tcp: add helper for AI algorithm

[safe/jmp/linux-2.6] / net / ipv4 / tcp_bic.c

diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
index 035f209..3b53fd1 100644 (file)
--- 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);
@@ -137,8 +137,7 @@ 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 in_flight)
 {
        struct tcp_sock *tp = tcp_sk(sk);
        struct bictcp *ca = inet_csk_ca(sk);
@@ -150,16 +149,7 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack,
                tcp_slow_start(tp);
        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);
        }
 
 }
@@ -198,12 +188,6 @@ static u32 bictcp_undo_cwnd(struct sock *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;
-}
-
 static void bictcp_state(struct sock *sk, u8 new_state)
 {
        if (new_state == TCP_CA_Loss)
@@ -213,11 +197,11 @@ 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;
@@ -231,7 +215,6 @@ static struct tcp_congestion_ops bictcp = {
        .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 +222,7 @@ 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);
 }