[TCP]: Congestion control API update.

Do some simple changes to make congestion control API faster/cleaner.
* use ktime_t rather than timeval
* merge rtt sampling into existing ack callback
  this means one indirect call versus two per ack.
* use flags bits to store options/settings

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 9 deletions

diff --git a/net/ipv4/tcp_illinois.c b/net/ipv4/tcp_illinois.c
index ae6298600886..8e3165917f72 100644
--- a/net/ipv4/tcp_illinois.c
+++ b/net/ipv4/tcp_illinois.c
@@ -83,9 +83,14 @@ static void tcp_illinois_init(struct sock *sk)
 }
 
 /* Measure RTT for each ack. */
-static void tcp_illinois_rtt_sample(struct sock *sk, u32 rtt)
+static void tcp_illinois_acked(struct sock *sk, u32 pkts_acked, ktime_t last)
 {
         struct illinois *ca = inet_csk_ca(sk);
+        u32 rtt;
+
+        ca->acked = pkts_acked;
+
+        rtt = ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC;
 
         /* ignore bogus values, this prevents wraparound in alpha math */
         if (rtt > RTT_MAX)
@@ -103,13 +108,6 @@ static void tcp_illinois_rtt_sample(struct sock *sk, u32 rtt)
         ca->sum_rtt += rtt;
 }
 
-/* Capture count of packets covered by ack, to adjust for delayed acks */
-static void tcp_illinois_acked(struct sock *sk, u32 pkts_acked)
-{
-        struct illinois *ca = inet_csk_ca(sk);
-        ca->acked = pkts_acked;
-}
-
 /* Maximum queuing delay */
 static inline u32 max_delay(const struct illinois *ca)
 {
@@ -325,12 +323,12 @@ static void tcp_illinois_info(struct sock *sk, u32 ext,
 }
 
 static struct tcp_congestion_ops tcp_illinois = {
+        .flags          = TCP_CONG_RTT_STAMP,
         .init           = tcp_illinois_init,
         .ssthresh       = tcp_illinois_ssthresh,
         .min_cwnd       = tcp_reno_min_cwnd,
         .cong_avoid     = tcp_illinois_cong_avoid,
         .set_state      = tcp_illinois_state,
-        .rtt_sample     = tcp_illinois_rtt_sample,
         .get_info       = tcp_illinois_info,
         .pkts_acked     = tcp_illinois_acked,