diff options
| author | Neal Cardwell <ncardwell@google.com> | 2013-03-04 06:23:05 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-20 13:10:58 -0700 |
| commit | d725632acb3bd015dd6abe2bb01b11a9385f10ea (patch) | |
| tree | 4db8ce8211ae559a5a5b440dbf1a484c0fa86341 | |
| parent | 280b2b998f326449aa18fe3d064c012deaaeaefb (diff) | |
| download | lwn-d725632acb3bd015dd6abe2bb01b11a9385f10ea.tar.gz lwn-d725632acb3bd015dd6abe2bb01b11a9385f10ea.zip | |
tcp: fix double-counted receiver RTT when leaving receiver fast path
[ Upstream commit aab2b4bf224ef8358d262f95b568b8ad0cecf0a0 ]
We should not update ts_recent and call tcp_rcv_rtt_measure_ts() both
before and after going to step5. That wastes CPU and double-counts the
receiver-side RTT sample.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv4/tcp_input.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index ad70a962c20e..66702d33f704 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5498,6 +5498,9 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, if (tcp_checksum_complete_user(sk, skb)) goto csum_error; + if ((int)skb->truesize > sk->sk_forward_alloc) + goto step5; + /* Predicted packet is in window by definition. * seq == rcv_nxt and rcv_wup <= rcv_nxt. * Hence, check seq<=rcv_wup reduces to: @@ -5509,9 +5512,6 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, tcp_rcv_rtt_measure_ts(sk, skb); - if ((int)skb->truesize > sk->sk_forward_alloc) - goto step5; - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPHPHITS); /* Bulk data transfer: receiver */ |