use valgrind to know time(in seconds) spent in each function

Question

is there any extension of valgrind, that can be used in the command window, that would help me know the time, in seconds, spent in each function in my C code?

thanks =)<

Answer 1

Valgrind isn't suited for measuring time, as running an application in valgrind distorts the results (slowdown, CPU vs. I/O). Thus valgrind profiling tool callgrind doesn't measure time but CPU instructions. Callgrind is only useful if your bottleneck is CPU-bound (thus CPU instructions matter), then CPU instructions measured will be in proportion to the time spent. It's not useful if heavy I/O or multiple processes are involved. Then you should use a sampling profiler, like sysprof or gprof (Edit 2020: perf). That checks in intervals which function the process is in, with less distorted results.