On 2018/08/02 18:23, Jason Wang wrote:
> On 2018年08月02日 16:41, Toshiaki Makita wrote:
>> On 2018/08/02 17:18, Jason Wang wrote:
>>> On 2018年08月01日 17:52, Tonghao Zhang wrote:
>>>>> +static void vhost_net_busy_poll_check(struct vhost_net *net,
>>>>> + struct vhost_virtqueue *rvq,
>>>>> + struct vhost_virtqueue *tvq,
>>>>> + bool rx)
>>>>> +{
>>>>> + struct socket *sock = rvq->private_data;
>>>>> +
>>>>> + if (rx)
>>>>> + vhost_net_busy_poll_try_queue(net, tvq);
>>>>> + else if (sock && sk_has_rx_data(sock->sk))
>>>>> + vhost_net_busy_poll_try_queue(net, rvq);
>>>>> + else {
>>>>> + /* On tx here, sock has no rx data, so we
>>>>> + * will wait for sock wakeup for rx, and
>>>>> + * vhost_enable_notify() is not needed. */
>>>> A possible case is we do have rx data but guest does not refill the rx
>>>> queue. In this case we may lose notifications from guest.
>>> Yes, should consider this case. thanks.
>> I'm a bit confused. Isn't this covered by the previous
>> "else if (sock && sk_has_rx_data(...))" block?
>
> The problem is it does nothing if vhost_vq_avail_empty() is true and
> vhost_enble_notify() is false.
If vhost_enable_notify() is false, guest will eventually kicks vq, no?
--
Toshiaki Makita
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