[NET]: Uninline the sk_stream_alloc_pskb

This function seems too big for inlining. Indeed, it saves
half-a-kilo when uninlined:

add/remove: 1/0 grow/shrink: 0/7 up/down: 195/-719 (-524)
function                                     old     new   delta
sk_stream_alloc_pskb                           -     195    +195
ip_rt_init                                   529     525      -4
__inet_lookup_listener                       284     274     -10
tcp_sendmsg                                 2583    2486     -97
tcp_sendpage                                1449    1305    -144
tso_fragment                                 417     267    -150
tcp_fragment                                1149     992    -157
__tcp_push_pending_frames                   1998    1841    -157

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 0 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index e055f25876df..6b35ab841db2 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -629,6 +629,33 @@ ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
 	return ret;
 }
 
+struct sk_buff *sk_stream_alloc_pskb(struct sock *sk,
+		int size, int mem, gfp_t gfp)
+{
+	struct sk_buff *skb;
+
+	/* The TCP header must be at least 32-bit aligned.  */
+	size = ALIGN(size, 4);
+
+	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
+	if (skb) {
+		skb->truesize += mem;
+		if (sk_stream_wmem_schedule(sk, skb->truesize)) {
+			/*
+			 * Make sure that we have exactly size bytes
+			 * available to the caller, no more, no less.
+			 */
+			skb_reserve(skb, skb_tailroom(skb) - size);
+			return skb;
+		}
+		__kfree_skb(skb);
+	} else {
+		sk->sk_prot->enter_memory_pressure();
+		sk_stream_moderate_sndbuf(sk);
+	}
+	return NULL;
+}
+
 static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
 			 size_t psize, int flags)
 {