Intel's Linux team has started implementing performance monitoring capabilities for next-gen Arrow Lake & Lunar Lake CPUs, moving one step closer to enablement.
Intel's New Linux Patches Aims At Improving Performance Monitoring, Featuring Dedicated Resources At a Core-Level For Arrow Lake & Lunar Lake CPUs
Phoronix reports that Team Blue has started working on the perf subsystem at the Linux kernel, which is a portion set for monitoring capabilities. With Linux 6.11, Intel has added "model-specific bits" for the upcoming generations, which have now been merged into the Git branch. Based on what patches suggest, the performance monitoring unit for the performance monitoring unit is quite similar to the previous Meteor Lake generation, with some modifications, as mentioned below:
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
The new PMU now includes three fixed counters for performance monitoring for the onboard E-Cores, while the P-Cores will now feature a PEBS (Performance Event Sampling), which records detailed information about branch instructions executed by the CPU. This allows individuals to zoom into a "branch level" of the processor, figuring out any potential bottleneck or misprediction. While the patch doesn't bring anything significant, it does show that troubleshooting will become more efficient with the upcoming architectures.
With Linux 6.11 expected to debut by September, Intel's processors will be able to leverage advanced capabilities. Intel's Lunar Lake CPUs are expected to debut in September while the Arrow Lake lineup is expected to land in October.
News Source: Phoronix
