[$] Separating memory descriptors from struct page

The kernel's memory-management subsystem is currently partway through a multi-year project to replace the page structure (which represents a page of physical memory) with memory descriptors. At the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, Vishal Moola ran a fast-paced session in the memory-management track to describe the current state of that work and what is likely to happen next.