Kernel

I’ve been using Linux for more than 15 years. I’ve administered servers, tuned kernels, experimented with filesystems, and read countless articles about swap, virtual memory, caching, and performance. I started with Ubuntu 4.x, spent years on Arch-based distributions, and today most of my work happens on Manjaro and Kubuntu. So I was surprised when I stumbled upon a feature that had apparently been helping my system for years without me realizing it: zswap. ...

I wanted an excuse to build a small real Linux app. Not a shell script. Not a giant desktop application. Not a kernel module. Just a focused program that talks to Linux through the interfaces the system already exposes, gives that data a shape, and presents it as something a normal desktop user can run. Desktop stutter turned out to be a good excuse. My own machine is not slow: modern CPU, fast NVMe storage, plenty of RAM, KDE Plasma on Wayland, and a current kernel. Most of the time it feels excellent. Then, once in a while, the pointer hesitates, a window animation misses a beat, audio gets a tiny crackle, or the browser pauses while a package update or build is running. ...

In 2022 I published this as a Mainline one-liner: add a PPA, mainline --install-latest, reboot. The commands still work. They were never the interesting part. Ubuntu does not have one kernel you “upgrade.” It has a shipping model. GA stays on the version that shipped on day one. HWE rolls forward from interim releases. OEM is a vendor-laptop cadence that is supposed to fold back. Mainline is a set of unofficial builds from kernel.ubuntu.com that Canonical does not support. DKMS is the reason jumping tracks is not free on a laptop. ...