Subject: Re: [PATCH RFC 1/4] virtio_net: pass vi around

From: "Michael S. Tsirkin" <[email-masked]>
Date: Fri, 24 Oct 2014 17:10:23 +0300

On Fri, Oct 24, 2014 at 10:02:15AM +0000, David Laight wrote:
> From: Michael S. Tsirkin
>  
> > Too many places poke at [rs]q->vq->vdev->priv just to get
> > the the vi structure.  Let's just pass the pointer around: seems
> > cleaner, and might even be faster.
> > 
> > Signed-off-by: Michael S. Tsirkin <[email-masked]>
> > ---
> >  drivers/net/virtio_net.c | 36 +++++++++++++++++++-----------------
> >  1 file changed, 19 insertions(+), 17 deletions(-)
> > 
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 57cbc7d..36f3dfc 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> ...
> >  static struct sk_buff *receive_big(struct net_device *dev,
> > +				   struct virtnet_info *vi,
> 
> Do you need to pass 'dev' here?
> Looks like it is obtainable from vi->dev (as below).
> 
> 	David
> 
> >  				   struct receive_queue *rq,
> >  				   void *buf,
> >  				   unsigned int len)
> >  {
> >  	struct page *page = buf;
> > -	struct sk_buff *skb = page_to_skb(rq, page, 0, len, PAGE_SIZE);
> > +	struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
> ...
> > -static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
> > +static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
> > +			void *buf, unsigned int len)
> >  {
> > -	struct virtnet_info *vi = rq->vq->vdev->priv;
> >  	struct net_device *dev = vi->dev;
> ...

It's a matter of style, isn't it?
We have dev to hand, it seems cleaner to just pass it around.

-- 
MST