[adwn]

> I wonder if Rust or similar could make the MMU transistors and energy budget redondant.

No, those concerns are completely independent of each other. Rust's memory safety protects from accidentally accessing the wrong memory within the same address space, while the MMU protects against accessing (accidentally or intentionally) any memory in other address spaces.

In addition, the address translation done by the MMU has many more applications, like swapping, memory-mapped files, shared memory, copy-on-write after fork, or stack guard pages, none of which can be done by software alone.

[flohofwoe]

> ...accessing the wrong memory within the same address space

On systems without MMU there's only one shared address space (like on the Amiga, you only had lightweight processes/threads called Exec Tasks which all ran in the same global address space).

Rust could definitely help to isolate memory accesses of applications that all run in the same address space.

[erwan577]

Rust should help with the stability issues that plagued the 80s/90s before fully enforced memory protection. Now I wonder if MMU really brings other benefits.

In my latest workstation, I do not use virtual memory to use the disk as extra memory for my running software, i use compressed memory as a disk cache. 30 years of progress has changed the requirements and usecases. Maybe the MMU will survive in a different form that would require a new name.

I read the 4k virtual memory pages and TLB caches are becoming a performance bottleneck so this needs to be redesigned anyway.