Example
The GNU gprof profiler, gprof, allows you to profile your code. To use it, you need to perform the following steps:
-
Build the application with settings for generating profiling information
-
Generate profiling information by running the built application
-
View the generated profiling information with gprof
In order to build the application with settings for generating profiling information, we add the -pg flag. So, for example, we could use
$ gcc -pg *.cpp -o app
or
$ gcc -O2 -pg *.cpp -o app
and so forth.
Once the application, say app, is built, execute it as usual:
$ ./app
This should produce a file called gmon.out.
To see the profiling results, now run
$ gprof app gmon.out
(note that we provide both the application as well as the generated output).
Of course, you can also pipe or redirect:
$ gprof app gmon.out | less
and so forth.
The result of the last command should be a table, whose rows are the functions, and whose columns indicate the number of calls, total time spent, self time spent (that is, time spent in the function excluding calls to children).
