commit 5fc24957defcc34df8fab6bf62bc1918e54607f8
Author: David S. Miller <[EMAIL PROTECTED]>
Date: Tue Feb 27 17:23:52 2007 -0800
[TCP]: Maintain cached fack counts in retransmit queue.
The fack count of any skb in the retransmit queue at any
given point in time is:
(skb->fack_count - head_skb->fack_count)
And we'll use this in the SACK processing loops.
Signed-off-by: David S. Miller <[EMAIL PROTECTED]>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index cce6b0e..80a572b 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -532,6 +532,7 @@ struct tcp_skb_cb {
__u32 seq; /* Starting sequence number */
__u32 end_seq; /* SEQ + FIN + SYN + datalen */
__u32 when; /* used to compute rtt's */
+ unsigned int fack_count; /* speed up SACK processing */
__u8 flags; /* TCP header flags. */
/* NOTE: These must match up to the flags byte in a
@@ -1272,6 +1273,12 @@ static inline void tcp_rb_unlink(struct sk_buff *skb,
struct rb_root *root)
static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff
*skb)
{
+ struct sk_buff *tail = tcp_write_queue_tail(sk);
+ unsigned int fc = 0;
+
+ if (tail)
+ fc = TCP_SKB_CB(tail)->fack_count + tcp_skb_pcount(skb);
+ TCP_SKB_CB(skb)->fack_count = fc;
__skb_queue_tail(&sk->sk_write_queue, skb);
tcp_rb_insert(skb, &tcp_sk(sk)->write_queue_rb);
}
@@ -1285,18 +1292,44 @@ static inline void tcp_add_write_queue_tail(struct sock
*sk, struct sk_buff *skb
sk->sk_send_head = skb;
}
+/* This is only used for tcp_send_synack(), so the write queue should
+ * be empty. If that stops being true, the fack_count assignment
+ * will need to be more elaborate.
+ */
static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff
*skb)
{
+ BUG_ON(!skb_queue_empty(&sk->sk_write_queue));
__skb_queue_head(&sk->sk_write_queue, skb);
+ TCP_SKB_CB(skb)->fack_count = 0;
tcp_rb_insert(skb, &tcp_sk(sk)->write_queue_rb);
}
+/* An insert into the middle of the write queue causes the fack
+ * counts in subsequent packets to become invalid, fix them up.
+ */
+static inline void tcp_reset_fack_counts(struct sock *sk, struct sk_buff
*first)
+{
+ struct sk_buff *prev = first->prev;
+ unsigned int fc = 0;
+
+ if (prev != (struct sk_buff *) &sk->sk_write_queue)
+ fc = TCP_SKB_CB(prev)->fack_count + tcp_skb_pcount(prev);
+
+ while (first != (struct sk_buff *)&sk->sk_write_queue) {
+ TCP_SKB_CB(first)->fack_count = fc;
+
+ fc += tcp_skb_pcount(first);
+ first = first->next;
+ }
+}
+
/* Insert buff after skb on the write queue of sk. */
static inline void tcp_insert_write_queue_after(struct sk_buff *skb,
struct sk_buff *buff,
struct sock *sk)
{
__skb_append(skb, buff, &sk->sk_write_queue);
+ tcp_reset_fack_counts(sk, buff);
tcp_rb_insert(skb, &tcp_sk(sk)->write_queue_rb);
}
@@ -1306,6 +1339,7 @@ static inline void tcp_insert_write_queue_before(struct
sk_buff *new,
struct sock *sk)
{
__skb_insert(new, skb->prev, skb, &sk->sk_write_queue);
+ tcp_reset_fack_counts(sk, new);
tcp_rb_insert(skb, &tcp_sk(sk)->write_queue_rb);
}
-
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