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| author | Stephen Hemminger <shemminger@linux-foundation.org> | 2007-07-25 23:49:34 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-07-31 02:27:57 -0700 |
| commit | 30cfd0baf0a0c4329fff1ef4b622919297969ec8 (patch) | |
| tree | 945a72f636ced1b443d894495704237e4cb7816d /net/ipv4/tcp_input.c | |
| parent | 6a302358d87fedaf7bda12b8e909265ebf1ce674 (diff) | |
| download | linux-30cfd0baf0a0c4329fff1ef4b622919297969ec8.tar.gz linux-30cfd0baf0a0c4329fff1ef4b622919297969ec8.tar.bz2 linux-30cfd0baf0a0c4329fff1ef4b622919297969ec8.zip | |
[TCP]: congestion control API pass RTT in microseconds
This patch changes the API for the callback that is done after an ACK is
received. It solves a couple of issues:
* Some congestion controls want higher resolution value of RTT
(controlled by TCP_CONG_RTT_SAMPLE flag). These don't really want a ktime, but
all compute a RTT in microseconds.
* Other congestion control could use RTT at jiffies resolution.
To keep API consistent the units should be the same for both cases, just the
resolution should change.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index fec8a7a4dbaf..4b255fe999d9 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2490,12 +2490,23 @@ 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) { + s32 rtt_us = -1; + + /* Is the ACK triggering packet unambiguous? */ + if (!(acked & FLAG_RETRANS_DATA_ACKED)) { + /* High resolution needed and available? */ + if (ca_ops->flags & TCP_CONG_RTT_STAMP && + !ktime_equal(last_ackt, + net_invalid_timestamp())) + rtt_us = ktime_us_delta(ktime_get_real(), + last_ackt); + else if (seq_rtt > 0) + rtt_us = jiffies_to_usecs(seq_rtt); + } - if (ca_ops->pkts_acked) - ca_ops->pkts_acked(sk, pkts_acked, last_ackt); + ca_ops->pkts_acked(sk, pkts_acked, rtt_us); + } } #if FASTRETRANS_DEBUG > 0 |