Re: [RFC PATCH v0 0/6] x86/AMD: Userspace address tagging

From: Dave Hansen
Date: Fri Mar 11 2022 - 11:51:22 EST


On 3/11/22 01:36, David Laight wrote:
> Wikipedia also notes:
> Intel has implemented a scheme with a 5-level page table, which allows
> Intel 64 processors to support a 57-bit virtual address space.
> Further extensions may allow full 64-bit virtual address space and
> physical memory by expanding the page table entry size to 128-bit,
> and reduce page walks in the 5-level hierarchy by using a larger 64 KiB
> page allocation size that still supports 4 KiB page operations for
> backward compatibility.
> If they implement 64K pages then you lose the extra bits.

I can't believe I need to say this: Wikipedia is not an authoritative
source about what anyone is going to do with their CPUs in the future.
Please don't base any Linux decisions off this information.