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authorStephen Hemminger <shemminger@linux-foundation.org>2007-07-25 23:49:34 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-07-31 02:27:57 -0700
commit30cfd0baf0a0c4329fff1ef4b622919297969ec8 (patch)
tree945a72f636ced1b443d894495704237e4cb7816d /net/ipv4/tcp_input.c
parent6a302358d87fedaf7bda12b8e909265ebf1ce674 (diff)
[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.c21
1 files changed, 16 insertions, 5 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index fec8a7a4dba..4b255fe999d 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