[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>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 8b404b1ef7c8..c209361ab74a 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -660,7 +660,7 @@ struct tcp_congestion_ops {
         /* new value of cwnd after loss (optional) */
         u32  (*undo_cwnd)(struct sock *sk);
         /* hook for packet ack accounting (optional) */
-        void (*pkts_acked)(struct sock *sk, u32 num_acked, ktime_t last);
+        void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us);
         /* get info for inet_diag (optional) */
         void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb);