This signal causes a process to terminate immediately. It cannot be caught or ignored. This is always signal #9 on all systems.
Do not use this signal lightly. The process will not have any chance to clean up. It may leave behind orphaned child processes, temporary files, allocated locks, active shared memory segments, busy sockets, and any number of other resource state inconsistencies. This can lead to surprising and hard to debug problems in the subsequent operation of the system.