tree 7da5bba73363087ade7aa031f937d08666f8e0ee
parent 356f039822b8d802138f7121c80d2a9286976dbd
author Eric Dumazet <eric.dumazet@gmail.com> 1292880171 +0000
committer David S. Miller <davem@davemloft.net> 1292957438 -0800

net: timestamp cloned packet in dev_queue_xmit_nit

Le vendredi 17 décembre 2010 à 10:26 +0100, Eric Dumazet a écrit :

>
> I think we can add this after latest Changli patch :
>
> He does one skb_clone() before calling the sniffers.
> We could set timestamp on this clone, instead of original skb.
>
> Problem solved.
>

[PATCH net-next-2.6] net: timestamp cloned packet in dev_queue_xmit_nit

Now we do one clone of skb if at least one sniffer might take packet,
we also can do the skb timestamping on the clone and let original packet
unchanged.

This is a generalization of commit 8caf153974f2 (net: sch_netem: Fix an
inconsistency in ingress netem timestamps.)

This way, we can have a good idea when packets are delivered to our
stack (tcpdump -i ifb0), while a tcpdump on original device gives
timestamps right before ingressing.

This also speedup our stack, avoiding taking timestamps if not needed.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Changli Gao <xiaosuo@gmail.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Jarek Poplawski <jarkao2@gmail.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>