golang函数调用计时

package main

import (
    "log"
    "time"
)

func f() {
    defer timeoutCheck("f slow", time.Now())
    time.Sleep(time.Second)
}

func timeoutCheck(tag string, start time.Time) {
    dis := time.Since(start).Seconds()
    if dis > 1 { 
        log.Println(tag, dis, "s")
    }   
}

func main() {
    f() 
}