Arch Linux

msr is a builtin module in the linux, linux-lts, linux-zen kernels so keeping the module in modules-load.conf generates an error on every boot.

> systemd-modules-load: Failed to find module 'msr'

Pre-5.10 LTS kernels in the AUR would need to load the module manually.

Looking at the code, specifically thd_engine_default.cpp, I fail to understand why we even need to load msr. IIUC, where msr is used, tcc sysfs which is supposedly available on linux 4.5+ is prefered over msr access, and also rapl device is also prefered over msr.

So I would suggest to load the rapl module and drop msr.
On my Broadwell system, the kernel seems to automatically load the following modules: rapl, intel_rapl_common, intel_rapl_msr. Looking at lsmod output, no other module seems to use the rapl modules and I don't see anything relevant in `/usr/lib/{modules-load,modprobe.d} (same /etc folders are empty).
I guess it's just the kernel who loads them so maybe we don't actaully need to load rapl.