What do I do, when my PC freezes?
Windows has ctrl+alt+del, does Linux Mint has something comparable? The only thing I know about is REISUB, but that borked my PC, so I am hesitant to use that again.
Are there any remaining alternatives to waiting and/or using the power button?
Edit: Thank you all for your insights and possible fixes. Crashes usually happened when I was running (cpu/ram?) heavy workload. Increasing swap space was not even on my radar, so I did that now. :) Hopefully Mint will run more stable now.
Tried F1-6, no love. Only thing that does respond is the mouse movement… keyboard only responds to input reisub. I think if I am at keyboard and the screen does not lock, any windows open will respond to mouse hover but not clicks… I need a linux doctor lol. Maybe a second display for outputting kernel logs, that would be fun for dev work. Though I feel like ssh is the defacto way to accomplish that… Anything we can accomplish with one host and two displays, no network?
Prompted GPT
It sounds like you’re encountering a kernel-level or X/Wayland-level freeze while developing. The fact that the keyboard is unresponsive except for REISUB suggests a deep hang in the graphical session or related system processes.
Here’s a practical way to debug and diagnose this issue with two displays and one host, without needing a network:
Setup for Debugging on Two Displays
-
Enable Persistent Kernel Logs on Second Display:
- Use a TTY session on your second display to monitor kernel logs.
- Connect your second display and switch to it using
Ctrl+Alt+F2(or F3-F6, depending on availability). - Login and run:
sudo tail -f /var/log/kern.logsudo dmesg -w - This will show you kernel logs in real time, which is often critical for diagnosing freezes.
-
Mirror Logs or Virtual Console Across Displays:
- If your second display doesn’t switch TTYs independently, use a terminal multiplexer (like
tmuxorscreen) to duplicate the kernel log view.- Start
tmuxin TTY1 and attach to it from TTY2:tmux tail -f /var/log/kern.logtmux attach
- Start
- If your second display doesn’t switch TTYs independently, use a terminal multiplexer (like
Improve Debugging Workflow
-
Set Up Magic SysRq for More Control:
- If your system allows
REISUB, the Magic SysRq key is already enabled. You can use other commands to debug live:- Sync and Kill Tasks:
Alt + SysRq + Fcan attempt to kill resource-hogging processes. - Toggle TTY:
Alt + SysRq + Rcan re-enable raw keyboard input if the GUI is frozen.
- Sync and Kill Tasks:
- If your system allows
-
Enable Kernel Debugging Outputs:
- Append
debugto your kernel boot parameters in GRUB:- Edit
/etc/default/grub:GRUB_CMDLINE_LINUX_DEFAULT="quiet splash debug" - Update GRUB and reboot:
sudo update-grub
- Edit
- This provides richer debugging output in logs.
- Append
-
Use a Non-GUI Target:
- For safer development, switch to a lower system target to prevent full GUI freezes:
sudo systemctl set-default multi-user.target- Reboot into a non-GUI mode where you can manually start your app, making it easier to debug without freezing the entire desktop.
- For safer development, switch to a lower system target to prevent full GUI freezes:
-
Forcefully Isolate the Process:
- Run your wallpaper application in a separate X server to isolate it:
xinit /path/to/your/app -- :1- This starts a new X session on display
:1while keeping your primary desktop untouched.
- This starts a new X session on display
- Run your wallpaper application in a separate X server to isolate it:
Tips to Prevent GUI Freezes During Development
- Limit CPU or Memory Usage:
- Use
ulimitto restrict resource usage of your program:ulimit -v 1048576 # Limit to 1GB virtual memory
- Use
- Log Debugging Information:
- Add debug prints in your app and log them to a file instead of stdout.