diff options
Diffstat (limited to 'net/ipv4/tcp_bic.c')
| -rw-r--r-- | net/ipv4/tcp_bic.c | 52 |
1 files changed, 19 insertions, 33 deletions
diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c index 035f2092d73..d5de69bc04f 100644 --- a/net/ipv4/tcp_bic.c +++ b/net/ipv4/tcp_bic.c @@ -1,18 +1,18 @@ /* * Binary Increase Congestion control for TCP - * + * Home page: + * http://netsrv.csc.ncsu.edu/twiki/bin/view/Main/BIC * This is from the implementation of BICTCP in * Lison-Xu, Kahaled Harfoush, and Injong Rhee. * "Binary Increase Congestion Control for Fast, Long Distance * Networks" in InfoComm 2004 * Available from: - * http://www.csc.ncsu.edu/faculty/rhee/export/bitcp.pdf + * http://netsrv.csc.ncsu.edu/export/bitcp.pdf * * Unless BIC is enabled and congestion window is large * this behaves the same as the original Reno. */ -#include <linux/config.h> #include <linux/mm.h> #include <linux/module.h> #include <net/tcp.h> @@ -30,7 +30,7 @@ static int fast_convergence = 1; static int max_increment = 16; static int low_window = 14; static int beta = 819; /* = 819/1024 (BICTCP_BETA_SCALE) */ -static int initial_ssthresh = 100; +static int initial_ssthresh; static int smooth_part = 20; module_param(fast_convergence, int, 0644); @@ -63,7 +63,6 @@ static inline void bictcp_reset(struct bictcp *ca) { ca->cnt = 0; ca->last_max_cwnd = 0; - ca->loss_cwnd = 0; ca->last_cwnd = 0; ca->last_time = 0; ca->epoch_start = 0; @@ -72,7 +71,11 @@ static inline void bictcp_reset(struct bictcp *ca) static void bictcp_init(struct sock *sk) { - bictcp_reset(inet_csk_ca(sk)); + struct bictcp *ca = inet_csk_ca(sk); + + bictcp_reset(ca); + ca->loss_cwnd = 0; + if (initial_ssthresh) tcp_sk(sk)->snd_ssthresh = initial_ssthresh; } @@ -127,7 +130,7 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd) } /* if in slow start or link utilization is very low */ - if (ca->loss_cwnd == 0) { + if (ca->last_max_cwnd == 0) { if (ca->cnt > 20) /* increase cwnd 5% per RTT */ ca->cnt = 20; } @@ -137,29 +140,19 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd) ca->cnt = 1; } -static void bictcp_cong_avoid(struct sock *sk, u32 ack, - u32 seq_rtt, u32 in_flight, int data_acked) +static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked) { struct tcp_sock *tp = tcp_sk(sk); struct bictcp *ca = inet_csk_ca(sk); - if (!tcp_is_cwnd_limited(sk, in_flight)) + if (!tcp_is_cwnd_limited(sk)) return; if (tp->snd_cwnd <= tp->snd_ssthresh) - tcp_slow_start(tp); + tcp_slow_start(tp, acked); else { bictcp_update(ca, tp->snd_cwnd); - - /* In dangerous area, increase slowly. - * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd - */ - if (tp->snd_cwnd_cnt >= ca->cnt) { - if (tp->snd_cwnd < tp->snd_cwnd_clamp) - tp->snd_cwnd++; - tp->snd_cwnd_cnt = 0; - } else - tp->snd_cwnd_cnt++; + tcp_cong_avoid_ai(tp, ca->cnt); } } @@ -195,13 +188,7 @@ static u32 bictcp_undo_cwnd(struct sock *sk) { const struct tcp_sock *tp = tcp_sk(sk); const struct bictcp *ca = inet_csk_ca(sk); - return max(tp->snd_cwnd, ca->last_max_cwnd); -} - -static u32 bictcp_min_cwnd(struct sock *sk) -{ - const struct tcp_sock *tp = tcp_sk(sk); - return tp->snd_ssthresh; + return max(tp->snd_cwnd, ca->loss_cwnd); } static void bictcp_state(struct sock *sk, u8 new_state) @@ -213,11 +200,11 @@ static void bictcp_state(struct sock *sk, u8 new_state) /* Track delayed acknowledgment ratio using sliding window * ratio = (15*ratio + sample) / 16 */ -static void bictcp_acked(struct sock *sk, u32 cnt) +static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt) { const struct inet_connection_sock *icsk = inet_csk(sk); - if (cnt > 0 && icsk->icsk_ca_state == TCP_CA_Open) { + if (icsk->icsk_ca_state == TCP_CA_Open) { struct bictcp *ca = inet_csk_ca(sk); cnt -= ca->delayed_ack >> ACK_RATIO_SHIFT; ca->delayed_ack += cnt; @@ -225,13 +212,12 @@ static void bictcp_acked(struct sock *sk, u32 cnt) } -static struct tcp_congestion_ops bictcp = { +static struct tcp_congestion_ops bictcp __read_mostly = { .init = bictcp_init, .ssthresh = bictcp_recalc_ssthresh, .cong_avoid = bictcp_cong_avoid, .set_state = bictcp_state, .undo_cwnd = bictcp_undo_cwnd, - .min_cwnd = bictcp_min_cwnd, .pkts_acked = bictcp_acked, .owner = THIS_MODULE, .name = "bic", @@ -239,7 +225,7 @@ static struct tcp_congestion_ops bictcp = { static int __init bictcp_register(void) { - BUG_ON(sizeof(struct bictcp) > ICSK_CA_PRIV_SIZE); + BUILD_BUG_ON(sizeof(struct bictcp) > ICSK_CA_PRIV_SIZE); return tcp_register_congestion_control(&bictcp); } |