Re: [PATCH]tickless: Fix tick nohz timer irq0 fail to increaase

[Peter Zijlstra]

On Mon, 2010-01-04 at 04:36 -0800, Arjan van de Ven wrote:
> > cause is that it is default to enable high resolution timer which
> > will force to oneshot broadcast mode.
> 
> using local apic in one shot mode is not a problem, I'd in fact call it
> a feature... 

lapic yes, broadcast not so much.

He mentioned he was using Nehelem-EX which is known broken in that it
stops the lapic in deeper C states and thus reverts to HPET broadcast
since there's not enough HPET timers to go around.

Something like processor.max_cstate=2 should fix that IIRC.

Jens ran into this on his shiny new box.

Disabling nohz is funny indeed, one wonders why he does that.

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