内存泄漏的问题 复制重试却不一样的结果，求助！

[shcw]

大佬，我看了这篇帖子 https://github.com/helios741/myblog/tree/new/learn_go/src/2021/08/go_feak_memory_lark 当我也想复现这个问题的时候出现了奇怪的情况，
内存一直不下来。。。

go版本：1.17.8 环境centos7
执行代码如下

package main

import (
	"fmt"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	log "github.com/sirupsen/logrus"
	"net/http"
	_ "net/http/pprof"
	"time"
)

func allocate(s int) {
	a := make([]byte, s*1024*1024)
	for i := 0; i < len(a); i += 4096 {
		a[i] = 'x'
	}
	fmt.Printf("alloc%c %d\n", a[0], s)
	a = nil
}

func main() {
	allocate(100)
	allocate(200)
	allocate(500)

	go func() {
		// Expose the registered metrics via HTTP.
		http.Handle("/metrics", promhttp.HandlerFor(
			prometheus.DefaultGatherer,
			promhttp.HandlerOpts{
				// Opt into OpenMetrics to support exemplars.
				EnableOpenMetrics: true,
			},
		))

		err := http.ListenAndServe(":8166", nil)
		if err != nil {
			log.Errorf("ListenAndServe: %+v", err)
		}
	}()

	time.Sleep(300 * time.Second)
}

希望大佬可以解答下