+ bluetooth-simplify-l2cap-streaming-mode-sending.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     bluetooth: simplify L2CAP Streaming mode sending
has been added to the -mm tree.  Its filename is
     bluetooth-simplify-l2cap-streaming-mode-sending.patch

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------------------------------------------------------
Subject: bluetooth: simplify L2CAP Streaming mode sending
From: "Gustavo F. Padovan" <padovan@profusion.mobi>

As we don't have any error control on the Streaming mode, i.e., we don't
need to keep a copy of the skb for later resending we don't need to call
skb_clone() on it.

Then we can go one further here, and dequeue the skb before sending it,
that also means we don't need to look to sk->sk_send_head anymore.

The patch saves memory and time when sending Streaming mode data.

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 net/bluetooth/l2cap.c |   24 +++++++-----------------
 1 file changed, 7 insertions(+), 17 deletions(-)

diff -puN net/bluetooth/l2cap.c~bluetooth-simplify-l2cap-streaming-mode-sending net/bluetooth/l2cap.c
--- a/net/bluetooth/l2cap.c~bluetooth-simplify-l2cap-streaming-mode-sending
+++ a/net/bluetooth/l2cap.c
@@ -1441,33 +1441,23 @@ static inline void l2cap_do_send(struct 
 
 static void l2cap_streaming_send(struct sock *sk)
 {
-	struct sk_buff *skb, *tx_skb;
+	struct sk_buff *skb;
 	struct l2cap_pinfo *pi = l2cap_pi(sk);
 	u16 control, fcs;
 
-	while ((skb = sk->sk_send_head)) {
-		tx_skb = skb_clone(skb, GFP_ATOMIC);
-
-		control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE);
+	while ((skb = skb_dequeue(TX_QUEUE(sk)))) {
+		control = get_unaligned_le16(skb->data + L2CAP_HDR_SIZE);
 		control |= pi->next_tx_seq << L2CAP_CTRL_TXSEQ_SHIFT;
-		put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE);
+		put_unaligned_le16(control, skb->data + L2CAP_HDR_SIZE);
 
 		if (pi->fcs == L2CAP_FCS_CRC16) {
-			fcs = crc16(0, (u8 *)tx_skb->data, tx_skb->len - 2);
-			put_unaligned_le16(fcs, tx_skb->data + tx_skb->len - 2);
+			fcs = crc16(0, (u8 *)skb->data, skb->len - 2);
+			put_unaligned_le16(fcs, skb->data + skb->len - 2);
 		}
 
-		l2cap_do_send(sk, tx_skb);
+		l2cap_do_send(sk, skb);
 
 		pi->next_tx_seq = (pi->next_tx_seq + 1) % 64;
-
-		if (skb_queue_is_last(TX_QUEUE(sk), skb))
-			sk->sk_send_head = NULL;
-		else
-			sk->sk_send_head = skb_queue_next(TX_QUEUE(sk), skb);