Subject: Re: [net-next rfc v7 2/3] virtio_net: multiqueue support

From: "Michael S. Tsirkin" <[email-masked]>
Date: Mon, 3 Dec 2012 13:00:37 +0200

On Mon, Dec 03, 2012 at 06:30:49PM +0800, Jason Wang wrote:
> On 12/03/2012 06:14 PM, Michael S. Tsirkin wrote:
> > On Tue, Nov 27, 2012 at 06:15:59PM +0800, Jason Wang wrote:
> >> > -	if (!try_fill_recv(&vi->rq, GFP_KERNEL))
> >> > -		schedule_delayed_work(&vi->rq.refill, 0);
> >> > +	for (i = 0; i < vi->max_queue_pairs; i++)
> >> > +		if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
> >> > +			schedule_delayed_work(&vi->rq[i].refill, 0);
> >> >  
> >> >  	mutex_lock(&vi->config_lock);
> >> >  	vi->config_enable = true;
> >> >  	mutex_unlock(&vi->config_lock);
> >> >  
> >> > +	BUG_ON(virtnet_set_queues(vi));
> >> > +
> >> >  	return 0;
> >> >  }
> >> >  #endif
> > Also crashing on device nack of command is also not nice.
> > In this case it seems we can just switch to
> > single-queue mode which should always be safe.
> 
> Not sure it's safe. It depends on the reason why this call fails. If we
> left a state that the driver only use single queue but the device use
> multi queues, we may still lost the network.

Not the way driver is currently written - you'll happily
process incoming packets from all queues so no problem?

-- 
MST