Curious to know the coolest things you achieved by configuring your kernel. I know kernel config can be boring, but I'm hoping someone will have an impressive answer.
For me I have a very lightweight kernel that runs wayland on nvidia without any issues to date.
As a Linux user of almost 30 years, compiling hundreds of kernels over the years has given me a great appreciation of pre-build kernels, and a profound gratitude for those who package them up into convenient distros that work out of the box and let me get on with the rest of my life.
Absolutely! If you're doing it to learn something, by all means compile your own kernel. Every Linux user should do that at least once in my opinion. But once the learning is done, the novelty wears off fast and it just becomes tedious.
Back when I was still using Gentoo, configuring your own kernel was a rite of passage. It was kind of fun to try and configure it as minimalist as possible to cut down on the kernel compile time. Also, understanding all the different options and possibilities. And thanks to use flags, you had access to all these different patch sets for the kernel, which took a lot of the pain out of trying things like experimental schedulers or filesystems.
Everybody gangsta until they set their block and filesystem drivers to module.
"Oh, did I need to rebuild the initrd too? Shhheeeeit, can I do that in a chroot from a livedisk or something?"
Compiling kernels makes no sense anymore.
Back in the days - Linux versions 2 and below - the kernel was much less modular, and resources wasn't as plentiful. So it often made sense to build kernels with the stuff you needed statically compiled for speed, and the rest left out fo save memory and shorten boot time. Not to mention, Lilo (the thing we used before Grub) had limitations with respect to kernel size.
Nowadays, Grub can load a kernel of any size from anywhere on the disk. There's plenty enough memory and CPU to leave the kernel core slightly bloated with stuff almost nobody needs with zero practical impact on boot time and memory usage, and most everything else is compiled as modules and loaded as needed - again with next to no boot time or running speed impact.
If you custom-build a kernel today, you'll boot a tiny bit faster and it'll run a tiny bit faster, and you'll have a tiny bit more free memory - all of which you will never notice. What you will notice however is that kernel updates are a PITA on a regular basis.
I have configured custom Android kernel builds to enable more USB drivers, enable module support, and tweak various other things. For one tangible example of the result: I could plug in a USB Wi-Fi adapter and use it to simultaneously connect to another Wi-Fi network with the internal NIC while also sharing my own AP over USB. On an Android device of all things. I have also adjusted kernel builds for SBCs (like Pi clones) to get things working at all.
I have never seen any reason to configure a custom kernel for my own desktop/laptop systems. Default builds for the distros I've used have been fine for me; if I'm ever dissatisfied with anything it's the version number rather than the defconfig. The RHEL/Rocky kernel omits a few features I want (like btrfs) but I'd rather stick to other distros on personal systems than tweak a distro that isn't even meant for tweaking.
The secureblue image I use disables numerous kernel modules, and enables many kernel mitigation argument.
The performance impact is minimal, hopefully that means a more secure system? I honestly don't know, nor do I change the default recommended by the developer.
camera drivers. the patch was submitted, but hadn't been merged yet, and I didn't want to wait.
I run linux-xanmod-anbox for root support in Waydroid (Android on Linux).
And I configured my kernel to support VFIO (Virtual Function Input Output).
So I can fully pass through one of my GPUs to my Ameliorated Windows KVM,
which I use for both work and gaming.Filesystem level encryption enabled on RHEL. For some damn reason, they turn it off in their kernel.
