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| author | Doug Leith <doug.leith@nuim.ie> | 2009-05-25 22:44:59 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-05-25 22:44:59 -0700 |
| commit | c80a5cdfc5ca6533cb893154f546370da1fdb8f0 (patch) | |
| tree | 963fef5f697a5953469441d5eaafbbad99fc64a8 /net/ipv4/tcp_vegas.c | |
| parent | 217cbfa856dc1cbc2890781626c4032d9e3ec59f (diff) | |
| download | lwn-c80a5cdfc5ca6533cb893154f546370da1fdb8f0.tar.gz lwn-c80a5cdfc5ca6533cb893154f546370da1fdb8f0.zip | |
tcp: tcp_vegas ssthresh bugfix
This patch fixes ssthresh accounting issues in tcp_vegas when cwnd decreases
Signed-off-by: Doug Leith <doug.leith@nuim.ie>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_vegas.c')
| -rw-r--r-- | net/ipv4/tcp_vegas.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c index a453aac91bd3..c6743eec9b7d 100644 --- a/net/ipv4/tcp_vegas.c +++ b/net/ipv4/tcp_vegas.c @@ -158,6 +158,11 @@ void tcp_vegas_cwnd_event(struct sock *sk, enum tcp_ca_event event) } EXPORT_SYMBOL_GPL(tcp_vegas_cwnd_event); +static inline u32 tcp_vegas_ssthresh(struct tcp_sock *tp) +{ + return min(tp->snd_ssthresh, tp->snd_cwnd-1); +} + static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) { struct tcp_sock *tp = tcp_sk(sk); @@ -221,11 +226,10 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) */ diff = tp->snd_cwnd * (rtt-vegas->baseRTT) / vegas->baseRTT; - if (diff > gamma && tp->snd_ssthresh > 2 ) { + if (diff > gamma && tp->snd_cwnd <= tp->snd_ssthresh) { /* Going too fast. Time to slow down * and switch to congestion avoidance. */ - tp->snd_ssthresh = 2; /* Set cwnd to match the actual rate * exactly: @@ -235,6 +239,7 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) * utilization. */ tp->snd_cwnd = min(tp->snd_cwnd, (u32)target_cwnd+1); + tp->snd_ssthresh = tcp_vegas_ssthresh(tp); } else if (tp->snd_cwnd <= tp->snd_ssthresh) { /* Slow start. */ @@ -250,6 +255,8 @@ static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) * we slow down. */ tp->snd_cwnd--; + tp->snd_ssthresh + = tcp_vegas_ssthresh(tp); } else if (diff < alpha) { /* We don't have enough extra packets * in the network, so speed up. |