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| author | Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> | 2007-06-15 15:08:43 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2007-06-15 15:08:43 -0700 |
| commit | b9ce204f0a265f819d10c943a607746abb62f245 (patch) | |
| tree | 45078d076bcd952d8820c590653939b312d06ac2 /net | |
| parent | 22b1a9203ea634ac0ee5240e021613da3328275f (diff) | |
| download | linux-3.10-b9ce204f0a265f819d10c943a607746abb62f245.tar.gz linux-3.10-b9ce204f0a265f819d10c943a607746abb62f245.tar.bz2 linux-3.10-b9ce204f0a265f819d10c943a607746abb62f245.zip | |
[TCP]: Congestion control API RTT sampling fix
Commit 164891aadf1721fca4dce473bb0e0998181537c6 broke RTT
sampling of congestion control modules. Inaccurate timestamps
could be fed to them without providing any way for them to
identify such cases. Previously RTT sampler was called only if
FLAG_RETRANS_DATA_ACKED was not set filtering inaccurate
timestamps nicely. In addition, the new behavior could give an
invalid timestamp (zero) to RTT sampler if only skbs with
TCPCB_RETRANS were ACKed. This solves both problems.
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_illinois.c | 3 | ||||
| -rw-r--r-- | net/ipv4/tcp_input.c | 6 | ||||
| -rw-r--r-- | net/ipv4/tcp_lp.c | 3 | ||||
| -rw-r--r-- | net/ipv4/tcp_vegas.c | 3 | ||||
| -rw-r--r-- | net/ipv4/tcp_veno.c | 3 |
5 files changed, 16 insertions, 2 deletions
diff --git a/net/ipv4/tcp_illinois.c b/net/ipv4/tcp_illinois.c index 4adc47c5535..b2b2256d3b8 100644 --- a/net/ipv4/tcp_illinois.c +++ b/net/ipv4/tcp_illinois.c @@ -90,6 +90,9 @@ static void tcp_illinois_acked(struct sock *sk, u32 pkts_acked, ktime_t last) ca->acked = pkts_acked; + if (ktime_equal(last, net_invalid_timestamp())) + return; + rtt = ktime_to_us(net_timedelta(last)); /* ignore bogus values, this prevents wraparound in alpha math */ diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index d6d0f9b6cdc..aaf6f66677f 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2409,7 +2409,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) int acked = 0; int prior_packets = tp->packets_out; __s32 seq_rtt = -1; - ktime_t last_ackt = ktime_set(0,0); + ktime_t last_ackt = net_invalid_timestamp(); while ((skb = tcp_write_queue_head(sk)) && skb != tcp_send_head(sk)) { @@ -2487,6 +2487,10 @@ 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); + /* Is the ACK triggering packet unambiguous? */ + if (acked & FLAG_RETRANS_DATA_ACKED) + last_ackt = net_invalid_timestamp(); + if (ca_ops->pkts_acked) ca_ops->pkts_acked(sk, pkts_acked, last_ackt); } diff --git a/net/ipv4/tcp_lp.c b/net/ipv4/tcp_lp.c index 43294ad9f63..e49836ce012 100644 --- a/net/ipv4/tcp_lp.c +++ b/net/ipv4/tcp_lp.c @@ -266,7 +266,8 @@ static void tcp_lp_pkts_acked(struct sock *sk, u32 num_acked, ktime_t last) struct tcp_sock *tp = tcp_sk(sk); struct lp *lp = inet_csk_ca(sk); - tcp_lp_rtt_sample(sk, ktime_to_us(net_timedelta(last))); + if (!ktime_equal(last, net_invalid_timestamp())) + tcp_lp_rtt_sample(sk, ktime_to_us(net_timedelta(last))); /* calc inference */ if (tcp_time_stamp > tp->rx_opt.rcv_tsecr) diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c index 73e19cf7df2..e218a51cece 100644 --- a/net/ipv4/tcp_vegas.c +++ b/net/ipv4/tcp_vegas.c @@ -117,6 +117,9 @@ void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, ktime_t last) struct vegas *vegas = inet_csk_ca(sk); u32 vrtt; + if (ktime_equal(last, net_invalid_timestamp())) + return; + /* Never allow zero rtt or baseRTT */ vrtt = ktime_to_us(net_timedelta(last)) + 1; diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c index 9edb340f2f9..ec854cc5fad 100644 --- a/net/ipv4/tcp_veno.c +++ b/net/ipv4/tcp_veno.c @@ -74,6 +74,9 @@ static void tcp_veno_pkts_acked(struct sock *sk, u32 cnt, ktime_t last) struct veno *veno = inet_csk_ca(sk); u32 vrtt; + if (ktime_equal(last, net_invalid_timestamp())) + return; + /* Never allow zero rtt or baseRTT */ vrtt = ktime_to_us(net_timedelta(last)) + 1; |