[SOLVED] How to kill process if it can't be killed?

Mr. Alex · 11-24-2013, 04:00 AM

Hello LQ.org.

I have problems with vlc and kdenlive. Sometimes they hang up and can't be terminated no matter what I do. For example I try to kill vlc with

Code:

killall vlc

which gives me no text output and does nothing to vlc. Or I

Code:

ps aux | grep vlc

and then

Code:

kill

whatever process that is (both as user and as root) and still no luck.
Try htop with "F9" and then different termination signals and none of them work. So the only way to actually terminate those processes for me is to reboot.

Can you suggest any other thing to terminate them without rebooting?

druuna · 11-24-2013, 04:08 AM

kill <PID> is a nice way to kill a process, if that does not work you could try kill -9 <PID>

If a process becomes a zombie you cannot kill or remove it, only option is to reboot.

Mr. Alex · 11-24-2013, 04:24 AM

Quote:

Originally Posted by druuna

kill <PID> is a nice way to kill a process, if that does not work you could try kill -9 <PID>

If it's a SIGKILL call, then I already tried it through htop. And zombie process shouldn't consume any CPU resources, right? Not in my case — VLC might load CPU 100% and still be hanging as zombie.

druuna · 11-24-2013, 04:45 AM

Quote:

Originally Posted by Mr. Alex

If it's a SIGKILL call, then I already tried it through htop.

Yep, kill -9 and kill -SIGKILL do the same thing. Have you tried it from the command line instead of using htop?

Quote:

And zombie process shouldn't consume any CPU resources, right?

Correct.

Quote:

Not in my case — VLC might load CPU 100% and still be hanging as zombie.

A zombie process is recognisable by the process status (the STAT field in ps or the S field in top). The status will be Z for a zombie process.

You can check for zombied processes like this:

Code:

ps aux | awk '{ print $8 " " $2 }' | grep -w Z

Mr. Alex · 11-24-2013, 04:48 AM

Quote:

Originally Posted by druuna

Have you tried it from the command line instead of using htop?

Probably not. Next time I have this situation, I'll try. But from here it doesn't seem to have any real difference.

Xeratul · 11-24-2013, 04:59 AM

pkill -9 chromi* <-- not sure

kill -9 <number#> that you find using ps aux

syg00 · 11-24-2013, 05:02 AM

Possibly running in interrupt context - that's "higher" (FSVO ...) than kernel context.

In which case it's crap code, and you're out of luck trying to kill it.

Just a guess.

jamison20000e · 11-24-2013, 02:20 PM

Also try:

Code:

sudo {...}

it's worked for me.

Mr. Alex · 11-25-2013, 07:42 AM

jamison20000e, I used sudo for this purpose. Back then it didn't help. Last time kdenlive froze, "kill -9" helped. Will see how it does with VLC.

rlug · 03-20-2014, 05:01 AM

Hi,

You can try good solution suggested at :
# What is Zombie Process ?
# How to Kill Zombie Process ?

Habitual · 03-21-2014, 03:29 PM

How to kill without the kill command