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Re: [Xen-devel] cpuidle causing Dom0 soft lockups

>>> Keir Fraser <keir.fraser@xxxxxxxxxxxxx> 21.01.10 12:03 >>>
>On 21/01/2010 10:53, "Jan Beulich" <JBeulich@xxxxxxxxxx> wrote:
>> I can see your point. But how can you consider shipping with something
>> apparently severely broken. As said before - the fact that this manifests
>> itself by hanging many-vCPU Dom0 has the very likely implication that
>> there are (so far unnoticed) problems with smaller Dom0-s. If I had a
>> machine at hand that supports C3, I'd try to do some measurements
>> with smaller domains...
>
>Well it's a fallback I guess. If we can't make progress on solving it then I
>suppose I agree.

Just fyi, we now also have seen an issue on a 24-CPU system that went
away with cpuidle=0 (and static analysis of the hang hinted in that
direction). All I can judge so far is that this likely has something to do
with our kernel's intensive use of the poll hypercall (i.e. we see vCPU-s
not waking up from the call despite there being pending unmasked or
polled for events).

Jan


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