When Profiling Cython Code, What Is `stringsource`?

I have a heavy Cython function that I'm trying to optimize. I am profiling per this following tutorial http://docs.cython.org/src/tutorial/profiling_tutorial.html. My profile out

Solution 1:

Okay, turns out I did have a memory view. I was calling an inline function that passed a statically typed numpy array to a memory view, thus invoking all those extra calls to stringsource. Replacing the memoryview type in the function call with a numpy type fixed this.