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Hi,
I have a client running AIX 5.1 and have found a couple of defunct processes
chewing up CPU usage.
We have tried killing these processes which comes back stating "Then
specified process does not exist" we have tried rebooting the machine but
the processes are still there. Can you tell me how to get rid of these or if
they are part of the unix kernal....
This is a quick screen shot of ps vg | head -10
516 - A 16329:01 0 12 19828 xx 0 19816 24.3 0.0
wait
774 - A 15528:23 0 12 19828 xx 0 19816 23.1 0.0
wait
1032 - A 15743:58 0 12 19828 xx 0 19816 23.5 0.0
wait
1290 - A 16005:45 0 12 19828 xx 0 19816 23.9 0.0
wait
# ps -ef | grep 1032
root 124662 169142 0 09:38:05 pts/106 0:00 grep 1032
# kill -1 1032
kill: 1032: 0403-003 The specified process does not exist.


Any suggestion would be much appreciated.


Cheers

Pedds : )

When a child process dies the parent process gets notified with a signal
(SIGCHLD). The child process stays as DEFUNCT (also called zombie) in the
process list until the parent process deals with signal (by calling wait() or
waitpid()). If you are not interested in your dying childs set the signal
handler for SIGCHLD to IGNORE. BTW, this is UNIX not AIX.

DEFUNCTs which stay in the process list are a programing error. Identify the
parent process with ps -ef and send the programer the man pages for wait() and
waitpid() :-)

Johannes


connect wrote:
> Hi,
> I have a client running AIX 5.1 and have found a couple of defunct processes
> chewing up CPU usage.
> We have tried killing these processes which comes back stating "Then
> specified process does not exist" we have tried rebooting the machine but
> the processes are still there. Can you tell me how to get rid of these or if
> they are part of the unix kernal....
> This is a quick screen shot of ps vg | head -10
> 516 - A 16329:01 0 12 19828 xx 0 19816 24.3 0.0
> wait
> 774 - A 15528:23 0 12 19828 xx 0 19816 23.1 0.0
> wait
> 1032 - A 15743:58 0 12 19828 xx 0 19816 23.5 0.0
> wait
> 1290 - A 16005:45 0 12 19828 xx 0 19816 23.9 0.0
> wait
> # ps -ef | grep 1032
> root 124662 169142 0 09:38:05 pts/106 0:00 grep 1032
> # kill -1 1032
> kill: 1032: 0403-003 The specified process does not exist.
>
>
> Any suggestion would be much appreciated.
>
>
> Cheers
>
> Pedds : )
>
>

> connect wrote:
> > Hi,
> > I have a client running AIX 5.1 and have found a couple of defunct
processes
> > chewing up CPU usage.
> > We have tried killing these processes which comes back stating "Then
> > specified process does not exist" we have tried rebooting the machine
but
> > the processes are still there. Can you tell me how to get rid of these
or if
> > they are part of the unix kernal....
> > This is a quick screen shot of ps vg | head -10
> > 516 - A 16329:01 0 12 19828 xx 0 19816 24.3
0.0
> > wait
> > 774 - A 15528:23 0 12 19828 xx 0 19816 23.1
0.0
> > wait
> > 1032 - A 15743:58 0 12 19828 xx 0 19816 23.5
0.0
> > wait
> > 1290 - A 16005:45 0 12 19828 xx 0 19816 23.9
0.0
> > wait
> > # ps -ef | grep 1032
> > root 124662 169142 0 09:38:05 pts/106 0:00 grep 1032
> > # kill -1 1032
> > kill: 1032: 0403-003 The specified process does not exist.
> >
> >
> > Any suggestion would be much appreciated.
> >
> >
> > Cheers
> >
> > Pedds : )
> >
"Johannes" <johannes.gross@gmx.net> schrieb im Newsbeitrag
news:cgh96v$vvd$03$1@news.t-online.com...
> When a child process dies the parent process gets notified with a signal
> (SIGCHLD). The child process stays as DEFUNCT (also called zombie) in the
> process list until the parent process deals with signal (by calling wait()
or
> waitpid()). If you are not interested in your dying childs set the signal
> handler for SIGCHLD to IGNORE. BTW, this is UNIX not AIX.
>
> DEFUNCTs which stay in the process list are a programing error. Identify
the
> parent process with ps -ef and send the programer the man pages for wait()
and
> waitpid() :-)
>
> Johannes
>
>
Hallo folks,

Pedds, from your screen output I would think that you have a 4-processor
server that is running a wait process for every cpu. Whenever the cpu is
idle the wait process kicks in an will appear to use the cpu. However these
wait processes run at the lowest priority possible and will NOT affect any
other program/application. Hence no need to kill them ;-)

Johannes, full marks for the effort but I doubt that the wait processes can
be explained the way you did. Btw. most zombies I have seen so far relate to
shell scripts that spawn off other processes without handling them properly
(i.e. not closing them again / waiting for them to close). And AIX 5L
improved to a great extend when it comes to zombies. While with 4.3 zombies
almost never disappeard without a reboot 5L will almost always manage to get
rid of those zombies within a reasonable time.

