tcp: add tcp_in_slow_start helper
Add a helper to test the slow start condition in various congestion
control modules and other places. This is to prepare a slight improvement
in policy as to exactly when to slow start.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index 06d3d66..28011fb 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -320,7 +320,7 @@
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 +439,7 @@
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);
}