$ pprofp -T /var/tmp/apd/pprof.PID 
main
define
require_once
require_once
  require_once
    define
    define
    define
    define
    define
    define
    function_exists
    zend_version
    version_compare
    define
    substr
    define
    define
    define
    ini_set
    register_shutdown_function
  define (x49)
require_once
  define (x21)
  ...
