diff options
| author | Kenneth Klette Jonassen <[email protected]> | 2015-04-11 02:17:49 +0200 |
|---|---|---|
| committer | David S. Miller <[email protected]> | 2015-04-13 13:54:25 -0400 |
| commit | 3d0d26c7976bf190c3f1d2efbc31462db8246bc0 (patch) | |
| tree | 09b3b238bb8292ad5a2eacc770ea63b5ef457d74 | |
| parent | 4577139b2dabf58973d59d157aae4ddd3bde863a (diff) | |
tcp: fix bogus RTT for CC when retransmissions are acked
Since retransmitted segments are not used for RTT estimation, previously
SACKed segments present in the rtx queue are used. This estimation can be
several times larger than the actual RTT. When a cumulative ack covers both
previously SACKed and retransmitted segments, CC may thus get a bogus RTT.
Such segments previously had an RTT estimation in tcp_sacktag_one(), so it
seems reasonable to not reuse them in tcp_clean_rtx_queue() at all.
Afaik, this has had no effect on SRTT/RTO because of Karn's check.
Signed-off-by: Kenneth Klette Jonassen <[email protected]>
Acked-by: Neal Cardwell <[email protected]>
Tested-by: Neal Cardwell <[email protected]>
Acked-by: Yuchung Cheng <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
| -rw-r--r-- | net/ipv4/tcp_input.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 031cf72cd05c..a7ef679dd3ea 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3099,17 +3099,15 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, if (sacked & TCPCB_SACKED_RETRANS) tp->retrans_out -= acked_pcount; flag |= FLAG_RETRANS_DATA_ACKED; - } else { + } else if (!(sacked & TCPCB_SACKED_ACKED)) { last_ackt = skb->skb_mstamp; WARN_ON_ONCE(last_ackt.v64 == 0); if (!first_ackt.v64) first_ackt = last_ackt; - if (!(sacked & TCPCB_SACKED_ACKED)) { - reord = min(pkts_acked, reord); - if (!after(scb->end_seq, tp->high_seq)) - flag |= FLAG_ORIG_SACK_ACKED; - } + reord = min(pkts_acked, reord); + if (!after(scb->end_seq, tp->high_seq)) + flag |= FLAG_ORIG_SACK_ACKED; } if (sacked & TCPCB_SACKED_ACKED) |