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,
or
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?