Created attachment 129907 [details] Output of qdbus org.kde.KWin /KWin supportInformation SUMMARY Kwin hangs in KWin::WindowPixmap::create() / xcb_request_check STEPS TO REPRODUCE I cannot consistently reproduce. I would estimate these occur roughly monthly with regular use, and occur during mundane activities such as switching windows or typing in a textbox. SOFTWARE/OS VERSIONS Linux/KDE Plasma: (available in About System) KDE Plasma Version: 5.12.9 KDE Frameworks Version: 5.44.0 Qt Version: 5.9.5 Kernel Version: 5.3.0-61-generic ADDITIONAL INFORMATION After several days using the KDE Plasma desktop, I suddenly found that all of the windows had become unresponsive. I could still move the mouse, but clicking didn't do anything. I could no longer change the volume with the volume buttons. Also, the panel clock stopped ticking upward. Fortunately, I could still use the keyboard to access a tty. This normally works from a tty: DISPLAY=:0 xdpyinfo but during these episodes it would hang indefinitely, even after switching back to the graphical display with Ctrl-Alt-F1 and then back again with Ctrl-Alt-F2. I believe this would also hang after running and switching back to the graphical window: DISPLAY=:0 qdbus org.kde.KWin /KWin supportInformation but I don't recall for sure. This also hung: DISPLAY=:0 kwin --replace and showed an error: qt.qpa.screen: QXcbConnection: Could not connect to display :0 Next tried this: DISPLAY=:0 kquitapp5 plasmashell && kstart5 plasmashell Got a different error after a timeout: "Quitting application plasmashell failed. Error reported was:\n\n org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bug security policy blocked the reply, the reply timeout expired, or the network connection was broken." In a later instance, I was able to revive the system like this: kill -USR1 $(pgrep kwin_x11) DISPLAY=:0 kwin --replace I found this sufficiently convincing that is was an issue with Kwin and not another component, so I thought I should report this bug. Backtraces and strace logs are attached, as is my ~/.config/kwinrc and the output of the "qdbus org.kde.KWin /KWin supportInformation" when it is in a responsive state.
Created attachment 129908 [details] kwinrc
Created attachment 129909 [details] First backtrace (less detailed)
Created attachment 129910 [details] Second backtrace (more detailed)
Created attachment 129911 [details] First strace (longer)
Created attachment 129912 [details] Second strace (shorter)
Downstream bug report: https://bugs.launchpad.net/ubuntu/+source/kwin/+bug/1886293
Same here, OpenSUSE Tumbleweed, all latest packages. The problem appeared about 2 weeks ago on my system and it is worse when I enable Compositing. At the moment it is switched off and even though this gives me a very laggy experience with screen updates and input hanging for seconds at times, at least I don't get a complete freeze (except for the mouse pointer) as described above. Here is the output from the support info request via DBUS: The following information should be used when requesting support on e.g. https://forum.kde.org. It provides information about the currently running instance, which options are used, what OpenGL driver and which effects are running. Please post the information provided underneath this introductory text to a paste bin service like https://paste.kde.org instead of pasting into support threads. ========================== Version ======= KWin version: 5.19.2 Qt Version: 5.15.0 Qt compile version: 5.15.0 XCB compile version: 1.14 Operation Mode: X11 only Build Options ============= KWIN_BUILD_DECORATIONS: yes KWIN_BUILD_TABBOX: yes KWIN_BUILD_ACTIVITIES: yes HAVE_DRM: yes HAVE_GBM: yes HAVE_EGL_STREAMS: yes HAVE_X11_XCB: yes HAVE_EPOXY_GLX: yes HAVE_WAYLAND_EGL: yes X11 === Vendor: The X.Org Foundation Vendor Release: 12008000 Protocol Version/Revision: 11/0 SHAPE: yes; Version: 0x11 RANDR: yes; Version: 0x14 DAMAGE: yes; Version: 0x11 Composite: yes; Version: 0x4 RENDER: yes; Version: 0xb XFIXES: yes; Version: 0x50 SYNC: yes; Version: 0x31 GLX: yes; Version: 0x0 Decoration ========== Plugin: org.kde.oxygen Theme: Plugin recommends border size: No Blur: 0 onAllDesktopsAvailable: true alphaChannelSupported: false closeOnDoubleClickOnMenu: false decorationButtonsLeft: 0, 6 decorationButtonsRight: 2, 9, 3, 4, 5 borderSize: 2 gridUnit: 10 font: Noto Sans,10,-1,0,75,0,0,0,0,0 smallSpacing: 2 largeSpacing: 10 Platform ========== Name: KWin::X11StandalonePlatform Options ======= focusPolicy: 0 nextFocusPrefersMouse: false clickRaise: true autoRaise: false autoRaiseInterval: 0 delayFocusInterval: 0 shadeHover: false shadeHoverInterval: 250 separateScreenFocus: false placement: 4 focusPolicyIsReasonable: true borderSnapZone: 10 windowSnapZone: 10 centerSnapZone: 0 snapOnlyWhenOverlapping: false rollOverDesktops: true focusStealingPreventionLevel: 1 operationTitlebarDblClick: 5000 operationMaxButtonLeftClick: 5000 operationMaxButtonMiddleClick: 5015 operationMaxButtonRightClick: 5014 commandActiveTitlebar1: 0 commandActiveTitlebar2: 28 commandActiveTitlebar3: 2 commandInactiveTitlebar1: 4 commandInactiveTitlebar2: 28 commandInactiveTitlebar3: 2 commandWindow1: 7 commandWindow2: 8 commandWindow3: 8 commandWindowWheel: 28 commandAll1: 10 commandAll2: 3 commandAll3: 14 keyCmdAllModKey: 16777251 showGeometryTip: false condensedTitle: false electricBorderMaximize: false electricBorderTiling: false electricBorderCornerRatio: 0.25 borderlessMaximizedWindows: false killPingTimeout: 5000 hideUtilityWindowsForInactive: true compositingMode: 1 useCompositing: false hiddenPreviews: 1 glSmoothScale: 2 xrenderSmoothScale: false maxFpsInterval: 16666666 refreshRate: 0 vBlankTime: 6000000 glStrictBinding: true glStrictBindingFollowsDriver: true glCoreProfile: false glPreferBufferSwap: 97 glPlatformInterface: 1 windowsBlockCompositing: false Screen Edges ============ desktopSwitching: false desktopSwitchingMovingClients: false cursorPushBackDistance: 1x1 timeThreshold: 150 reActivateThreshold: 350 actionTopLeft: 0 actionTop: 0 actionTopRight: 0 actionRight: 0 actionBottomRight: 0 actionBottom: 0 actionBottomLeft: 0 actionLeft: 0 Screens ======= Multi-Head: no Active screen follows mouse: no Number of Screens: 1 Screen 0: --------- Name: eDP1 Geometry: 0,0,1920x1080 Scale: 1 Refresh Rate: 60.049 Compositing =========== Compositing is not active
Link to forum post from 2020-04-04: https://www.kubuntuforums.net/showthread.php/76643-debugging-advice-for-infrequent-hangs-in-kwin-plasmashell
Is it still an issue?
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!