When I was a kid I though that profiling would be either very complicated or a lot of work. gprof seemed to be a highly-praised profiler, so I installed it (very easy as well, using the Ubuntu Software Center). In Qt Creator, I got it to work within 5 minutes! I put a
how-to-use-gprof example at my website, so you can benefit as well!
Have fun profiling, Bilderbikkel