Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 72/75] ipv4: set transport header earlier | Date | Tue, 30 Jul 2013 11:45:16 -0700 |
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3.8.13.6 -stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet <edumazet@google.com>
[ Upstream commit 21d1196a35f5686c4323e42a62fdb4b23b0ab4a3 ]
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@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- 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 f1395a6..e1e5a6a 100644 --- a/net/ipv4/ip_input.c +++ b/net/ipv4/ip_input.c @@ -190,10 +190,7 @@ static int ip_local_deliver_finish(struct sk_buff *skb) { struct net *net = dev_net(skb->dev); - __skb_pull(skb, ip_hdrlen(skb)); - - /* Point into the IP datagram, just past the header. */ - skb_reset_transport_header(skb); + __skb_pull(skb, skb_network_header_len(skb)); rcu_read_lock(); { @@ -442,6 +439,8 @@ 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; + /* Remove any debris in the socket control block */ memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); -- 1.8.1.2
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