From 9772efb970780aeed488c19d8b4afd46c3b484af Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 10 Nov 2005 17:09:53 -0800 Subject: [TCP]: Appropriate Byte Count support This is an updated version of the RFC3465 ABC patch originally for Linux 2.6.11-rc4 by Yee-Ting Li. ABC is a way of counting bytes ack'd rather than packets when updating congestion control. The orignal ABC described in the RFC applied to a Reno style algorithm. For advanced congestion control there is little change after leaving slow start. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index e4306565493..4cb5e6f408d 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -89,6 +89,7 @@ int sysctl_tcp_frto; int sysctl_tcp_nometrics_save; int sysctl_tcp_moderate_rcvbuf = 1; +int sysctl_tcp_abc = 1; #define FLAG_DATA 0x01 /* Incoming frame contained data. */ #define FLAG_WIN_UPDATE 0x02 /* Incoming ACK was a window update. */ @@ -1247,6 +1248,7 @@ void tcp_enter_loss(struct sock *sk, int how) tp->snd_cwnd_cnt = 0; tp->snd_cwnd_stamp = tcp_time_stamp; + tp->bytes_acked = 0; tcp_clear_retrans(tp); /* Push undo marker, if it was plain RTO and nothing @@ -1904,6 +1906,7 @@ tcp_fastretrans_alert(struct sock *sk, u32 prior_snd_una, TCP_ECN_queue_cwr(tp); } + tp->bytes_acked = 0; tp->snd_cwnd_cnt = 0; tcp_set_ca_state(sk, TCP_CA_Recovery); } @@ -2310,6 +2313,9 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag) if (before(ack, prior_snd_una)) goto old_ack; + if (sysctl_tcp_abc && icsk->icsk_ca_state < TCP_CA_CWR) + tp->bytes_acked += ack - prior_snd_una; + if (!(flag&FLAG_SLOWPATH) && after(ack, prior_snd_una)) { /* Window is constant, pure forward advance. * No more checks are required. @@ -4370,6 +4376,7 @@ discard: EXPORT_SYMBOL(sysctl_tcp_ecn); EXPORT_SYMBOL(sysctl_tcp_reordering); +EXPORT_SYMBOL(sysctl_tcp_abc); EXPORT_SYMBOL(tcp_parse_options); EXPORT_SYMBOL(tcp_rcv_established); EXPORT_SYMBOL(tcp_rcv_state_process); -- cgit v1.2.3-18-g5258