SUMMARY If a task has multiple windows and they're combined, hovering over several tasks causes plasmashell to take up 99-100% of a CPU core and it either hangs or crashes plasmashell, or crashes the entire desktop. STEPS TO REPRODUCE 1. Task Manager Settings -> Behavior -> Combine into single button (enabled) 2. Open a program that has multiple windows 3. Hover multiple times over the task manager OBSERVED RESULT Hang or crash of plasmashell, or crash of desktop. SOFTWARE/OS VERSIONS Linux: Fedora 34 (kernel 5.11.17 x86_64) KDE Plasma Version: 5.21.4 KDE Frameworks Version: 5.80.0 Qt Version: 5.15.2 ADDITIONAL INFORMATION I recorded a video of the bug: https://youtu.be/psYGavxnnOI
Can you reproduce the issue on X11?
(In reply to Bharadwaj Raju from comment #1) > Can you reproduce the issue on X11? On X11, the task manager still lags and plasmashell also fully loads one thread, but there are no hangs or crashes.
Can you please attach a backtrace of the crash? See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
(In reply to Nate Graham from comment #3) > Can you please attach a backtrace of the crash? See > https://community.kde.org/Guidelines_and_HOWTOs/Debugging/ > How_to_create_useful_crash_reports I tried attaching gdb to a running plasmashell process, but after entering 'continue' in gdb, plasmashell freezes or crashes. So I started a new plasmashell process with gdb, which does work and lets me trigger the bug. But after the bug makes plasmashell crash, entering 'thread apply all bt full' in gdb returns nothing and 'bt' returns "No stack.". Reading symbols from plasmashell... Reading symbols from /usr/lib/debug/usr/bin/plasmashell-5.21.4-1.fc34.x86_64.debug... (gdb) r -n Starting program: /usr/bin/plasmashell -n [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". [New Thread 0x7fffe3cfb640 (LWP 21262)] [New Thread 0x7fffe1b91640 (LWP 21282)] [New Thread 0x7fffe096e640 (LWP 21283)] [New Thread 0x7fffd6449640 (LWP 21284)] [New Thread 0x7fffd5c48640 (LWP 21285)] [New Thread 0x7fffd5447640 (LWP 21286)] [New Thread 0x7fffd4c46640 (LWP 21287)] [New Thread 0x7fffbffff640 (LWP 21288)] [New Thread 0x7fffbf7fe640 (LWP 21289)] [New Thread 0x7fffbeffd640 (LWP 21290)] [New Thread 0x7fffbe7fc640 (LWP 21291)] [New Thread 0x7fffbdffb640 (LWP 21292)] [New Thread 0x7fffbd7fa640 (LWP 21293)] [New Thread 0x7fffbcff9640 (LWP 21294)] [New Thread 0x7fff9bfff640 (LWP 21295)] [Thread 0x7fff9bfff640 (LWP 21295) exited] kf.plasma.quick: Applet preload policy set to 1 [New Thread 0x7fff9bfff640 (LWP 21297)] qt.svg: <input>:406:376: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:407:130: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:408:130: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:408:393: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:409:130: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:410:129: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:411:129: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:412:129: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:413:129: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:413:379: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:413:631: Could not add child element to parent element because the types are incorrect. trying to show an empty dialog file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:146:19: QML Loader: Binding loop detected for property "height" file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:146:19: QML Loader: Binding loop detected for property "height" qt.qpa.wayland: Wayland does not support QWindow::requestActivate() [New Thread 0x7fff92a90640 (LWP 21315)] [New Thread 0x7fff9228e640 (LWP 21316)] [New Thread 0x7fff9168d640 (LWP 21317)] [New Thread 0x7fff90a19640 (LWP 21320)] [New Thread 0x7fff7bfff640 (LWP 21321)] [New Thread 0x7fff7b7fe640 (LWP 21322)] [New Thread 0x7fff7affd640 (LWP 21323)] [New Thread 0x7fff7a7fc640 (LWP 21324)] [New Thread 0x7fff79ffb640 (LWP 21325)] qt.qpa.wayland: Wayland does not support QWindow::requestActivate() qt.qpa.wayland: Wayland does not support QWindow::requestActivate() Entry is not valid "kontact.desktop" QSharedPointer(0x5555562f88c0) Entry is not valid "ktp-contactlist.desktop" QSharedPointer(0x555556303410) Entry is not valid "kontact.desktop" QSharedPointer(0x5555562f9430) Entry is not valid "ktp-contactlist.desktop" QSharedPointer(0x555556244820) Both point size and pixel size set. Using pixel size. Both point size and pixel size set. Using pixel size. Both point size and pixel size set. Using pixel size. file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/DigitalClock.qml:305:13: QML PropertyChanges: Cannot assign to non-existent property "font.minimumPixelSize" trying to show an empty dialog file:///usr/share/plasma/plasmoids/org.kde.panel/contents/ui/main.qml:30:1: QML DropArea (parent or ancestor of QQuickLayoutAttached): Binding loop detected for property "minimumHeight" file:///usr/share/plasma/plasmoids/org.kde.plasma.kicker/contents/ui/CompactRepresentation.qml:49: TypeError: Cannot read property 'width' of null qt.qpa.wayland: Wayland does not support QWindow::requestActivate() [New Thread 0x7fff63bd7640 (LWP 21347)] Cyclic dependency detected between "file:///usr/share/plasma/plasmoids/org.kde.plasma.notifications/contents/ui/global/Globals.qml" and "file:///usr/share/plasma/plasmoids/org.kde.plasma.notifications/contents/ui/NotificationHeader.qml" [New Thread 0x7fff62849640 (LWP 21357)] qt.qpa.wayland: Wayland does not support QWindow::requestActivate() [New Thread 0x7fff619ea640 (LWP 21362)] [New Thread 0x7fff60de8640 (LWP 21363)] [New Thread 0x7fff53fff640 (LWP 21364)] file:///usr/lib64/qt5/qml/org/kde/plasma/components/ModelContextMenu.qml:38:1: QML ModelContextMenu: Accessible must be attached to an Item org.kde.plasma.pulseaudio: No object for name "alsa_output.usb-FiiO_DigiHug_USB_Audio-01.analog-stereo.monitor" The Wayland connection broke. Did the Wayland compositor die? [Thread 0x7fff7affd640 (LWP 21323) exited] [Thread 0x7fff63bd7640 (LWP 21347) exited] [Thread 0x7fff79ffb640 (LWP 21325) exited] [Thread 0x7fff7a7fc640 (LWP 21324) exited] [Thread 0x7fff60de8640 (LWP 21363) exited] [Thread 0x7fff62849640 (LWP 21357) exited] [Thread 0x7fff53fff640 (LWP 21364) exited] [Thread 0x7fff7b7fe640 (LWP 21322) exited] [Thread 0x7fff619ea640 (LWP 21362) exited] [Thread 0x7fff90a19640 (LWP 21320) exited] [Thread 0x7fff9168d640 (LWP 21317) exited] [Thread 0x7fff9bfff640 (LWP 21297) exited] [Thread 0x7fffbcff9640 (LWP 21294) exited] [Thread 0x7fff92a90640 (LWP 21315) exited] [Thread 0x7fffbd7fa640 (LWP 21293) exited] [Thread 0x7fff9228e640 (LWP 21316) exited] [Thread 0x7fffbe7fc640 (LWP 21291) exited] [Thread 0x7fffbeffd640 (LWP 21290) exited] [Thread 0x7fffbf7fe640 (LWP 21289) exited] [Thread 0x7fffbffff640 (LWP 21288) exited] [Thread 0x7fff7bfff640 (LWP 21321) exited] [Thread 0x7fffd4c46640 (LWP 21287) exited] [Thread 0x7fffd5447640 (LWP 21286) exited] [Thread 0x7fffd6449640 (LWP 21284) exited] [Thread 0x7fffe096e640 (LWP 21283) exited] [Thread 0x7fffe1b91640 (LWP 21282) exited] [Thread 0x7fffe3cfb640 (LWP 21262) exited] [Thread 0x7ffff165b940 (LWP 21227) exited] [Thread 0x7fffd5c48640 (LWP 21285) exited] --Type <RET> for more, q to quit, c to continue without paging-- [Inferior 1 (process 21227) exited with code 01] (gdb) thread apply all bt full (gdb) bt No stack. (gdb) q
Just load plasmashell into gdb before it crashes: ``` killall plasmashell gdb /usr/bin/plasmashell run [make it crash] bt ```
(In reply to Nate Graham from comment #5) > Just load plasmashell into gdb before it crashes: > > > ``` > killall plasmashell > gdb /usr/bin/plasmashell > run > [make it crash] > bt > ``` That is what I did; see my previous comment.
