return err;
}
+
+/*
+ * Linear increase during slow start
+ */
+void tcp_slow_start(struct tcp_sock *tp)
+{
+ if (sysctl_tcp_abc) {
+ /* RFC3465: Slow Start
+ * 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 (tp->bytes_acked < tp->mss_cache)
+ return;
+
+ /* We MAY increase by 2 if discovered delayed ack */
+ if (sysctl_tcp_abc > 1 && tp->bytes_acked > 2*tp->mss_cache) {
+ if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+ tp->snd_cwnd++;
+ }
+ }
+ tp->bytes_acked = 0;
+
+ if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+ tp->snd_cwnd++;
+}
+EXPORT_SYMBOL_GPL(tcp_slow_start);
+
/*
* TCP Reno congestion control
* This is special case used for fallback as well.
{
struct tcp_sock *tp = tcp_sk(sk);
- if (in_flight < tp->snd_cwnd)
+ if (!tcp_is_cwnd_limited(sk, in_flight))
return;
- if (tp->snd_cwnd <= tp->snd_ssthresh) {
- /* In "safe" area, increase. */
- if (tp->snd_cwnd < tp->snd_cwnd_clamp)
- tp->snd_cwnd++;
- } else {
- /* In dangerous area, increase slowly.
- * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd
- */
- if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
- if (tp->snd_cwnd < tp->snd_cwnd_clamp)
- tp->snd_cwnd++;
- tp->snd_cwnd_cnt = 0;
- } else
- tp->snd_cwnd_cnt++;
- }
+ /* 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: Apppriate 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 {
+ /* In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd */
+ if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
+ if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+ tp->snd_cwnd++;
+ tp->snd_cwnd_cnt = 0;
+ } else
+ tp->snd_cwnd_cnt++;
+ }
}
EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid);