in doubt]