[NET]: Rate limiting for socket allocation failure messages.

This patch limits the warning messages when socket allocation failures
happen. It happens under memory pressure.

Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/socket.c b/net/socket.c
index b4848ce..6d261bf 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1178,7 +1178,8 @@
  */
 
 	if (!(sock = sock_alloc())) {
-		printk(KERN_WARNING "socket: no more sockets\n");
+		if (net_ratelimit())
+			printk(KERN_WARNING "socket: no more sockets\n");
 		err = -ENFILE;		/* Not exactly a match, but its the
 					   closest posix thing */
 		goto out;