Re: [kvm-devel] [PATCH 0/2] Batch writes to MMIO

[Avi K. <av...@qu...>]

Anthony Liguori wrote:
> Avi Kivity wrote:
>   
>> Anthony Liguori wrote:
>>     
>>> The ne2k is pretty mmio heavy.  You should be able to observe a boost 
>>> with something like iperf (guest=>host) I would think if this is a 
>>> real savings.
>>>
>>>       
>> If we're just improving ne2k, the complexity isn't worth it.  We have 
>> two better nics which are widely supported in guests.
>>     
>
> Sure, but the ne2k should be pretty close to an optimal synthetic 
> benchmark for batching.  If we don't see a big improvement with it, 
> we're probably not going to see a big improvement with it for anything.
>   

I disagree.  If there are other inefficiencies in ne2k, they will mask 
any performance improvement from batching.  So whatever result we get 
will be inconclusive.

I don't expect any massive performance improvement except for splash 
screens.  I'll be happy to settle for a few percent with e1000 or scsi 
or ide.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.