From f61e29018a30c738e1298e1b13be956aa17ee17b Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Sun, 11 Jun 2006 23:01:02 -0700 Subject: [PATCH] [TCP] Westwood: fix first sample Need to update send sequence number tracking after first ack. Rework of patch from Luca De Cicco. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/ipv4/tcp_westwood.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c index 29eb258b6d..62a96b71b0 100644 --- a/net/ipv4/tcp_westwood.c +++ b/net/ipv4/tcp_westwood.c @@ -22,6 +22,7 @@ struct westwood { u32 accounted; u32 rtt; u32 rtt_min; /* minimum observed RTT */ + u8 first_ack; /* flag which infers that this is the first ack */ }; @@ -52,6 +53,7 @@ static void tcp_westwood_init(struct sock *sk) w->rtt_min = w->rtt = TCP_WESTWOOD_INIT_RTT; w->rtt_win_sx = tcp_time_stamp; w->snd_una = tcp_sk(sk)->snd_una; + w->first_ack = 1; } /* @@ -91,6 +93,15 @@ static void westwood_update_window(struct sock *sk) struct westwood *w = inet_csk_ca(sk); s32 delta = tcp_time_stamp - w->rtt_win_sx; + /* Initialise w->snd_una with the first acked sequence number in order + * to fix mismatch between tp->snd_una and w->snd_una for the first + * bandwidth sample + */ + if (w->first_ack) { + w->snd_una = tcp_sk(sk)->snd_una; + w->first_ack = 0; + } + /* * See if a RTT-window has passed. * Be careful since if RTT is less than @@ -180,7 +191,7 @@ static void tcp_westwood_event(struct sock *sk, enum tcp_ca_event event) { struct tcp_sock *tp = tcp_sk(sk); struct westwood *w = inet_csk_ca(sk); - + switch(event) { case CA_EVENT_FAST_ACK: westwood_fast_bw(sk); -- 2.39.5