** Changed in: mutter (Ubuntu Lunar)
       Status: In Progress => Fix Committed

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https://bugs.launchpad.net/bugs/2007262

Title:
  Ubuntu's GNOME desktop is higher latency than necessary

Status in mutter package in Ubuntu:
  Fix Committed
Status in mutter source package in Jammy:
  Triaged
Status in mutter source package in Kinetic:
  Triaged
Status in mutter source package in Lunar:
  Fix Committed

Bug description:
  [ Impact ]

  Ubuntu's GNOME desktop is higher latency than necessary. It's stuck in
  triple buffering when it should be dropping to double buffering during
  light rendering.

  [ Test Plan ]

  1. Add this to /etc/environment:

       MUTTER_DEBUG=kms

  2. Reboot and log into a Wayland session.

  3. Open a Terminal and run:

       journalctl -f /usr/bin/gnome-shell | grep 'Swap buffers'

  4. Drag the Terminal window rapidly with the mouse (a high sample rate
  mouse will also help).

  Observed bug: "KMS: Swap buffers: 2 frames pending (triple-buffering)"
  Expected fix: "KMS: Swap buffers: 1 frames pending (double-buffering)"

  If you don't at first confirm the bug prior to the fix then try
  dragging the window to the top bar before wiggling it or opening the
  overview to make the render load higher. The fix will make the log
  messages return to double buffering much sooner and stay there more
  reliably.

  [ Where problems could occur ]

  Any part of the smoothness of the desktop experience could be impacted
  since the fix involves changing the frame clock for frame scheduling.

  [ Other Info ]

  Upstream fix:
  
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1441/diffs?commit_id=17ea73d0570318926899c4e3e4821a8b7b21edae

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