Messages in this thread | | | Date | Tue, 14 Sep 2010 11:52:57 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: Interrupt latency on some 945GM platforms |
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On Tue, 14 Sep 2010, Vasily Khoruzhick wrote:
> В сообщении от 14 of September 2010 03:55:32 автор Venkatesh Pallipadi > написал: > > > Whats the clockevent in this case ("Tick Device" section of > > /proc/timer_list). clocksource= option only changes the clocksource used > > to maintain > > timeofday. But, timer interrupt (clockevent) source will not change. > > Wondering how just the clocksource change is making the diff here.. > > > > Also, if clocksource tsc has a higher rating than HPET. The reason > > HPET is getting used as clocksource in the first place seems to be due > > to TSC is not a dependable clocksource on this platform (may be it > > stops in C3). So, I am not sure forcing it to tsc will be a good > > thing. May be clocksource=acpi_pm is a better thing to try. > > > > Thanks, > > Venki > > I investigated it a bit and found out that single nohz=off option helps. Just > changing clocksource doesn't help, but it works smoothly with any clocksource > with nohz=off. So, it seems that something wrong with intel driver while > system is in tickless mode.
Can you try with NOHZ enabled and the following on the kernel command line:
processor.max_cstate=1
Make sure that CONFIG_ACPI_PROCESSOR is set to "y" and not to "m"
If that works, then try
processor.max_cstate=2
Thanks,
tglx | |