topic Re: Killing a defunct process in Operating System - HP-UX

Killing a defunct process

Nahmad_1 — Mon, 16 Jun 2008 13:00:22 GMT

Hi There

When we run GUE on HP-UX X-Windows a defunct X-windows process sometimes stay there.

What is best and easiest way to kill it ?

Thanks

Nahmad

Re: Killing a defunct process

Dennis Handly — Mon, 16 Jun 2008 13:09:34 GMT

A defunct process is a zombie. The only way you kill zombies is by killing the zombie master, its parent. (You can read all about this by doing an advanced search for zombie master.)
A process that has a parent of init (1) isn't a zombie.
So what do you really have?

Re: Killing a defunct process

Mike Miller_8 — Mon, 16 Jun 2008 15:25:06 GMT

Many zombie'd processes will not respond to the kill command. A system reboot will clear them. If a non-root process is the parent, killing the parent process can sometimes clear the zombie as well (though this sometimes leaves ports locked).

Re: Killing a defunct process

SKR_1 — Mon, 16 Jun 2008 17:45:18 GMT

Reboot of the box will be the better option to kill these defunct processes.

Thanks

Re: Killing a defunct process

Laurent Menase — Mon, 16 Jun 2008 19:39:31 GMT

kill the parent process will always remove defunct process ( zombies)

zombies are processes which are dead and which are waiting that the parent process acknowledge their exit status. It only keep a very limited amount of memory.
Parent process must issue a waitpid()/wait3()... to cleanup zombies

When an application is masking SIGCHILD, zombies are automatically cleandup.

When killing the parent process, it is attached to the process 1 init.
init calls waitpid() cleaning up zombies automatically.

The only case when zombies can't be cleanup is when for whatever reason parent process can't be stopped or killed.