tcp: switch tcp_clock_ns() to CLOCK_TAI base

Eric Dumazet · davem330 · commit 72b0094f9182 · 2018-09-21T19:37:59.000-07:00
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 25db26a ("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
@@ -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)

Original file line number	Diff line number	Diff line change
`@@ -732,7 +732,7 @@ void tcp_send_window_probe(struct sock *sk);`
`732`	`732`
`733`	`733`	`static inline u64 tcp_clock_ns(void)`
`734`	`734`	`{`
`735`		`- return local_clock();`
	`735`	`+ return ktime_get_tai_ns();`
`736`	`736`	`}`
`737`	`737`
`738`	`738`	`static inline u64 tcp_clock_us(void)`