From: Eric Dumazet <edumazet@google.com>
Date: Fri, 21 Sep 2018 15:51:46 +0000 (-0700)
Subject: tcp: switch tcp_clock_ns() to CLOCK_TAI base
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=72b0094f918294e6cb8cf5c3b4520d928fbb1a57;p=linux.git

tcp: switch tcp_clock_ns() to CLOCK_TAI base

TCP pacing is either implemented in sch_fq or internally.
We have the goal of being able to offload pacing on the NICS.

TCP will soon provide per skb skb->tstamp as early departure time.

Like ETF in commit 25db26a91364 ("net/sched: Introduce the ETF Qdisc")
we chose CLOCK_T as the clock base, so that TCP and pacers can share
a common clock, to get better RTT samples (without pacing artificially
inflating these samples).

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 770917d0caa71..c6f0bc1dc6782 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -732,7 +732,7 @@ void tcp_send_window_probe(struct sock *sk);
 
 static inline u64 tcp_clock_ns(void)
 {
-	return local_clock();
+	return ktime_get_tai_ns();
 }
 
 static inline u64 tcp_clock_us(void)