diff options
| author | Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> | 2008-09-20 21:25:52 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-09-20 21:25:52 -0700 |
| commit | 90638a04ad8484b6b6c567656fb3f6d0689e23da (patch) | |
| tree | 87a14ffe430d4663ec4df268459c78d07a4e75a2 /net | |
| parent | ef9da47c7cc64d69526331f315e76b5680d4048f (diff) | |
| download | linux-90638a04ad8484b6b6c567656fb3f6d0689e23da.tar.gz linux-90638a04ad8484b6b6c567656fb3f6d0689e23da.tar.bz2 linux-90638a04ad8484b6b6c567656fb3f6d0689e23da.zip | |
tcp: don't clear lost_skb_hint when not necessary
Most importantly avoid doing it with cumulative ACK. However,
since we have lost_cnt_hint in the picture as well needing
adjustments, it's not as trivial as dealing with
retransmit_skb_hint (and cannot be done in the all place we
could trivially leave retransmit_skb_hint untouched).
With the previous patch, this should mostly remove O(n^2)
behavior while cumulative ACKs start flowing once rexmit
after a lossy round-trip made it through.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_input.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 44a4fffc2cc3..85627f83665f 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2844,6 +2844,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets) int flag = 0; u32 pkts_acked = 0; u32 reord = tp->packets_out; + u32 prior_sacked = tp->sacked_out; s32 seq_rtt = -1; s32 ca_seq_rtt = -1; ktime_t last_ackt = net_invalid_timestamp(); @@ -2925,9 +2926,11 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets) tcp_unlink_write_queue(skb, sk); sk_wmem_free_skb(sk, skb); - tcp_clear_retrans_hints_partial(tp); + tp->scoreboard_skb_hint = NULL; if (skb == tp->retransmit_skb_hint) tp->retransmit_skb_hint = NULL; + if (skb == tp->lost_skb_hint) + tp->lost_skb_hint = NULL; } if (skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) @@ -2946,6 +2949,15 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets) /* Non-retransmitted hole got filled? That's reordering */ if (reord < prior_fackets) tcp_update_reordering(sk, tp->fackets_out - reord, 0); + + /* No need to care for underflows here because + * the lost_skb_hint gets NULLed if we're past it + * (or something non-trivial happened) + */ + if (tcp_is_fack(tp)) + tp->lost_cnt_hint -= pkts_acked; + else + tp->lost_cnt_hint -= prior_sacked - tp->sacked_out; } tp->fackets_out -= min(pkts_acked, tp->fackets_out); |