SUMMARY Please refer additional to https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1041044 (The bug is not related to Mozilla Firefox, but it occurs most often using it.) It seems that webpages with intense graphics can cause the system freeze. But there are other events where the system freezes obvious in other applications. it is possible to login remote from another PC, so the kernel and OS is still alive. Requesting a kill of a process or a shutdown does not work - a hard reset of the PC is needed. In many cases the process plasmashell is going into 100% cpu usage. When another process is going into 100% cpu usage (like Firefox) and it is killed, then plasmashell goes into 100% cpu usage. There is another PC running Debian 12 that has sometimes the same freeze problem, so it is not a hardware problem. Any tips how to debug this would be helpful and will be reported. STEPS TO REPRODUCE It is a big problem that there is no specific application or reproductive steps to freeze the system. The best way is to use Firefox with intense graphic sites, like windy.com, starting a video of the wheather situation for 2 hours. Avoiding such use cases the system runs stable without freeze. 1. Start Firefox and call a heavy duty webpage 2. KDE suddenly freezes including the mouse pointer 3. System does not react on anything, but a remote-login via ssh is possible 4. Hard reset needed. OBSERVED RESULT System freezes suddenly. EXPECTED RESULT No freeze like in Debian 11 SOFTWARE/OS VERSIONS Linux/KDE Plasma: Debian 12 (bookworm) stable Kernel 6.1.0-11-amd64 (64-bit) KDE Plasma Version: 5.27.5 KDE Frameworks Version: 5.103.0 Qt Version: 5.15.8 ADDITIONAL INFORMATION Did not occure in previous versions (KDE Plasma Version 5.20.5)
Do you have the plasma-browser-integration plugin enabled in Firefox? If so, can you try disabling it and seeing if that helps?
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(In reply to Nate Graham from comment #1) > Do you have the plasma-browser-integration plugin enabled in Firefox? If so, > can you try disabling it and seeing if that helps? No - this plugin is not installed. As already written this bug is not related to Firefox only. Yesterday KDE freezes within another application, but Firefox did have 100% CPU usage as application in the background. KDE seems always to freeze when using the mouse clicking some action.
Is this still happening in a recent version of Plasma, like 6.2.5 or later?
Thank you for showing interest for this bug. Nobody could help to find out the reason for this bug. (In reply to Nate Graham from comment #4) > Is this still happening in a recent version of Plasma, like 6.2.5 or later? So far only tested in Debian 12 stable (bookworm) that uses KDE framework 5.103.0 This error occurs so often a day that I give up working with Debian 12 and i am working with Debian 11 (bullseye). In Debian 11 this error occurs very rarely. So I assume this is getting harder from every KDE version after framework 5.78.0. The freeze seems to occur only in special graphic activity. This PC is running with an old hardware that contains a NVidia GeForce GT 430. There is no proprietary graphic driver any more and the nouveau driver must be used. Another problem could be the AMD Phenom II X4 945 Processor, that has only an rudimentary multimedia instruction set. My feeling says that this could be the reason, when instructions are used that are not implemented. Specially using Firefox causes this freeze of the complete KDE, but it occurs in other applications too. The hardware runs still stable and has enough performance for the own work, so it is annoying to give it up.
Created attachment 177415 [details] Version of KDE in Debian 12 It would already help to understand why the KDE hangs complete in the process plasmashell ? (The kernel and rest of the system is alive) https://bugs.debian.org/cgi-bin/bugreport.cgi?att=1;bug=1041044;filename=foto_2023-07-29_09-38-46.png;msg=15
🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME. For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging. Thank you for helping us make KDE software even better for everyone!
Yes - Info is needed howto debug the plasmashell?
