[PATCH net-next 4/9] tcp: add tcp_wstamp_ns socket field

[Eric Dumazet]

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 <eduma...@google.com>
---
 include/linux/tcp.h   |  2 ++
 include/net/tcp.h     | 12 +-----------
 net/ipv4/tcp_output.c | 16 ++++++++++++++++
 3 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 
263e37271afda18f3d61c99272d34da15dfdca29..848f5b25e178288ce870637b68a692ab88dc7d4d
 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -248,6 +248,8 @@ struct tcp_sock {
                syn_smc:1;      /* SYN includes SMC */
        u32     tlp_high_seq;   /* snd_nxt at the time of TLP retransmit. */
 
+       u64     tcp_wstamp_ns;  /* departure time for next sent data packet */
+
 /* RTT measurement */
        u64     tcp_mstamp;     /* most recent packet received/sent */
        u32     srtt_us;        /* smoothed round trip time << 3 in usecs */
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 
0ca5ea10dc06f3552597c94de31dcd0c8e0ecc32..370198fdc65d3e863104665e20faefd0e5a09b92
 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -752,17 +752,7 @@ static inline u32 tcp_time_stamp_raw(void)
        return div_u64(tcp_clock_ns(), NSEC_PER_SEC / TCP_TS_HZ);
 }
 
-
-/* Refresh 1us clock of a TCP socket,
- * ensuring monotically increasing values.
- */
-static inline void tcp_mstamp_refresh(struct tcp_sock *tp)
-{
-       u64 val = tcp_clock_us();
-
-       if (val > tp->tcp_mstamp)
-               tp->tcp_mstamp = val;
-}
+void tcp_mstamp_refresh(struct tcp_sock *tp);
 
 static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0)
 {
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 
b95aa72d88233dd6376a70ccd7cbb13744444889..5a8105e84f7c1a876bbd15e8050c2574c1fbe162
 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);
 
-- 
2.19.0.444.g18242da7ef-goog