[$] A high-memory elimination timeline for the kernel

Arnd Bergmann began his 2025 LinuxPlumbers Conference session on the future of 32-bit support in theLinux kernel by saying that it was to be a followup to his September talk on the same topic. Thefocus this time, though, was on the kernel's "high memory" abstraction, andwhen it could be removed. It seems that the kernel community will need tosupport 32-bit systems for some time yet, even if it might be possible toremove some functionality, including support for large amounts of memory onthose systems, more quickly.