You might also consider doing something like:
strace -cirtv -p 11808
strace -cirtv -o /tmp/datrace.log -p 11808
The first will spew lots of system calls to the screen and it may get lost, the second redirects the output to the file /tmp/datrace.log. This will give you a trace of all the low level system calls that directadmin is making as well as how long it is spending in each call. I suggest doing the second format and let it run for a minute or two of high CPU usage, then CTRL-C out of it. Then open the /tmp/datrace.log file and look for system calls that that are either in a loop (good reason for high CPU) or ones that have a high relative times. The ones with the high relative times may point you to a reason why the CPU usage is high. You may or may not want to add the 'f' flag to the above commands, that tells strace to also follow child processes, which might also be where the issue is. I would do it without the 'f' flag first so there are fewer lines to parse.