zero copy with PACKET_MMAP

[ratheesh kannoth]

Hi ,

The link

https://www.kernel.org/doc/Documentation/networking/packet_mmap.txt
talks about achieving zero copy. But i find a deep packet copy ( of
length snaplen= skb->len ) here
http://lxr.free-electrons.com/source/net/packet/af_packet.c#L1841.

Is there anything missing/wrong in my understanding ?


Thanks,
Ratheesh

[Daniel Borkmann]

On 02/27/2014 07:40 AM, ratheesh kannoth wrote:
...

Post by ratheesh kannoth
https://www.kernel.org/doc/Documentation/networking/packet_mmap.txt
talks about achieving zero copy. But i find a deep packet copy ( of
length snaplen= skb->len ) here
http://lxr.free-electrons.com/source/net/packet/af_packet.c#L1841.
Is there anything missing/wrong in my understanding ?

The zero-copy is between user and kernel space.