Writing a Type-Safe Linux Perf Interface in Zig
15 hours ago
- #Performance Monitoring
- #Zig
- #Linux
- The author is building a microbenchmarking library for Zig called pyk/bench, aiming for speed and accuracy.
- To measure performance beyond wall clock time, the author uses Linux's perf_event_open system call to access CPU cycles, instruction counts, and cache misses.
- The initial approach to using perf_event_open was non-type-safe, involving hardcoded structs that required manual updates when changing event configurations.
- A type-safe approach was developed using Zig's comptime feature to generate structs dynamically based on requested events, ensuring compile-time safety and reducing manual errors.
- The type-safe implementation includes a Group function that creates a custom struct for event measurements, automatically handling event grouping and data reading from the kernel.
- The author contributed to the Zig standard library by adding a missing constant (PERF_EVENT_IOC_ID) necessary for retrieving event IDs via ioctl.
- The final implementation provides a clean, safe interface for performance monitoring in Zig, leveraging compile-time checks to prevent runtime errors.