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| author | Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> | 2007-04-30 11:42:20 +0400 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-30 11:58:16 +0400 |
| commit | d551e4541dd60ae53459f77a971f2d6043431f5f (patch) | |
| tree | cb328b1ec7ae32ad054c9d08de0274e4056a868f /net/ipv4/tcp_output.c | |
| parent | 575ee7140dabe9b9c4f66f4f867039b97e548867 (diff) | |
| download | linux-d551e4541dd60ae53459f77a971f2d6043431f5f.tar.xz | |
[TCP] FRTO: RFC4138 allows Nagle override when new data must be sent
This is a corner case where less than MSS sized new data thingie
is awaiting in the send queue. For F-RTO to work correctly, a
new data segment must be sent at certain point or F-RTO cannot
be used at all. RFC4138 allows overriding of Nagle at that
point.
Implementation uses frto_counter states 2 and 3 to distinguish
when Nagle override is needed.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index b5fa3c19afee..0faacf9c419d 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1035,8 +1035,10 @@ static inline int tcp_nagle_test(struct tcp_sock *tp, struct sk_buff *skb, if (nonagle & TCP_NAGLE_PUSH) return 1; - /* Don't use the nagle rule for urgent data (or for the final FIN). */ - if (tp->urg_mode || + /* Don't use the nagle rule for urgent data (or for the final FIN). + * Nagle can be ignored during F-RTO too (see RFC4138). + */ + if (tp->urg_mode || (tp->frto_counter == 2) || (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)) return 1; |