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Calixte
Asked: 2018-05-10 08:08:03 +0800 CST

CPU constantly near 100% and computer overheating after upgrade to 18.04

  • 772

It's definitely not a hardware issue, as it only started right after the upgrade, but there are no programs detected by the system monitor that use any significant amount of CPU.

Edit: It seems there are two Xorg processes running at the same time, one from my user and another from gdm. The problem solves itself if I kill one or the other... The only hick is that I had to do that everytime I booted.

I switched to lightdm and rebooted. This solved the problem. Now there is only one Xorg process, owned by the user root, which is kind of confusing... Should I report that as a GDM bug?

System Monitor | Processes enter image description here

upgrade cpu overheating 18.04

2 Answers

  1. Best Answer

    This seemed to have been caused by a gdm bug that was creating a duplicate Xorg process. I switched to lightdm and the problem went away.

    • Step 1: Install lightdm if it isn't installed on your machine

    In the terminal, type

    sudo apt install lightdm

    Then enter your password

    • Step 2: Switch from GDM for lightdm (this will change how your login screen appears)

    In the terminal, type

    sudo dpkg-reconfigure lightdm

    Then select lightdm in the menu that appears using the arrow keys

    • 3

  2. I've just created following script, which automatically kills second Xorg process. Works fine for me. can be run from root crontab, every minute, or some other way after user login:

    #!/bin/bash
#
# automatically kills second Xorg process

PID_GDM=$(ps -ef | grep Xorg | grep -v grep | grep "^gdm" | awk '{print $2}')
PID_USER=$(ps -ef | grep Xorg | grep -v grep | grep -v "^gdm" | awk '{print $2}')
if [ ! -z "$PID_GDM" ] && [ ! -z "$PID_USER" ]
then
    echo Killing $PID_GDM 
    kill -9 $PID_GDM 
fi
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