cfs_quota.go

package main

import (
	"flag"
	"time"
	"sync/atomic"
	"hash/adler32"
	"fmt"
	"os"
	"runtime"
)

// test how cfs_quota affect cpu intensive task
// docker run -it --cpu-period=100000 --cpu-quota=400000 -v `pwd`:/tmp --entrypoint bash test_image
// /tmp/cfs_quota -c 8 -d 10s 

var c = flag.Int("c", 4, "groutine count")
var t = flag.Duration("t", 1*time.Second, "tick to print result")
var d = flag.Duration("d", 30*time.Second, "test duration")

var s = []byte(`Adler-32 is composed of two sums accumulated per byte: s1 is
the sum of all bytes, s2 is the sum of all s1 values. Both sums
are done modulo 65521. s1 is initialized to 1, s2 to zero.  The
Adler-32 checksum is stored as s2*65536 + s1 in most-
significant-byte first (network) order.`)

func burnCpu(n int) {
	for i := 0; i < n; i++ {
		adler32.Checksum(s)
	}
}

func main() {
	flag.Parse()
	fmt.Println(runtime.NumCPU(), runtime.GOMAXPROCS(-1))
	tickC := time.Tick(*t)
	stopC := time.After(*d)

	var taskCount int32
	for i := 0; i < *c; i ++ {
		go func() {
			for {
				//s := time.Now()
				burnCpu(5000)
				//fmt.Println("cost: ", time.Since(s))
				atomic.AddInt32(&taskCount, 1)
			}
		}()
	}

	var count int32 = 0
	for {
		select {
		case <- tickC:
			cur := atomic.LoadInt32(&taskCount)
			fmt.Printf("%v: %d\n", time.Now(), cur - count)
			count = cur
		case <- stopC:
			fmt.Println("avg process speed: ", atomic.LoadInt32(&taskCount)/int32((*d).Seconds()))
			os.Exit(0)

		}
	}
}