Re: Disconnection
Re: Disconnection
- Subject: Re: Disconnection
- From: Justin Walker <email@hidden>
- Date: Sun, 23 Nov 2003 16:14:48 -0800
On Sunday, November 23, 2003, at 03:51 PM, Constantinos Antoniou wrote:
Well, there are the so called zombie processes (I think they are
called stuck (?) under OSX) that indeed cannot be killed. A reboot is
the only way to get rid of them.
No. Zombie processes are not unkillable. These processes consume no
resources[*], and do not interfere with things like shutdown. They are
artifacts of the parent/child structure of processes.
A zombie process is one which has called exit, and for which all
termination operations are complete. The only reason it hangs around
is that its parent has not yet "reaped" it. This state is necessary so
that a parent process can verify the exit status of its children, and
optionally retrieve some resource usage information for the process.
See 'man 2 wait' for some details.
A 'stuck' process is neither a zombie nor an uninterruptible process.
It's a runnable-but-not-running process that has a sufficiently low
priority that it hasn't gotten a chance, recently, to run (it is
necessary for a process to run at least in kernel mode, to update its
own priority). 'top' shows the number of such processes, but not which
ones are stuck. If you are really interested, this is handled in the
kernel in file osfmk/kern/sched_prim.c.
Regards,
Justin
[*] A zombie process has a process table entry, but that is the only
system resource allocated to it.
--
/~\ The ASCII Justin C. Walker, Curmudgeon-at-Large
\ / Ribbon Campaign
X Help cure HTML Email
/ \
_______________________________________________
x11-users mailing list | email@hidden
Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/x11-users
X11 for Mac OS X FAQ: http://developer.apple.com/qa/qa2001/qa1232.html
Report issues, request features, feedback: http://developer.apple.com/bugreporter
Do not post admin requests to the list. They will be ignored.