When will the stack of a goroutine shrink?

[tapi...@gmail.com]

From the outputs of the following program,

it looks the stack of a goroutine doesn't shrink immediately.

Will it shrink at some point eventually?

package main

func f(i int) byte {
    type T int // avoid f being inline
    var a [1<<20]byte // make stack grow
    return a[i]
}

func main(){
    var x int
    println(&x) // 0xc000034770
    f(100)
    println(&x) // 0xc0002fff70
   
    // It looks the stack hasn't shrunk here.
   
    f(100)
    println(&x) // 0xc0002fff70
}

[Ian Lance Taylor]

Stack shrinking occurs during garbage collection, and only if the
goroutine isn't doing anything and isn't sitting in a system call or a
cgo call.

Ian

[tapi...@gmail.com]

Thanks for the explanation.