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[TCP]: congestion control API pass RTT in microseconds

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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>
This commit is contained in:
Stephen Hemminger
2007-07-25 23:49:34 -07:00
committed by David S. Miller
parent 6a302358d8
commit 30cfd0baf0
12 changed files with 39 additions and 29 deletions
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6
net/ipv4/tcp_vegas.c
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@@ -112,16 +112,16 @@ EXPORT_SYMBOL_GPL(tcp_vegas_init);
* o min-filter RTT samples from a much longer window (forever for now)
* to find the propagation delay (baseRTT)
*/
void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, ktime_t last)
void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, s32 rtt_us)
{
struct vegas *vegas = inet_csk_ca(sk);
u32 vrtt;
if (ktime_equal(last, net_invalid_timestamp()))
if (rtt_us < 0)
return;
/* Never allow zero rtt or baseRTT */
vrtt = ktime_to_us(net_timedelta(last)) + 1;
vrtt = rtt_us + 1;
/* Filter to find propagation delay: */
if (vrtt < vegas->baseRTT)