A lot. Billions of dollars are spent to combat it and research on food and agriculture to solve hunger has been going for years.

>The vast majority of hungry people live in developing regions, which saw a 42 percent reduction in the prevalence of undernourished people between 1990–92 and 2012–14.

http://www.worldhunger.org/2015-world-hunger-and-poverty-fac...

> 9 million already due of hunger every year, what is the world doing about that presently?

Most of it is because of conflicts. Poverty is decreasing fast across the globe and there were relatively a lot more people dying from hunger in the 80s.