If you’re new to this series, I’ve been documenting the process I went through upgrading my old PXA166-based Chumby 8’s 2.6.28 Linux kernel to a modern 6.x version. Here are links to parts 1, 2, 3, 4, 5, 6, 7, and 8. At this point in the project, all of the main hardware peripherals were working great. I noticed something odd when running top though. The CPU usage was always really high, and it wasn’t obvious why.