netdev - [RESEND] can: omit unneeded skb

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Date:	Tue, 06 Jan 2009 11:18:54 +0100
From:	Oliver Hartkopp <oliver@...tkopp.net>
To:	David Miller <davem@...emloft.net>
CC:	Urs Thuermann <urs.thuermann@...kswagen.de>,
	Linux Netdev List <netdev@...r.kernel.org>
Subject: [RESEND] can: omit unneeded skb_clone() calls

The AF_CAN core delivered always cloned sk_buffs to the AF_CAN
protocols, although this was _only_ needed by the can-raw protocol.
With this (additionally documented) change, the AF_CAN core calls the
callback functions of the registered AF_CAN protocols with the original
(uncloned) sk_buff pointer and let's the can-raw protocol do the
skb_clone() itself which omits all unneeded skb_clone() calls for other
AF_CAN protocols.

Signed-off-by: Oliver Hartkopp <oliver@...tkopp.net>
Signed-off-by: Urs Thuermann <urs.thuermann@...kswagen.de>
---

Hello Dave,

this is a simple (and tested) improvement to omit superfluous skb_clone() 
calls in the CAN core.

Please check if it's ok for the current merge window as it is not really a fix.

If it's not ok, i'll resubmit it when net-next-2.6 re-opens.

The resend was due to a removal of these parentheses:

-	if ((!ro->recv_own_msgs) && (skb->sk == sk))
+	if (!ro->recv_own_msgs && skb->sk == sk)

Thanks,
Oliver

View attachment "omit_skbclone_resend.patch" of type "text/x-patch" (3452 bytes)