Commit f5a7833e authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

net_sched: add a tracepoint for qdisc creation 



With this tracepoint, we could know when qdisc's are created,
especially those default qdisc's.

Sample output:

  tc-736   [001] ...1    56.230107: qdisc_create: dev=ens3 kind=pfifo parent=1:0
  tc-736   [001] ...1    56.230113: qdisc_create: dev=ens3 kind=hfsc parent=ffff:ffff
  tc-738   [001] ...1    56.256816: qdisc_create: dev=ens3 kind=pfifo parent=1:100
  tc-739   [001] ...1    56.267584: qdisc_create: dev=ens3 kind=pfifo parent=1:200
  tc-740   [001] ...1    56.279649: qdisc_create: dev=ens3 kind=fq_codel parent=1:100
  tc-741   [001] ...1    56.289996: qdisc_create: dev=ens3 kind=pfifo_fast parent=1:200
  tc-745   [000] .N.1   111.687483: qdisc_create: dev=ens3 kind=ingress parent=ffff:fff1

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a34dac0b

include/trace/events/qdisc.h

+23 −0
Original line number Diff line number Diff line
@@ -96,6 +96,29 @@ TRACE_EVENT(qdisc_destroy, 
		  TC_H_MAJ(__entry->handle) >> 16, TC_H_MIN(__entry->handle))

);



TRACE_EVENT(qdisc_create,



	TP_PROTO(const struct Qdisc_ops *ops, struct net_device *dev, u32 parent),



	TP_ARGS(ops, dev, parent),



	TP_STRUCT__entry(

		__string(	dev,		dev->name	)

		__string(	kind,		ops->id		)

		__field(	u32,		parent		)

	),



	TP_fast_assign(

		__assign_str(dev, dev->name);

		__assign_str(kind, ops->id);

		__entry->parent = parent;

	),



	TP_printk("dev=%s kind=%s parent=%x:%x",

		  __get_str(dev), __get_str(kind),

		  TC_H_MAJ(__entry->parent) >> 16, TC_H_MIN(__entry->parent))

);



#endif /* _TRACE_QDISC_H */



/* This part must be outside protection */

net/sched/sch_api.c

+3 −0
Original line number Diff line number Diff line
@@ -32,6 +32,8 @@ 
#include <net/pkt_sched.h>

#include <net/pkt_cls.h>



#include <trace/events/qdisc.h>



/*



   Short review.
@@ -1283,6 +1285,7 @@ static struct Qdisc *qdisc_create(struct net_device *dev, 
	}



	qdisc_hash_add(sch, false);

	trace_qdisc_create(ops, dev, parent);



	return sch;

net/sched/sch_generic.c

+3 −1
Original line number Diff line number Diff line
@@ -896,8 +896,10 @@ struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, 
	}

	sch->parent = parentid;



	if (!ops->init || ops->init(sch, NULL, extack) == 0)

	if (!ops->init || ops->init(sch, NULL, extack) == 0) {

		trace_qdisc_create(ops, dev_queue->dev, parentid);

		return sch;

	}



	qdisc_put(sch);

	return NULL;

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