net: Disambiguate kernel message

Some of our machines were reporting:

TCP: too many of orphaned sockets

even when the number of orphaned sockets was well below the
limit.

We print a different message depending on whether we're out
of TCP memory or there are too many orphaned sockets.

Also move the check out of line and cleanup the messages
that were printed.

Signed-off-by: Arun Sharma <asharma@fb.com>
Suggested-by: Mohan Srinivasan <mohan@fb.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: David Miller <davem@davemloft.net>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 4 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 06373b4a449a..a34f5cfdd44c 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1876,6 +1876,20 @@ void tcp_shutdown(struct sock *sk, int how)
 }
 EXPORT_SYMBOL(tcp_shutdown);
 
+bool tcp_check_oom(struct sock *sk, int shift)
+{
+        bool too_many_orphans, out_of_socket_memory;
+
+        too_many_orphans = tcp_too_many_orphans(sk, shift);
+        out_of_socket_memory = tcp_out_of_memory(sk);
+
+        if (too_many_orphans && net_ratelimit())
+                pr_info("TCP: too many orphaned sockets\n");
+        if (out_of_socket_memory && net_ratelimit())
+                pr_info("TCP: out of memory -- consider tuning tcp_mem\n");
+        return too_many_orphans || out_of_socket_memory;
+}
+
 void tcp_close(struct sock *sk, long timeout)
 {
         struct sk_buff *skb;
@@ -2015,10 +2029,7 @@ adjudge_to_death:
         }
         if (sk->sk_state != TCP_CLOSE) {
                 sk_mem_reclaim(sk);
-                if (tcp_too_many_orphans(sk, 0)) {
-                        if (net_ratelimit())
-                                printk(KERN_INFO "TCP: too many of orphaned "
-                                       "sockets\n");
+                if (tcp_check_oom(sk, 0)) {
                         tcp_set_state(sk, TCP_CLOSE);
                         tcp_send_active_reset(sk, GFP_ATOMIC);
                         NET_INC_STATS_BH(sock_net(sk),