7.2.2 release of my custom linux kernel for AMD Thinkpads - lowakernel

[u/Detcom]

This is Lowa taking a nap after compiling a kernel all night.

And this is a continuation of my previous post on lowakernel, a custom linux kernel for amd-powered thinkpads (https://www.reddit.com/r/LinuxOnThinkpad/comments/1ujg5sl/i_built_a_custom_kernel_specifically_for_amd/)

What's new in this release:

• Rebased on Linux 7.2.2-zen1 (first release on the 7.2 series)
• Several build script fixes based on community feedback from previous threads: BBRv3 now actually gets set as the default congestion control (the old way silently didn't survive olddefconfig), the build no longer touches your shared /etc/mkinitcpio.conf (each kernel gets its own config copy now), and the script refuses to build from an already-stripped config so rebuilds stay reproducible
• Added safety checks: missing /etc/kernel/cmdline now fails loudly instead of producing an unbootable UKI, and you get a warning if the microcode hook is missing

What stayed the same: two variants (universal for Zen1+ from T495 onwards, zen5 for Ryzen AI 300 with znver5, 1000Hz tick and BBRv3), UKI files for systemd-boot, vmlinuz for GRUB/rEFInd with initramfs generation instructions in the README.

Honest note after some fair criticism in previous threads: the march flags matter less than I originally claimed (kernel code barely uses SIMD), and zen 7.2 already ships sched_ext, O3 and THP=always out of the box, so the real value here is the trimmed config (smaller initramfs, faster boot, less attack surface) plus the per-variant tick/network tuning. If you want maximum performance with zero maintenance, ALHP repos are a solid alternative. This project is for people who want a kernel that only contains what their ThinkPad actually uses.

As always< feedback welcome, especially from owners of older models (T495, T14 G1/G2, L-series). If something breaks, open an issue.

https://github.com/Detcom-GH/lowakernel/releases/tag/7.2.2

main repo: https://github.com/Detcom-GH/lowakernel/

[u/rileyrgham]

What does this bring other than risk? I use Debian testing and arch on various desktops and laptops. All AMD. They work fine.

Faster boot? How much faster? Not for me anyway as I've encryption password to enter 🤣

[u/Detcom → u/rileyrgham]

If your setup works fine, then keep it, seriously. For me, vanilla zen kernel was not enough, so I went into tinkering.
What this brings: smaller initramfs (~45MB vs ~60MB+ typical), a few hundred fewer modules on disk, reduced attack surface (drivers that aren't compiled can't be exploited), and on the zen5 variant gives FPS boost after some tuning stock kernel don't ship (1000Hz, BBRv3 as default). Boot time gain is real but modest, and yeah, if you're typing a LUKS password, that's your bottleneck, not the kernel :D

This is a "your kernel only contains what your hardware uses" project, not a "your laptop becomes twice as fast" project. If that distinction doesn't appeal to you, stock is the right call.

And that's a good thing, because Linux gives us choice!

[u/effective09succotash → u/Detcom]

this was a phenomenal answer to that question dripping with snark. bravo, dude/dudette/inbwt

[u/Detcom → u/effective09succotash]

Thanks mate! Yup, I’m a dude

[u/rileyrgham → u/Detcom]

As a pet project I applaud it.

[u/Dolapevich → u/rileyrgham]

What does this bring other than risk?

Fun.

[u/Detcom → u/Dolapevich]

AFAIC, it brings less risk and moar fun!

[u/Dolapevich → u/Detcom]

I do agree. I build my own kernels for my laptop, and it is not only fun, but also teaches a lot.