https://blog.wongcw.com/2018/10/13/mozilla%e6%9b%b4%e6%96%b0%e4%ba%86firefox%e6%af%8f%e5%a4%9c%e6%9e%84%e5%bb%ba%e7%89%88%e7%9a%84aboutperformance%e4%bf%a1%e6%81%af%e9%a1%b5/