AMD Details Zen 6 IBS Memory Profiler for Tiered Memory

AMD engineer Bharata Bhasker Rao presented the IBS Memory Profiler for Zen 6 at Linux Plumbers Conference 2026: a lighter sampling instance that reports the physical address and source (DRAM or CXL) of each data memory access. On a 256 GB CXL test system, XSBench ran 4.57x faster versus 1.18x for the current method, Graph500 hit 3.17x versus 2.34x, while Redis saw no gain. The pghot patches remain in development; EPYC Venice is in production.

• Zen 6 adds a separate lightweight IBS instance sampling only data memory accesses
• XSBench test: 4.57x speedup versus 1.18x for the current method
• Graph500: 3.17x versus 2.34x, Redis showed no gain
• Per-folio promotion cost fell from 26.1 to 15.8 microseconds