From: Rob Clark <robdcl...@chromium.org>
While migrating some code from wq to kthread_worker, I found that I
missed the execute_start/end tracepoints. So add similar tracepoints
for kthread_work. And for completeness, queue_work tracepoint (although
this one differs slightly from the matching workqueue tracepoint).
Signed-off-by: Rob Clark <robdcl...@chromium.org>
---
include/trace/events/sched.h | 84 ++++++++++++++++++++++++++++++++++++
kernel/kthread.c | 9 ++++
2 files changed, 93 insertions(+)
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index fec25b9cfbaf..349d9872e807 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -5,6 +5,7 @@
#if !defined(_TRACE_SCHED_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_SCHED_H
+#include <linux/kthread.h>
#include <linux/sched/numa_balancing.h>
#include <linux/tracepoint.h>
#include <linux/binfmts.h>
@@ -51,6 +52,89 @@ TRACE_EVENT(sched_kthread_stop_ret,
TP_printk("ret=%d", __entry->ret)
);
+/**
+ * sched_kthread_work_queue_work - called when a work gets queued
+ * @worker: pointer to the kthread_worker
+ * @work: pointer to struct kthread_work
+ *
+ * This event occurs when a work is queued immediately or once a
+ * delayed work is actually queued (ie: once the delay has been
+ * reached).
+ */
+TRACE_EVENT(sched_kthread_work_queue_work,
+
+ TP_PROTO(struct kthread_worker *worker,
+ struct kthread_work *work),
+
+ TP_ARGS(worker, work),
+
+ TP_STRUCT__entry(
+ __field( void *, work )
+ __field( void *, function)
+ __field( void *, worker)
+ ),
+
+ TP_fast_assign(
+ __entry->work = work;
+ __entry->function = work->func;
+ __entry->worker = worker;
+ ),
+
+ TP_printk("work struct=%p function=%ps worker=%p",
+ __entry->work, __entry->function, __entry->worker)
+);
+
+/**
+ * sched_kthread_work_execute_start - called immediately before the work
callback
+ * @work: pointer to struct kthread_work
+ *
+ * Allows to track kthread work execution.
+ */
+TRACE_EVENT(sched_kthread_work_execute_start,
+
+ TP_PROTO(struct kthread_work *work),
+
+ TP_ARGS(work),
+
+ TP_STRUCT__entry(
+ __field( void *, work )
+ __field( void *, function)
+ ),
+
+ TP_fast_assign(
+ __entry->work = work;
+ __entry->function = work->func;
+ ),
+
+ TP_printk("work struct %p: function %ps", __entry->work,
__entry->function)
+);
+
+/**
+ * sched_kthread_work_execute_end - called immediately after the work callback
+ * @work: pointer to struct work_struct
+ * @function: pointer to worker function
+ *
+ * Allows to track workqueue execution.
+ */
+TRACE_EVENT(sched_kthread_work_execute_end,
+
+ TP_PROTO(struct kthread_work *work, kthread_work_func_t function),
+
+ TP_ARGS(work, function),
+
+ TP_STRUCT__entry(
+ __field( void *, work )
+ __field( void *, function)
+ ),
+
+ TP_fast_assign(
+ __entry->work = work;
+ __entry->function = function;
+ ),
+
+ TP_printk("work struct %p: function %ps", __entry->work,
__entry->function)
+);
+
/*
* Tracepoint for waking up a task:
*/
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 3edaa380dc7b..c1e59d6bf802 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -704,8 +704,15 @@ int kthread_worker_fn(void *worker_ptr)
raw_spin_unlock_irq(&worker->lock);
if (work) {
+ kthread_work_func_t func = work->func;
__set_current_state(TASK_RUNNING);
+ trace_sched_kthread_work_execute_start(work);
work->func(work);
+ /*
+ * Avoid dereferencing work after this point. The trace
+ * event only cares about the address.
+ */
+ trace_sched_kthread_work_execute_end(work, func);
} else if (!freezing(current))
schedule();
@@ -834,6 +841,8 @@ static void kthread_insert_work(struct kthread_worker
*worker,
{
kthread_insert_work_sanity_check(worker, work);
+ trace_sched_kthread_work_queue_work(worker, work);
+
list_add_tail(&work->node, pos);
work->worker = worker;
if (!worker->current_work && likely(worker->task))
--
2.26.2
