Trace, a powerful tool for go scheduling and performance analysis

Trace usage example

import (
	"fmt"
	"log"
	"os"
	"runtime/trace"
	"sync"
)

func main() {
	//runtime.GOMAXPROCS(1)
	// 1. 创建trace持久化的文件句柄
	f, err := os.Create("trace.out")
	if err != nil {
		log.Fatalf("failed to create trace output file: %v", err)
	}
	defer func() {
		if err := f.Close(); err != nil {
			log.Fatalf("failed to close trace file: %v", err)
		}
	}()

	// 2. trace绑定文件句柄
	if err := trace.Start(f); err != nil {
		log.Fatalf("failed to start trace: %v", err)
	}
	defer trace.Stop()

	var wg sync.WaitGroup
	wg.Add(2)

	go func() {
		fmt.Println(`Hello`)
		wg.Done()
	}()

	go func() {
		fmt.Println(`World`)
		wg.Done()
	}()

	wg.Wait()
}

The terminal first executes go run main.go

Then execute go tool trace trace.out and the program will open a page using the default browser

 

• View trace: View the trace, you can see this execution, how many P (processors) are started, and which P the coroutine is executed on. Assist in understanding the scheduling model GMP
• Goroutine analysis: Goroutine analysis, you can view the total number of coroutines and specific coroutine executions
• Network blocking profile: Network blocking profile
• Synchronization blocking profile: Synchronization blocking profile
• Syscall blocking profile: System call blocking profile. You can see which part of the program takes time.
• Scheduler latency profile: Scheduling latency profile
• User defined tasks: User-defined tasks
• User defined regions: User-defined regions
• Minimum mutator utilization: Minimum mutator utilization

Reference links:

Go's performance analysis tool trace - Jianshu