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waylandsink / gtkwaylandsink: do not use drm dumb pool when importing DMAbuf buffers

Describe your issue

After about a minute, preview or video playback exit itself silently.

After investigations, DMAbuf memory leakage is observed: identfied with command: $> watch "cat /sys/kernel/debug/dma_buf/bufinfo | grep attached " (fd count grows continuously)

A simpler unit test shows that this problem come when waylandsink is fed with DMABuf while configured to setup a DRM Dumb pool (drm-device property): $> gst-launch-1.0 v4l2src io-mode=4 ! waylandsink drm-device=/dev/dri/card0

Expected Behavior

No premature exit and no memory leakage.

Setup

  • STM32MP25-EV evaluation board
  • GStreamer-1.22 + "Add DRM Dumb allocation support into Wayland Sinks" merge request: !3801 (commits)F0qlMZrDMs3PrcLpsvK618Vf61

Steps to reproduce the bug

$> gst-launch-1.0 v4l2src io-mode=4 ! waylandsink drm-device=/dev/dri/card0 (no premature exit) $> watch "cat /sys/kernel/debug/dma_buf/bufinfo | grep attached " (fd count must be stable)

How reproducible is the bug?

100%

Solutions you have tried

Root cause of issue is not 100% clear but there is no need to use internal DRM dumb pool if buffer to render is already a DMABuf: just import it and render it. A patch has been made consequently that fixes issue:

diff --git a/ext/wayland/gstwaylandsink.c b/ext/wayland/gstwaylandsink.c
index 24a7174..99f6f29 100644
--- a/ext/wayland/gstwaylandsink.c
+++ b/ext/wayland/gstwaylandsink.c
@@ -912,7 +912,7 @@ gst_wayland_sink_show_frame (GstVideoSink * vsink, GstBuffer * buffer)
      * offloading the compositor from a copy helps maintaining a smoother
      * desktop.
      */
-    if (!self->skip_dumb_buffer_copy) {
+    if (!wbuf && !self->skip_dumb_buffer_copy) {
       GstVideoFrame src, dst;
 
       if (!gst_wayland_activate_drm_dumb_pool (self)) {

Related non-duplicate issues

Same issue has been observed on gtkwaylandsink (same duplicated code as waylandsink so same issue).

Edited by Hugues Fruchet