Work has begun on the transfer of GNOME Mutter to multi-threaded rendering

In the code of the Mutter window manager, developed as part of the GNOME 3.34 development cycle, is included initial support for new transactional (atomic) API
KMS (Atomic Kernel Mode Setting) for switching video modes, allowing you to check the correctness of the parameters before actually changing the hardware state at once and, if necessary, roll back the change.

From a practical standpoint, support for the new API is the first step in moving Mutter to a multi-threaded model, in which code interacting with the video subsystem, OpenGL-related components, and the main GLib event loop are executed in separate threads, which will allow parallelization of rendering operations on multi-core systems. GNOME 3.34 is scheduled for release on September 11th.

Source: opennet.ru