workqueue: add queue_work and activate_work trace points
These two tracepoints allow tracking when and how a work is queued and
activated. This patch is based on Frederic's patch to add queue_work
trace point.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
diff --git a/include/trace/events/workqueue.h b/include/trace/events/workqueue.h
index ec9d724..7d49729 100644
--- a/include/trace/events/workqueue.h
+++ b/include/trace/events/workqueue.h
@@ -25,6 +25,59 @@
);
/**
+ * workqueue_queue_work - called when a work gets queued
+ * @req_cpu: the requested cpu
+ * @cwq: pointer to struct cpu_workqueue_struct
+ * @work: pointer to struct work_struct
+ *
+ * This event occurs when a work is queued immediately or once a
+ * delayed work is actually queued on a workqueue (ie: once the delay
+ * has been reached).
+ */
+TRACE_EVENT(workqueue_queue_work,
+
+ TP_PROTO(unsigned int req_cpu, struct cpu_workqueue_struct *cwq,
+ struct work_struct *work),
+
+ TP_ARGS(req_cpu, cwq, work),
+
+ TP_STRUCT__entry(
+ __field( void *, work )
+ __field( void *, function)
+ __field( void *, workqueue)
+ __field( unsigned int, req_cpu )
+ __field( unsigned int, cpu )
+ ),
+
+ TP_fast_assign(
+ __entry->work = work;
+ __entry->function = work->func;
+ __entry->workqueue = cwq->wq;
+ __entry->req_cpu = req_cpu;
+ __entry->cpu = cwq->gcwq->cpu;
+ ),
+
+ TP_printk("work struct=%p function=%pf workqueue=%p req_cpu=%u cpu=%u",
+ __entry->work, __entry->function, __entry->workqueue,
+ __entry->req_cpu, __entry->cpu)
+);
+
+/**
+ * workqueue_activate_work - called when a work gets activated
+ * @work: pointer to struct work_struct
+ *
+ * This event occurs when a queued work is put on the active queue,
+ * which happens immediately after queueing unless @max_active limit
+ * is reached.
+ */
+DEFINE_EVENT(workqueue_work, workqueue_activate_work,
+
+ TP_PROTO(struct work_struct *work),
+
+ TP_ARGS(work)
+);
+
+/**
* workqueue_execute_start - called immediately before the workqueue callback
* @work: pointer to struct work_struct
*
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 026f778..cb2ccfb 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -997,6 +997,7 @@
/* gcwq determined, get cwq and queue */
cwq = get_cwq(gcwq->cpu, wq);
+ trace_workqueue_queue_work(cpu, cwq, work);
BUG_ON(!list_empty(&work->entry));
@@ -1004,6 +1005,7 @@
work_flags = work_color_to_flags(cwq->work_color);
if (likely(cwq->nr_active < cwq->max_active)) {
+ trace_workqueue_activate_work(work);
cwq->nr_active++;
worklist = gcwq_determine_ins_pos(gcwq, cwq);
} else {
@@ -1679,6 +1681,7 @@
struct work_struct, entry);
struct list_head *pos = gcwq_determine_ins_pos(cwq->gcwq, cwq);
+ trace_workqueue_activate_work(work);
move_linked_works(work, pos, NULL);
__clear_bit(WORK_STRUCT_DELAYED_BIT, work_data_bits(work));
cwq->nr_active++;