GNOME Is Also Getting Fixed Up For Lower CPU Usage With NVIDIA Graphics

Last week I wrote about NVIDIA contributing a fix to KDE/KWin for avoiding high CPU usage when using the proprietary GeForce graphics driver. That fix ended up being due to the KWin compositor making incorrect assumptions about GLX swap buffers behavior. It turns out GNOME also needs a similar fix.

The news coverage of NVIDIA figuring out the fix for KDE also happened to help GNOME developers in figuring out some long-standing similar troubles on their side. Canonical's prolific GNOME contributor, Daniel Van Vugt, has been looking at the NVIDIA high CPU usage bug and was able to confirm he already ended up having a previous but still open merge request that fixes the issue by accident.

Going back to 2017 have been GNOME bug reports about high CPU usage when rendering on NVIDIA GPUs and the problem evaded GNOME developers until now. This merge request to consolidate all frame throttling code into clutter-stage-cogl ends up addressing the NVIDIA problem. This merge request has been open now for the past three months, hopefully now there is enough motivation to act upon it with review and getting the code merged for GNOME 3.34.

In addition to addressing the NVIDIA high CPU usage bug, this updated code also takes care of a related NVIDIA performance drop with Mutter and under GNOME on Wayland where the mouse cursor could be stuck at 60Hz while the display's refresh rate is greater than 60Hz.

It's a pity the code wasn't merged ahead of last month's GNOME 3.32.0 release, but at least now it will hopefully get acted upon soon.