Linux 6.11 To Add Perf Support For Intel Arrow Lake & Lunar Lake

The latest Linux kernel enablement work for upcoming Intel Arrow Lake and Lunar Lake processors is perf subsystem support.

For perf event reporting and similar integration within the mainline Linux kernel, Linux 6.11 is set to add the model-specific bits for Arrow Lake (ARL) and Lunar Lake (LNL). Merged this week into tip/tip.git's "perf/core" Git branch is the necessary Arrow Lake and Lunar Lake support patches.

The cstate perf support for Lunar Lake does confirm that PC8 residency is removed compared to prior generations. The perf integration for Lunar Lake and Arrow Lake does reveal a few of the hardware details around the performance monitoring unit (PMU) with these upcoming processors:

From PMU's perspective, Lunar Lake and Arrow Lake are similar to the previous generation Meteor Lake. Both are hybrid platforms, with e-core and p-core.

The key differences include:
- The e-core supports 3 new fixed counters
- The p-core supports an updated PEBS Data Source format
- More GP counters (Updated event constraint table)
- New Architectural performance monitoring V6 (New Perfmon MSRs aliasing, umask2, eq).
- New PEBS format V6 (Counters Snapshotting group)
- New RDPMC metrics clear mode

Now being in perf/core ensures that the support will be merged for the upcoming Linux 6.11 merge window opening later this month. Linux 6.11 stable in turn should be out in September.