| Message ID | 1373943799.10804.96.camel@edumazet-glaptop |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Hello. On 16-07-2013 7:03, Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > 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> > --- > 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 netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, 2013-07-16 at 17:24 +0400, Sergei Shtylyov wrote: > > + 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. I am well aware of this, I chose the convention used in this function and file. # grep ihl net/ipv4/ip_input.c opt->optlen = iph->ihl*4 - sizeof(struct iphdr); if (iph->ihl > 5 && ip_rcv_options(skb)) if (iph->ihl < 5 || iph->version != 4) if (!pskb_may_pull(skb, iph->ihl*4)) if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl))) } else if (len < (iph->ihl*4)) Thanks -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Mon, 15 Jul 2013 20:03:19 -0700 > From: Eric Dumazet <edumazet@google.com> > > 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> Applied and queued up for -stable, thanks Eric. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 @@ -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(); { @@ -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; + /* Remove any debris in the socket control block */ memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));