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authorDavid S. Miller <davem@davemloft.net>2005-09-01 22:47:01 -0700
committerDavid S. Miller <davem@davemloft.net>2005-09-01 22:47:01 -0700
commit6475be16fd9b3c6746ca4d18959246b13c669ea8 (patch)
tree03e0da36680ddb227591a4007fa4e6f18d82782c /net/ipv4/tcp_output.c
parentef015786152adaff5a6a8bf0c8ea2f70cee8059d (diff)
[TCP]: Keep TSO enabled even during loss events.
All we need to do is resegment the queue so that we record SACK information accurately. The edges of the SACK blocks guide our resegmenting decisions. With help from Herbert Xu. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_output.c')
-rw-r--r--net/ipv4/tcp_output.c55
1 files changed, 20 insertions, 35 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 75b68116682..6094db5e11b 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -428,11 +428,11 @@ static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb, unsigned
* packet to the list. This won't be called frequently, I hope.
* Remember, these are still headerless SKBs at this point.
*/
-static int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss_now)
+int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss_now)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *buff;
- int nsize;
+ int nsize, old_factor;
u16 flags;
nsize = skb_headlen(skb) - len;
@@ -490,18 +490,29 @@ static int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned
tp->left_out -= tcp_skb_pcount(skb);
}
+ old_factor = tcp_skb_pcount(skb);
+
/* Fix up tso_factor for both original and new SKB. */
tcp_set_skb_tso_segs(sk, skb, mss_now);
tcp_set_skb_tso_segs(sk, buff, mss_now);
- if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) {
- tp->lost_out += tcp_skb_pcount(skb);
- tp->left_out += tcp_skb_pcount(skb);
- }
+ /* If this packet has been sent out already, we must
+ * adjust the various packet counters.
+ */
+ if (after(tp->snd_nxt, TCP_SKB_CB(buff)->end_seq)) {
+ int diff = old_factor - tcp_skb_pcount(skb) -
+ tcp_skb_pcount(buff);
- if (TCP_SKB_CB(buff)->sacked&TCPCB_LOST) {
- tp->lost_out += tcp_skb_pcount(buff);
- tp->left_out += tcp_skb_pcount(buff);
+ tp->packets_out -= diff;
+ if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) {
+ tp->lost_out -= diff;
+ tp->left_out -= diff;
+ }
+ if (diff > 0) {
+ tp->fackets_out -= diff;
+ if ((int)tp->fackets_out < 0)
+ tp->fackets_out = 0;
+ }
}
/* Link BUFF into the send queue. */
@@ -1350,12 +1361,6 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
if (before(TCP_SKB_CB(skb)->seq, tp->snd_una)) {
if (before(TCP_SKB_CB(skb)->end_seq, tp->snd_una))
BUG();
-
- if (sk->sk_route_caps & NETIF_F_TSO) {
- sk->sk_route_caps &= ~NETIF_F_TSO;
- sock_set_flag(sk, SOCK_NO_LARGESEND);
- }
-
if (tcp_trim_head(sk, skb, tp->snd_una - TCP_SKB_CB(skb)->seq))
return -ENOMEM;
}
@@ -1370,22 +1375,8 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
return -EAGAIN;
if (skb->len > cur_mss) {
- int old_factor = tcp_skb_pcount(skb);
- int diff;
-
if (tcp_fragment(sk, skb, cur_mss, cur_mss))
return -ENOMEM; /* We'll try again later. */
-
- /* New SKB created, account for it. */
- diff = old_factor - tcp_skb_pcount(skb) -
- tcp_skb_pcount(skb->next);
- tp->packets_out -= diff;
-
- if (diff > 0) {
- tp->fackets_out -= diff;
- if ((int)tp->fackets_out < 0)
- tp->fackets_out = 0;
- }
}
/* Collapse two adjacent packets if worthwhile and we can. */
@@ -1993,12 +1984,6 @@ int tcp_write_wakeup(struct sock *sk)
TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
if (tcp_fragment(sk, skb, seg_size, mss))
return -1;
- /* SWS override triggered forced fragmentation.
- * Disable TSO, the connection is too sick. */
- if (sk->sk_route_caps & NETIF_F_TSO) {
- sock_set_flag(sk, SOCK_NO_LARGESEND);
- sk->sk_route_caps &= ~NETIF_F_TSO;
- }
} else if (!tcp_skb_pcount(skb))
tcp_set_skb_tso_segs(sk, skb, mss);