[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)
 {