After every boot of my PC and log in to KDE I observe a very slow performance of Kwin. This is noticeable especially when moving windows over the screen. The bug disappears after re-enabling Kwin effect (with Alt+Shift+F12). Reproducible: Always Steps to Reproduce: 1. Boot the PC. 2. Log in to KDE. 3. Open a few windows (some could be in the full screen mode and some not). 4. Try to drag windows and observe they are almost 1/3 screen behind the mouse cursor. 5. Press Alt+Shift+F12 to disable Kwin effects 6. Press Alt+Shift+F12 again to enable Kwin effects 7. Observe the lag has gone I am using nvidia blob. In KDE's settings I have OpenGL 3.1 (reproducible with other OpenGL versions as well) and raster graphic system. Please let me know if I can be of more help.
please specify which version you are using. You selected a 5.x version but raster graphics system option does not exist in 5.x any more. Best provide the output of: qdbus org.kde.KWin /KWin supportInformation when the problem is present.
description sounds like triple buffer misdetection. as there's more than one report, we've to assume that sth. one some machines and/or during startup seems to break the heuristics. @alexander, do you have triple buffering enabled? grep -i triple /var/log/Xorg.0.log
Created attachment 90604 [details] Xorg log @Martin, oops, sorry, I do use kde 4.14, will be able to provide the requested output later today. @Thomas, seems no, the provided command returned no output. Xorg log attached.
To enable triple buffering: --- /etc/X11/xorg.conf.d/20-nvidia.conf --- Section "Device" Identifier "Default nvidia Device" Driver "nvidia" Option "TripleBuffer" "True" EndSection ---- Have you exported __GL_YIELD? env | grep __GL_YIELD In case not, this might be a really troublesome condition, since a) triple buffering is not available b) but kwin thinks it is, so it will perform a synced swap -> c) swapping blocks with cpu load (busy wait) --> d) our timing calculation will be messed up (we're gonna loose a frame to the blocking swap)
Created attachment 90624 [details] KWin supportInformation
@Thomas, Added triple buffering config, the entire configuration: http://pastie.org/pastes/9856407/text?key=unggt7alw0oik5od9rmlfw Also forgot to mention, I have 2 monitors, one is 2560x1440, and another 1280x1024. >> Have you exported __GL_YIELD? Yes, $ env | grep __GL_YIELD => __GL_YIELD=USLEEP Testing if addid triple buffer config helps now.
@Thomas, adding triple buffering seems solves the problem. Will do more testing today.
Thanks. If you should not want to use TB for any reason, you can hint that to kwin export KWIN_TRIPLE_BUFFER=0
Just wanted to confirm that this is also valid for Kwin 5, but the performance in Kwin 5 is much-much better! Moving windows is almost the same fast as if compositing is disabled.
(In reply to Thomas Lübking from comment #4) > To enable triple buffering: > > --- /etc/X11/xorg.conf.d/20-nvidia.conf --- > > Section "Device" > Identifier "Default nvidia Device" > Driver "nvidia" > Option "TripleBuffer" "True" > EndSection > > ---- > > Have you exported __GL_YIELD? > env | grep __GL_YIELD > > In case not, this might be a really troublesome condition, since > a) triple buffering is not available > b) but kwin thinks it is, so it will perform a synced swap > -> c) swapping blocks with cpu load (busy wait) > --> d) our timing calculation will be messed up (we're gonna loose a frame > to the blocking swap) This works for me. (Fedora 21, kwin 5.2.0)
Git commit 0788890233850ca598af55abe52641d7b4254f14 by Thomas Lübking. Committed on 11/11/2015 at 21:15. Pushed by luebking into branch 'master'. re-detect triple-buffering after compositor resume and also hint the proper blocking condition (if turning off swap control) The detection vars are global, but the swap control requirement is not preserved, so the detection must re-occur. Alternatively (and better) the swap control should be saved and re-applied, but there's trouble on initial detection REVIEW: 125659 M +8 -3 eglonxbackend.cpp M +7 -3 glxbackend.cpp http://commits.kde.org/kwin/0788890233850ca598af55abe52641d7b4254f14
*** Bug 362312 has been marked as a duplicate of this bug. ***
I think this remains a problem or there was a regression. Gentoo KDE 5.6.5 nVidia proprietary drivers 367.35 nVidia-xconfig xorg.conf I have to twiddle the Compositor settings for the tearing to stop.
This issue report is quite old. Can you please confirm, that it still persists with Plasma 5.23?
Dear Bug Submitter, This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information as soon as possible and set the bug status as REPORTED. Due to regular bug tracker maintenance, if the bug is still in NEEDSINFO status with no change in 30 days the bug will be closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging If you have already provided the requested information, please mark the bug as REPORTED so that the KDE team knows that the bug is ready to be confirmed. Thank you for helping us make KDE software even better for everyone!
This bug has been in NEEDSINFO status with no change for at least 30 days. The bug is now closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging Thank you for helping us make KDE software even better for everyone!