[wplug] killing process that will not die

[Michael Skowvron]

John Harrold wrote:

> i don't remember what the process state was. he needed to use mozilla for
> mail, so i told him to reboot. i just wanted to know how to deal with this
> for future reference. what would i do in the case where the process is
> waiting for disk io?

If the process did not respond to the kill signal then it was almost 
surely stuck waiting on a lock. My best guess would be a kernel 
semaphore lock, probably related to thread synchronization. The thread 
may have beed in the middle of exiting and was unable to free a resource.

In this state, sending more signals to it by any method would have no 
effect. Almost guaranteed, this would be a but; but without a kernel 
crash dump (something that's almost impossible to get on a PC) there's 
no way to know if it's a kernel bug or a Mozilla bug.

In reality, there was nothing you could do. You had to reboot. There 
would be no way to "unstick" or release the condition that was blocking 
the thread.

Michael