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authorIlpo Järvinen <ilpo.jarvinen@helsinki.fi>2007-06-15 15:08:43 -0700
committerDavid S. Miller <davem@davemloft.net>2007-06-15 15:08:43 -0700
commitb9ce204f0a265f819d10c943a607746abb62f245 (patch)
tree45078d076bcd952d8820c590653939b312d06ac2 /net/ipv4/tcp_input.c
parent22b1a9203ea634ac0ee5240e021613da3328275f (diff)
downloadop-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/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c6
1 files changed, 5 insertions, 1 deletions
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);
}
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