Cannot locate debugging symbols and a lot of idle CPU usage

问题

I'm new to VTune Amplifier and I'm trying to profile OpenCV with a very basic application. Following this guide on recommended compiler options, I compiled OpenCV via CMake with CMAKE_BUILD_TYPE=RelWithDebInfo and -DWITH_OPENMP=ON so both -O2 and -g options are included and OpenMP enabled. My testing OpenCV application is compiled with

g++ -I/home/luca/Dropbox/SURFSPM/opencvInstall/include -O3 -g -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.o" -o "main.o" "../main.cpp"

via eclipse. However, when I try to analyze my application this is the collection Log:

Data collection is completed successfully
    Sunday, February 05, 2017 AM11:44:53 CET  The result file '/home/luca/intel/amplxe/projects/OpenCV/r000hs/r000hs.amplxe' is successfully created and added to the project OpenCV. 

Finalization completed with warnings 
    Sunday, February 05, 2017 AM11:45:01 CET  Result finalization has completed with warnings that may affect the representation of the analysis data. Please see details below. 
    Cannot locate file `[stack]'.
    Cannot locate debugging symbols for file `/lib/x86_64-linux-gnu/libgcc_s.so.1'.
    Cannot match the module with the symbol file `/usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21': checksum is different. Make sure to specify the correct path to the symbol file in the Binary/Symbol Search list of directories.
    Cannot locate debugging symbols for file `/usr/lib/x86_64-linux-gnu/libstdc++.so.6'.
    Cannot locate debugging symbols for file `/opt/intel/vtune_amplifier_xe_2017.1.0.486011/lib64/runtime/libittnotify_collector.so'.
    Cannot locate debugging symbols for file `/lib64/ld-linux-x86-64.so.2'.
    Cannot locate debugging symbols for file `/usr/lib/x86_64-linux-gnu/libpng12.so.0'.
    Cannot locate debugging symbols for file `/usr/local/lib/libopencv_xfeatures2d.so.3.1'.
    Cannot locate debugging symbols for file `/opt/intel/vtune_amplifier_xe_2017.1.0.486011/lib64/libtpsstool.so'.
    Cannot locate debugging symbols for file `/usr/local/lib/libopencv_core.so.3.1'.
    Cannot locate debugging symbols for file `/usr/local/lib/libopencv_imgcodecs.so.3.1'.
    Cannot locate debugging symbols for file `/usr/local/lib/libopencv_imgproc.so.3.1'.

In addition, as you can see from the following image, most of the time the CPU usage is in idle:

Which make me think that this warning messages are important and I'm doing something wrong.

来源：https://stackoverflow.com/questions/42051354/cannot-locate-debugging-symbols-and-a-lot-of-idle-cpu-usage

标签

c++

OpenCV

profiling

vtune

intel-parallel-studio