topic Re: SIGKILL failures in Operating System - HP-UX

SIGKILL failures

Michael Soulier — Thu, 06 Jul 2000 14:19:21 GMT

Here I am, with a process failing to exit on its own, so after trying a SIGTERM, I use a SIGKILL. Now, I know that the process can't catch a SIGKILL, because it's handled by the OS, and the OS is God with respect to system resources.

To my astonishment, the process casually ignores the SIGKILL.

This should never, ever happen, and it has only happened to me on HPUX. Not Solaris, not Linux, just HPUX. I'm very curious as to why this is, and what is being done to fix it. I use HPUX 10.20 all day, so this is rather important.

Thanks people,

Mike

Re: SIGKILL failures

Andreas Voss — Thu, 06 Jul 2000 14:41:53 GMT

Hi,

in my knowledge one thing that could prevent a kill -9 is an open to an I/O device by the proccess for e. g. a tar command exits after I/O has been satisfied.

Re: SIGKILL failures

Patrick Wessel — Thu, 06 Jul 2000 14:44:18 GMT

If a process is hung awaiting the completion of I/O, it may not receive the signal and hence die.

Re: SIGKILL failures

Michael Soulier — Thu, 06 Jul 2000 14:44:20 GMT

Well, both of the cases where this keeps plaguing me is with regards to networking. Either a server bound to a port that refuses to die, or a client connecting to a port that refuses to.

This shouldn't happen to my knowledge. This feels like a bug.

Re: SIGKILL failures

Michael Soulier — Thu, 06 Jul 2000 14:45:45 GMT

On every other Unix I've been on, the OS interrupts the waiting I/O and kills it. Why not on HPUX?

Re: SIGKILL failures

Ralf Hildebrandt — Fri, 07 Jul 2000 06:35:16 GMT

Is the process you're trying to kill listed as ? If so, it's a zombie. Zombies cannot be killed (unless you kill their parent). If init (process 1) is the parent, all you can do is reboot.

Re: SIGKILL failures

Michael Soulier — Mon, 10 Jul 2000 17:32:17 GMT

No, the processes weren't zombies, and yes, they were inherited by init.

Why does that matter? I kill processes under init owned by myself in a standard account in Linux all the time. This really feels like a bug to me.

Re: SIGKILL failures

Tim Malnati — Mon, 10 Jul 2000 17:49:14 GMT

Each case that I've seen like this seems to be associated with memory management. Something like a runaway has gobbled up 500 Meg of memory and the system seems to keep the process alive until it's given back to the system. Not that this is correct, but it's what I've seen.