CPP Joules

Energy Measurement tool for CPP/CUDA programs

• Uses Intel RAPL interface to get energy values
• Uses NVML interface for getting GPU energy values
• Needs read access to powercap in linux
• Needs a 64bit windows system with nvml in system32

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Installation Instructions

Linux

• To use without installing into lib folder

chmod +x installer.sh
./installer.sh

• Install to lib (requires cmake and make)

  mkdir build
  cd build
  cmake ..
  sudo cmake --build . --target install

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Windows

.\installer.bat

• cppJoules folder will be added
• Can be included as #include "cppJoules/include/cppJoules.h" //Relative path
• To use with g++, nvcc use -lCPP_Joules along with -L./cppJoules to add this path to linker search
• Keep a copy of the dll along with you .exe file to run

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Usage

#include "cppJoules/include/cppJoules.h"
int main()
{
  EnergyTracker tracker;
  tracker.start();
  // Code Snippet Here 
  tracker.stop();
  tracker.calculate_energy();
  tracker.print_energy();
  return 0;
}

To compile example file filename.cpp

  g++ filename.cpp -lCPP_Joules -L./cppJoules

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Common Errors

• undefined refrence

  /usr/bin/ld: /usr/local/lib/libCPP_Joules.so: undefined reference to `dlopen'
  /usr/bin/ld: /usr/local/lib/libCPP_Joules.so: undefined reference to `dlsym'
  

  • Use -ldl in the compile options

• cppJoules not found

  • Add -L/path/to/file
  • Example -L./cppJoules

• rapl domains are not visible

  • set read access to the sockets
  • One way would be to

    sudo chmod +r -R /sys/class/powercap/  
    

    Make sure to remove access after experiments.