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| author | Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> | 2007-02-21 22:56:19 -0800 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-25 22:23:01 -0700 |
| commit | 9ead9a1d385ae2c52a6dcf2828d84ce66be04fc2 (patch) | |
| tree | 3346cc7d0428f213ac7d07c41d1d0accc4a741f9 /net/ipv4/tcp_input.c | |
| parent | 522e7548a9bd40305df41c0beae69448b7620d6b (diff) | |
| download | linux-9ead9a1d385ae2c52a6dcf2828d84ce66be04fc2.tar.gz linux-9ead9a1d385ae2c52a6dcf2828d84ce66be04fc2.tar.bz2 linux-9ead9a1d385ae2c52a6dcf2828d84ce66be04fc2.zip | |
[TCP] FRTO: Separated response from FRTO detection algorithm
FRTO spurious RTO detection algorithm (RFC4138) does not include response
to a detected spurious RTO but can use different response algorithms.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index b21e232d5d33..c5be3d0465f5 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2467,6 +2467,15 @@ static int tcp_ack_update_window(struct sock *sk, struct tcp_sock *tp, return flag; } +/* A very conservative spurious RTO response algorithm: reduce cwnd and + * continue in congestion avoidance. + */ +static void tcp_conservative_spur_to_response(struct tcp_sock *tp) +{ + tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh); + tcp_moderate_cwnd(tp); +} + static void tcp_process_frto(struct sock *sk, u32 prior_snd_una) { struct tcp_sock *tp = tcp_sk(sk); @@ -2488,12 +2497,7 @@ static void tcp_process_frto(struct sock *sk, u32 prior_snd_una) */ tp->snd_cwnd = tcp_packets_in_flight(tp) + 2; } else { - /* Also the second ACK after RTO advances the window. - * The RTO was likely spurious. Reduce cwnd and continue - * in congestion avoidance - */ - tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh); - tcp_moderate_cwnd(tp); + tcp_conservative_spur_to_response(tp); } /* F-RTO affects on two new ACKs following RTO. |