Hello. On 16-07-2013 7:03, Eric Dumazet wrote:
From: Eric Dumazet <edumazet@xxxxxxxxxx>
commit 45f00f99d6e ("ipv4: tcp: clean up tcp_v4_early_demux()") added a performance regression for non GRO traffic, basically disabling IP early demux.
IPv6 stack resets transport header in ip6_rcv() before calling IP early demux in ip6_rcv_finish(), while IPv4 does this only in ip_local_deliver_finish(), _after_ IP early demux.
GRO traffic happened to enable IP early demux because transport header is also set in inet_gro_receive()
Instead of reverting the faulty commit, we can make IPv4/IPv6 behave the same : transport_header should be set in ip_rcv() instead of ip_local_deliver_finish()
ip_local_deliver_finish() can also use skb_network_header_len() which is faster than ip_hdrlen()
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Neal Cardwell <ncardwell@xxxxxxxxxx> Cc: Tom Herbert <therbert@xxxxxxxxxx> --- net/ipv4/ip_input.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c index 3da817b..15e3e68 100644 --- a/net/ipv4/ip_input.c +++ b/net/ipv4/ip_input.c
[...]
@@ -437,6 +434,8 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, goto drop; } + skb->transport_header = skb->network_header + iph->ihl*4;
Spaces around * wouldn't hurt, to be consistent with the rest of the statement and the Linux style in common.
WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html