Profiling OAI

I’ve been studying the OAI architecture. Part of that is profiling the code.

GPROF

To use gprof, I modifyed the cmake_targets/CmakeLists.txt file. I just appended this to the top:

set(CMAKE_CXX_FLAGS   ${CMAKE_CXX_FLAGS} "-pg")

I then compiled it like normal.

./build_oai --eNB -w USRP

I ran the lte-softmodem for a few seconds. This generates an output gmon.out that we can load into gprof.

gprof ./lte_build_oai/build/lte-softmodem gmon.out > ~/profile_results

The output is here. THIS IS PROBABLY WRONG. IT PROBABLY IS ONLY THE MAIN THREAD.

Valgrind

Valgrind is way more powerful! Install valgrind and a few other packages.

sudo apt install valgrind kcachegrind graphviz

Compile OAI with gdb flags:

./cmake_targerts/build_oai -g --eNB -w USRP

Run OAI through valgrind with callgrind on:

sudo -E valgrind --tool=callgrind ./cmake_targets/lte_build_oai/build/lte-softmodem -O YOUR.CONF

This will generate an output like callgrind.out.PID

Change the permisions of this sudo chmod 777 callgrind.out.PID since you ran the lte-softmodem as sudo.

Open this in kcachegrind. Just launch kcachegrind in the terminal then click open. My callgrind output is here. Once you open this, you can generate call graphs for any function!

!()[../init_SI.png]