SUMMARY Whole Plasma session freezes with the "Fall Apart" desktop effect being enabled when dragging windows to the corners of the screen (especially the ones at the bottom) STEPS TO REPRODUCE 1. Boot KDE Neon. 2. Go to System Settings -> Desktop Effects. 3. Enable the "Fall Apart" one and click Apply. 4. Grab whatever window (I tried with the System Settings one and Dolphin) by the title and go to the corners of the screen and back, similar to how you would snap windows into corner tiles, except that you don't release the mouse button this time. Let's say drag windows on diagonals from the center of the screen towards the corners and back. 5. If if Plasma doesn't freeze from the first try, keep trying a few more times until it does, especially at the bottom-left and bottom-right corners. OBSERVED RESULT After dragging a window towards and outwards of the bottom left and right corners, Plasma freezes completely and nothing could be done, except the force reboot of the computer by holding the power button pressed. EXPECTED RESULT Just because I sometimes like to drag windows to edges and corners of the screen, see the animation and continue dragging them to other edges or corners or towards the middle of the screen, so I never let them snap to some side, it should not freeze the whole session leaving me to force reboot the computer and losing stuff in opened files or web browser. So my first expectation would be that Plasma do not freezes whatever I do. My second expectation would be to have a still working tool, triggered by pressing CTRL+ALT+DEL, like I had in Windows 7, so that I could at least still recover / restart Plasma. This is even more important when the OS is live booted so any files that I might have already downloaded in the Downloads folder or saved in the Desktop folder will be gone if I have to reboot the computer. SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE Plasma Version: 6.2.90 KDE Frameworks Version: 6.11.0 Qt Version: 6.8.1 Kernel Version: 6.8.0-51-generic (64-bit) Graphics Platform: Wayland ADDITIONAL INFORMATION Hardware: Laptop Dell Inspiron 5770 Graphics Processor 1: Mesa Intel® UHD Graphics 620 (main) Graphics Processor 2: AMD Radeon R5 M465 Series
I did 2 more tests trying to reproduce the freeze. On Plasma 6.2.5 (Debian testing) installed on M.2 SSD (WD Blue SN570) I could not reproduce it no matter how much time I spent dragging windows in and out of the orners of the screen. On Plasma 6.3 (Neon testing) running in live mode from a USB pen drive, Lexar LJDP20-64G, that looks like this: https://www.bhphotovideo.com/images/images2000x2000/lexar_ljdp20_64gcrbna_64gb_p20_jumpdrive_usb_1113012.jpg And was made bootable with Ventoy, I managed to reproduce it again! This time by moving around Konsole's window in an out of the top-left and top-right corners, it froze this time while in the top-left corner, if it's any help. After it froze I noticed that the Lexar's USB drive's LED light continued to blink a lot for about a minute until it stopped. When the blinking stopped the screen was still frozen and completely unresponsive so I still had to do the forced shutdown. But this looks to me like moving windows fast around the screen and touching corners multiple times in a successions might do too many reads or writes for the USB storage to handle and that's why it freezes while doing the same things on the M.2 SSD does not. So outside of KDE Neon in live boot mode on a slow USB pen drive, might be hard to reproduce.
On current git master Wayland, I cannot reproduce this — either that the Fall Apart effect gets triggered for tiling actions, or that it causes a hang.
Can you attach a debugger to kwin and get its backtrace when the session is frozen? https://community.kde.org/KWin/Debugging
(In reply to Vlad Zahorodnii from comment #3) > Can you attach a debugger to kwin and get its backtrace when the session is > frozen? https://community.kde.org/KWin/Debugging I'm not sure! I have never done that. And that tutorial I think it will take a while to read and follow, if I can do it. I'm not sure if I explained this properly, I can reproduce it only on KDE Neon running directly from the USB flash drive. KDE Neon is booted in live mode so even if something is being written automatically or by me triggering to some log file, I cannot get that file as it's gone after reboot and if I remember well, the only thing that I could do when the session freezes was a force reboot by holding the power button for a few seconds. I'm not sure, but I thing that Ctrl + Alt + F3 was not working either! (but this I will try again to be sure) So, the next time I'll try to reproduce this, I'll have to configure a log file to be written outside of KDE Neon. My USB drive, that I made bootable with Ventoy has an extra partition where I can put data permanently. Or I can open the driver where I have Debian + Plasma 6.25 and navigate tot the Desktop folder. (Hopefully writing there doesn't break my installation. I can try the USB extra partition and later the install partition if the USB is just too slow to handle both running KDE Neon and writing that log file. Here I don't know how to tell Plasma / Kwin, to write the log file in the partition and folder where I can access it later. And I'm not sure that tutorial covers it. As this: The logs for Wayland are located in: ~/.local/share/sddm/wayland-session.log Doesn't help me as they are still inside temporary booted image, which will be wiped by the reboot. And this: KDE neon Neon has the debug symbols in its regular repository. It's pretty bad as in my opinion they should've been installed by for such a testing distro. In my case it's even worse worse as I have internet only from a mobile hotspot. So if they are too large, they will consume too much from my monthly data plan and I can't do it. So my questions for the moment are: 1. Are those debug symbols needed and are they really big, like more than 500 MiB? 2. Is there a easy way to divert the log file(s) to a custom location, like another disk / partition? I can't wipe my installed OS or have a spare computer to install KDE Neon. But in case it's not possible to divert the log file(s), I think Ventoy has a tutorial do do a persistence file and I can config it to be used by KDE Neon, but when I used a persistence file like that with any distro, after booting it everything was really sluggish. So I would prefer to avoid this alternative is possible and just directly divert the log file to a permanent partition.
