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authorEric Dumazet <edumazet@google.com>2018-09-21 08:51:49 -0700
committerDavid S. Miller <davem@davemloft.net>2018-09-21 19:37:59 -0700
commit9799ccb0e984a5c1311b22a212e7ff96e8b736de (patch)
tree85061422e73b7f752c2e5c568ba57367e28d31a1 /net/ipv4
parent142537e419234c396890a22806b8644dce21b132 (diff)
downloadlinux-9799ccb0e984a5c1311b22a212e7ff96e8b736de.tar.gz
tcp: add tcp_wstamp_ns socket field
TCP will soon provide earliest departure time on TX skbs.
It needs to track this in a new variable.

tcp_mstamp_refresh() needs to update this variable, and
became too big to stay an inline.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/tcp_output.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index b95aa72d8823..5a8105e84f7c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -45,6 +45,22 @@
 
 #include <trace/events/tcp.h>
 
+/* Refresh clocks of a TCP socket,
+ * ensuring monotically increasing values.
+ */
+void tcp_mstamp_refresh(struct tcp_sock *tp)
+{
+	u64 val = tcp_clock_ns();
+
+	/* departure time for next data packet */
+	if (val > tp->tcp_wstamp_ns)
+		tp->tcp_wstamp_ns = val;
+
+	val = div_u64(val, NSEC_PER_USEC);
+	if (val > tp->tcp_mstamp)
+		tp->tcp_mstamp = val;
+}
+
 static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 			   int push_one, gfp_t gfp);