net: Make inet_twsk_put similar to sock_put

By separating the freeing code from the refcounting decrementing.
Probably reducing icache pressure when we still have reference counts to
go.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/inet_timewait_sock.c

@@ -49,19 +49,22 @@ static void __inet_twsk_kill(struct inet_timewait_sock *tw,
 	inet_twsk_put(tw);
 }
 
-void inet_twsk_put(struct inet_timewait_sock *tw)
+static noinline void inet_twsk_free(struct inet_timewait_sock *tw)
 {
-	if (atomic_dec_and_test(&tw->tw_refcnt)) {
-		struct module *owner = tw->tw_prot->owner;
-		twsk_destructor((struct sock *)tw);
+	struct module *owner = tw->tw_prot->owner;
+	twsk_destructor((struct sock *)tw);
 #ifdef SOCK_REFCNT_DEBUG
-		printk(KERN_DEBUG "%s timewait_sock %p released\n",
-		       tw->tw_prot->name, tw);
+	pr_debug("%s timewait_sock %p released\n", tw->tw_prot->name, tw);
 #endif
-		release_net(twsk_net(tw));
-		kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);
-		module_put(owner);
-	}
+	release_net(twsk_net(tw));
+	kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);
+	module_put(owner);
+}
+
+void inet_twsk_put(struct inet_timewait_sock *tw)
+{
+	if (atomic_dec_and_test(&tw->tw_refcnt))
+		inet_twsk_free(tw);
 }
 EXPORT_SYMBOL_GPL(inet_twsk_put);