[$] Policy groups for memory management

The kernel's control-groupsubsystem works well for resource management, Chris Li said at thebeginning of his memory-management-track session at the 2026 Linux Storage,Filesystem, Memory Management, and BPF Summit. Control groups workless well for other use cases, though. He was there to present hisproposed enhancement, called "policy groups", that would address some ofthe shortcomings that he has encountered. A consensus on how this featureshould look still seems distant, though.