I’ve had this problem a few times. Some application becomes unresponsive and starts using 99% CPU. Last time it was OnlyOffice failing to open a large spreadsheet. As a result, the whole desktop becomes unresponsive. The cursor moves with a lag of several seconds making it impossible to click on anything. I created the shortcut Ctrl+Alt+Del to start the system monitor but all I get is the bouncing icon when you start an app but the window never appears. Clicking on the “X” to close Onlyoffice also doesn’t do anything.
As a result, it’s not possible to kill the app that uses 99% CPU or even check which app it is. The computer is unresponsive and needs to be hard reset by pressing the power button. Whatever documents weren’t saved are gone.
Is there any better way to close an app in a situation like this? On Windows for example, the Ctrl+Alt+Del shortcut takes precedence over anything else and the task manager always remains responsive enough to terminate the offending application and go back to work.
In my experience, if the computer is locking up this badly, it’s usually because you’re hard running out of RAM, and Linux really doesn’t like that. It’ll flail and lock itself trying to figure out whether it should oom-kill something. Some distributions cut the swap file, which makes the problem a lot worse. Create a decently sized swap file and you’ll save yourself from most of these.
I have ZRAM for Swap (default for Fedora). Would it be a good idea to add a Swap file as well? Do I need to tell btrfs not to do copy-on-write for this file (don’t think Fedora actually takes snapshots)?
maybe you are referring to distros that replace HDD/SSD swap with zram swap. That make the situation far better.
HDD/SSD are too slow at paging out to stop OOM Killer running.
zram swap is a solution to that issue.