In programming context, you can call a function. This usage is listed on the dictionary ("cause the execution of (a subroutine)" by Oxford), and although I wasn't able to confirm with the dictionaries I have, I'm assuming call as a noun can be used in the same manner.
So when I want to rewrite
By calling this function multiple times, ...
using call as a noun, which preposition do I use?
By multiple calls for this function,
By multiple calls of this function,
seems to fit in (to me), and both are found on the internet, as How to limit calls for a function, but to surely process it afterwards and Counting recursive calls of a function.
Which should I choose?