How to profile my C++ application on linux

Question

I would like to profile my c++ application on linux. I would like to find out how much time my application spent on CPU processing vs time spent on block by IO/being idle.

Answer 1

I can recommend valgrind's callgrind tool in conjunction with KCacheGrind for visualization. KCacheGrind makes it pretty easy to see where the hotspots are.

Note: It's been too long since I used it, so I'm not sure if you'll be able to get I/O Wait time out of that. Perhaps in conjunction with iostat or pidstat you'll be able to see where all the time was spent.