Subject: Re: [RFC PATCH 00/17] virtual-bus

From: Avi Kivity <[email-masked]>
Date: Fri, 03 Apr 2009 14:54:02 +0300

Herbert Xu wrote:
> On Fri, Apr 03, 2009 at 02:46:04PM +0300, Avi Kivity wrote:
>   
>> The host writes the packet to tap, at which point it is consumed from  
>> its point of view.  The host would like to mention that if there was an  
>> API to notify it when the packet was actually consumed, then it would  
>> gladly use it.  Bonus points if this involves not copying the packet.
>>     
>
> We're using write(2) for this, no? 

Yes.

> That should invoke netif_rx_ni
> which blocks until the packet is "processed", which usually means
> that it's placed on the NIC's hardware queue.
>   

It doesn't copy and queue the packet?  We use O_NONBLOCK and poll() so 
we can tell when we can queue without blocking.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.