Indeed, because this wouldn't make much sense given the tenfold slowdown. Callgrind collect information about how many instructions were executed and who has be

Indeed, because this wouldn't make much sense given the tenfold slowdown. Callgrind collect information about how many instructions were executed and who has been calling who. It's just a different profiling metric. I love valgrind/callgrind and it has proven extremely valuable. As always, choose the right tool for the job.