qdisc: add new field for qdisc_enqueue tracepoint

qdisc_enqueue tracepoint can work with qdisc:qdisc_dequeue
to measure packets latency in qdisc queues.

Add a new field txq for it, then we can retrieve more info.
Signed-off-by: NTonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/trace/events/qdisc.h

@@ -54,6 +54,7 @@ TRACE_EVENT(qdisc_enqueue,
 
 	TP_STRUCT__entry(
 		__field(struct Qdisc *, qdisc)
+		__field(const struct netdev_queue *, txq)
 		__field(void *,	skbaddr)
 		__field(int, ifindex)
 		__field(u32, handle)
@@ -62,6 +63,7 @@ TRACE_EVENT(qdisc_enqueue,
 
 	TP_fast_assign(
 		__entry->qdisc = qdisc;
+		__entry->txq	 = txq;
 		__entry->skbaddr = skb;
 		__entry->ifindex = txq->dev ? txq->dev->ifindex : 0;
 		__entry->handle	 = qdisc->handle;