From ca2eb5679f8ddffff60156af42595df44a315ef0 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Tue, 5 Feb 2013 07:25:17 +0000 Subject: tcp: remove Appropriate Byte Count support TCP Appropriate Byte Count was added by me, but later disabled. There is no point in maintaining it since it is a potential source of bugs and Linux already implements other better window protection heuristics. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/ipv4/tcp_cong.c | 30 +----------------------------- 1 file changed, 1 insertion(+), 29 deletions(-) (limited to 'net/ipv4/tcp_cong.c') diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c index cdf2e707bb10..019c2389a341 100644 --- a/net/ipv4/tcp_cong.c +++ b/net/ipv4/tcp_cong.c @@ -317,28 +317,11 @@ void tcp_slow_start(struct tcp_sock *tp) snd_cwnd = 1U; } - /* RFC3465: ABC Slow start - * Increase only after a full MSS of bytes is acked - * - * TCP sender SHOULD increase cwnd by the number of - * previously unacknowledged bytes ACKed by each incoming - * acknowledgment, provided the increase is not more than L - */ - if (sysctl_tcp_abc && tp->bytes_acked < tp->mss_cache) - return; - if (sysctl_tcp_max_ssthresh > 0 && tp->snd_cwnd > sysctl_tcp_max_ssthresh) cnt = sysctl_tcp_max_ssthresh >> 1; /* limited slow start */ else cnt = snd_cwnd; /* exponential increase */ - /* RFC3465: ABC - * We MAY increase by 2 if discovered delayed ack - */ - if (sysctl_tcp_abc > 1 && tp->bytes_acked >= 2*tp->mss_cache) - cnt <<= 1; - tp->bytes_acked = 0; - tp->snd_cwnd_cnt += cnt; while (tp->snd_cwnd_cnt >= snd_cwnd) { tp->snd_cwnd_cnt -= snd_cwnd; @@ -378,20 +361,9 @@ void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) /* In "safe" area, increase. */ if (tp->snd_cwnd <= tp->snd_ssthresh) tcp_slow_start(tp); - /* In dangerous area, increase slowly. */ - else if (sysctl_tcp_abc) { - /* RFC3465: Appropriate Byte Count - * increase once for each full cwnd acked - */ - if (tp->bytes_acked >= tp->snd_cwnd*tp->mss_cache) { - tp->bytes_acked -= tp->snd_cwnd*tp->mss_cache; - if (tp->snd_cwnd < tp->snd_cwnd_clamp) - tp->snd_cwnd++; - } - } else { + else tcp_cong_avoid_ai(tp, tp->snd_cwnd); - } } EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid); -- cgit v1.2.1