24.9 Profiling
While benchmarking measures the performance of specific, isolated code paths, profiling analyzes the runtime behavior of an entire application to identify bottlenecks – sections where the program spends the most time or consumes the most resources (CPU, memory). Profiling is essential for guiding optimization efforts effectively.
Profiling typically involves using external, often platform-specific tools:
- Linux:
perf, Valgrind (specifically Callgrind), Heaptrack - macOS: Instruments (Xcode developer tools)
- Windows: Visual Studio Profiler, Intel VTune Profiler
- Cross-platform: Tracy Profiler
Integrating these tools with Rust builds often involves compiling with debug information (debug = true in Cargo.toml profile, even for release builds intended for profiling) and then running the compiled executable under the profiler’s control.
The Rust Performance Book provides an excellent, detailed guide on various profiling tools and techniques applicable to Rust programs. Covering profiling in depth is beyond the scope of this chapter.