This appears to be a fairly complex subject. See https://news.ycombinator.com/item?id=11216950 https://news.ycombinator.com/item?id=11216950 and the original L

This appears to be a fairly complex subject. See https://news.ycombinator.com/item?id=11216950 https://news.ycombinator.com/item?id=11216950 and the original LWN article that it depends from.