What to do when Killl -9 doesn't work to end a process?
Assuming the problem is not a "defunct" process,.....
I have seen cases where kill'ing a process with a 9 didn't work.
All of the cases I've seen were a result of the process being "hung"
in the kernel waiting for an event.
We had problems in the past killing programs that were communicating
over a serial port, and it was hung trying to "CLOSE" the port ...
...as soon as we reconnected the serial device, the CLOSE succeeded
and the process exited.
In those days we used "crash" to perform a stack trace on the process
(after first determining its process table slot number). I understand
that "crash" has been replaced by "kdb" and its command set is different.
But, that may be a place for you to start.