Re: [RFC PATCH net-next 02/12] vhost_net: introduce vhost_exceeds_weight()

[Jason Wang]

On 2018å05æ22æ 00:29, Jesse Brandeburg wrote:
> On Mon, 21 May 2018 17:04:23 +0800 Jason wrote:
> > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> > ---
> >   drivers/vhost/net.c | 13 ++++++++-----
> >   1 file changed, 8 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> > index 15d191a..de544ee 100644
> > --- a/drivers/vhost/net.c
> > +++ b/drivers/vhost/net.c
> > @@ -479,6 +479,12 @@ static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter,
> >   	return len;
> >   }
> >   
> > +static bool vhost_exceeds_weight(int pkts, int total_len)
> > +{
> > +	return unlikely(total_len >= VHOST_NET_WEIGHT) ||
> > +	       unlikely(pkts >= VHOST_NET_PKT_WEIGHT);
> I was going to say just one unlikely, but then the caller of this
> function also says unlikely(vhost_exceeds...), so I think you should
> just drop the unlikely statements here (both of them)

Ok.

> > +}
> > +
> >   /* Expects to be always run from workqueue - which acts as
> >    * read-size critical section for our kind of RCU. */
> >   static void handle_tx(struct vhost_net *net)
> > @@ -570,7 +576,6 @@ static void handle_tx(struct vhost_net *net)
> >   			msg.msg_control = NULL;
> >   			ubufs = NULL;
> >   		}
> > -
> unrelated whitespace changes?

Yes.

Thanks

> >   		total_len += len;
> >   		if (total_len < VHOST_NET_WEIGHT &&
> >   		    !vhost_vq_avail_empty(&net->dev, vq) &&
> > @@ -600,8 +605,7 @@ static void handle_tx(struct vhost_net *net)
> >   		else
> >   			vhost_zerocopy_signal_used(net, vq);
> >   		vhost_net_tx_packet(net);
> > -		if (unlikely(total_len >= VHOST_NET_WEIGHT) ||
> > -		    unlikely(++sent_pkts >= VHOST_NET_PKT_WEIGHT)) {
> > +		if (unlikely(vhost_exceeds_weight(++sent_pkts, total_len))) {
> >   			vhost_poll_queue(&vq->poll);
> >   			break;
> >   		}
> > @@ -887,8 +891,7 @@ static void handle_rx(struct vhost_net *net)
> >   		if (unlikely(vq_log))
> >   			vhost_log_write(vq, vq_log, log, vhost_len);
> >   		total_len += vhost_len;
> > -		if (unlikely(total_len >= VHOST_NET_WEIGHT) ||
> > -		    unlikely(++recv_pkts >= VHOST_NET_PKT_WEIGHT)) {
> > +		if (unlikely(vhost_exceeds_weight(++recv_pkts, total_len))) {
> >   			vhost_poll_queue(&vq->poll);
> >   			goto out;
> >   		}