Not quite; you did *generally* that but not *exactly* that. Please try doing *exactly* (character for character) what I suggested.
It's not crashing, its exiting. Hence why there is no backtrace with the commands given. >The Wayland connection broke. Did the Wayland compositor die? It'll be the same as that other global removal race.
(In reply to Nate Graham from comment #5) > Just load plasmashell into gdb before it crashes: > > > ``` > killall plasmashell > gdb /usr/bin/plasmashell > run > [make it crash] > bt > ``` (In reply to Nate Graham from comment #7) > Not quite; you did *generally* that but not *exactly* that. Please try doing > *exactly* (character for character) what I suggested. It's the same thing... $ killall plasmashell $ gdb /usr/bin/plasmashell GNU gdb (GDB) Fedora 10.1-14.fc34 Copyright (C) 2020 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "x86_64-redhat-linux-gnu". Type "show configuration" for configuration details. For bug reporting instructions, please see: <https://www.gnu.org/software/gdb/bugs/>. Find the GDB manual and other documentation resources online at: <http://www.gnu.org/software/gdb/documentation/>. For help, type "help". Type "apropos word" to search for commands related to "word"... Reading symbols from /usr/bin/plasmashell... Reading symbols from /usr/lib/debug/usr/bin/plasmashell-5.21.4-1.fc34.x86_64.debug... (gdb) run Starting program: /usr/bin/plasmashell [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". [New Thread 0x7fffe3cfb640 (LWP 4972)] [New Thread 0x7fffe1b91640 (LWP 4996)] [New Thread 0x7fffe096e640 (LWP 4997)] [New Thread 0x7fffd6449640 (LWP 4998)] [New Thread 0x7fffd5c48640 (LWP 4999)] [New Thread 0x7fffd5447640 (LWP 5000)] [New Thread 0x7fffd4c46640 (LWP 5001)] [New Thread 0x7fffbffff640 (LWP 5002)] [New Thread 0x7fffbf7fe640 (LWP 5003)] [New Thread 0x7fffbeffd640 (LWP 5004)] [New Thread 0x7fffbe7fc640 (LWP 5005)] [New Thread 0x7fffbdffb640 (LWP 5006)] [New Thread 0x7fffbd7fa640 (LWP 5007)] [New Thread 0x7fffbcff9640 (LWP 5008)] [New Thread 0x7fff9bfff640 (LWP 5009)] [Thread 0x7fff9bfff640 (LWP 5009) exited] kf.plasma.quick: Applet preload policy set to 1 [New Thread 0x7fff9bfff640 (LWP 5010)] qt.svg: <input>:406:376: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:407:130: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:408:130: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:408:393: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:409:130: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:410:129: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:411:129: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:412:129: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:413:129: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:413:379: Could not add child element to parent element because the types are incorrect. qt.svg: <input>:413:631: Could not add child element to parent element because the types are incorrect. trying to show an empty dialog file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:146:19: QML Loader: Binding loop detected for property "height" file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:146:19: QML Loader: Binding loop detected for property "height" qt.qpa.wayland: Wayland does not support QWindow::requestActivate() [New Thread 0x7fff92a90640 (LWP 5039)] [New Thread 0x7fff9228e640 (LWP 5040)] [New Thread 0x7fff9168d640 (LWP 5041)] [New Thread 0x7fff90a19640 (LWP 5044)] [New Thread 0x7fff83fff640 (LWP 5045)] [New Thread 0x7fff837fe640 (LWP 5046)] [New Thread 0x7fff82ffd640 (LWP 5047)] [New Thread 0x7fff827fc640 (LWP 5048)] qt.qpa.wayland: