[TCP]: Kill extra cwnd validate in __tcp_push_pending_frames().
The tcp_cwnd_validate() function should only be invoked
if we actually send some frames, yet __tcp_push_pending_frames()
will always invoke it. tcp_write_xmit() does the call for us,
so the call here can simply be removed.
Also, tcp_write_xmit() can be marked static.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 5e63ed0..a6375ca 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -511,35 +511,6 @@
return skb->next == (struct sk_buff *)&sk->sk_write_queue;
}
-/* Push out any pending frames which were held back due to
- * TCP_CORK or attempt at coalescing tiny packets.
- * The socket must be locked by the caller.
- */
-void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp,
- unsigned cur_mss, int nonagle)
-{
- struct sk_buff *skb = sk->sk_send_head;
-
- if (skb) {
- if (!tcp_skb_is_last(sk, skb))
- nonagle = TCP_NAGLE_PUSH;
- if (!tcp_snd_test(sk, skb, cur_mss, nonagle) ||
- tcp_write_xmit(sk, nonagle))
- tcp_check_probe_timer(sk, tp);
- }
- tcp_cwnd_validate(sk, tp);
-}
-
-void __tcp_data_snd_check(struct sock *sk, struct sk_buff *skb)
-{
- struct tcp_sock *tp = tcp_sk(sk);
-
- if (after(TCP_SKB_CB(skb)->end_seq, tp->snd_una + tp->snd_wnd) ||
- tcp_packets_in_flight(tp) >= tp->snd_cwnd ||
- tcp_write_xmit(sk, tp->nonagle))
- tcp_check_probe_timer(sk, tp);
-}
-
int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp)
{
struct sk_buff *skb = sk->sk_send_head;
@@ -841,6 +812,26 @@
return mss_now;
}
+/* Congestion window validation. (RFC2861) */
+
+static inline void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp)
+{
+ __u32 packets_out = tp->packets_out;
+
+ if (packets_out >= tp->snd_cwnd) {
+ /* Network is feed fully. */
+ tp->snd_cwnd_used = 0;
+ tp->snd_cwnd_stamp = tcp_time_stamp;
+ } else {
+ /* Network starves. */
+ if (tp->packets_out > tp->snd_cwnd_used)
+ tp->snd_cwnd_used = tp->packets_out;
+
+ if ((s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= tp->rto)
+ tcp_cwnd_application_limited(sk);
+ }
+}
+
/* This routine writes packets to the network. It advances the
* send_head. This happens as incoming acks open up the remote
* window for us.
@@ -848,7 +839,7 @@
* Returns 1, if no segments are in flight and we have queued segments, but
* cannot send anything now because of SWS or another problem.
*/
-int tcp_write_xmit(struct sock *sk, int nonagle)
+static int tcp_write_xmit(struct sock *sk, int nonagle)
{
struct tcp_sock *tp = tcp_sk(sk);
unsigned int mss_now;
@@ -901,6 +892,34 @@
return 0;
}
+/* Push out any pending frames which were held back due to
+ * TCP_CORK or attempt at coalescing tiny packets.
+ * The socket must be locked by the caller.
+ */
+void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp,
+ unsigned cur_mss, int nonagle)
+{
+ struct sk_buff *skb = sk->sk_send_head;
+
+ if (skb) {
+ if (!tcp_skb_is_last(sk, skb))
+ nonagle = TCP_NAGLE_PUSH;
+ if (!tcp_snd_test(sk, skb, cur_mss, nonagle) ||
+ tcp_write_xmit(sk, nonagle))
+ tcp_check_probe_timer(sk, tp);
+ }
+}
+
+void __tcp_data_snd_check(struct sock *sk, struct sk_buff *skb)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (after(TCP_SKB_CB(skb)->end_seq, tp->snd_una + tp->snd_wnd) ||
+ tcp_packets_in_flight(tp) >= tp->snd_cwnd ||
+ tcp_write_xmit(sk, tp->nonagle))
+ tcp_check_probe_timer(sk, tp);
+}
+
/* This function returns the amount that we can raise the
* usable window based on the following constraints
*