4 ms·

I should've been more clear, Firefox is just an example, my problem is the mouse pointer being affected by heavy load of any kind on the GPU/UI thread. As cold

by ttarr 5y ago

I should've been more clear, Firefox is just an example, my problem is the mouse pointer being affected by heavy load of any kind on the GPU/UI thread. As coldblues said, it's probably Mutter not having an independent thread for the mouse pointer, X11's pointer handling is independent from Mutter/KWin it seems. See the demo here to know exactly what I'm talking about: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1241 https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1241

sph 5y ago
Weird, I'm not seeing it, not even with a GPU heavy game being rendered in a window.
- ttarr 5y ago
  Interesting! 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.
  - 1_player 5y ago
    I'm on 4K at 2x scaling.
- wander_homer 5y ago
  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`.
  - sph 5y ago
    Smooth mouse input, especially when using high-DPI mice, is something that's been fixed in GNOME 42 due to release soon. https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1915 https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1915
    - jancsika 5y ago
      From that link: > 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.
  - Daunk 5y ago
    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.
quotemstr 5y ago
> the mouse pointer being affected by heavy load of any kind on the GPU/UI thread. It's because of stuff like this that we should treat UIs more like real time systems. There's really no good reason at all that a modern machine can't render every frame perfectly every time regardless of system load --- it's due to inadequate attention paid to isolating real-time-ish paths like mouse cursor movement, composition, input event dispatch, and so on from app-induced loads that we get weird responsiveness issues. X actually did a better job in this particular respect than your typical Wayland compositor --- it used interrupt driven mouse cursor rendering, for example.

by ttarr 5y ago

sph 5y ago

Weird, I'm not seeing it, not even with a GPU heavy game being rendered in a window.

ttarr 5y ago
Interesting! 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.
- 1_player 5y ago
  I'm on 4K at 2x scaling.
wander_homer 5y ago
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`.
- sph 5y ago
  Smooth mouse input, especially when using high-DPI mice, is something that's been fixed in GNOME 42 due to release soon. https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1915 https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1915
  - jancsika 5y ago
    From that link: > 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.
- Daunk 5y ago
  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.

quotemstr 5y ago

> the mouse pointer being affected by heavy load of any kind on the GPU/UI thread. It's because of stuff like this that we should treat UIs more like real time systems. There's really no good reason at all that a modern machine can't render every frame perfectly every time regardless of system load --- it's due to inadequate attention paid to isolating real-time-ish paths like mouse cursor movement, composition, input event dispatch, and so on from app-induced loads that we get weird responsiveness issues. X actually did a better job in this particular respect than your typical Wayland compositor --- it used interrupt driven mouse cursor rendering, for example.