[TCP]: slow_start_after_idle should influence cwnd validation too

For the cases that slow_start_after_idle are meant to deal
with, it is almost a certainty that the congestion window
tests will think the connection is application limited and
we'll thus decrease the cwnd there too.  This defeats the
whole point of setting slow_start_after_idle to zero.

So test it there too.

We do not cancel out the entire tcp_cwnd_validate() function
so that if the sysctl is changed we still have the validation
state maintained.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 688b95594f2e..3c24881f2a65 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -943,7 +943,8 @@ static void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp)
                 if (tp->packets_out > tp->snd_cwnd_used)
                         tp->snd_cwnd_used = tp->packets_out;
 
-                if ((s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto)
+                if (sysctl_tcp_slow_start_after_idle &&
+                    (s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto)
                         tcp_cwnd_application_limited(sk);
         }
 }