free up memory used by profile feature

Signed-off-by: Eddy Petrișor <eddy.petrisor@gmail.com>
make.1: Explain how -P works

Signed-off-by: Eddy Petrișor <eddy.petrisor@gmail.com>
remove the warnings generated by the new code

Signed-off-by: Eddy Petrișor <eddy.petrisor@gmail.com>