ARM: exynos: prepare for sparse IRQ

[firefly-linux-kernel-4.4.55.git] / net / ipv4 / tcp_cong.c

diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index 291f2ed7cc311649a72700d65098b6d70ba338b5..019c2389a341f6254185c8b9169d9b09c8c16c78 100644 (file)
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -310,35 +310,24 @@ void tcp_slow_start(struct tcp_sock *tp)
 {
        int cnt; /* increase in packets */
        unsigned int delta = 0;
+       u32 snd_cwnd = tp->snd_cwnd;
 
-       /* RFC3465: ABC Slow start
-        * Increase only after a full MSS of bytes is acked
-        *
-        * TCP sender SHOULD increase cwnd by the number of
-        * previously unacknowledged bytes ACKed by each incoming
-        * acknowledgment, provided the increase is not more than L
-        */
-       if (sysctl_tcp_abc && tp->bytes_acked < tp->mss_cache)
-               return;
+       if (unlikely(!snd_cwnd)) {
+               pr_err_once("snd_cwnd is nul, please report this bug.\n");
+               snd_cwnd = 1U;
+       }
 
        if (sysctl_tcp_max_ssthresh > 0 && tp->snd_cwnd > sysctl_tcp_max_ssthresh)
                cnt = sysctl_tcp_max_ssthresh >> 1;     /* limited slow start */
        else
-               cnt = tp->snd_cwnd;                     /* exponential increase */
-
-       /* RFC3465: ABC
-        * We MAY increase by 2 if discovered delayed ack
-        */
-       if (sysctl_tcp_abc > 1 && tp->bytes_acked >= 2*tp->mss_cache)
-               cnt <<= 1;
-       tp->bytes_acked = 0;
+               cnt = snd_cwnd;                         /* exponential increase */
 
        tp->snd_cwnd_cnt += cnt;
-       while (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
-               tp->snd_cwnd_cnt -= tp->snd_cwnd;
+       while (tp->snd_cwnd_cnt >= snd_cwnd) {
+               tp->snd_cwnd_cnt -= snd_cwnd;
                delta++;
        }
-       tp->snd_cwnd = min(tp->snd_cwnd + delta, tp->snd_cwnd_clamp);
+       tp->snd_cwnd = min(snd_cwnd + delta, tp->snd_cwnd_clamp);
 }
 EXPORT_SYMBOL_GPL(tcp_slow_start);
 
@@ -372,20 +361,9 @@ void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
        /* In "safe" area, increase. */
        if (tp->snd_cwnd <= tp->snd_ssthresh)
                tcp_slow_start(tp);
-
        /* In dangerous area, increase slowly. */
-       else if (sysctl_tcp_abc) {
-               /* RFC3465: Appropriate Byte Count
-                * increase once for each full cwnd acked
-                */
-               if (tp->bytes_acked >= tp->snd_cwnd*tp->mss_cache) {
-                       tp->bytes_acked -= tp->snd_cwnd*tp->mss_cache;
-                       if (tp->snd_cwnd < tp->snd_cwnd_clamp)
-                               tp->snd_cwnd++;
-               }
-       } else {
+       else
                tcp_cong_avoid_ai(tp, tp->snd_cwnd);
-       }
 }
 EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid);