Created attachment 175849 [details] T4400_drm_info.txt After upgrading to Plasma 6.2, if I enable Night Light, the mouse movements become laggy, and animations are rendered slowly. This problem was not present at all in Plasma 6.1.
Created attachment 175850 [details] i3-1005g1_drm_info.txt
Operating System: Manjaro Linux KDE Plasma Version: 6.2.3 KDE Frameworks Version: 6.8.0 Qt Version: 6.8.0 Kernel Version: 6.11.7-1-MANJARO (64-bit) Graphics Platform: Wayland
Same here. Operating System: Fedora Linux 41 KDE Plasma Version: 6.2.3 KDE Frameworks Version: 6.8.0 Qt Version: 6.8.0 Kernel Version: 6.11.8-300.fc41.x86_64 (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 PRO 7840U w/ Radeon 780M Graphics Memory: 58.5 GiB of RAM Graphics Processor: AMD Radeon 780M Manufacturer: LENOVO Product Name: 21K5CTO1WW System Version: ThinkPad P14s Gen 4
*** This bug has been marked as a duplicate of bug 495167 ***
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/6967
Git commit 77c81aef08ba841f30f77745787d06973ecea170 by Xaver Hugl. Committed on 05/01/2025 at 03:14. Pushed by zamundaaa into branch 'master'. backends/drm: fall back to applying night light in non-linear space when linear fails While this isn't correct for gamma 2.2 with non-zero black level, it's close enough for most people, and it's definitely preferable for less capable hardware to have good performance over slightly more correct night light. M +20 -9 src/backends/drm/drm_output.cpp https://invent.kde.org/plasma/kwin/-/commit/77c81aef08ba841f30f77745787d06973ecea170
I didn't want to be fast to report it, but after well testing 6.3 then 6.3.1, it seems the fix makes it possible to use the desktop with night light enabled, but there is still a degradation of performance, it's like 25% of speed is lost, this became apparent the more I use the same session for many hours. But upon disabling night color that speed is instantly regained and mouse and animations revert to their normal speed and smoothness. Operating System: Manjaro Linux KDE Plasma Version: 6.3.1 KDE Frameworks Version: 6.11.0 Qt Version: 6.8.2 Kernel Version: 6.6.78-1-MANJARO (64-bit) Graphics Platform: Wayland
Some performance impact is expected, as the shaders get a little bit increased in complexity, but it shouldn't be noticeable. Please attach the output of kscreen-doctor -o, set https://invent.kde.org/plasma/kwin/-/wikis/Environment-Variables#kwin_log_performance_data, reboot and then use the system for a minute with night light off, and attach the csv KWin put in your home folder here. Then enable night light, log out, log in again, and after a minute attach the csv you get then here as well.
(In reply to Zamundaaa from comment #8) > Some performance impact is expected, as the shaders get a little bit > increased in complexity, but it shouldn't be noticeable. > > Please attach the output of kscreen-doctor -o, set > https://invent.kde.org/plasma/kwin/-/wikis/Environment- > Variables#kwin_log_performance_data, reboot and then use the system for a > minute with night light off, and attach the csv KWin put in your home folder > here. Then enable night light, log out, log in again, and after a minute > attach the csv you get then here as well. Sorry I was away from home. Output of "kscreen-doctor -o": Output: 1 LVDS-1 enabled connected priority 1 Panel Modes: 1:1366x768@60*! 2:1024x768@60 3:1280x720@60 Geometry: 0,0 1366x768 Scale: 1 Rotation: 1 Overscan: 0 Vrr: incapable RgbRange: unknown HDR: incapable Wide Color Gamut: incapable ICC profile: none Color profile source: sRGB Color power preference: prefer efficiency and performance Brightness control: supported, set to 65% and dimming to 100%
Created attachment 178795 [details] NIGHT_LIGHT_OFF_kwin perf statistics LVDS-1.csv
Created attachment 178796 [details] NIGHT_LIGHT_ON_kwin perf statistics LVDS-1.csv
hmm, my tool to look at those stats says that performance was even worse with night light off. Did you maybe get the files mixed up? Either way, in both cases, nearly all commits (86% with night light, 96% without) are dropped because they happen too late. In 6.3.3 (will be released next week), you'll be able to use https://invent.kde.org/plasma/kwin/-/wikis/Environment-Variables#kwin_drm_override_safety_margin to increase the safety margin - please test with 2000, 3000 and if that doesn't improve things 5000 or even 8000.
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(In reply to Zamundaaa from comment #12) > hmm, my tool to look at those stats says that performance was even worse > with night light off. Did you maybe get the files mixed up? > > Either way, in both cases, nearly all commits (86% with night light, 96% > without) are dropped because they happen too late. In 6.3.3 (will be > released next week), you'll be able to use > https://invent.kde.org/plasma/kwin/-/wikis/Environment- > Variables#kwin_drm_override_safety_margin to increase the safety margin - > please test with 2000, 3000 and if that doesn't improve things 5000 or even > 8000. I tried to change KWIN_DRM_OVERRIDE_SAFETY_MARGIN to 2000, 3000 and 5000 and turn on/off light night, but in each test the slowness is always present when night light is enabled. I attached various results in each test.
Created attachment 179628 [details] TEST_NIGHT_LIGHT_AND_KWIN_DRM_OVERRIDE_SAFETY_MARGIN