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From: Jason Wang <jasowang@redhat.com>
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Date: Mon, 28 Sep 2015 14:12:56 +0800
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Subject: Re: [Qemu-devel] [PATCH v11 09/12] netfilter: add a netbuffer filter
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To: Markus Armbruster <armbru@redhat.com>, Yang Hongyang <yanghy@cn.fujitsu.com>
Cc: thuth@redhat.com, stefanha@redhat.com, zhang.zhanghailiang@huawei.com, lizhijian@cn.fujitsu.com, qemu-devel@nongnu.org



On 09/25/2015 11:07 PM, Markus Armbruster wrote:
> Yang Hongyang <yanghy@cn.fujitsu.com> writes:
>
>> On 09/24/2015 05:12 PM, Markus Armbruster wrote:
>>> Yang Hongyang <yanghy@cn.fujitsu.com> writes:
>>>
>>>> This filter is to buffer/release packets, this feature can be used
>>>> when using MicroCheckpointing, or other Remus like VM FT solutions, you
>>> What's "Remus"?

[...]

>>>
>>>> +
>>>> +static void filter_buffer_release_timer(void *opaque)
>>>> +{
>>>> +    NetFilterState *nf = opaque;
>>>> +    FilterBufferState *s = FILTER_BUFFER(nf);
>>> Style nit: blank line between declarations and statements, please.
>>>
>>>> +    filter_buffer_flush(nf);
>>> Is purging correct here?
> When the timer expires, we flush as many buffered packets as we can,
> then throw away the rest.  Why throw them away?  Shouldn't we leave them
> in the buffer, and only throw away packets when the buffer is full?

May need a "FIXME" or "TODO" here. I think this is for simplicity. We
could queue the packet if the receiver or next filter could not receive
packets. But currently there's no way for the next filter or recivier to
notify us that it can receive more packet. This could be done in the future.