Valgrind is a powerful tool for performance and correctness analysis of code.
This mini-howto discusses how to set your development environment up,
such that you can profile a running olsr daemon and later analyze its
recordings using a graphical frontend called Kcachegrind.

First patch your makefile such that the debug symbols are not removed after
compilation

    diff -r 26494c58ff86 Makefile.inc
    --- a/Makefile.inc Wed Jan 09 22:01:18 2008 +0100
    +++ b/Makefile.inc Thu Jan 10 14:46:27 2008 +0100
    @@ -5,10 +5,10 @@
    #
    # activate debugging with 1 or deactivate with 0
    -DEBUG ?= 0
    +DEBUG ?= 1
    # compile OLSR_PRINTF out
    -NO_DEBUG_MESSAGES ?= 0
    +NO_DEBUG_MESSAGES ?= 1

Next run valgrind with the following command line options.

valgrind --tool=callgrind -v --dump-instr=yes --trace-jump=yes ./olsrd -d 0 -nofork

Finally load kcachgrind to display the profiling data. (watch out the callgrind
data are written with a umask of 600 as user root - so you may want to chown or
chmod the file, otherwise kcachegrind cannot open your data and will display an
empty screen)