diff options
| 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/ipv4 | |
| parent | 22b1a9203ea634ac0ee5240e021613da3328275f (diff) | |
| download | op-kernel-dev-b9ce204f0a265f819d10c943a607746abb62f245.zip op-kernel-dev-b9ce204f0a265f819d10c943a607746abb62f245.tar.gz | |
[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/ipv4')
| -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 4adc47c..b2b2256 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 d6d0f9b..aaf6f666 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 43294ad..e49836c 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 73e19cf..e218a51 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 9edb340..ec854cc 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; |
