leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[TCP]: Fix and simplify microsecond rtt sampling

Browse Source 
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>
This commit is contained in:
John Heffner 2006-09-28 14:47:38 -07:00 committed by David S. Miller
parent bfbea8a886
commit 8ea333eb5d
1 changed files with 8 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
net/ipv4/tcp_input.c
View File

@ -2239,13 +2239,12 @@ static int tcp_tso_acked(struct sock *sk, struct sk_buff *skb,
return acked; 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); 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. */ /* 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; u32 pkts_acked = 0;
void (*rtt_sample)(struct sock *sk, u32 usrtt) void (*rtt_sample)(struct sock *sk, u32 usrtt)
= icsk->icsk_ca_ops->rtt_sample; = icsk->icsk_ca_ops->rtt_sample;
struct timeval tv;
while ((skb = skb_peek(&sk->sk_write_queue)) && while ((skb = skb_peek(&sk->sk_write_queue)) &&
skb != sk->sk_send_head) { 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; seq_rtt = -1;
} else if (seq_rtt < 0) { } else if (seq_rtt < 0) {
seq_rtt = now - scb->when; seq_rtt = now - scb->when;
if (rtt_sample) skb_get_timestamp(skb, &tv);
(*rtt_sample)(sk, tcp_usrtt(skb));
} }
if (sacked & TCPCB_SACKED_ACKED) if (sacked & TCPCB_SACKED_ACKED)
tp->sacked_out -= tcp_skb_pcount(skb); 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) { } else if (seq_rtt < 0) {
seq_rtt = now - scb->when; seq_rtt = now - scb->when;
if (rtt_sample) skb_get_timestamp(skb, &tv);
(*rtt_sample)(sk, tcp_usrtt(skb));
} }
tcp_dec_pcount_approx(&tp->fackets_out, skb); tcp_dec_pcount_approx(&tp->fackets_out, skb);
tcp_packets_out_dec(tp, 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) { if (acked&FLAG_ACKED) {
tcp_ack_update_rtt(sk, acked, seq_rtt); tcp_ack_update_rtt(sk, acked, seq_rtt);
tcp_ack_packets_out(sk, tp); 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) if (icsk->icsk_ca_ops->pkts_acked)
icsk->icsk_ca_ops->pkts_acked(sk, pkts_acked); icsk->icsk_ca_ops->pkts_acked(sk, pkts_acked);