Re: [PATCH 2 of 2] Avoid vcpu migration of paused vcpus

[Juergen Gross <juergen.gross@ts.fujitsu.com>]

On 03/22/2012 12:20 PM, Keir Fraser wrote:
> On 22/03/2012 10:22, "Juergen Gross"<juergen.gross@ts.fujitsu.com>  wrote:
>
>> On 03/22/2012 11:12 AM, Keir Fraser wrote:
>>> Your original patch didn't touch this code. Was that an omission in the
>>> original version? On reflection I prefer your original patch to this new
>>> approach. I'll apply it if you still believe your original patch is complete
>>> and correct as it stands.
>> I like my second patch more :-)
>>
>> It covers more cases, not just poweroff. In hibernate case no vcpu pinnings
>> will be lost. Today all vcpus pinned to a cpu other than 0 will lose their
>> pinnings at cpu offlining. At reactivation those pinnings will not be
>> restored automatically. My patch will cover that by checking availability
>> of the cpus after reactivation.
>>
>> Poweroff (which was my primary concern) works with both versions. I did not
>> test other ACPI state changes with either version, but would expect better
>> results in hibernate case with my second approach.
> How about the attached patch? Which is similar to your original patch except
> I added the global state variable, and I added a check for it to
> cpu_disable_scheduler(). It's nice and small. :-)

Would you mind putting it in 4.1, too?


Juergen

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Juergen Gross                 Principal Developer Operating Systems
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