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>

1 files changed, 1 insertions, 0 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index a3f4647341db..adbdb503db0c 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2573,6 +2573,7 @@ static int __net_init tcp_sk_init(struct net *net)
                        sizeof(init_net.ipv4.sysctl_tcp_wmem));
         }
         net->ipv4.sysctl_tcp_comp_sack_delay_ns = NSEC_PER_MSEC;
+        net->ipv4.sysctl_tcp_comp_sack_nr = 44;
         net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;
         spin_lock_init(&net->ipv4.tcp_fastopen_ctx_lock);
         net->ipv4.sysctl_tcp_fastopen_blackhole_timeout = 60 * 60;