Wayland does not support QWindow::requestActivate() qt.qpa.wayland: Wayland does not support QWindow::requestActivate() Entry is not valid "kontact.desktop" QSharedPointer(0x5555562ea250) Entry is not valid "ktp-contactlist.desktop" QSharedPointer(0x5555562f77f0) Entry is not valid "kontact.desktop" QSharedPointer(0x5555562ea8c0) Entry is not valid "ktp-contactlist.desktop" QSharedPointer(0x5555562603c0) Both point size and pixel size set. Using pixel size. Both point size and pixel size set. Using pixel size. Both point size and pixel size set. Using pixel size. file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/DigitalClock.qml:305:13: QML PropertyChanges: Cannot assign to non-existent property "font.minimumPixelSize" trying to show an empty dialog file:///usr/share/plasma/plasmoids/org.kde.panel/contents/ui/main.qml:30:1: QML DropArea (parent or ancestor of QQuickLayoutAttached): Binding loop detected for property "minimumHeight" file:///usr/share/plasma/plasmoids/org.kde.plasma.kicker/contents/ui/CompactRepresentation.qml:49: TypeError: Cannot read property 'width' of null qt.qpa.wayland: Wayland does not support QWindow::requestActivate() [New Thread 0x7fff67fff640 (LWP 5074)] Cyclic dependency detected between "file:///usr/share/plasma/plasmoids/org.kde.plasma.notifications/contents/ui/global/Globals.qml" and "file:///usr/share/plasma/plasmoids/org.kde.plasma.notifications/contents/ui/NotificationHeader.qml" [New Thread 0x7fff6704a640 (LWP 5090)] qt.qpa.wayland: Wayland does not support QWindow::requestActivate() [New Thread 0x7fff6620a640 (LWP 5107)] [New Thread 0x7fff65608640 (LWP 5108)] [New Thread 0x7fff64a07640 (LWP 5109)] org.kde.plasma.pulseaudio: No object for name "alsa_output.usb-FiiO_DigiHug_USB_Audio-01.analog-stereo.monitor" file:///usr/lib64/qt5/qml/org/kde/plasma/components/ModelContextMenu.qml:38:1: QML ModelContextMenu: Accessible must be attached to an Item The Wayland connection broke. Did the Wayland compositor die? [Thread 0x7fff6704a640 (LWP 5090) exited] [Thread 0x7fff64a07640 (LWP 5109) exited] [Thread 0x7fff6620a640 (LWP 5107) exited] [Thread 0x7fff67fff640 (LWP 5074) exited] [Thread 0x7fff827fc640 (LWP 5048) exited] [Thread 0x7fff82ffd640 (LWP 5047) exited] [Thread 0x7fff837fe640 (LWP 5046) exited] [Thread 0x7fff83fff640 (LWP 5045) exited] [Thread 0x7fff90a19640 (LWP 5044) exited] [Thread 0x7fff9168d640 (LWP 5041) exited] [Thread 0x7fff9228e640 (LWP 5040) exited] [Thread 0x7fff92a90640 (LWP 5039) exited] [Thread 0x7fff9bfff640 (LWP 5010) exited] [Thread 0x7fffbcff9640 (LWP 5008) exited] [Thread 0x7fffbd7fa640 (LWP 5007) exited] [Thread 0x7fffbdffb640 (LWP 5006) exited] [Thread 0x7fffbe7fc640 (LWP 5005) exited] [Thread 0x7fffbeffd640 (LWP 5004) exited] [Thread 0x7fffbf7fe640 (LWP 5003) exited] [Thread 0x7fffbffff640 (LWP 5002) exited] [Thread 0x7fffd4c46640 (LWP 5001) exited] [Thread 0x7fffd5447640 (LWP 5000) exited] [Thread 0x7fffd5c48640 (LWP 4999) exited] [Thread 0x7fffd6449640 (LWP 4998) exited] [Thread 0x7fffe096e640 (LWP 4997) exited] [Thread 0x7fffe1b91640 (LWP 4996) exited] [Thread 0x7fffe3cfb640 (LWP 4972) exited] [Thread 0x7ffff165b940 (LWP 4925) exited] --Type <RET> for more, q to quit, c to continue without paging-- [Inferior 1 (process 4925) exited with code 01] (gdb) bt No stack. (gdb) thread apply all bt full (gdb) quit
(In reply to David Edmundson from comment #8) > It's not crashing, its exiting. Hence why there is no backtrace with the > commands given. > > >The Wayland connection broke. Did the Wayland compositor die? > > It'll be the same as that other global removal race. Bug 414834 or Bug 435009 or something else?
