Re: process mystery

["James K. Lowden" <jklowden%schemamania.org@localhost>]

On Sat, 26 Mar 2016 13:57:28 +0700
Robert Elz <kre%munnari.OZ.AU@localhost> wrote:

>     Date:        Fri, 25 Mar 2016 21:47:55 -0400
>     From:        "James K. Lowden" <jklowden%schemamania.org@localhost>
>     Message-ID:
> <20160325214755.046f613b2866378396d60076%schemamania.org@localhost>
> 
>   | I guess my only option is to send SIGKILL to the processes in DE
>   | state,
> 
> That won't work, uninterruptible means what it says - the process is
> stuck in the kernel somewhere, you need to look and see what its
> wchan is (ps -l wiil show you)

Thank you for your analysis.  It took awhile to get back to this, but
the situation hasn't changed.  

$ ps -l -p 3419
 UID  PID PPID CPU PRI NI VSZ RSS WCHAN STAT TTY       TIME COMMAND
1000 3419    1   0   0  0   0   0 -     DE   ttyp9- 0:00.00
(utmp_update)

I don't know what wchan is, apart from what the ps manpage says.  Looks
like it's waiting on event "-", which would seem to support your
"stuck" theory.  

> If you need to know what lock, you need to use gdb on the kernel and
> get a backtrace of the stuck process.

I don't need to know the kernel status unless someone here is curious.
I'm mostly interested in understanding my options short of rebooting.  

>   | Does the utmp_update cascade suggest anything?  
> 
> A process with a fork() bug probably.  

OK, nothing I did then.  :-/

> Do you know what the original parent of the utmp_updates was ?

No.  I was fooling around with various forms of "xterm -e", and I
suspect xterm hosted the original ppid, but I'm not sure.  

Regards, 

--jkl