Simpleperf Debug Skill

When to Use

Use this skill when you need hardware-level CPU performance insights on Meta Quest devices:

• Classifying whether an app is CPU-bound, memory-bound, or I/O-bound
• Finding CPU hotspot functions consuming the most cycles
• Measuring kernel vs userspace CPU overhead per thread
• Identifying cache-thrashing or branch-prediction issues
• Supplementing Perfetto trace analysis with hardware PMU counter data

This skill complements hz-perfetto-debug. Perfetto shows what your app is doing over time. Simpleperf shows where the CPU is spending hardware cycles — cache misses, branch mispredictions, and instruction throughput that Perfetto can't see.

VR Performance Context

Quest devices run on mobile ARM SoCs with strict thermal and power budgets. CPU-bound apps hit frame drops when:

| Refresh Rate | CPU Frame Budget | Notes |