This is driving me insane!!

I have a program that works absolutely fine. I'd like some benchmarks on the program, so I added some timing code and I've been trying to write that data plus a few other pieces of information to a file. In the middle of my program's execution it suddenly exits with a segmentation fault error. It also says "Address is not mapped".

I write to plenty of other files throughout the course of the program, but for some reason these benchmarks cause a program.

Can you guys think of a generic reason why this could be occurring? Could I be trying to write too much data to the file and it's running out of memory?

Thanks.