Technical Intelligence Report: 2026-02-28

Executive Summary

  • Linux Kernel Preparations for Zen 6: AMD has begun queuing patches for the Linux 7.1 kernel (expected April 2026) to support next-generation Zen 6 processors.
  • Profiling Enhancements: The updates focus specifically on the perf subsystem, enhancing Instruction-Based Sampling (IBS) for future EPYC “Venice” CPUs, improving latency filtering and multi-socket profiling capabilities.

🤖 ROCm Updates & Software

[2026-02-28] AMD Prepares Linux For Instruction-Based Sampling Improvements With Zen 6

Source: Phoronix

Key takeaway relevant to AMD:

  • Developer Impact: These updates are critical for developers and system administrators using EPYC “Venice” (Zen 6) systems, as they significantly improve the granularity and safety of low-level performance profiling via the Linux perf tool.
  • Security & Usability: The introduction of hardware-assisted privilege filtering allows unprivileged users to utilize IBS safely, removing previous software-based barriers.

Summary:

  • AMD has submitted patches to the tip/tip.git branch, targeting the Linux 7.1 kernel merge window in April 2026.
  • The patches introduce support for new Instruction-Based Sampling (IBS) capabilities found in upcoming Zen 6 processors.
  • These improvements address race conditions, privilege filtering, and specific event sampling (latency/streaming stores).

Details:

  • Target Architecture: The patches are designed for “future” AMD processors, explicitly identified as next-gen Zen 6 (likely EPYC Venice).
  • Technical Improvements & Capabilities:
    • Race Condition Elimination: Introduces an “Alternate disable bit” with control-only Model Specific Registers (MSRs). This eliminates the Read-Modify-Write (RMW) race condition present in existing IBS_{FETCH|OP}_CTL MSRs.
    • RIP Bit 63 Filtering: Leveraging hardware-assisted privilege filtering via RIP (Instruction Pointer) bit 63 status. This enables IBS usage for unprivileged users without requiring complex software-based privilege filtering logic.
    • Latency Thresholds: Adds a fetch latency threshold filter, allowing developers to capture only high-latency fetch events (filtering only when values exceed a programmable threshold).
    • Streaming-Store Filter: Provides the ability to optionally record samples exclusively for instructions performing streaming stores.
    • Remote Socket Indication: Adds support for indicating the data source for remote sockets during load/store instruction sampling, critical for optimizing NUMA-aware workloads on multi-socket EPYC servers.
  • Timeline: Currently in the perf/core Git branch; expected to merge into the mainline kernel with Linux 7.1 in April.