diff options
| author |   Yuchung Cheng <ycheng@google.com> | 2018-08-29 14:53:56 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-08-31 23:03:00 -0700 |
| commit | 7788174e8726c309d8bfd8aeca743cefd6943616 (patch) | |
| tree | c22fbe4b578d94cf9e813fa8831a3bfb798717e8 /net/ipv4/tcp.c | |
| parent | net_sched: add missing tcf_lock for act_connmark (diff) | |
| download | linux-dev-7788174e8726c309d8bfd8aeca743cefd6943616.tar.xz linux-dev-7788174e8726c309d8bfd8aeca743cefd6943616.zip | |
tcp: change IPv6 flow-label upon receiving spurious retransmission
Currently a Linux IPv6 TCP sender will change the flow label upon
timeouts to potentially steer away from a data path that has gone
bad. However this does not help if the problem is on the ACK path
and the data path is healthy. In this case the receiver is likely
to receive repeated spurious retransmission because the sender
couldn't get the ACKs in time and has recurring timeouts.
This patch adds another feature to mitigate this problem. It
leverages the DSACK states in the receiver to change the flow
label of the ACKs to speculatively re-route the ACK packets.
In order to allow triggering on the second consecutive spurious
RTO, the receiver changes the flow label upon sending a second
consecutive DSACK for a sequence number below RCV.NXT.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index b8af2fec5ad5..8c4235c098fd 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2595,6 +2595,8 @@ int tcp_disconnect(struct sock *sk, int flags) tp->compressed_ack = 0; tp->bytes_sent = 0; tp->bytes_retrans = 0; + tp->duplicate_sack[0].start_seq = 0; + tp->duplicate_sack[0].end_seq = 0; tp->dsack_dups = 0; tp->reord_seen = 0; |