fgprof

fgprof is a sampling Go profiler that allows you to analyze On-CPU as well as Off-CPU (e.g. I/O) time together. Go's builtin sampling CPU profiler can only show On-CPU time, but it's better than fgprof at that. Go also includes tracing profilers that can analyze I/O, but they can't be combined with the CPU profiler. fgprof is designed for analyzing applications with mixed I/O and CPU workloads. This kind of profiling is also known as wall-clock profiling. If this is the first time you hear about fgprof, you should start by reading about The Problem & How it Works. fgprof is compatible with the go tool pprof visualizer. Which tool you prefer is up to you, but one thing I like about Gregg's tool is that you can filter the plaintext files using grep which can be very useful when analyzing large programs.