HOWTO: Compile Linux kernel (on Ubuntu, applies to any distro)

Happy CPUs when compiling the kernel

Ubuntu 20.04 comes with Linux kernel 5.4.0-37. I had to reboot every time my machine wake up from sleep to fix screen flickering issues. Latest stable kernel (5.7.2) fixed this issue for me.

Notes,

• It's easy to start with a working config and test the kernel first
• If it's working, move on to remove things you don't need. This will result in a smaller kernel
• Kernel modules built against the running kernel have to be recompiled. Notably Nvidia drivers and VirtualBox

Steps to compile the kernel,

1. Download latest stable from kernel.org

2. Unzip
   ➜ tar xf linux-5.7.2.tar.xz && cd linux-5.7.2

3. Copy existing config (make things easy)
   ➜ cp /boot/config-$(uname -r) .config

4. Use terminal based configuration tool
   ➜ make menuconfig
   If you have relatively recent hardware, this step will take most of your time. Add/remove stuff based on your hardware

5. Compile the kernel with Clang (Remove CC for compiling with gcc - the default C compiler)
   make CC=clang -j12

6. Install the kernel
   sudo make install

7. Update grub
   sudo update-grub

8. Reboot
   sudo reboot

Comments

[GeoEduca]

according to your experience, because it is better to compile,
like this: make CC=clang -j4
and not, like this: make -j4
Or is it that there are factors that determine when to use one or the other ?

[Matt Curcio]

These look like notes I make for my own benefit. ;))