GNOME 3.38's Mutter Gets More Optimizations - ~10% Lower Render Time In Some Scenarios

Even more optimizations have now been queued up for GNOME 3.38 launching this month.

On top of a number of performance optimizations that landed over the past half-year, hitting Mutter's code-base this weekend for the imminent 3.37.92 milestone is another tweak. Canonical's Daniel van Vugt provided an improvement to cull actors that don't intersect the redraw clip.

This optimization is quite beneficial as he explained in the merge request, "This was inspired by the activities overview where idle windows and workspace previews were being needlessly repainted. In that particular case this yields more than 10% reduction in render time. But it probably helps in other situations too."

Additionally, this background optimization has also been merged ahead of Mutter 3.38. This change avoids painting most wallpaper in the overview area. He found this change reduces the Intel GPU power usage by around 10% and also reduces render times by around or slightly less than 10%.

Separately, Daniel also commented he is still exploring the work on triple buffering when needing to ramp up the GPU clock frequencies particularly for Intel graphics. But that work will likely lead to a new version of the patches and is going to be too late to see for GNOME 3.38.0.