int ret = 0;
/* all algorithms must implement ssthresh and cong_avoid ops */
- if (!ca->ssthresh || !ca->cong_avoid || !ca->min_cwnd) {
+ if (!ca->ssthresh || !ca->cong_avoid) {
printk(KERN_ERR "TCP %s does not implement required ops\n",
ca->name);
return -EINVAL;
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.
/* In dangerous area, increase slowly. */
else if (sysctl_tcp_abc) {
- /* RFC3465: Apppriate Byte Count
+ /* RFC3465: Appropriate Byte Count
* increase once for each full cwnd acked
*/
if (tp->bytes_acked >= tp->snd_cwnd*tp->mss_cache) {
}
EXPORT_SYMBOL_GPL(tcp_reno_ssthresh);
-/* Lower bound on congestion window. */
-u32 tcp_reno_min_cwnd(struct sock *sk)
+/* Lower bound on congestion window with halving. */
+u32 tcp_reno_min_cwnd(const struct sock *sk)
{
const struct tcp_sock *tp = tcp_sk(sk);
return tp->snd_ssthresh/2;