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/core/dev.c b/net/core/dev.c
index b370230..1c15b18 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -132,6 +132,7 @@
#include <linux/hashtable.h>
#include <linux/vmalloc.h>
#include <linux/if_macvlan.h>
+#include <linux/errqueue.h>
#include "net-sysfs.h"
@@ -2876,6 +2877,9 @@
skb_reset_mac_header(skb);
+ if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
+ __skb_tstamp_tx(skb, NULL, skb->sk, SCM_TSTAMP_SCHED);
+
/* Disable soft irqs for various locks below. Also
* stops preemption for RCU.
*/
