Wayland's Weston Now Supports EGL Partial Updates For Better Performance

Thanks to longtime open-source Linux graphics developer Daniel Stone, Wayland's Weston reference compositor now has support for the EGL_KHR_partial_update extension to provide for potentially better performance.

The EGL_KHR_partial_update extension was led by Arm years ago to allow for efficient partial updates of surfaces ready to be displayed and for ignoring surfaces that are unchanged between frames.

Stone does a good job summarizing the benefit in the Git commit:

partial_update is an EGL extension which allows us to inform the driver ahead of time the limits of the areas we'll be writing to. This helps performance for GPU hardware which renders into a local tile buffer: informing the driver of the rendering extents means it can avoid fetching unchanged tiles into the tile buffer and subsequently writing them out.

The extension complements rather than replaces EGL_EXT_buffer_age (used before partial_update to know which areas we need to update) and EGL_KHR_swap_buffers_with_damage (used after partial_update to inform the winsys of the changed region).

Wayland's Weston continues advancing nicely thanks to the likes of Collabora and other contributors.