I've got a Debian 9.13 machine for running LinuxCNC, with KDE/Plasma (5.8.6) desktop. Generally everything works well, but every now and again, the desktop will freeze. The mouse still moves the cursor, the screen still goes to sleep after the set time and can be woken up with keyboard input, I can ssh to it, and amazingly, LinuxCNC g-code interpretation continues and the CNC machine keeps working.

But I can't move or activate windows, or do anything else. It forces me to restart the machine, which means losing positioning reference on the CNC machine.

Is there any way to diagnose and fix the issue?

Is there any way to recover this without having to re-launch LinuxCNC?

Thanks,
Rick

Hi,

Try:
Ctrl-Alt-T to get a terminal. Then "killall plasmashell" to stop the shell. Next "plasmashell &" to restart Plasma. Last "disown" to put the process in the background, leaving a functional Plasma desktop. (Don't type the quote marks, I used them as separators.)

Best regards,
bruce

bruceontheice wrote:Ctrl-Alt-T to get a terminal. Then "killall plasmashell" to stop the shell. Next "plasmashell &" to restart Plasma. Last "disown" to put the process in the background, leaving a functional Plasma desktop. (Don't type the quote marks, I used them as separators.)

I can't get a Terminal, but I can ssh into the machine remotely. I'll try the rest.

Does killing plasmashell kill the apps running (that were launched from the terminal via Plasma), or will their windows restore?

Well, it happened again, mid-close of an alert (you can see its ghost still displayed). Ctrl-Alt-T didn't do anything, so I sshed into it, killed plasmashell. Now the plasmashell process is <defunct>, and the screen is unchanged. Have to reboot.

JetForMe wrote:I've got a Debian 9.13 machine for running LinuxCNC, with KDE/Plasma (5.8.6) desktop. Generally everything works well, but every now and again, the desktop will freeze. The mouse still moves the cursor, the screen still goes to sleep after the set time and can be woken up with keyboard input, I can ssh to it, and amazingly, LinuxCNC g-code interpretation continues and the CNC machine keeps working.

But I can't move or activate windows, or do anything else. It forces me to restart the machine, which means losing positioning reference on the CNC machine.

Is yours a dual-monitor setup? I saw your post while looking for solution to a similar problem of mine. I am on Mageia 7.1 and Plasmashell 5.15.4. My KDE runs OK while I am working only on the laptop. But when I hook it up to a monitor, plasmashell randomly freezes. The panels are no longer active, but I can continue working on the existing windows, and also switch between them using alt+tab. The only way to come back from the freeze is to kill and launch plasmashell again (I run killall plasmashell and then plasmashaell again from the alt+F2 menu.)

Still trying to find a solution for this.

mt13 wrote:Is yours a dual-monitor setup? I saw your post while looking for solution to a similar problem of mine. I am on Mageia 7.1 and Plasmashell 5.15.4. My KDE runs OK while I am working only on the laptop. But when I hook it up to a monitor, plasmashell randomly freezes. The panels are no longer active, but I can continue working on the existing windows, and also switch between them using alt+tab. The only way to come back from the freeze is to kill and launch plasmashell again (I run killall plasmashell and then plasmashaell again from the alt+F2 menu.)

Nope, just the single monitor.

When you kill plasmashell, does the screen change in any way? I kill plasmashell, but it became defunct rather than being killed. I didn't try launching it again to see if that fixed anything. I also have to ssh in to do this; nothing like alt+F2 works for me.

JetForMe wrote:When you kill plasmashell, does the screen change in any way?

Just a flicker and then the plasma panels (task bar, etc.) go away, and then when I launch plasmashell again, they come back.

It seems with the laptop + monitor setup there are multiple reports of the problem that I am facing. Following this thread now. viewtopic.php?f=289&t=164123

Good luck with your problem; sorry couldn't help you!