Re: [PATCH] KVM: disable halt_poll_ns as default for s390x

[Paolo Bonzini <pbonzini@redhat.com>]

On 24/09/2015 13:06, Christian Borntraeger wrote:
> Am 18.09.2015 um 13:29 schrieb Paolo Bonzini:
>>
>>
>> On 18/09/2015 12:54, Christian Borntraeger wrote:
>>>> -/* halt polling only reduces halt latency by 5-7 us, 500us is enough */
>>>> -static unsigned int halt_poll_ns = 500000;
>>>> +/* Architectures should define their poll value according to the halt latency */
>>>> +static unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT;
>>>
>>> Yes, I prefer this over disabling it via Kconfig. There are benchmarks which
>>> benefit from polling on s390. Furthermore it seems that the latency
>>> strongly depends on timing of the architecture so making it per arch is
>>> probably the right thing to do.
>>
>> Perhaps a #ifndef is better than replicating the 500us default in all
>> architectures?  Or should the default be 0?
> 
> Any guidance from your side? All different proposals are certainly ok.
> Are you going to take Davids patch or shall he respin?

I've committed the patch as is, and I'm preparing a pull request.

Paolo