To install oprofile (and gui):
sudo apt-get install oprofile oprofile-gui

To start profiling:
sudo oprof_start

Settings isnide the oprof GUI:
inside setup, check "profile kernel"
	check "profile user binaries"
	make sure CPU_CLK_UNHALTED event is highlighted (or equivalent, I'm on AMD64)
inside configuration, check "no kernel image"

Click "reset sample files" (if available) to clear out previous data
Click "Start"
Run Dexter; let it run for a while
Click "Stop"
Click "Save and quit"

To view a report of the symbol summary including libs:
opreport --demangle=smart --symbols dexter.bin |more