OP is asking about Linux phones. HarmonyOS doesn't even run Linux kernel at all.

HarmonyOS 5.x+ both discards the common Unix-like Linux kernel and replaces the previous multiple-kernel, kernel agnostic system from OpenHarmony with its own bespoke HarmonyOS microkernel as a single framework.

https://en.wikipedia.org/wiki/HarmonyOS#:~:text=HarmonyOS%20...