← Back to DatabaseHow to Fix CFS: scheduling while atomic
Topic: Linux Ubuntu Boot Errors | Status: Updated
What is this error?
The "CFS: scheduling while atomic" error in Linux Ubuntu indicates that the Completely Fair Scheduler (CFS) has attempted to schedule a task while the system is in an atomic context, which is not allowed. This typically occurs due to bugs in device drivers or kernel modules, making the system unstable during boot.
How to Fix It
To resolve this error, follow the steps below systematically. It's important to ensure that you have a backup of your important data before proceeding.
- Boot into Recovery Mode: Restart your computer and hold the Shift key to access the GRUB menu. Select "Advanced options for Ubuntu" and then choose a recovery mode option (usually the second item).
- Select Root Shell: In the recovery menu, choose "Drop to root shell prompt". This grants you root access to the system.
- Check for Update and Cleanup: Run the following commands to update your system and remove unnecessary packages:
apt update
apt upgrade
apt autoremove
- Identify Recent Changes: Review any recent kernel updates or changes you made to system configurations, specifically in drivers. Boot into a previous kernel version if applicable.
- Check Kernel Modules: If you suspect a specific kernel module or driver is causing the issue, try blacklisting it by adding its name to the blacklist configuration file:
echo "blacklist " >> /etc/modprobe.d/blacklist.conf
- Reboot the System: After making changes, type `reboot` to restart your system and check if the problem is resolved.
- Log Analysis: If the issue persists, review system logs located in /var/log/, particularly dmesg and syslog, for additional clues about the malfunctioning component.
- Seek Additional Support: If solutions above fail, consider seeking help on community forums or consult the official Ubuntu documentation for further guidance.
Disclaimer: This is an educational guide. We are not responsible for data loss. Always backup your system.
