These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / net / ipv4 / tcp_cubic.c

diff --git a/kernel/net/ipv4/tcp_cubic.c b/kernel/net/ipv4/tcp_cubic.c
index 06d3d66..448c261 100644 (file)
--- a/kernel/net/ipv4/tcp_cubic.c
+++ b/kernel/net/ipv4/tcp_cubic.c
@@ -151,6 +151,27 @@ static void bictcp_init(struct sock *sk)
                tcp_sk(sk)->snd_ssthresh = initial_ssthresh;
 }
 
+static void bictcp_cwnd_event(struct sock *sk, enum tcp_ca_event event)
+{
+       if (event == CA_EVENT_TX_START) {
+               struct bictcp *ca = inet_csk_ca(sk);
+               u32 now = tcp_time_stamp;
+               s32 delta;
+
+               delta = now - tcp_sk(sk)->lsndtime;
+
+               /* We were application limited (idle) for a while.
+                * Shift epoch_start to keep cwnd growth to cubic curve.
+                */
+               if (ca->epoch_start && delta > 0) {
+                       ca->epoch_start += delta;
+                       if (after(ca->epoch_start, now))
+                               ca->epoch_start = now;
+               }
+               return;
+       }
+}
+
 /* calculate the cubic root of x using a table lookup followed by one
  * Newton-Raphson iteration.
  * Avg err ~= 0.195%
@@ -320,7 +341,7 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
        if (!tcp_is_cwnd_limited(sk))
                return;
 
-       if (tp->snd_cwnd <= tp->snd_ssthresh) {
+       if (tcp_in_slow_start(tp)) {
                if (hystart && after(ack, ca->end_seq))
                        bictcp_hystart_reset(sk);
                acked = tcp_slow_start(tp, acked);
@@ -439,7 +460,7 @@ static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt_us)
                ca->delay_min = delay;
 
        /* hystart triggers when cwnd is larger than some threshold */
-       if (hystart && tp->snd_cwnd <= tp->snd_ssthresh &&
+       if (hystart && tcp_in_slow_start(tp) &&
            tp->snd_cwnd >= hystart_low_window)
                hystart_update(sk, delay);
 }
@@ -450,6 +471,7 @@ static struct tcp_congestion_ops cubictcp __read_mostly = {
        .cong_avoid     = bictcp_cong_avoid,
        .set_state      = bictcp_state,
        .undo_cwnd      = bictcp_undo_cwnd,
+       .cwnd_event     = bictcp_cwnd_event,
        .pkts_acked     = bictcp_acked,
        .owner          = THIS_MODULE,
        .name           = "cubic",