From d3edd06ea8ea9e03de6567fda80b8be57e21a537 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 21 Sep 2018 08:51:50 -0700 Subject: tcp: provide earliest departure time in skb->tstamp Switch internal TCP skb->skb_mstamp to skb->skb_mstamp_ns, from usec units to nsec units. Do not clear skb->tstamp before entering IP stacks in TX, so that qdisc or devices can implement pacing based on the earliest departure time instead of socket sk->sk_pacing_rate Packets are fed with tcp_wstamp_ns, and following patch will update tcp_wstamp_ns when both TCP and sch_fq switch to the earliest departure time mechanism. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'net/ipv4/tcp_output.c') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 5a8105e84f7c..957f7a0e21c0 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1014,7 +1014,7 @@ static void tcp_internal_pacing(struct sock *sk, const struct sk_buff *skb) static void tcp_update_skb_after_send(struct tcp_sock *tp, struct sk_buff *skb) { - skb->skb_mstamp = tp->tcp_mstamp; + skb->skb_mstamp_ns = tp->tcp_wstamp_ns; list_move_tail(&skb->tcp_tsorted_anchor, &tp->tsorted_sent_queue); } @@ -1061,7 +1061,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, if (unlikely(!skb)) return -ENOBUFS; } - skb->skb_mstamp = tp->tcp_mstamp; + skb->skb_mstamp_ns = tp->tcp_wstamp_ns; inet = inet_sk(sk); tcb = TCP_SKB_CB(skb); @@ -1165,8 +1165,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, skb_shinfo(skb)->gso_segs = tcp_skb_pcount(skb); skb_shinfo(skb)->gso_size = tcp_skb_mss(skb); - /* Our usage of tstamp should remain private */ - skb->tstamp = 0; + /* Leave earliest departure time in skb->tstamp (skb->skb_mstamp_ns) */ /* Cleanup our debris for IP stacks */ memset(skb->cb, 0, max(sizeof(struct inet_skb_parm), @@ -3221,10 +3220,10 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, memset(&opts, 0, sizeof(opts)); #ifdef CONFIG_SYN_COOKIES if (unlikely(req->cookie_ts)) - skb->skb_mstamp = cookie_init_timestamp(req); + skb->skb_mstamp_ns = cookie_init_timestamp(req); else #endif - skb->skb_mstamp = tcp_clock_us(); + skb->skb_mstamp_ns = tcp_clock_ns(); #ifdef CONFIG_TCP_MD5SIG rcu_read_lock(); @@ -3440,7 +3439,7 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn) err = tcp_transmit_skb(sk, syn_data, 1, sk->sk_allocation); - syn->skb_mstamp = syn_data->skb_mstamp; + syn->skb_mstamp_ns = syn_data->skb_mstamp_ns; /* Now full SYN+DATA was cloned and sent (or not), * remove the SYN from the original skb (syn_data) -- cgit v1.2.3