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| author | Yousuk Seung <ysseung@google.com> | 2017-12-07 13:41:34 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-12-08 10:07:02 -0500 |
| commit | d4761754b4fb2ef8d9a1e9d121c4bec84e1fe292 (patch) | |
| tree | 5a55983a564530e094904c68883a4ce77b69724b /net/ipv4/tcp.c | |
| parent | 195bd525d5f6e338b948d9a6b25bfaae86291353 (diff) | |
| download | op-kernel-dev-d4761754b4fb2ef8d9a1e9d121c4bec84e1fe292.zip op-kernel-dev-d4761754b4fb2ef8d9a1e9d121c4bec84e1fe292.tar.gz | |
tcp: invalidate rate samples during SACK reneging
Mark tcp_sock during a SACK reneging event and invalidate rate samples
while marked. Such rate samples may overestimate bw by including packets
that were SACKed before reneging.
< ack 6001 win 10000 sack 7001:38001
< ack 7001 win 0 sack 8001:38001 // Reneg detected
> seq 7001:8001 // RTO, SACK cleared.
< ack 38001 win 10000
In above example the rate sample taken after the last ack will count
7001-38001 as delivered while the actual delivery rate likely could
be much lower i.e. 7001-8001.
This patch adds a new field tcp_sock.sack_reneg and marks it when we
declare SACK reneging and entering TCP_CA_Loss, and unmarks it after
the last rate sample was taken before moving back to TCP_CA_Open. This
patch also invalidates rate samples taken while tcp_sock.is_sack_reneg
is set.
Fixes: b9f64820fb22 ("tcp: track data delivery rate for a TCP connection")
Signed-off-by: Yousuk Seung <ysseung@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Priyaranjan Jha <priyarjha@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 | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index bf97317..f08eebe 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2412,6 +2412,7 @@ int tcp_disconnect(struct sock *sk, int flags) tp->snd_cwnd_cnt = 0; tp->window_clamp = 0; tcp_set_ca_state(sk, TCP_CA_Open); + tp->is_sack_reneg = 0; tcp_clear_retrans(tp); inet_csk_delack_init(sk); /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0 |
