Image

Intel Enhances Performance Monitoring Capabilities with New Linux Patches for Lunar Lake & Arrow Lake

7/09/2024

Intel Enhances Performance Monitoring Capabilities with New Linux Patches for Lunar Lake & Arrow Lake

Intel’s Linux team is making significant strides in performance monitoring for next-gen CPUs, specifically targeting Arrow Lake and Lunar Lake architectures. These patches bring us one step closer to seamless enablement.

The Quest for Improved Performance Monitoring

Phoronix recently reported that Intel’s Team Blue is actively working on the perf subsystem within the Linux kernel. With the upcoming Linux 6.11 release, Intel has introduced “model-specific bits” tailored for Arrow Lake (ARL) and Lunar Lake (LNL). These patches have already been merged into the Git branch, signaling a promising development.

Lunar Lake and Arrow Lake: A Familiar Landscape

From the perspective of the Performance Monitoring Unit (PMU), both Lunar Lake and Arrow Lake share similarities with the previous Meteor Lake generation. These new CPUs are hybrid platforms, featuring both e-cores and p-cores. However, there are key differences that set them apart:

  1. E-Core Enhancements:

    • The e-core now supports three new fixed counters.
    • More general-purpose (GP) counters have been added (with an updated event constraint table).
    • Architectural performance monitoring V6 introduces new Perfmon MSRs (aliasing, umask2, eq).
    • PEBS format V6 includes counters snapshotting groups.
    • New RDPMC metrics clear mode.

  2. P-Core Improvements:

    • The p-core features an updated PEBS Data Source format.
    • PEBS records detailed information about branch instructions executed by the CPU.
    • Troubleshooting becomes more efficient as users can zoom into the “branch level” to identify bottlenecks or mispredictions.

What’s Next?

While these patches may not introduce groundbreaking changes, they pave the way for more efficient troubleshooting and performance analysis. With Linux 6.11 slated for a September debut, Intel’s processors will harness these advanced capabilities. Expect Lunar Lake CPUs to arrive in September, followed by the Arrow Lake lineup in October.

Stay tuned for further updates as Intel continues to refine its next-gen CPUs!