Profiling and tracing help you understand what your Rust program is doing while it runs. Profiling focuses on where time and resources are spent, while tracing records execution events so you can follow the behavior of code paths in detail. This page is about reading that runtime data, identifying the parts of a program that deserve attention, and making informed performance decisions.
Find Rust Performance Bottlenecks
Learn profiling and tracing workflows to interpret runtime data, spot hotspots, and improve real application performance.
Start LearningWhat Profiling and Tracing Show
Core Areas to Explore
CPU profiling workflows
Learn how CPU profiling helps reveal where execution time accumulates during a run. The goal is to see which functions and code paths appear most often in the profile so you can focus your attention efficiently.
Memory profiling basics
Memory profiling helps you observe allocation activity and understand how memory use changes over time. It is useful when you want to detect growth patterns, frequent allocations, or unexpected pressure on the allocator.
Trace collection and analysis
Tracing captures event data that can be reviewed after the program finishes or while it runs. By analyzing traces, you can connect runtime behavior to specific operations and understand how execution unfolds across the application.
Hotspot identification
Hotspots are the parts of a program that consume the most time or activity. Profiling and tracing make these areas easier to spot so you can prioritize the code that will likely benefit the most from investigation.
Reading profiler output
Profiler output often includes function lists, call stacks, and summaries that need careful interpretation. Understanding these reports helps you distinguish meaningful patterns from noise and avoid drawing conclusions too early.
5practical workflows covered from collection to analysis
3core data types to interpret: CPU, memory, and trace output
1goal: find bottlenecks faster in real Rust applications
When should I use profiling instead of tracing?
Use profiling when you want to understand where time or memory pressure is concentrated. Use tracing when you need event-by-event visibility into how execution flows through the program.
Do I need advanced Rust knowledge to start?
No. A beginner can start by learning how to read profiler summaries and trace output. The main skill is interpreting runtime data and asking the right performance questions.
What should I look for in profiler results?
Focus on repeated functions, large call stacks, and sections that appear disproportionately expensive. Those patterns often point to the best place to investigate first.
How does tracing help with performance work?
Tracing provides context around what happened during execution. That context helps you connect a slowdown or allocation spike to the code path that produced it.