netdev - [PATCH V2 1/2] af_packet: make tpacket_rcv to not set status value before run

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Date:	Mon, 23 Mar 2015 09:11:12 +0300
From:	Alexander Drozdov <al.drozdov@...il.com>
To:	"David S. Miller" <davem@...emloft.net>,
	Jonathan Corbet <corbet@....net>
Cc:	Daniel Borkmann <dborkman@...hat.com>,
	Eric Dumazet <edumazet@...gle.com>,
	Al Viro <viro@...iv.linux.org.uk>,
	Willem de Bruijn <willemb@...gle.com>,
	"Michael S. Tsirkin" <mst@...hat.com>, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org, Tobias Klauser <tklauser@...tanz.ch>,
	linux-doc@...r.kernel.org, linux-api@...r.kernel.org,
	Alexander Drozdov <al.drozdov@...il.com>
Subject: [PATCH V2 1/2] af_packet: make tpacket_rcv to not set status value before run_filter

It is just an optimization. We don't need the value of status variable
if the packet is filtered.

Signed-off-by: Alexander Drozdov <al.drozdov@...il.com>
---
 net/packet/af_packet.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index f8db706..6ecf8dd 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1910,14 +1910,15 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
 		}
 	}
 
-	if (skb->ip_summed == CHECKSUM_PARTIAL)
-		status |= TP_STATUS_CSUMNOTREADY;
-
 	snaplen = skb->len;
 
 	res = run_filter(skb, sk, snaplen);
 	if (!res)
 		goto drop_n_restore;
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL)
+		status |= TP_STATUS_CSUMNOTREADY;
+
 	if (snaplen > res)
 		snaplen = res;
 
-- 
1.9.1

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