Comment by burnt-resistor

That's what the OS VMM subsystem provides... abstraction and management of the memory hierarchy to decide what RAM to use and what RAM regions gets discarded or swapped to/from disk.

If an OS were built entirely around a single instance of HiPE/BEAM similar to LING, it might be possible. For efficiency of apps, ditch GC where possible and use precise memory allocation. When that's not possible, use thread-local, immutable storage pools of objects like BEAM so GC can be concurrent and parallel. The messiest way is to do it like the JVM and other systems that throw all objects into a single pool and require pausing the world and expensive graph walks to clean up.