netdev - Re: [PATCH net-next v7 3/4] net: vhost: factor out busy polling logic to vhost_net_busy

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Date:   Thu, 2 Aug 2018 16:18:39 +0800
From:   Jason Wang <jasowang@...hat.com>
To:     Tonghao Zhang <xiangxia.m.yue@...il.com>
Cc:     mst@...hat.com, makita.toshiaki@....ntt.co.jp,
        virtualization@...ts.linux-foundation.org,
        Linux Kernel Network Developers <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next v7 3/4] net: vhost: factor out busy polling logic
 to vhost_net_busy_poll()



On 2018年08月01日 17:52, Tonghao Zhang wrote:
>>> +
>>> +             cpu_relax();
>>> +     }
>>> +
>>> +     preempt_enable();
>>> +
>>> +     if (!rx)
>>> +             vhost_net_enable_vq(net, vq);
>> No need to enable rx virtqueue, if we are sure handle_rx() will be
>> called soon.
> If we disable rx virtqueue in handle_tx and don't send packets from
> guest anymore(handle_tx is not called), so we can wake up for sock rx.
> so the network is broken.

Not sure I understand here. I mean is we schedule work for handle_rx(), 
there's no need to enable it since handle_rx() will do this for us.

Thanks