dtrace showed matched probes but nothing in output on FreeBSD 9.1-RELEASE

[John Luk]

Hi all,
I'm a newbie in dtrace, and I following this tutorial from Oracle:
http://docs.oracle.com/cd/E19205-01/820-4221/ to learn dtrace. In the
example of test.c and ufunc.d, I expected output like this:

 % dtrace -s ufunc.d -c ./a.out a.out

    dtrace: script 'ufunc.d' matched 5 probes
    dtrace: pid 27210 has exited

    inet_makeaddr            1
    foo1                     1
    foo                      1
    main                     1
    __fsr                    1


But I got this instead:

# dtrace -s ufunc.d  -c ./a.out a.out
dtrace: script 'ufunc.d' matched 5 probes
dtrace: pid 86498 has exited

#

My system info:
root at home:/home/spin6lock/test # dtrace -V
dtrace: Sun D 1.7
root at home:/home/spin6lock/test # uname -a
FreeBSD 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Mon Oct 28 20:52:03 CST
2013     root at xiangling:/usr/obj/usr/src/sys/DTRACE  amd64

Any clues? Thanks in advanced.

Cheers,
spin6lock