The application is compiled with -O0 -g -pg and gprof is run with its default settings.
Check to make sure that all of your modules have the -pg flag. If any one is missing it, you could have these results.
(self-answer) I believe it was static declarations.
来源：https://stackoverflow.com/questions/4177152/why-does-gprof-occasionally-not-print-number-of-calls-for-particular-functions