This could be High CPU 0 usage again.
top shows basically nothing. I logged out and back in, still at 100% on CPU 0. iotop shows no activity.
find / -type f -name core -exec ls -l {} ; shows no core files.
What should I do to track this down?
Last time, it took a reboot. There is no swupd running that ps can find.
The screenshot in your other thread shows that only rngd consumes CPU, is it the same case? Does sudo systemctl stop rngd help?
I will try that the next time it happens. I have a screen shot of today’s incident and it shows rgnd with 1:03.18. So, it looks like it is the same.
I logged out, and back in. Still high CPU 0 consumption.
I followed a number of steps I found on a web link, one of which was your request to try.
systemctl stop rngd
did not affect CPU 0 consumption by the system. Red as shown by top.
root # systemctl daemon-reload
root # systemctl stop rngd
root # systemctl start rngd
root # systemctl status rngd
● rngd.service - Hardware RNG Entropy Gatherer Daemon
Loaded: loaded (/usr/lib/systemd/system/rngd.service; disabled; vendor pre>
Active: active (running) since Mon 2020-02-24 21:31:49 PST; 15s ago
Main PID: 131695 (rngd)
Tasks: 1 (limit: 18773)
Memory: 92.0K
CGroup: /system.slice/rngd.service
└─131695 /sbin/rngd -f
Feb 24 21:31:49 clr-d6103c7369ca47e4b28575f210a5a426 systemd[1]: Started Hardwa>
Hmm…so what process causes the high CPU usage, what do htop say? Have you checked after stopping rngd? Is the spike on CPU0 only shown for a short period after launching htop (if so, i guess its normal) or does it remain (if so, you should be able to identify the process)?
I ran only top, not htop. I did stop rngd, but no noticeable change occurred. After logging out and back in, whatever it was, was still running.
Since top did not show a busy process, the load average was 0.41, and the color was red, I assume it was something in the kernel?
One screenshot shows 1 running process, top, and another shows 2 running processes, and the other was pool-gnome-shel. But something is wrong in the kernel, since the process tree is not showing anyone busy, and the cpu is not charged to a process. It has to be down in the kernel. I am not a kernel guy, although, perhaps it is time to start! 
It took rebooting for the problem to go away.
I thought this was interesting, but it is not from the problem system:
dmesg | grep \-22
[ 1.688890] nouveau 0000:01:00.0: DRM: failed to create kernel channel, -22
So there isn’t really a visible process that drains the CPU? The following command should show the three processes with the most CPU usage, maybe this help to identify the problematic process?
sudo ps -eo pid,cmd,%cpu --sort=-%cpu | head -n4It happened again. I saw nothing new in htop. Small load average of 0.44, nothing garnering more than 2 percent of a CPU,
Today, I put the laptop to sleep (not hibernation - Clear Linux does not do that). I think it may have happened when I closed the last tab on FireFox and there were no more FireFox tasks or processes. Something to play with.
Since nothing turns up on top/htop, it has to be something run amuck in the kernel.
