Profiling

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USING SCOREP & CUBE: (I was unable to get good result with forked application)
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rm -rf CMakeCache.txt CMakeFiles/ cmake_install.cmake Makefile 
export SCOREP_ENABLE_PROFILING=1
export SCOREP_EXPERIMENT_DIRECTORY=sdh
export PATH=$PATH:/root/local/bin/
CXX="scorep /usr/bin/g++" cmake3 .
./DisplayImage
scorep-score -r sdh/profile.cubex ... or cube sdh/profile.cubex


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USING VALGRIND, CALLGRIND AND KCACHEGRIND: (Takes lot of time. Slows down the execution)
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valgrind --tool=callgrind --dump-instr=yes -v ./a.out  ...........for callgraph and cache information
kcachegrind callgrind.out.5*

g++ -g mem.c
valgrind --tool=memcheck --leak-check=yes ./a.out  ..........for mem leaks

g++ -g mem.c
valgrind --tool=massif ./a.out  ...........for mem leaks
ms_print massif.out.931  ..........for command line display
massif-visualizer massif.out.931  ..............for visual display


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USING GPROF: (easy to use and interpret but results not clear...  Only profiles in "user space". Cannot see bottlenecks that occur in external shared libraries (like libc) or the kernel)
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g++ -g -pg fork.cpp
./a.out
gprof ./a.out gmon.out


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USING PPROF: (easy to use but cannot profile in forked() applications. workaround is to use startprofile after fork())
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while compiling link the executable with libprofiler.so or -lprofiler
CPUPROFILE=sdh.prof ./DisplayImage ........will generate sdh.prof in current directory
pprof --text ./DisplayImage sdh.prof .........for text output
pprof --gv ./DisplayImage sdh.prof .........for graphical output
pprof --callgrind ./DisplayImage sdh.prof > sdh.callgrind .........for kcachegrind graphical output
kcachegrind sdh.callgrind


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USING OPERF: (can be used for forked as well as multithreaded programs)
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operf ./DisplayImage
OR
operf -e CPU_CLK_UNHALTED:500000,l2_requests:80000 ./DisplayImage
opreport -l .... see manpage for more options
ocount -e l2_requests:0x41 ./DisplayImage  ... will give total count of L2 cache miss. man ocount