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/include/linux/skbuff.h b/include/linux/skbuff.h
index 0e35b3a..50e1e9b 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -229,7 +229,7 @@
/* generate hardware time stamp */
SKBTX_HW_TSTAMP = 1 << 0,
- /* generate software time stamp */
+ /* generate software time stamp when queueing packet to NIC */
SKBTX_SW_TSTAMP = 1 << 1,
/* device driver is going to provide hardware time stamp */
@@ -247,9 +247,12 @@
* all frags to avoid possible bad checksum
*/
SKBTX_SHARED_FRAG = 1 << 5,
+
+ /* generate software time stamp when entering packet scheduling */
+ SKBTX_SCHED_TSTAMP = 1 << 6,
};
-#define SKBTX_ANY_SW_TSTAMP SKBTX_SW_TSTAMP
+#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | SKBTX_SCHED_TSTAMP)
#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
/*
@@ -2695,6 +2698,10 @@
void skb_complete_tx_timestamp(struct sk_buff *skb,
struct skb_shared_hwtstamps *hwtstamps);
+void __skb_tstamp_tx(struct sk_buff *orig_skb,
+ struct skb_shared_hwtstamps *hwtstamps,
+ struct sock *sk, int tstype);
+
/**
* skb_tstamp_tx - queue clone of skb with send time stamps
* @orig_skb: the original outgoing packet