tcp: add tcp_comp_sack_nr sysctl
This per netns sysctl allows for TCP SACK compression fine-tuning.
This limits number of SACK that can be compressed.
Using 0 disables SACK compression.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 6a1dae3..aebb29a 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5106,7 +5106,8 @@ static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible)
return;
}
- if (!tcp_is_sack(tp) || tp->compressed_ack >= 44)
+ if (!tcp_is_sack(tp) ||
+ tp->compressed_ack >= sock_net(sk)->ipv4.sysctl_tcp_comp_sack_nr)
goto send_now;
tp->compressed_ack++;