tcp: Combat per-cpu skew in orphan tests.

[net-next-2.6.git] / include / net / tcp.h

diff --git a/include/net/tcp.h b/include/net/tcp.h
index df6a2eb20193f935bc72204ca22c7f2f21b5070f..eaa9582779d029a9362c32b3816fed8c157e4d3e 100644 (file)
--- 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 */