I did a quick test by reproducing the crash and then try to enter a virtual terminal but none of the: CTRL + ALT + F1 CTRL + ALT + F3 CTRL + ALT + F7 Combinations mentioned in that page: Or any other in the range: CTRL + ALT + F1-F12 Work! Nothing responds to any keys pressed, I cannot enter any terminal! I think it's the classical Kwin crash where everything is completely frozen and nothing responds to the keyboard. So whatever I do, I need to do it before the crash. A Perl or Bash script, with a variable where I can specify where to put the log file, that I can start before doing my crash test, would've been perfect. Or at least a command where I can edit the log file destination part. I'll see if I can somehow modify the Wayland command here: https://community.kde.org/KWin/Debugging#TL;DR_for_bug_reporters To write to an external partition.
I just ran into something similar to this. Based on the description it is likely the same crash. I don't have the "Fall Apart" effect turned on but I do use the wobbly windows effect. But essentially, when I drag a window to the upper edge of my monitor to cause it to snap to fullscreen, it frequently causes a complete freeze of my system. It doesn't respond to keyboard inputs nor mouse inputs, the only thing I can do is force reboot the system. Frequency seems to be something like 1/10 or 1/15 tries. It is a bit random. I'm on a multi-monitor setup, and when reproducing this I've so far been dragging the window from my left monitor diagonally up to the upper edge of the right monitor. Not sure if that is necessary or not yet but that is how I initially ran into this and have successfully reproduced it like that. I've been able to reproduce it using the Dolphin file manager window. I have been able to log into the PC through SSH and attach a gdb debugger, and then reproduce the crash with it running. I will attach the file that was produced from that session, hopefully I did it correctly. REPRODUCTION STEPS 1. Have the Wobbly Windows effect turned on. 2. Open a Dolphin window. 3. Grab the title bar of the window. 4. Drag the window diagonally up to the top edge of your other monitor. 5. If it freezes it will freeze immediately when trying to snap/unsnap to/from fullscreen. SYSTEM DETAILS Operating System: Arch Linux KDE Plasma Version: 6.3.0 KDE Frameworks Version: 6.11.0 Qt Version: 6.8.2 Kernel Version: 6.12.7-zen3-xanmod1-1-bore (64-bit) Graphics Platform: Wayland Processors: 24 × AMD Ryzen 9 5900X 12-Core Processor Memory: 31.3 GiB of RAM Graphics Processor: NVIDIA GeForce RTX 4070 Manufacturer: Micro-Star International Co., Ltd. Product Name: MS-7D54 System Version: 1.0
Created attachment 178606 [details] GDB session output
Sorry for the spam. I've now confirmed that I can also reproduce this by just snapping the window to the top on the same monitor, so it's not necessary to drag it across monitors.
(In reply to Robert Svensson from comment #7) > Created attachment 178606 [details] > GDB session output I'm so happy that at you can capture and upload some log file! :-) As I tried and tried, but I still didn't know ho to make Kwin write to any file that I can find later. That tutorial with so many commands some that didn't even work on my OS was too confusing. I can now make it freeze on the installed system Debian system too, compared to KDE Neon from USB stick as when I first succeeded. But similar to you, I cannot make it anymore with the Fall Apart effect, but with the Wobbly windows one. I noticed that if I increase the wobbliness (like 3 quarters towards the 'More' side) the easier it gets to trigger the freeze. It still takes a while, but I can do it less than 2 minutes if I continue to move the wobbling window around the bottom-left corner of the screen. But I'm not sure if the problem that you're reporting it's the same as mine or it's this one: https://bugs.kde.org/show_bug.cgi?id=499913 Or this one, that happens on X (not on Wayland): https://bugs.kde.org/show_bug.cgi?id=500015
(In reply to John from comment #9) > (In reply to Robert Svensson from comment #7) > > Created attachment 178606 [details] > > GDB session output > > I'm so happy that at you can capture and upload some log file! :-) > As I tried and tried, but I still didn't know ho to make Kwin write to any > file that I can find later. > That tutorial with so many commands some that didn't even work on my OS was > too confusing. > > I can now make it freeze on the installed system Debian system too, compared > to KDE Neon from USB stick as when I first succeeded. > But similar to you, I cannot make it anymore with the Fall Apart effect, but > with the Wobbly windows one. > I noticed that if I increase the wobbliness (like 3 quarters towards the > 'More' side) the easier it gets to trigger the freeze. > It still takes a while, but I can do it less than 2 minutes if I continue to > move the wobbling window around the bottom-left corner of the screen. > > But I'm not sure if the problem that you're reporting it's the same as mine > or it's this one: > https://bugs.kde.org/show_bug.cgi?id=499913 > Or this one, that happens on X (not on Wayland): > https://bugs.kde.org/show_bug.cgi?id=500015 Ah I see. There are some similar crashes happening here. I do in fact believe that it may be the same as 499913 now that I read the description and comments in there. Yours was the first one that came up in my searching and seemed very close. It's possible this issue is still the same too I suppose, since it is very similar.
*** This bug has been marked as a duplicate of bug 493797 ***