Re: CONFIG_NO_HZ: missed ticks, stall (keyb IRQ required) [2.6.18-rc4-mm1]

[Ingo Molnar <mingo@elte.hu>]

* Len Brown <len.brown@intel.com> wrote:

> So given that C3 on every known system that has shipped to date breaks 
> the LAPIC timer (and apparently this applies to C2 on these AMD 
> boxes), dynticks needs a solid story for co-existing with C3.

check out 2.6.19-rc4-mm2: it detects this breakage and works it around 
by using the PIT as a clock-events source. That did the trick on my 
laptop which has this problem too. I agree with you that degrading the 
powersaving mode is not an option.

we've got a question about HPET: it seems all recent hardware has it, 
but the BIOS rarely mentions it, so the Linux driver does not enable 
HPET. Is there any chance to enable HPET (in the chipset?) - this would 
probably be a higher-quality clock-events source than the PIT.

	Ingo