diff options
| author | Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> | 2007-10-11 17:36:13 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2007-10-11 17:36:13 -0700 |
| commit | b08d6cb22c777c8c91c16d8e3b8aafc93c98cbd9 (patch) | |
| tree | 139b1f2636c42698bd7b0f0ccd61f0e1b8a826ab /net/ipv4/tcp_input.c | |
| parent | f785a8e28b9d103c7473655743b6ac1bc3cd3a58 (diff) | |
| download | lwn-b08d6cb22c777c8c91c16d8e3b8aafc93c98cbd9.tar.gz lwn-b08d6cb22c777c8c91c16d8e3b8aafc93c98cbd9.zip | |
[TCP]: Limit processing lost_retrans loop to work-to-do cases
This addition of lost_retrans_low to tcp_sock might be
unnecessary, it's not clear how often lost_retrans worker is
executed when there wasn't work to do.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index d5e0fcc22a3b..0a42e9340346 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1112,7 +1112,8 @@ static int tcp_is_sackblock_valid(struct tcp_sock *tp, int is_dsack, * * Search retransmitted skbs from write_queue that were sent when snd_nxt was * less than what is now known to be received by the other end (derived from - * SACK blocks by the caller). + * SACK blocks by the caller). Also calculate the lowest snd_nxt among the + * remaining retransmitted skbs to avoid some costly processing per ACKs. */ static int tcp_mark_lost_retrans(struct sock *sk, u32 received_upto) { @@ -1120,6 +1121,7 @@ static int tcp_mark_lost_retrans(struct sock *sk, u32 received_upto) struct sk_buff *skb; int flag = 0; int cnt = 0; + u32 new_low_seq = 0; tcp_for_write_queue(skb, sk) { u32 ack_seq = TCP_SKB_CB(skb)->ack_seq; @@ -1151,9 +1153,15 @@ static int tcp_mark_lost_retrans(struct sock *sk, u32 received_upto) NET_INC_STATS_BH(LINUX_MIB_TCPLOSTRETRANSMIT); } } else { + if (!new_low_seq || before(ack_seq, new_low_seq)) + new_low_seq = ack_seq; cnt += tcp_skb_pcount(skb); } } + + if (tp->retrans_out) + tp->lost_retrans_low = new_low_seq; + return flag; } @@ -1481,8 +1489,8 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ } } - if (tp->retrans_out && highest_sack_end_seq && - after(highest_sack_end_seq, tp->high_seq) && + if (tp->retrans_out && + after(highest_sack_end_seq, tp->lost_retrans_low) && icsk->icsk_ca_state == TCP_CA_Recovery) flag |= tcp_mark_lost_retrans(sk, highest_sack_end_seq); |