Excuse me - I said -- profil - I intended to say  ptrace(2)....   long day -- aging brain bits.

http://man.cat-v.org/unix_7th/2/ptrace

The debugger system call that allows you to a processed memory.   

On Fri, May 12, 2017 at 4:40 PM, Jeremy C. Reed <reed@reedmedia.net> wrote:
profil code somewhere in here?
https://github.com/weiss/original-bsd/commits/master/sys/kern/kern_clock.c?after=b44636d7febc9dcf553118bd320571864188351d+104

that has the sccs history back to April 1980 for src/sys/sys/clock.c