What is the equivalent of Ctrl + Alt + Del from Windows on elementary? A keyboard short cut that gets special handling and will allow to unfreeze desktop environment / kill resource hogging processes.
Freezes happen rarely but most solutions I read about for linux don't seem to work on elementary. Is there any "offical" solution for this use case?
Not sure, if your system freezes completely, or if it's "just" the desktop.
In case you are very new to linux and didn't already know:
Try switching to a Terminal by pressing CTRL+ALT+F1 or ...+F2 (your desktop should be at ...+F7)
From there you can view all active processes using the command
ps
Each process has an ID. You can force-quit any process using the command
kill ID
If you're curious, here is more info on the ps-command. I hope I didn't completely misinterpret your linux-knowledge. :)
ps nothing is included except "ps" and "bash".
Commented
Apr 28, 2022 at 16:29
ps auwx to p (allowing me to still use ps without conflicts in other scripts or commands) because ps on its own is, as you have seen, kind of useless. Check man ps for other options.
Commented
Sep 12 at 5:58
this is what I do when it happens to me...
press the power button from your PC and it'll send you to lock screen, then you can log back or restart the PC from the power menu
or run terminal by pressing Ctrl + Alt + F1 and try killall wingpanel and press Ctrl + Alt + F7 to bring back the interface
if it doesn't work then go back to terminal and try sudo reboot
Probably not what the OP wants, but still good to know:
You can hard reset your computer by pressing Alt+Shift+SysRq (often this is a combinaion Fn+PrintScreen)+B. This is useful if nothing else helps.
It doesn't make much sense but removing wingpanel-indicator-power resolved hangups problem for me.
My system was not completely freezing like you reported. But I was having quick hangups for example when opening a new tab in chrome.
sudo apt-get remove wingpanel-indicator-power
I had the same problem with Elementary os , is a problem caused by the video driver nouveau , here is the link of the discussion of the problem ( https://bbs.archlinux.org/viewtopic.php?id=234763 ) . I solved with this command:
sudo ubuntu-drivers autoinstall
used it since 1 month and it seems to be fine , before while using it 8 hours it froze 3 times
Paul's answer is functional, and is in fact what I started with. But as the OP notes in a comment, it's not very user-friendly.
tl;dr: Another option is to renice processes.
My current situation was caused by a web page and chrome not playing nicely (the web page has a bug I was inspecting, and saw there were over 100K nodes in a drop down option list, but went ahead and clicked the "see all" button, knowing it would probably cause badness). I started with CTRL+ALT+F6, then after logging on, double-checked that there wasn't some other issue by running top, and seeing PyCharm was using more processor time than Chrome, I ran
ps auwx | grep -i chrome
to take a look at the chrome instances. I was going to just use killall to close all the chrome instances, but as I was refreshing my memory on killall via man killall, I decided to check out some of the "see also" programs:
SEE ALSO
kill(1), fuser(1), pgrep(1), pidof(1), pkill(1), ps(1), kill(2), regex(3).
I took a look at man pkill, which also gives info for pgrep. In the examples section was this helpful bit:
EXAMPLES
<snip>
Example 4: Make all netscape processes run nicer:
$ renice +4 $(pgrep netscape)
I knew about renice, but it had been a long time since I'd had to use it, so I had forgotten about it. I checked the output for what I thought I wanted with:
pgrep chrome
and saw it wouldn't match anything I didn't want it to. I then ran:
renice +4 $(pgrep chrome)
When I switched back to the desktop (CTRL+ALT+F7) this allowed me to actually interact with the browser and kill the one offending window (IDK if it would have worked for just one tab, but in my case they were one and the same), leaving the other 44 chrome processes running. The level of niceness needed probably depends on how borked your system is.
While this isn't "my 80-year-old dad could do it" friendly, it at least avoids a system reboot, and avoids killing more than necessary. Some things to note about niceness, from man renice:
NOTES
Users other than the superuser may only alter the priority of processes they
own. Furthermore, an unprivileged user can only increase the ``nice value''
(i.e., choose a lower priority) and such changes are irreversible unless (since
Linux 2.6.12) the user has a suitable ``nice'' resource limit (see ulimit(1) and
getrlimit(2)).
The superuser may alter the priority of any process and set the priority to any
value in the range -20 to 19. Useful priorities are: 19 (the affected processes
will run only when nothing else in the system wants to), 0 (the ``base'' sched‐
uling priority), anything negative (to make things go very fast).
Also note that you can renice from within top by pressing r while viewing processes.
