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| author | John Heffner <jheffner@psc.edu> | 2006-09-28 14:47:38 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2006-09-28 18:03:08 -0700 |
| commit | 8ea333eb5da3e3219f570220c56bca09f6f4d25a (patch) | |
| tree | 97e76b5aa8a8cd795dc65768fe5c75a4135a5ec1 | |
| parent | bfbea8a8869a0e21b97605841d04190d63665d19 (diff) | |
| download | linux-8ea333eb5da3e3219f570220c56bca09f6f4d25a.tar.gz linux-8ea333eb5da3e3219f570220c56bca09f6f4d25a.tar.bz2 linux-8ea333eb5da3e3219f570220c56bca09f6f4d25a.zip | |
[TCP]: Fix and simplify microsecond rtt sampling
This changes the microsecond RTT sampling so that samples are taken in
the same way that RTT samples are taken for the RTO calculator: on the
last segment acknowledged, and only when the segment hasn't been
retransmitted.
Signed-off-by: John Heffner <jheffner@psc.edu>
Acked-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/tcp_input.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 85c966316668..3f884cea14ff 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2239,13 +2239,12 @@ static int tcp_tso_acked(struct sock *sk, struct sk_buff *skb, return acked; } -static u32 tcp_usrtt(const struct sk_buff *skb) +static u32 tcp_usrtt(struct timeval *tv) { - struct timeval tv, now; + struct timeval now; do_gettimeofday(&now); - skb_get_timestamp(skb, &tv); - return (now.tv_sec - tv.tv_sec) * 1000000 + (now.tv_usec - tv.tv_usec); + return (now.tv_sec - tv->tv_sec) * 1000000 + (now.tv_usec - tv->tv_usec); } /* Remove acknowledged frames from the retransmission queue. */ @@ -2260,6 +2259,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) u32 pkts_acked = 0; void (*rtt_sample)(struct sock *sk, u32 usrtt) = icsk->icsk_ca_ops->rtt_sample; + struct timeval tv; while ((skb = skb_peek(&sk->sk_write_queue)) && skb != sk->sk_send_head) { @@ -2308,8 +2308,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) seq_rtt = -1; } else if (seq_rtt < 0) { seq_rtt = now - scb->when; - if (rtt_sample) - (*rtt_sample)(sk, tcp_usrtt(skb)); + skb_get_timestamp(skb, &tv); } if (sacked & TCPCB_SACKED_ACKED) tp->sacked_out -= tcp_skb_pcount(skb); @@ -2322,8 +2321,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) } } else if (seq_rtt < 0) { seq_rtt = now - scb->when; - if (rtt_sample) - (*rtt_sample)(sk, tcp_usrtt(skb)); + skb_get_timestamp(skb, &tv); } tcp_dec_pcount_approx(&tp->fackets_out, skb); tcp_packets_out_dec(tp, skb); @@ -2335,6 +2333,8 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) if (acked&FLAG_ACKED) { tcp_ack_update_rtt(sk, acked, seq_rtt); tcp_ack_packets_out(sk, tp); + if (rtt_sample && !(acked & FLAG_RETRANS_DATA_ACKED)) + (*rtt_sample)(sk, tcp_usrtt(&tv)); if (icsk->icsk_ca_ops->pkts_acked) icsk->icsk_ca_ops->pkts_acked(sk, pkts_acked); |