Re: [PATCH v15 00/17] Provide a zero-copy method on KVM virtio-net.

From: David Miller
Date: Wed Nov 10 2010 - 12:46:22 EST


From: xiaohui.xin@xxxxxxxxx
Date: Wed, 10 Nov 2010 17:23:28 +0800

> From: Xin Xiaohui <xiaohui.xin@xxxxxxxxx>
>
>>2) The idea to key off of skb->dev in skb_release_data() is
>> fundamentally flawed since many actions can change skb->dev on you,
>> which will end up causing a leak of your external data areas.
>
> How about this one? If the destructor_arg is not a good candidate,
> then I have to add an apparent field in shinfo.

If destructor_arg is actually a net_device pointer or similar,
you will need to take a reference count on it or similar.

Which means --> good bye performance especially on SMP.

You're going to be adding new serialization points and at
least two new atomics per packet.
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