From 7ec6c033ac8c20aa468b5d4838cdafcceea997f7 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 26 May 2020 21:35:25 -0700 Subject: [PATCH] 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 Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- include/trace/events/qdisc.h | 23 +++++++++++++++++++++++ net/sched/sch_api.c | 3 +++ net/sched/sch_generic.c | 4 +++- 3 files changed, 29 insertions(+), 1 deletion(-) diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h index 2b948801afa33..330d32d84485b 100644 --- a/include/trace/events/qdisc.h +++ b/include/trace/events/qdisc.h @@ -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 */ diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 0d99df1e764db..9a3449b56bd60 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -32,6 +32,8 @@ #include #include +#include + /* 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; diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index abaa446ed01a6..a4271e47f220b 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -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; -- 2.39.5