[$] The future of memory tiering

Memory tiering is the practice of dividing physical memory into separatelevels according to its performance characteristics, then allocating thatmemory in a (hopefully) optimal manner for the workload the system isrunning. The subject came up repeatedly during the 2023 Linux Storage, Filesystem,Memory-Management and BPF Summit. One session, led by David Rientjes,focused directly on tiering and how it might be better supported by theLinux kernel.