GNOME 42 Lands DMA-BUF Feedback Support For Better Multi-GPU, Proper Direct Scanout

Mutter landed a prominent addition today for GNOME 42: the Wayland compositor now supports the recently introduced DMA-BUF feedback extension.

Wayland-Protocols 1.24 back in November introduced the DMA-BUF feedback extension. This "feedback" support for DMA-BUF was designed with multi-GPU setups in mind where needing to know about the capabilities of the GPU device powering the compositor in relation to the capabilities of any secondary GPU(s) to ensure the efficient and compatible exchange of buffers.

The extension was two years in the making for the feedback/hints to improve multi-GPU handling under Wayland as well as better supporting direct scanout behavior. After making it into Wayland-Protocols, Weston 10 is adding support for the protocol and now GNOME's Mutter has it too for the GNOME 42 release this spring.

The merge request had been open for five months before getting green-lit today for this better multi-GPU and direct scanout handling for native Wayland clients.

On the graphics driver side, Mesa 22.0's EGL code has DMA-BUF feedback support.