Re: Nautilus Zombies

[hobbit aloss ukuu org uk]

On Mon, May 13, 2002 at 05:41:44PM +1200 or thereabouts, Rob Brown-Bayliss wrote:
 
> I have noticed thta nautilus is creating 100 zombie sh processes for
> each instance currently running.  When killed all the zombies also
> vanish.

Do you mean something like this in 'top', 'gtop' or 'procman'? 
(This is Mozilla, which does the same as Nautilus and Evolution:)

  PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME COMMAND
31375 hobbit    19   0 41212  40M 15136 R    50.1  8.1   5:39 mozilla-bin
31382 hobbit     9   0 41212  40M 15136 S     1.1  8.1   0:02 mozilla-bin
31383 hobbit	 9   0 41212  40M 15136 S     1.1  8.1   0:02 mozilla-bin
31385 hobbit	 9   0 41212  40M 15136 S     1.1  8.1   0:02 mozilla-bin
31388 hobbit	 9   0 41212  40M 15136 S     1.1  8.1   0:02 mozilla-bin

"zombie" means something very specific on UNIX when you're talking
about processes. Its one that was spawned by a parent, whose parent
has died, and which now can't be killed. It will show up as a "Z"
in the state column of top. Often it seems to say "<defunct>" in
the command column on my box. And even though it's doing nothing,
it sits there cluttering up the display of 'top' and other programs.

What I pasted (and edited a bit to look even more typical, because
Mozilla wouldn't actually spawn more!) is instead an example of how 
threads show up on top on Linux. Threads are light-weight processes. 
And they vary from UNIX to UNIX in their implementation. (They may also
vary in how they show up as a result, I suppose, but I don't know.)
I bet this is what you are seeing. Mozilla, Nautilus and Evolution are 
apps that use them which GNOME users see a lot, and this confusion comes 
up a lot.

You can spot these threads because they all have the same amount of
memory and shared memory and all but one will have almost identical
lines for CPU and time. The highest-up-the-screen one will have more
of those. And the rest will be sequentially-numbered or very close
to it. 

Thing is: they're all the same: they're all -sharing- that 40M (above)
and 15M of shared memory. There are not five separate instances of
40M totalling 200M being used here. It's one instance of 40M, being
shared by the lot. "top" is just not able to show that. When you close
the app, all the threads will go away.

When you have a zombie, however, it just won't die. Hence the name!

> I am useing the lates nautilus and mozilla from ximan and was wondering
> if this is normal or not...

If the above resembles what you are seeing, then you are seeing 
threads, and they're normal.

Telsa