[5/5] media: v4l2-mem2mem: add v4l2_m2m_stream_on/off tracepoints

Commit Message

Emil Velikov May 17, 2021, 6:38 p.m. UTC

From: Emil Velikov <[e-mail]>

v4l2_m2m_stream_on/off are essentially the start/end points in between
which jobs can be scheduled. Userspace can easily request a stream_off,
while the last job is being processed - we might want to indicate that
in the traces.

Signed-off-by: Emil Velikov <[e-mail]>
---
 drivers/media/v4l2-core/v4l2-mem2mem.c |  2 ++
 drivers/media/v4l2-core/v4l2-trace.c   |  2 ++
 include/trace/events/v4l2.h            | 34 ++++++++++++++++++++++++++
 3 files changed, 38 insertions(+)

Patch

diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index a83d3e4e7a85..6aa4ecafac6b 100644
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -852,6 +852,7 @@  int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 	int ret;
 
 	vq = v4l2_m2m_get_vq(m2m_ctx, type);
+	trace_v4l2_m2m_stream_on(m2m_ctx, vq);
 	ret = vb2_streamon(vq, type);
 	if (!ret)
 		v4l2_m2m_try_schedule(m2m_ctx);
@@ -895,6 +896,7 @@  int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 		wake_up(&m2m_ctx->finished);
 	}
 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
+	trace_v4l2_m2m_stream_off(m2m_ctx, &q_ctx->q);
 
 	return 0;
 }
diff --git a/drivers/media/v4l2-core/v4l2-trace.c b/drivers/media/v4l2-core/v4l2-trace.c
index b70208101f3c..ce9d393eb69e 100644
--- a/drivers/media/v4l2-core/v4l2-trace.c
+++ b/drivers/media/v4l2-core/v4l2-trace.c
@@ -19,3 +19,5 @@  EXPORT_TRACEPOINT_SYMBOL_GPL(v4l2_m2m_run_job);
 EXPORT_TRACEPOINT_SYMBOL_GPL(v4l2_m2m_cancel_job_wait);
 EXPORT_TRACEPOINT_SYMBOL_GPL(v4l2_m2m_cancel_job);
 EXPORT_TRACEPOINT_SYMBOL_GPL(v4l2_m2m_finish_job);
+EXPORT_TRACEPOINT_SYMBOL_GPL(v4l2_m2m_stream_on);
+EXPORT_TRACEPOINT_SYMBOL_GPL(v4l2_m2m_stream_off);
diff --git a/include/trace/events/v4l2.h b/include/trace/events/v4l2.h
index a545f6a13d0a..a48a8859a4ef 100644
--- a/include/trace/events/v4l2.h
+++ b/include/trace/events/v4l2.h
@@ -326,6 +326,7 @@  TRACE_EVENT(v4l2_m2m_buf_done,
 /*
  * v4l_m2m job tracing
  * expected order of events:
+ *	v4l2_m2m_stream_on		<= userspace request to start stream processing
  * 	v4l2_m2m_schedule 		<= start of a job trace
  * 	[v4l2_m2m_schedule_failed*]
  *	v4l2_m2m_queue_job		<= job queued on list of ready jobs
@@ -333,6 +334,7 @@  TRACE_EVENT(v4l2_m2m_buf_done,
  *	[v4l2_m2m_cancel_job_wait]	<= job cancelled, but waiting for completion as it is already running
  *	[v4l2_m2m_cancel_job*]		<= job cancelled
  *	v4l2_m2m_finish_job		<= job finished, end of trace
+ *	v4l2_m2m_stream_off		<= userspace request to stop stream processing
  *
  *	events in [] indicate optional events, that may appear, but usually would not be expected
  *	events with * indicate terminal events that end a trace early
@@ -435,6 +437,38 @@  DEFINE_EVENT(v4l2_m2m_event_class, v4l2_m2m_finish_job,
 	TP_ARGS(ctx)
 );
 
+DECLARE_EVENT_CLASS(v4l2_m2m_streaming_class,
+	TP_PROTO(struct v4l2_m2m_ctx *ctx, struct vb2_queue *queue),
+	TP_ARGS(ctx, queue),
+
+	TP_STRUCT__entry(
+		__field(int, minor)
+		__field(struct v4l2_fh *, fh)
+		__field(u32, type)
+	),
+
+	TP_fast_assign(
+		struct v4l2_fh *owner = ctx->cap_q_ctx.q.owner;
+
+		__entry->minor = owner ? owner->vdev->minor : -1;
+		__entry->fh = owner;
+		__entry->type = queue->type;
+
+	),
+	TP_printk("minor = %d, fh = %p, type = %p",
+		__entry->minor, __entry->fh, show_type(__entry->type))
+)
+
+DEFINE_EVENT(v4l2_m2m_streaming_class, v4l2_m2m_stream_on,
+	TP_PROTO(struct v4l2_m2m_ctx *ctx, struct vb2_queue *queue),
+	TP_ARGS(ctx, queue)
+);
+
+DEFINE_EVENT(v4l2_m2m_streaming_class, v4l2_m2m_stream_off,
+	TP_PROTO(struct v4l2_m2m_ctx *ctx, struct vb2_queue *queue),
+	TP_ARGS(ctx, queue)
+);
+
 #ifdef CREATE_TRACE_POINTS
 #define __trace_array_name(a, arr, num) (((unsigned)(a)) < num ? arr[a] : "unknown")
 static inline void __trace_sprint_v4l2_format(char *str, size_t size, struct v4l2_format *p)