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!
(In reply to Bug Janitor Service from comment #12) > 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. What info is needed? I still have the bug, it's not resolved for me. Plasma still lags and sometimes crashes when hovering the task manager.
Should hopefully be fixed in Plasma 5.22, as it would appear that this is the same issue as Bug 414834 which is fixed in that version. *** This bug has been marked as a duplicate of bug 414834 ***
(In reply to Nate Graham from comment #14) > Should hopefully be fixed in Plasma 5.22, as it would appear that this is > the same issue as Bug 414834 which is fixed in that version. > > *** This bug has been marked as a duplicate of bug 414834 *** I upgraded to 5.22.1, but the bug has not been resolved. Hovering the task manager when one or more programs with multiple windows are open still causes CPU spikes and still hangs or crashes plasmashell.
Still cannot reproduce on Wayland.
Plasma also crashes on Arch Linux and neon unstable, see bug 439681.
Can you run plasmashell with WAYLAND_DEBUG=1 environment variable and post the output here? It might be a duplicate of bug 447717
(In reply to Vlad Zahorodnii from comment #18) > Can you run plasmashell with WAYLAND_DEBUG=1 environment variable and post > the output here? It might be a duplicate of bug 447717 I'm on plasma 5.23.5 now, and the bug is different. Hovering combined tasks still increases load on one CPU core a lot, about 80-90%, but not 100% anymore. And it also doesn't cause much noticeable lag, nor a crash. However, there's a new bug. The task bar freezes randomly. Sometimes after a few minutes, sometimes after a few hours. The freeze appears to be only visual, because clicking a program on the taskbar still opens/restores its window.
(In reply to Vlad Zahorodnii from comment #18) > Can you run plasmashell with WAYLAND_DEBUG=1 environment variable and post > the output here? It might be a duplicate of bug 447717 Here is an archive of the logs: https://files.catbox.moe/k0gx78.xz plasmashell 2022-01-22 18:14:33.log - Taskbar froze at 20:30. So 2h16m after logging started. plasmashell 2022-01-23 18:50:05.log - Taskbar crashed (SIGABRT) at 19:20. So 30m after logging started. plasmashell 2022-01-23 19:21:49.log - Taskbar crashed (SIGABRT) at 23:10. So 3h49m after logging started. plasmashell 2022-01-29 20:01:00.log - Taskbar froze at 20:32:20. So 31m20s after logging started.
> However, there's a new bug. The task bar freezes randomly That was Bug 449163, which is fixed now. Let's keep this bug for the excessive CPU usage issue. What Plasma theme are you using? Breeze, or something else? If it's something else, can you reproduce the issue when using the Breeze Plasma theme?
(In reply to Nate Graham from comment #23) > > However, there's a new bug. The task bar freezes randomly > That was Bug 449163, which is fixed now. > > Let's keep this bug for the excessive CPU usage issue. I can't, because I don't get that bug anymore. I'm on version 5.24 at the moment. It's just the occasional freeze/crash now. > What Plasma theme are you using? Breeze, or something else? If it's > something else, can you reproduce the issue when using the Breeze Plasma > theme? I'm using Breeze (Dark).
I can confirm that, while I used to get this issue (which often would result in plasmashell OOMing), I've not been able to reproduce it recently. There's still a (minor but noticeable) slowdown on a busy system when hovering over a lot of combined tasks, but it doesn't render the system unusable in the way that it used to. So it's definitely fixed as of 5.24.1 here. Thanks!
> I can't, because I don't get that bug anymore. I'm on version 5.24 at the moment. > It's just the occasional freeze/crash now. OK, then let's close this and get a new bug report for that. Preferably, one bug report per freeze/crash. Thanks!