AMD details Zen 6 hardware sampling for tiered-memory page placement

AMD has described a memory-profiling feature planned for Zen 6 that samples data accesses and reports their physical addresses and source, including DRAM or external memory such as CXL. The goal is to help Linux place frequently accessed pages in faster tiers. In AMD's tests on a system with 256 logical CPUs and 256GB of CXL memory, some workloads improved more with the profiler-assisted approach than with the existing method, while Redis showed no gain and another benchmark regressed slightly. The pghot kernel changes remain in development, and the results are AMD's own measurements.