Can you get a backtrace of what plasmashell is doing when it's hung? Run gdb attach -p $(pidof plasmashell) in a terminal window while it's hung If it says "--Type for more, q to quit, c to continue without paging--" at the bottom of the terminal window, press the "c" key. When you see a prompt that says "(gdb)", type "bt" and press the enter key. If it says "--Type for more, q to quit, c to continue without paging--" at the bottom of the terminal window, press the "c" key. Copy-and-paste the contents of the terminal window into a comment here. Thanks!
Thank you TraceyC. I will try this directly in Debian 12, because the hanging can be provoked good using Mozilla Firefox there. Normally when the process of the plasmashell is hanging, the PC cannot be used locally any more, because the screen (X-Server), mouse and keyboard is blocked complete. But I can open an SSH-shell remote from another PC via the LAN. Would it be helpful to start gdb remote via SSH in a shell before the hanging / freezing? How can this be done and how the needed informations can be gathered?
Can you try the steps outlined in [https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Retrieving_a_backtrace_with_GDB](https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Retrieving_a_backtrace_with_GDB)? Basically installing running plasmashell inside gdb until the crash occurs. Sometimes this will help if no crash report/coredump is automatically generated. If the system is actually hard-crashing, it might well be a graphics card or kernel bug. Just to make sure, do you see anything relevant in "journalctl -S today" after the crash happens (and rebooting)?
Here are now some results, splitted in two posts. Yesterday tried to provoke the hanger on Debian 12, but Murphy didn't allow ir. :-) So booted Debian 11 (as normal) and I could get a hanger there. After a remote login via SSH I could find out that it hangs in firefox and afterwords in thunderbird. Starting gdb I get Attaching to process 1979 [New LWP 2027] [New LWP 2079] [New LWP 2080] [New LWP 2081] [New LWP 2082] [New LWP 2090] [New LWP 2091] [New LWP 2162] [New LWP 2164] [New LWP 2168] [New LWP 2169] [New LWP 2170] [New LWP 2171] [New LWP 2173] [New LWP 2178] [New LWP 2179] [New LWP 2194] [New LWP 2206] [New LWP 2207] [New LWP 2212] [New LWP 2214] After killing firefox I was able to open another local terminal mit CTRL+ALT+F2 with an interesting result. There was the text: [TTM] Buffer eviction failed nouveau 0:00:01:00.0 DRM: GPU lockup - switching to software fbcon But afterwards the KDE was still dead, ACPI-Boot did not work, a hard reset was needed.
Today I could get the hanger in Debian 12 starting https://slidealama.eu/ in Firefox. Again top shows the hang in Firefox. Started again gdb on this process with the same result: [New LWP 11245] [New LWP 11292] [New LWP 11320] [New LWP 11374] [New LWP 11442] [New LWP 11458] [New LWP 11460] [New LWP 11461] [New LWP 11462] [New LWP 11471] [New LWP 11472] [New LWP 11474] [New LWP 11489] [New LWP 11494] After that killing Firefox still freezes the complete system, but now it hangs in the plasmashell. Switching to another local console did not work. PID USER PR NI VIRT RES SHR S %CPU %MEM ZEIT+ BEFEHL 2015 usr1 20 0 1591140 301316 138572 D 100,3 3,7 7:54.07 plasmashell Now tried to use gdb: # gdb attach -p 2015 GNU gdb (Debian 13.1-3) 13.1 Copyright (C) 2023 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-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"... attach: Datei oder Verzeichnis nicht gefunden. Attaching to process 2015 After that there was no prompt or output and gdb simply blocked the ssh-shell. Even trying to open another gdb in a new ssh-shell did not work. warning: process 2015 is already traced by process 11731 ptrace: Die Operation ist nicht erlaubt. The PC did not react on ACPI-boot and a hard reset was needed. What can be tested now?
I think you need to take the issue up with Debian at this point.
(In reply to Nate Graham from comment #14) > I think you need to take the issue up with Debian at this point. No - there is definitely a bug in KDE. The primary Error is a "GPU lockup" so there will be an bug in the Nouveau driver. But there is another Error that KDE freezes completely.