[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, 8 insertions, 17 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 633389390788..051f0f815f17 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2402,14 +2402,6 @@ static int tcp_tso_acked(struct sock *sk, struct sk_buff *skb,
         return acked;
 }
 
-static u32 tcp_usrtt(struct timeval *tv)
-{
-        struct timeval now;
-
-        do_gettimeofday(&now);
-        return (now.tv_sec - tv->tv_sec) * 1000000 + (now.tv_usec - tv->tv_usec);
-}
-
 /* Remove acknowledged frames from the retransmission queue. */
 static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
 {
@@ -2420,9 +2412,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
         int acked = 0;
         __s32 seq_rtt = -1;
         u32 pkts_acked = 0;
-        void (*rtt_sample)(struct sock *sk, u32 usrtt)
-                = icsk->icsk_ca_ops->rtt_sample;
-        struct timeval tv = { .tv_sec = 0, .tv_usec = 0 };
+        ktime_t last_ackt = ktime_set(0,0);
 
         while ((skb = tcp_write_queue_head(sk)) &&
                skb != tcp_send_head(sk)) {
@@ -2471,7 +2461,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
                                 seq_rtt = -1;
                         } else if (seq_rtt < 0) {
                                 seq_rtt = now - scb->when;
-                                skb_get_timestamp(skb, &tv);
+                                last_ackt = skb->tstamp;
                         }
                         if (sacked & TCPCB_SACKED_ACKED)
                                 tp->sacked_out -= tcp_skb_pcount(skb);
@@ -2484,7 +2474,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
                         }
                 } else if (seq_rtt < 0) {
                         seq_rtt = now - scb->when;
-                        skb_get_timestamp(skb, &tv);
+                        last_ackt = skb->tstamp;
                 }
                 tcp_dec_pcount_approx(&tp->fackets_out, skb);
                 tcp_packets_out_dec(tp, skb);
@@ -2494,13 +2484,14 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
         }
 
         if (acked&FLAG_ACKED) {
+                const struct tcp_congestion_ops *ca_ops
+                        = inet_csk(sk)->icsk_ca_ops;
+
                 tcp_ack_update_rtt(sk, acked, seq_rtt);
                 tcp_ack_packets_out(sk);
-                if (rtt_sample && !(acked & FLAG_RETRANS_DATA_ACKED))
-                        (*rtt_sample)(sk, tcp_usrtt(&tv));
 
-                if (icsk->icsk_ca_ops->pkts_acked)
-                        icsk->icsk_ca_ops->pkts_acked(sk, pkts_acked);
+                if (ca_ops->pkts_acked)
+                        ca_ops->pkts_acked(sk, pkts_acked, last_ackt);
         }
 
 #if FASTRETRANS_DEBUG > 0