[BUG] System crashes under combined CPU+memory load on linux-cachyos (7.1.1-2) but stable on linux-cachyos-lts – likely amd_pstate vs acpi-cpufreq regression

[AhmedAlfahdi]

Pre-flight checklist

• I have searched existing issues and this is not a duplicate.
• I have read the Contributing Guidelines.
• I have verified the issue is reproducible with the latest available CachyOS kernel.
• I have tried to reproduce the issue on Arch Linux's linux kernel.

Upstream / vanilla kernel check

I have not tested with a vanilla/upstream kernel

Kernel variant

linux-cachyos (EEVDF, Clang)

System information (cachyos-bugreport.sh)

https://paste.cachyos.org/p/d5f5d19.log
____________________________________________

Manual system information (if cachyos-bugreport.sh is unavailable)

Bug description

System crashes randomly, sometime while just browsing or even in idle state.

Steps to reproduce

1. Using latest CachyOS kernel
2. System crashes randomly

Expected behavior

No crashing

Actual behavior

Crashes when using latest Kernel but doesn't crash when using LTS kernel

Logs / stack traces

❯ pacman -Q | grep linux-cachyos
linux-cachyos 7.1.1-2
linux-cachyos-headers 7.1.1-2
linux-cachyos-lts 6.18.36-1
linux-cachyos-lts-headers 6.18.36-1

~
❯ cpupower frequency-info | grep driver
  driver: acpi-cpufreq

Additional system information

Problem: System crashes under combined CPU+memory load on the latest CachyOS kernel, but works fine on LTS.

Kernel versions:

Unstable: linux-cachyos 7.1.1-2 

Stable: linux-cachyos-lts 6.18.36-1

Stress test command used.

a) Combined CPU + Memory Stress (Crashes on latest kernel, passes on LTS)

stress --cpu 12 --vm 4 --vm-bytes 1G --timeout 1800s

Latest kernel (7.1.1-2): system crashed/reset during test (before completion).
LTS kernel (6.18.10-1): test completed successfully (exit code 0).

b) Memory-Only Stress (Passes on both kernels)

stress --vm 4 --vm-bytes 2G --timeout 600s

Latest kernel (7.1.1-2): passed.
LTS kernel: passed.

Observations:

LTS uses acpi-cpufreq.

The crash does not occur on LTS.

Additional info: The hardware is a Ryzen 5 2600X, B450 motherboard, RX 590 GPU, running KDE Wayland.