go - GOMAXPROCS already be 2, but program still hang

Question

I already set runtime.GOMAXPROCS(2), but this program still hang when output some numbers. I can see high cpu used by this program(more than 100%), but I can't understand why the for loop goroutine can make my program not work.

go version is 1.4.2 on linux/amd64, and my pc has 4 CPUs.

here is the code:

package main

import "fmt"
import "runtime"
import "time"

func forever() {
    for {
    }   
}

func show() {
    for number := 1; number < 999999; number++ {
        time.Sleep(1000)
        fmt.Println(number)
    }   
}

func main() {
    runtime.GOMAXPROCS(2)
    go show()
    go forever()
    for {
        time.Sleep(1000)
    }   
} 

Answer 1

Waitting for answers