Commit c092dd5f authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: switch tcp_internal_pacing() to tcp_wstamp_ns 



Now TCP keeps track of tcp_wstamp_ns, recording the earliest
departure time of next packet, we can remove duplicate code
from tcp_internal_pacing()

This removes one ktime_get_tai_ns() call, and a divide.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ab408b6d

net/ipv4/tcp_output.c

+4 −13
Original line number Diff line number Diff line
@@ -993,21 +993,12 @@ enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer) 
	return HRTIMER_NORESTART;

}



static void tcp_internal_pacing(struct sock *sk, const struct sk_buff *skb)

static void tcp_internal_pacing(struct sock *sk)

{

	u64 len_ns;

	u32 rate;



	if (!tcp_needs_internal_pacing(sk))

		return;

	rate = sk->sk_pacing_rate;

	if (!rate || rate == ~0U)

		return;



	len_ns = (u64)skb->len * NSEC_PER_SEC;

	do_div(len_ns, rate);

	hrtimer_start(&tcp_sk(sk)->pacing_timer,

		      ktime_add_ns(ktime_get_tai_ns(), len_ns),

		      ns_to_ktime(tcp_sk(sk)->tcp_wstamp_ns),

		      HRTIMER_MODE_ABS_PINNED_SOFT);

	sock_hold(sk);

}
@@ -1026,7 +1017,8 @@ static void tcp_update_skb_after_send(struct sock *sk, struct sk_buff *skb) 
		 */

		if (rate != ~0U && rate && tp->data_segs_out >= 10) {

			tp->tcp_wstamp_ns += div_u64((u64)skb->len * NSEC_PER_SEC, rate);

			/* TODO: update internal pacing here */



			tcp_internal_pacing(sk);

		}

	}

	list_move_tail(&skb->tcp_tsorted_anchor, &tp->tsorted_sent_queue);
@@ -1167,7 +1159,6 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, 
		tcp_event_data_sent(tp, sk);

		tp->data_segs_out += tcp_skb_pcount(skb);

		tp->bytes_sent += skb->len - tcp_header_size;

		tcp_internal_pacing(sk, skb);

	}



	if (after(tcb->end_seq, tp->snd_nxt) || tcb->seq == tcb->end_seq)

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