On Wed, Jul 4, 2018 at 5:18 PM Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
>
>
> On 2018年07月04日 15:59, Toshiaki Makita wrote:
> > On 2018/07/04 13:31, xiangxia.m.yue@xxxxxxxxx wrote:
> > ...
> >> +static void vhost_net_busy_poll(struct vhost_net *net,
> >> + struct vhost_virtqueue *rvq,
> >> + struct vhost_virtqueue *tvq,
> >> + bool rx)
> >> +{
> >> + unsigned long uninitialized_var(endtime);
> >> + unsigned long busyloop_timeout;
> >> + struct socket *sock;
> >> + struct vhost_virtqueue *vq = rx ? tvq : rvq;
> >> +
> >> + mutex_lock_nested(&vq->mutex, rx ? VHOST_NET_VQ_TX: VHOST_NET_VQ_RX);
> >> +
> >> + vhost_disable_notify(&net->dev, vq);
> >> + sock = rvq->private_data;
> >> + busyloop_timeout = rx ? rvq->busyloop_timeout : tvq->busyloop_timeout;
> >> +
> >> + preempt_disable();
> >> + endtime = busy_clock() + busyloop_timeout;
> >> + while (vhost_can_busy_poll(tvq->dev, endtime) &&
> >> + !(sock && sk_has_rx_data(sock->sk)) &&
> >> + vhost_vq_avail_empty(tvq->dev, tvq))
> >> + cpu_relax();
> >> + preempt_enable();
> >> +
> >> + if ((rx && !vhost_vq_avail_empty(&net->dev, vq)) ||
> >> + (!rx && (sock && sk_has_rx_data(sock->sk)))) {
> >> + vhost_poll_queue(&vq->poll);
> >> + } else if (vhost_enable_notify(&net->dev, vq) && rx) {
> > Hmm... on tx here sock has no rx data, so you are waiting for sock
> > wakeup for rx and vhost_enable_notify() seems not needed. Do you want
> > this actually?
> >
> > } else if (rx && vhost_enable_notify(&net->dev, vq)) {
>
> Right, rx need to be checked first here.
thanks， if we dont call the vhost_enable_notify for tx. so we dont
need to call vhost_disable_notify for tx?
@@ -451,7 +451,9 @@ static void vhost_net_busy_poll(struct vhost_net *net,
tvq->busyloop_timeout;
mutex_lock_nested(&vq->mutex, rx ? VHOST_NET_VQ_TX: VHOST_NET_VQ_RX);
- vhost_disable_notify(&net->dev, vq);
+
+ if (rx)
+ vhost_disable_notify(&net->dev, vq);
preempt_disable();
endtime = busy_clock() + busyloop_timeout;
> Thanks
>
> >> + vhost_disable_notify(&net->dev, vq);
> >> + vhost_poll_queue(&vq->poll);
> >> + }
>
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