1 files changed, 30 insertions, 6 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index df6a2eb2019..3e4b33e3660 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -268,11 +268,21 @@ static inline int between(__u32 seq1, __u32 seq2, __u32 seq3)
         return seq3 - seq2 >= seq1 - seq2;
 }
 
-static inline int tcp_too_many_orphans(struct sock *sk, int num)
+static inline bool tcp_too_many_orphans(struct sock *sk, int shift)
 {
-        return (num > sysctl_tcp_max_orphans) ||
-                (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
-                 atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2]);
+        struct percpu_counter *ocp = sk->sk_prot->orphan_count;
+        int orphans = percpu_counter_read_positive(ocp);
+
+        if (orphans << shift > sysctl_tcp_max_orphans) {
+                orphans = percpu_counter_sum_positive(ocp);
+                if (orphans << shift > sysctl_tcp_max_orphans)
+                        return true;
+        }
+
+        if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
+            atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2])
+                return true;
+        return false;
 }
 
 /* syncookies: remember time of last synqueue overflow */
@@ -465,8 +475,22 @@ extern unsigned int tcp_current_mss(struct sock *sk);
 /* Bound MSS / TSO packet size with the half of the window */
 static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize)
 {
-        if (tp->max_window && pktsize > (tp->max_window >> 1))
-                return max(tp->max_window >> 1, 68U - tp->tcp_header_len);
+        int cutoff;
+
+        /* When peer uses tiny windows, there is no use in packetizing
+         * to sub-MSS pieces for the sake of SWS or making sure there
+         * are enough packets in the pipe for fast recovery.
+         *
+         * On the other hand, for extremely large MSS devices, handling
+         * smaller than MSS windows in this way does make sense.
+         */
+        if (tp->max_window >= 512)
+                cutoff = (tp->max_window >> 1);
+        else
+                cutoff = tp->max_window;
+
+        if (cutoff && pktsize > cutoff)
+                return max_t(int, cutoff, 68U - tp->tcp_header_len);
         else
                 return pktsize;
 }