--- include/net/tcp.h

+++ include/net/tcp.h

@@ -259,11 +259,21 @@ static inline int between(__u32 seq1, __

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 */

@@ -501,8 +511,22 @@ extern unsigned int tcp_current_mss(stru

/* 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;

}