From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jason Wang <jasowang@redhat.com>
Subject: Re: [PATCH net-next v7 3/4] net: vhost: factor out busy polling logic
 to vhost_net_busy_poll()
Date: Thu, 2 Aug 2018 16:18:39 +0800
Message-ID: <b4ffd376-6fa8-4d0c-5c3a-82d1b6e924d6@redhat.com>
References: <1533092454-37196-1-git-send-email-xiangxia.m.yue@gmail.com>
 <1533092454-37196-4-git-send-email-xiangxia.m.yue@gmail.com>
 <30e62749-3cbd-ae88-6582-c20087884b20@redhat.com>
 <CAMDZJNWX7L4P0yO+-PeDFu_tmtLSntihO7rcLPB2GK4eN9zbwQ@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Cc: mst@redhat.com, makita.toshiaki@lab.ntt.co.jp,
        virtualization@lists.linux-foundation.org,
        Linux Kernel Network Developers <netdev@vger.kernel.org>
To: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Return-path: <netdev-owner@vger.kernel.org>
Received: from mx3-rdu2.redhat.com ([66.187.233.73]:45120 "EHLO mx1.redhat.com"
        rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP
        id S1726224AbeHBKIq (ORCPT <rfc822;netdev@vger.kernel.org>);
        Thu, 2 Aug 2018 06:08:46 -0400
In-Reply-To: <CAMDZJNWX7L4P0yO+-PeDFu_tmtLSntihO7rcLPB2GK4eN9zbwQ@mail.gmail.com>
Content-Language: en-US
Sender: netdev-owner@vger.kernel.org
List-ID: <netdev.vger.kernel.org>



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