Messages in this thread | | | Subject | Re: PM-Timer clock source is slow. Try something else: How slow? What other source(s)? | From | john stultz <> | Date | Wed, 29 Nov 2006 17:32:09 -0800 |
| |
On Wed, 2006-11-29 at 16:56 -0800, Linda Walsh wrote: > I recently noticed this message in my bootup that I don't remember > from before: > > PCI: Probing PCI hardware (bus 00) > * Found PM-Timer Bug on the chipset. Due to workarounds for a bug, > * this clock source is slow. Consider trying other clock sources
This basically means that your chipset has a bug which requires the ACPI PM timer to be read three times in order to get a valid reading.
This will cause gettimeofday/clock_gettime to take longer to execute, which is what is meant by "slow" (rather then the counter's frequency being incorrect).
> How would this affect my clock? It says to try another > clock source, what type of clock source would it be suggesting I > use? Another chip already in the computer? It is an Intel 440BX > chipset; on an Dell motherboard. Would that be likely to have > another chip source that is compensating? > > I don't notice a significant clock slowdown, but I'm running NTP, > so that could be masking the problem.
Unless you're running performance critical programs that utilize gettimeofday/clock_gettime, you probably won't notice anything. Time should still function properly. If you are having performance issues, you can try using a different clocksource (the TSC is probably safe, but not necessarily).
thanks -john
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |