diff options
| -rw-r--r-- | src/runtime/pprof/pprof.go | 63 |
1 files changed, 62 insertions, 1 deletions
diff --git a/src/runtime/pprof/pprof.go b/src/runtime/pprof/pprof.go index b7c41f13de..25f7ed6eb1 100644 --- a/src/runtime/pprof/pprof.go +++ b/src/runtime/pprof/pprof.go @@ -4,8 +4,69 @@ // Package pprof writes runtime profiling data in the format expected // by the pprof visualization tool. +// +// Profiling a Go program +// +// The first step to profiling a Go program is to enable profiling. +// Support for profiling benchmarks built with the standard testing +// package is built into go test. For example, the following command +// runs benchmarks in the current directory and writes the CPU and +// memory profiles to cpu.prof and mem.prof: +// +// go test -cpuprofile cpu.prof -memprofile mem.prof -bench . +// +// To add equivalent profiling support to a standalone program, add +// code like the following to your main function: +// +// var cpuprofile = flag.String("cpuprofile", "", "write cpu profile `file`") +// var memprofile = flag.String("memprofile", "", "write memory profile to `file`") +// +// func main() { +// flag.Parse() +// if *cpuprofile != "" { +// f, err := os.Create(*cpuprofile) +// if err != nil { +// log.Fatal("could not create CPU profile: ", err) +// } +// if err := pprof.StartCPUProfile(f); err != nil { +// log.Fatal("could not start CPU profile: ", err) +// } +// defer pprof.StopCPUProfile() +// } +// ... +// if *memprofile != "" { +// f, err := os.Create(*memprofile) +// if err != nil { +// log.Fatal("could not create memory profile: ", err) +// } +// runtime.GC() // get up-to-date statistics +// if err := pprof.WriteHeapProfile(f); err != nil { +// log.Fatal("could not write memory profile: ", err) +// } +// f.Close() +// } +// } +// +// There is also a standard HTTP interface to profiling data. Adding +// the following line will install handlers under the /debug/pprof/ +// URL to download live profiles: +// +// import _ "net/http/pprof" +// +// See the net/http/pprof package for more details. +// +// Profiles can then be visualized with the pprof tool: +// +// go tool pprof cpu.prof +// +// There are many commands available from the pprof command line. +// Commonly used commands include "top", which prints a summary of the +// top program hot-spots, and "web", which opens an interactive graph +// of hot-spots and their call graphs. Use "help" for information on +// all pprof commands. +// // For more information about pprof, see -// http://github.com/google/pprof/. +// https://github.com/google/pprof/blob/master/doc/pprof.md. package pprof import ( |