diff options
| author | Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> | 2007-08-09 14:53:36 +0300 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-10-10 16:47:58 -0700 |
| commit | 1b6d427bb7eb69e6dc4f194a5b0f4a382a16ff82 (patch) | |
| tree | d67f6ea9a5f581f83b4d8228fc2964c70f940d5a /net/ipv4 | |
| parent | d02596e32925edaeccee0af8eb6c229b5615de42 (diff) | |
[TCP]: Reduce sacked_out with reno when purging write_queue
Previously TCP had a transitional state during which reno
counted segments that are already below the current window into
sacked_out, which is now prevented. In addition, re-try now
the unconditional S+L skb catching.
This approach conservatively calls just remove_sack and leaves
reset_sack() calls alone. The best solution to the whole problem
would be to first calculate the new sacked_out fully (this patch
does not move reno_sack_reset calls from original sites and thus
does not implement this). However, that would require very
invasive change to fastretrans_alert (perhaps even slicing it to
two halves). Alternatively, all callers of tcp_packets_in_flight
(i.e., users that depend on sacked_out) should be postponed
until the new sacked_out has been calculated but it isn't any
simpler alternative.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp_input.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index bf4fc3516fb9..f8af018dd224 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2187,7 +2187,7 @@ static void tcp_mtup_probe_success(struct sock *sk, struct sk_buff *skb) * tcp_xmit_retransmit_queue(). */ static void -tcp_fastretrans_alert(struct sock *sk, int prior_packets, int flag) +tcp_fastretrans_alert(struct sock *sk, int pkts_acked, int flag) { struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); @@ -2273,12 +2273,8 @@ tcp_fastretrans_alert(struct sock *sk, int prior_packets, int flag) if (!(flag & FLAG_SND_UNA_ADVANCED)) { if (IsReno(tp) && is_dupack) tcp_add_reno_sack(sk); - } else { - int acked = prior_packets - tp->packets_out; - if (IsReno(tp)) - tcp_remove_reno_sacks(sk, acked); - do_lost = tcp_try_undo_partial(sk, acked); - } + } else + do_lost = tcp_try_undo_partial(sk, pkts_acked); break; case TCP_CA_Loss: if (flag&FLAG_DATA_ACKED) @@ -2577,6 +2573,9 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) tcp_ack_update_rtt(sk, acked, seq_rtt); tcp_ack_packets_out(sk); + if (IsReno(tp)) + tcp_remove_reno_sacks(sk, pkts_acked); + if (ca_ops->pkts_acked) { s32 rtt_us = -1; @@ -2927,7 +2926,7 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag) if ((flag & FLAG_DATA_ACKED) && !frto_cwnd && tcp_may_raise_cwnd(sk, flag)) tcp_cong_avoid(sk, ack, prior_in_flight, 0); - tcp_fastretrans_alert(sk, prior_packets, flag); + tcp_fastretrans_alert(sk, prior_packets - tp->packets_out, flag); } else { if ((flag & FLAG_DATA_ACKED) && !frto_cwnd) tcp_cong_avoid(sk, ack, prior_in_flight, 1); |