I can easily reproduce the stuttering cursor on GNOME Wayland on all of my systems by doing this:
* move the mouse cursor evenly in a straight motion
* while moving press `Super+a` to open the application list
During the animation, i.e. when GNOME Shell is busy, the mouse cursor noticeably stutters for a moment. On my faster systems it's less apparent but still visible, except when I set the CPU governor to `performance`.
I recently tried the new Ubuntu 22.04 LTS and the mouse stuttering was unbearable while running games via Wine.
I had to switch back to Xorg to get rid of it.
> Nothing has been done here to avoid potential wayland event queue overflows, as IIUC this is being worked on separately. Although I should probably also mention that this hasn't been seen in the wild during this work.
What's your monitor like? Sometimes I suspect it's because of my 4K monitor (with 1.5x scaling), that's a lot of pixels to shuffle, especially if the rendering code/pipeline is not optimised[0].
Testing my setup with a 1080p/75hz monitor[1], it's crazy fast and responsive, but mouse acceleration curve (and scroll), not speed, is still weird.
[0]See Ubuntu pushing for triple buffering for example, and other optimisation work on the past.
[1]Apparently that causes huge speedup, as it affects frame scheduling, according to one GUADEC talk by a Mutter dev.
* move the mouse cursor evenly in a straight motion
* while moving press `Super+a` to open the application list
During the animation, i.e. when GNOME Shell is busy, the mouse cursor noticeably stutters for a moment. On my faster systems it's less apparent but still visible, except when I set the CPU governor to `performance`.