Re: TODO list for qemu+KVM networking performance v2

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jun 10, 2009 at 07:08:49PM +0300, Avi Kivity wrote:
> Michael S. Tsirkin wrote:
>> On Wed, Jun 10, 2009 at 06:18:01PM +0300, Avi Kivity wrote:
>>   
>>> Michael S. Tsirkin wrote:
>>>     
>>>> But I don't understand how aio will make implementing it easier -
>>>> or are you merely saying that it will make it worthwhile?
>>>>         
>>> If you have aio, the the NIC and the guest proceed in parallel.  If 
>>> the  guest is faster (likely), then when it sends the next packet it 
>>> will see  that interrupts are disabled and not notify again.  Once 
>>> aio complete we  can recheck the queue; if it's empty we reenable 
>>> notifications.  If  there's still stuff in it we submit it with 
>>> notifications disabled.
>>>     
>>
>> So you are saying that with aio we won't need this optimization at all?
>> I guess it's late in the day, and my mind is fuzzy...
>>   
>
> No, I'm saying with aio the optimization becomes worthwhile.  But I  
> joined late in the thread so we may be talking about different things.

Oh, I see that. What Rusty's saying is that it's not as
trivial as it seems, and I agree. And at some point it
seemed like he was saying it's easier to implement with
aio, but that probably was just my misunderstanding.

-- 
MST