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-rw-r--r--net/ipv4/tcp_output.c40
1 files changed, 31 insertions, 9 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8327e5e86d1..0a4cd24b657 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -887,6 +887,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
+ unsigned int tso_segs, cwnd_quota;
int sent_pkts;
/* If we are closed, the bytes will have to remain here.
@@ -896,19 +897,31 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle)
if (unlikely(sk->sk_state == TCP_CLOSE))
return 0;
+ skb = sk->sk_send_head;
+ if (unlikely(!skb))
+ return 0;
+
+ tso_segs = tcp_init_tso_segs(sk, skb);
+ cwnd_quota = tcp_cwnd_test(tp, skb);
sent_pkts = 0;
- while ((skb = sk->sk_send_head) &&
- tcp_snd_test(sk, skb, mss_now,
- tcp_skb_is_last(sk, skb) ? nonagle :
- TCP_NAGLE_PUSH)) {
- if (skb->len > mss_now) {
- if (tcp_fragment(sk, skb, mss_now))
+
+ while (cwnd_quota >= tso_segs) {
+ if (unlikely(!tcp_nagle_test(tp, skb, mss_now,
+ (tcp_skb_is_last(sk, skb) ?
+ nonagle : TCP_NAGLE_PUSH))))
+ break;
+
+ if (unlikely(!tcp_snd_wnd_test(tp, skb, mss_now)))
+ break;
+
+ if (unlikely(skb->len > mss_now)) {
+ if (unlikely(tcp_fragment(sk, skb, mss_now)))
break;
}
TCP_SKB_CB(skb)->when = tcp_time_stamp;
tcp_tso_set_push(skb);
- if (tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC)))
+ if (unlikely(tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC))))
break;
/* Advance the send_head. This one is sent out.
@@ -917,10 +930,19 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle)
update_send_head(sk, tp, skb);
tcp_minshall_update(tp, mss_now, skb);
- sent_pkts = 1;
+ sent_pkts++;
+
+ /* Do not optimize this to use tso_segs. If we chopped up
+ * the packet above, tso_segs will no longer be valid.
+ */
+ cwnd_quota -= tcp_skb_pcount(skb);
+ skb = sk->sk_send_head;
+ if (!skb)
+ break;
+ tso_segs = tcp_init_tso_segs(sk, skb);
}
- if (sent_pkts) {
+ if (likely(sent_pkts)) {
tcp_cwnd_validate(sk, tp);
return 0;
}