Marcelo Tosatti wrote on 2013-01-09:
> On Wed, Jan 09, 2013 at 08:07:31AM +0000, Zhang, Yang Z wrote:
>>>>    if(check_request(KVM_REQ_, ....)) {
>>>>            ioapic_lock();          (*)
>>>>            update local EOI exit bitmap from IOAPIC
>> In my patch, it traverses IOAPIC entry once and only updates target
>> vcpus's eoi exit bitmap. Then make request for all vcpus. With your
>> suggestion , all vcpus will traverse all IOAPIC entries. Though ioapic
> entry write is rare, it's still not reasonable.
> 
> It should be fast, and very rare (as in once during system
> initialization, or device hotplug).
Ok. Will revise the patch follow your suggestion.

> 
> Is there a particular case that makes it necessary to optimize scanning?
No. 

>> 
>>>>            ioapic_unlock();
>>>>    }
>>>> 
>>> Fine by me. Looks simpler.
>>> 
>>>> 
>>>> 
>>>> (*) plus any other lock that paths that update the map take
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>>> 
>>>>> Best regards,
>>>>> Yang
>>> 
>>> --
>>>                     Gleb.
>> 
>> 
>> Best regards,
>> Yang


Best regards,
Yang

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