Remove the zombie persistent process from the command line

Question

I run adb regularly and sometimes it stops working.

$ ps aux user1 4175 0.0 0.0 0 0 ? Zl Feb27 0:03 [adb] <defunct> 

This zombie process stops adb, and I cannot get adb to work again without restarting the computer.

I tried to send

 kill 4175 kill -9 4175 kill-17 4175 

but nothing "burns" the zombie process.

How can I get adb to work again without restarting my computer?

In addition, I use:

 Linux user1 2.6.32-38-generic #83-Ubuntu SMP Wed Jan 4 11:12:07 UTC 2012 x86_64 GNU/Linux 

Answer 1

The only kill command that uses the zombie process is the one that kills its parent, because after that it will respond to init , which will then continue to use it.

It is impossible if it is a kernel thread, though ...

Answer 2

I also see this often. This is because the thread is stuck in kernel mode when the program exits. You can see this with ps mx:

 # ps mx 17188 ? - 1:49 [adb] <defunct> - - Zl 0:01 - - - Dl 1:46 - 

A “D” state of the second thread indicates that the thread is in kernel mode and cannot be killed. You can learn more about this here:

http://ntucsie2007.wikidot.com/linux-defunct-zombie-processes

Unfortunately, I think adb will need to be changed in order to exit cleanly.