Perlin noise causing Unity to Freeze; am I doing something wrong?

So I’m trying to make a function that places tiles psuedorandomly in a tile map using perlin noise; problem is that whenever I call the function ‘Mathf.PerlinNoise()’ unity freezes and eventually crashes (Note: I’ve tried this with small values for ‘size’). I’ve also had this problem with simpler code in the past and in different versions of unity; am I calling it wrong perhaps or might it be my computer?

 public Vector2Int size;

    void changeMap(int x, int y, Tile place)
    {
        tileMap.SetTile(new Vector3Int(x, y, 0), place);
    }

    void makeLevel(int X, int Y)
    {
        if (Input.GetButtonDown("Jump"))
        {
            for (x = 0; x < X; y++)
            {
                for (y = 0; y < Y; y++)
                {
                    if(Mathf.PerlinNoise(x/X, y/Y) > 0.8)
                    {
                        changeMap(x, y, tile);
                    }
                }
            }
        }
    }

    private void Update()
    {
        makeLevel(size.x,size.y);
    }

Update: running PerlinNoise() once is fine.

for (x = 0; x < X; y++)
{
    for (y = 0; y < Y; y++)
    {

...

The crash isn’t to do with perlin noise, more the fact that you have an infinite loop (you run the outer loop until x reaches X, but never actually increment it - instead you increment y twice).