tcp: add some mibs to track collapsing

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index e6291dde3348..9f8a80ba17bd 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1415,6 +1415,7 @@ static int tcp_shifted_skb(struct sock *sk, struct sk_buff *prev,
 
         if (skb->len > 0) {
                 BUG_ON(!tcp_skb_pcount(skb));
+                NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SACKSHIFTED);
                 return 0;
         }
 
@@ -1436,6 +1437,8 @@ static int tcp_shifted_skb(struct sock *sk, struct sk_buff *prev,
         tcp_unlink_write_queue(skb, sk);
         sk_wmem_free_skb(sk, skb);
 
+        NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SACKMERGED);
+
         return 1;
 }
 
@@ -1594,6 +1597,7 @@ noop:
         return skb;
 
 fallback:
+        NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SACKSHIFTFALLBACK);
         return NULL;
 }