The lunar fix is proposed in: https://salsa.debian.org/gnome-team/mutter/-/merge_requests/88
** Description changed: [ 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 ] - TODO + 1. Add this to /etc/environment: + + MUTTER_DEBUG=kms + + 2. Reboot and log in. + + 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 ** Description changed: [ 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 + MUTTER_DEBUG=kms - 2. Reboot and log in. + 2. Reboot and log into a Wayland session. 3. Open a Terminal and run: - journalctl -f /usr/bin/gnome-shell | grep 'Swap buffers' + 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 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/2007262 Title: Ubuntu's GNOME desktop is higher latency than necessary Status in mutter package in Ubuntu: In Progress 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 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2007262/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
