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From: Jason Wang <jasowang@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement
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To: Wen Congyang <wency@cn.fujitsu.com>, Zhang Chen <zhangchen.fnst@cn.fujitsu.com>, qemu devel <qemu-devel@nongnu.org>
Cc: zhanghailiang <zhang.zhanghailiang@huawei.com>, Li Zhijian <lizhijian@cn.fujitsu.com>, Gui jianfeng <guijianfeng@cn.fujitsu.com>, "eddie.dong" <eddie.dong@intel.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Yang Hongyang <hongyang.yang@easystack.cn>



On 03/17/2016 02:18 PM, Wen Congyang wrote:
>>>>>>> >>>>>> +                s->state = 0;
>>>>>>> >>>>>> +                /* FIXME: do something ? */
>>>>> >>>>
>>>>> >>>> This needs some thought, but at least reset the fd handler and state is
>>>>> >>>> needed.
>>> >> Maybe we can read the data from the chardev, and drop it?
>>> >>
>>> >> Thanks
>>> >> Wen Congyang
>>> >>
>> > 
>> > No function difference, but reading and dropping will cost extra cpu
>> > which seems not good.
> If we reset and receive it again, the unread data will be auto dropped?

If socket receive queue is not full, the data will be buffered there
(but the queue will be purged after qemu process exits). Otherwise it
will be dropped.

> If so, I think reset the fd handler is better choice.
>
> Thanks
> Wen Congyang
>