wifi: cfg80211: add tracing for wiphy work

Add trace events to trace when wiphy works are queued (or
delayed ones scheduled), and other APIs are called. Also
add an event when the worker starts, before acquiring the
mutex, to be able to see potential delays due to locking.
Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
Reviewed-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://msgid.link/20240506210002.bf1840a1d22d.I4abba048c1c4017345640219cf1384a0b2288dd3@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/core.c

@@ -421,6 +421,8 @@ static void cfg80211_wiphy_work(struct work_struct *work)
 
 	rdev = container_of(work, struct cfg80211_registered_device, wiphy_work);
 
+	trace_wiphy_work_worker_start(&rdev->wiphy);
+
 	wiphy_lock(&rdev->wiphy);
 	if (rdev->suspended)
 		goto out;
@@ -434,6 +436,7 @@ static void cfg80211_wiphy_work(struct work_struct *work)
 			schedule_work(work);
 		spin_unlock_irq(&rdev->wiphy_work_lock);
 
+		trace_wiphy_work_run(&rdev->wiphy, wk);
 		wk->func(&rdev->wiphy, wk);
 	} else {
 		spin_unlock_irq(&rdev->wiphy_work_lock);
@@ -1066,6 +1069,7 @@ void cfg80211_process_wiphy_works(struct cfg80211_registered_device *rdev,
 		list_del_init(&wk->entry);
 		spin_unlock_irqrestore(&rdev->wiphy_work_lock, flags);
 
+		trace_wiphy_work_run(&rdev->wiphy, wk);
 		wk->func(&rdev->wiphy, wk);
 
 		spin_lock_irqsave(&rdev->wiphy_work_lock, flags);
@@ -1610,6 +1614,8 @@ void wiphy_work_queue(struct wiphy *wiphy, struct wiphy_work *work)
 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 	unsigned long flags;
 
+	trace_wiphy_work_queue(wiphy, work);
+
 	spin_lock_irqsave(&rdev->wiphy_work_lock, flags);
 	if (list_empty(&work->entry))
 		list_add_tail(&work->entry, &rdev->wiphy_work_list);
@@ -1626,6 +1632,8 @@ void wiphy_work_cancel(struct wiphy *wiphy, struct wiphy_work *work)
 
 	lockdep_assert_held(&wiphy->mtx);
 
+	trace_wiphy_work_cancel(wiphy, work);
+
 	spin_lock_irqsave(&rdev->wiphy_work_lock, flags);
 	if (!list_empty(&work->entry))
 		list_del_init(&work->entry);
@@ -1639,6 +1647,8 @@ void wiphy_work_flush(struct wiphy *wiphy, struct wiphy_work *work)
 	unsigned long flags;
 	bool run;
 
+	trace_wiphy_work_flush(wiphy, work);
+
 	spin_lock_irqsave(&rdev->wiphy_work_lock, flags);
 	run = !work || !list_empty(&work->entry);
 	spin_unlock_irqrestore(&rdev->wiphy_work_lock, flags);
@@ -1660,6 +1670,8 @@ void wiphy_delayed_work_queue(struct wiphy *wiphy,
 			      struct wiphy_delayed_work *dwork,
 			      unsigned long delay)
 {
+	trace_wiphy_delayed_work_queue(wiphy, &dwork->work, delay);
+
 	if (!delay) {
 		del_timer(&dwork->timer);
 		wiphy_work_queue(wiphy, &dwork->work);

net/wireless/trace.h

@@ -242,6 +242,80 @@
 		}						\
 	} while (0)
 
+/*************************************************************
+ *			wiphy work traces		     *
+ *************************************************************/
+
+DECLARE_EVENT_CLASS(wiphy_work_event,
+	TP_PROTO(struct wiphy *wiphy, struct wiphy_work *work),
+	TP_ARGS(wiphy, work),
+	TP_STRUCT__entry(
+		WIPHY_ENTRY
+		__field(void *, instance)
+		__field(void *, func)
+	),
+	TP_fast_assign(
+		WIPHY_ASSIGN;
+		__entry->instance = work;
+		__entry->func = work ? work->func : NULL;
+	),
+	TP_printk(WIPHY_PR_FMT " instance=%p func=%pS",
+		  WIPHY_PR_ARG, __entry->instance, __entry->func)
+);
+
+DEFINE_EVENT(wiphy_work_event, wiphy_work_queue,
+	TP_PROTO(struct wiphy *wiphy, struct wiphy_work *work),
+	TP_ARGS(wiphy, work)
+);
+
+DEFINE_EVENT(wiphy_work_event, wiphy_work_run,
+	TP_PROTO(struct wiphy *wiphy, struct wiphy_work *work),
+	TP_ARGS(wiphy, work)
+);
+
+DEFINE_EVENT(wiphy_work_event, wiphy_work_cancel,
+	TP_PROTO(struct wiphy *wiphy, struct wiphy_work *work),
+	TP_ARGS(wiphy, work)
+);
+
+DEFINE_EVENT(wiphy_work_event, wiphy_work_flush,
+	TP_PROTO(struct wiphy *wiphy, struct wiphy_work *work),
+	TP_ARGS(wiphy, work)
+);
+
+TRACE_EVENT(wiphy_delayed_work_queue,
+	TP_PROTO(struct wiphy *wiphy, struct wiphy_work *work,
+		 unsigned long delay),
+	TP_ARGS(wiphy, work, delay),
+	TP_STRUCT__entry(
+		WIPHY_ENTRY
+		__field(void *, instance)
+		__field(void *, func)
+		__field(unsigned long, delay)
+	),
+	TP_fast_assign(
+		WIPHY_ASSIGN;
+		__entry->instance = work;
+		__entry->func = work->func;
+		__entry->delay = delay;
+	),
+	TP_printk(WIPHY_PR_FMT " instance=%p func=%pS delay=%ld",
+		  WIPHY_PR_ARG, __entry->instance, __entry->func,
+		  __entry->delay)
+);
+
+TRACE_EVENT(wiphy_work_worker_start,
+	TP_PROTO(struct wiphy *wiphy),
+	TP_ARGS(wiphy),
+	TP_STRUCT__entry(
+		WIPHY_ENTRY
+	),
+	TP_fast_assign(
+		WIPHY_ASSIGN;
+	),
+	TP_printk(WIPHY_PR_FMT, WIPHY_PR_ARG)
+);
+
 /*************************************************************
  *			rdev->ops traces		     *
  *************************************************************/