% valgrind --tool=callgrind --dump-instr=yes -v \
          --instr-atstart=no /usr/sbin/apache2 -X

% chmod a+rw callgrind.out.*
 - hit the server to warm it up -
% callgrind_control -i on
 - hit the server -
% callgrind_control -i off
% callgrind_control -k
 - Hit ^C in valgrind terminal -

% kcachegrind callgrind.out.*