net-timestamp: SCHED timestamp on entering packet scheduler
Kernel transmit latency is often incurred in the packet scheduler.
Introduce a new timestamp on transmission just before entering the
scheduler. When data travels through multiple devices (bonding,
tunneling, ...) each device will export an individual timestamp.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/socket.c b/net/socket.c
index 255d9b8..3a2778d 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -617,6 +617,9 @@
*tx_flags |= SKBTX_HW_TSTAMP;
if (sk->sk_tsflags & SOF_TIMESTAMPING_TX_SOFTWARE)
*tx_flags |= SKBTX_SW_TSTAMP;
+ if (sk->sk_tsflags & SOF_TIMESTAMPING_TX_SCHED)
+ *tx_flags |= SKBTX_SCHED_TSTAMP;
+
if (sock_flag(sk, SOCK_WIFI_STATUS))
*tx_flags |= SKBTX_WIFI_STATUS;
}