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 <[email protected]>
Signed-off-by: Neal Cardwell <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: Nandita Dukkipati <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 950cfec..dba22fc 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -989,6 +989,11 @@
#define TCP_INFINITE_SSTHRESH 0x7fffffff
+static inline bool tcp_in_slow_start(const struct tcp_sock *tp)
+{
+ return tp->snd_cwnd <= tp->snd_ssthresh;
+}
+
static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp)
{
return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH;
@@ -1065,7 +1070,7 @@
const struct tcp_sock *tp = tcp_sk(sk);
/* If in slow start, ensure cwnd grows to twice what was ACKed. */
- if (tp->snd_cwnd <= tp->snd_ssthresh)
+ if (tcp_in_slow_start(tp))
return tp->snd_cwnd < 2 * tp->max_packets_out;
return tp->is_cwnd_limited;
