When you use Callgrind to profile a program, the program is transformed into an intermediate format and then is run in a virtual processor emulated by valgrind. That makes possible to keep track of operations and that makes the program run much more slower than otherwise.
sudo apt-get install valgrind kcachegrind graphviz
Not necessarily required but useful to have the debugging information in the binary so if it’s possible compile with the -g option.
gcc -g -o program program.c
# check options man valgrind # profile valgrind --tool=callgrind <program> [program-options] # profile with additional options e.g. valgrind --tool=callgrind --dump-instr=yes --simulate-cache=yes --collect-jumps=yes <program> [program-options]
For more details on Callgrind’s features and way of working, it’s worth checking out its site.
KCahcegrind is a graphical program and its interface is quite self-explanatory. If it is run from the directory where Callgrind just stored its reports into, it opens those by default.