Benchmarking & Profiling

Benchmarking

This lesson explains the main concept clearly with beginner-friendly examples and background so you can learn why the code works.

Benchmarks live in _test.go files and use the *testing.B argument.

func BenchmarkFib(b *testing.B) {
    for i := 0; i < b.N; i++ { fib(20) }
}

Run with the -bench flag:

$ go test -bench=.

Profiling CPU & Memory

$ go test -cpuprofile=cpu.out -memprofile=mem.out ./...
$ go tool pprof cpu.out

Inside the pprof REPL you can type top, list Fib, web (requires Graphviz).

Race Detector

Detect data races in concurrent code:

$ go run -race main.go