linux perf: how to interpret and find hotspots

Question

I tried out linux\' perf utility today and am having trouble in interpreting its results. I\'m used to valgrind\'s callgrind which is of course a totally different approach

Answer 1

Ok, these functions might be slow, but how do I find out where they are getting called from? As all these hotspots lie in external libraries I see no way to optimize my code.

Are you sure that your application someapp is built with the gcc option -fno-omit-frame-pointer (and possibly its dependant libraries) ? Something like this:

g++ -m64 -fno-omit-frame-pointer -g main.cpp