$ time go run test.go 

real	0m0.802s
user	0m0.320s
sys	0m0.345s

$ /usr/bin/time -v go run test.go  
Command being timed: "go run test.go"
	User time (seconds): 0.12
	System time (seconds): 0.06
	Percent of CPU this job got: 115%
	Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.16
	Average shared text size (kbytes): 0
	Average unshared data size (kbytes): 0
	Average stack size (kbytes): 0
	Average total size (kbytes): 0
	Maximum resident set size (kbytes): 41172
	Average resident set size (kbytes): 0
	Major (requiring I/O) page faults: 1
	Minor (reclaiming a frame) page faults: 15880
	Voluntary context switches: 897
	Involuntary context switches: 183
	Swaps: 0
	File system inputs: 256
	File system outputs: 2664
	Socket messages sent: 0
	Socket messages received: 0
	Signals delivered: 0
	Page size (bytes): 4096
	Exit status: 0

package main
import (
	"log"
	"runtime"
	"time"
)
func main(){
	log.Println("start...")
	test()
	log.Println("force gc...")
	runtime.GC()//強(qiáng)調(diào)調(diào)用gc回收
	log.Println("done...")
	time.Sleep(3600*time.Second)
}
func test(){
	//由于切片可以動(dòng)態(tài)擴(kuò)容，所以這里使用slice進(jìn)行測(cè)試
	container := make([]int, 8)
	log.Println("==> loop start...")
	for i := 0; i < 32*1000*1000; i++ {
		container = append(container, i)
	}
	log.Println("==> loop end...")
}

$go build -o test && ./test

$top -p $(pidof test)

$ GODEBUG='gctrace=1' ./test

        gc # @#s #%: #+#+# ms clock, #+#/#/#+# ms cpu, #->#-># MB, # MB goal, # P
	gc #        GC次數(shù)的編號(hào)，每次GC時(shí)遞增
	@#s         距離程序開(kāi)始執(zhí)行時(shí)的時(shí)間
	#%          GC占用的執(zhí)行時(shí)間百分比
	#+...+#     GC使用的時(shí)間
	#->#-># MB  GC開(kāi)始，結(jié)束，以及當(dāng)前活躍堆內(nèi)存的大小，單位M
	# MB goal   全局堆內(nèi)存大小
	# P         使用processor的數(shù)量

gc 3 @0.134s 1%: 0.003+28+0.002 ms clock, 0.007+0/0.049/24+0.005 ms cpu, 178->178->100 MB, 180 MB goal, 2 P