Talk: The Basics of Profiling
Talk: The Basics of Profiling - Mathieu Ropert - CppCon 2021
Resources:
Good talk on profiling. Differentiate between optimization (aka “Here’s how I made things faster”) to profiling (aka “Here’s how I found what was slow”).
Two types of profilers: sampling vs instrumentation.
Sampling
Sampling profiling in a nutshell is: Attach to program, periodically interrupt and record the stack trace.
The runtime per function is a result of statistically averaging. It works out of the box without any code changes as long as minimal debug information is compiled into the binary.
Example tool: Intel vTune.
Instrumentation
You add explicit hooks into your code which record metrics at runtime. This is more accurate (e.g. not affected by inlining).
Recompilation and linking to 3rd party is needed.
Example tool: Optick.