drm: add per-event vblank event trace points

Allows us to track each process that requests and completes events.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_irq.c

@@ -588,6 +588,7 @@ static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
 		return -ENOMEM;
 
 	e->pipe = pipe;
+	e->base.pid = current->pid;
 	e->event.base.type = DRM_EVENT_VBLANK;
 	e->event.base.length = sizeof e->event;
 	e->event.user_data = vblwait->request.signal;
@@ -615,6 +616,9 @@ static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
 	DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
 		  vblwait->request.sequence, seq, pipe);
 
+	trace_drm_vblank_event_queued(current->pid, pipe,
+				      vblwait->request.sequence);
+
 	e->event.sequence = vblwait->request.sequence;
 	if ((seq - vblwait->request.sequence) <= (1 << 23)) {
 		e->event.tv_sec = now.tv_sec;
@@ -622,6 +626,8 @@ static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
 		drm_vblank_put(dev, e->pipe);
 		list_add_tail(&e->base.link, &e->base.file_priv->event_list);
 		wake_up_interruptible(&e->base.file_priv->event_wait);
+		trace_drm_vblank_event_delivered(current->pid, pipe,
+						 vblwait->request.sequence);
 	} else {
 		list_add_tail(&e->base.link, &dev->vblank_event_list);
 	}
@@ -752,6 +758,8 @@ void drm_handle_vblank_events(struct drm_device *dev, int crtc)
 		drm_vblank_put(dev, e->pipe);
 		list_move_tail(&e->base.link, &e->base.file_priv->event_list);
 		wake_up_interruptible(&e->base.file_priv->event_wait);
+		trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
+						 e->event.sequence);
 	}
 
 	spin_unlock_irqrestore(&dev->event_lock, flags);

drivers/gpu/drm/drm_trace.h

@@ -11,22 +11,51 @@
 #define TRACE_INCLUDE_FILE drm_trace
 
 TRACE_EVENT(drm_vblank_event,
-
 	    TP_PROTO(int crtc, unsigned int seq),
-
 	    TP_ARGS(crtc, seq),
-
 	    TP_STRUCT__entry(
 		    __field(int, crtc)
 		    __field(unsigned int, seq)
 		    ),
+	    TP_fast_assign(
+		    __entry->crtc = crtc;
+		    __entry->seq = seq;
+		    ),
+	    TP_printk("crtc=%d, seq=%d", __entry->crtc, __entry->seq)
+);
 
+TRACE_EVENT(drm_vblank_event_queued,
+	    TP_PROTO(pid_t pid, int crtc, unsigned int seq),
+	    TP_ARGS(pid, crtc, seq),
+	    TP_STRUCT__entry(
+		    __field(pid_t, pid)
+		    __field(int, crtc)
+		    __field(unsigned int, seq)
+		    ),
 	    TP_fast_assign(
+		    __entry->pid = pid;
 		    __entry->crtc = crtc;
 		    __entry->seq = seq;
 		    ),
+	    TP_printk("pid=%d, crtc=%d, seq=%d", __entry->pid, __entry->crtc, \
+		      __entry->seq)
+);
 
-	TP_printk("crtc=%d, seq=%d", __entry->crtc, __entry->seq)
+TRACE_EVENT(drm_vblank_event_delivered,
+	    TP_PROTO(pid_t pid, int crtc, unsigned int seq),
+	    TP_ARGS(pid, crtc, seq),
+	    TP_STRUCT__entry(
+		    __field(pid_t, pid)
+		    __field(int, crtc)
+		    __field(unsigned int, seq)
+		    ),
+	    TP_fast_assign(
+		    __entry->pid = pid;
+		    __entry->crtc = crtc;
+		    __entry->seq = seq;
+		    ),
+	    TP_printk("pid=%d, crtc=%d, seq=%d", __entry->pid, __entry->crtc, \
+		      __entry->seq)
 );
 
 #endif /* _DRM_TRACE_H_ */

include/drm/drmP.h

@@ -403,6 +403,8 @@ struct drm_pending_event {
 	struct drm_event *event;
 	struct list_head link;
 	struct drm_file *file_priv;
+	pid_t pid; /* pid of requester, no guarantee it's valid by the time
+		      we deliver the event, for tracing only */
 	void (*destroy)(struct drm_pending_event *event);
 };