Langsdorf, Mark wrote:
* On Thu, Oct 27, 2005 at 01:04 PM (+0100), Jonathan Brooks wrote:
I have an AMD Athlon64 X2 machine running SuSE 10 (x86_64) on an Nvidia Nforce4 Ultra motherboard, and have noticed that the system clock has become unstable (it runs too fast). Not sure when it occurred, but I have been getting a lot of error messages like this in dmesg:
warning: many lost ticks. Your time source seems to be instable or some driver is hogging interupts rip acpi_processor_idle+0x12f/0x37f [processor] I had a very similar (or the same?) problem on a "Tyan Thunder K8SE 2892G3NR" dual Opteron machine running SuSE Linux 9.3: The system time ran much too fast (minutes were almost running like seconds), the screen saver started only seconds after not moving the mouse or pressing a key and the log file was full of these messages ("many lost ticks").
My notice was that it especially happend when the CPU usage grew, so I suppose it was related to the "powernow" feature of the CPU, because at least on Opteron systems SuSE's "power management" changes the CPU clock based on the load.
After I upgraded to the most recent vanilla kernel the problem was gone.
The powernow-k8 driver in SL9.3 caused clock instability on SMP machines that did not support HPET timers; SL10.0 and the mainstream kernel support PMTimer for those machines. That's most likely what you were seeing.
The single processor, dual-core problem is believed to be something different and is under investigation at AMD. We will make a statement as soon as we have definite information.
-Mark Langsdorf AMD, Inc.
Wow! Wasn't expecting to get an answer straight from the horse's mouth (so to speak) :) So can you confirm that the kernel options clock=pmtmr and notsc will not have any effect on this problem, and we should wait for a resolution from AMD? Sorry for the request for clarification, but I'm stumbling around in the dark on this matter, and don't want to waste any more time on the problem - especially if it's all fruitless. Best wishes, Jon. -- Jonathan Brooks (Ph.D.) Research Assistant. PaIN Group, Department of Human Anatomy & Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX tel: +44(0)1865-282654 fax: +44(0)1865-282656 web: http://www.fmrib.ox.ac.uk/~jon