tcp_bbr: fix bbr pacing rate for internal pacing

This commit makes BBR use only the MSS (without any headers) to
calculate pacing rates when internal TCP-layer pacing is used.

This is necessary to achieve the correct pacing behavior in this case,
since tcp_internal_pacing() uses only the payload length to calculate
pacing delays.

Signed-off-by: Kevin Yang <yyd@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 14 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8e08b409c71e..f8f6129160dd 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -973,17 +973,6 @@ enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer)
         return HRTIMER_NORESTART;
 }
 
-/* BBR congestion control needs pacing.
- * Same remark for SO_MAX_PACING_RATE.
- * sch_fq packet scheduler is efficiently handling pacing,
- * but is not always installed/used.
- * Return true if TCP stack should pace packets itself.
- */
-static bool tcp_needs_internal_pacing(const struct sock *sk)
-{
-        return smp_load_acquire(&sk->sk_pacing_status) == SK_PACING_NEEDED;
-}
-
 static void tcp_internal_pacing(struct sock *sk, const struct sk_buff *skb)
 {
         u64 len_ns;
@@ -995,9 +984,6 @@ static void tcp_internal_pacing(struct sock *sk, const struct sk_buff *skb)
         if (!rate || rate == ~0U)
                 return;
 
-        /* Should account for header sizes as sch_fq does,
-         * but lets make things simple.
-         */
         len_ns = (u64)skb->len * NSEC_PER_SEC;
         do_div(len_ns, rate);
         hrtimer_start(&tcp_sk(sk)->pacing_timer,