Regards,
Andreas

On 2004-08-24, connect <pamato@ultradata.com.au> wrote:

> I have a client running AIX 5.1 and have found a couple of defunct processes
> chewing up CPU usage.

Those are not defunct processes. Defunct processes by definition cannot eat
processor time, they only occupy an entry in the process table. Defunct
processes appear as "<defunct>" in the ps listing. They are also known as
"zombies".

> the processes are still there. Can you tell me how to get rid of these or if
> they are part of the unix kernal....

You can't kill these. You don't want to kill these, either. :-) Each processor
has a "wait" process that runs when there is nothing else to run. It is the
"idle process", so to speak.

--
Jurjen Oskam
"I often reflect that if "privileges" had been called "responsibilities" or
"duties", I would have saved thousands of hours explaining to people why
they were only gonna get them over my dead body." - Lee K. Gleason, VMS sysadmin

On 2004-08-25, Andreas Schulze <b79xan@gmx.de> wrote:

> Btw. most zombies I have seen so far relate to
> shell scripts that spawn off other processes without handling them properly
> (i.e. not closing them again / waiting for them to close). And AIX 5L
> improved to a great extend when it comes to zombies. While with 4.3 zombies
> almost never disappeard without a reboot 5L will almost always manage to get
> rid of those zombies within a reasonable time.

If you have a long-running process that doesn't properly wait for its
children, the zombies will exist for as long as the parent process exists.
When the parent process exits, the remaining zombies get re-parented to the
parent process of the process that just exited. If that process is long-running
and doesn't reap the zombies, the zombies will remain. Only when the zombies
ultimately get reparented to init will they eventually be reaped (and thus
disappear). The improvement in AIX5L lies in the fact that init reaps any
zombies that get reparented to it.

--
Jurjen Oskam
"I often reflect that if "privileges" had been called "responsibilities" or
"duties", I would have saved thousands of hours explaining to people why
they were only gonna get them over my dead body." - Lee K. Gleason, VMS sysadmin

Andreas,

you are right. I was misled because Pedd was talking of "defunct" processes. As
Jurjen pointed out they are just the idle processes, one for each cpu.

Johannes


Andreas Schulze wrote:
>>connect wrote:
>>
>>>Hi,
>>>I have a client running AIX 5.1 and have found a couple of defunct
>
> processes
>
>>>chewing up CPU usage.
>>>We have tried killing these processes which comes back stating "Then
>>>specified process does not exist" we have tried rebooting the machine
>
> but
>
>>>the processes are still there. Can you tell me how to get rid of these
>
> or if
>
>>>they are part of the unix kernal....
>>>This is a quick screen shot of ps vg | head -10
>>> 516 - A 16329:01 0 12 19828 xx 0 19816 24.3
>
> 0.0
>
>>>wait
>>> 774 - A 15528:23 0 12 19828 xx 0 19816 23.1
>
> 0.0
>
>>>wait
>>> 1032 - A 15743:58 0 12 19828 xx 0 19816 23.5
>
> 0.0
>
>>>wait
>>> 1290 - A 16005:45 0 12 19828 xx 0 19816 23.9
>
> 0.0
>
>>>wait
>>># ps -ef | grep 1032
>>> root 124662 169142 0 09:38:05 pts/106 0:00 grep 1032
>>># kill -1 1032
>>>kill: 1032: 0403-003 The specified process does not exist.
>>>
>>>
>>>Any suggestion would be much appreciated.
>>>
>>>
>>>Cheers
>>>
>>>Pedds : )
>>>
>
> "Johannes" <johannes.gross@gmx.net> schrieb im Newsbeitrag
> news:cgh96v$vvd$03$1@news.t-online.com...
>
>>When a child process dies the parent process gets notified with a signal
>>(SIGCHLD). The child process stays as DEFUNCT (also called zombie) in the
>>process list until the parent process deals with signal (by calling wait()
>
> or
>
>>waitpid()). If you are not interested in your dying childs set the signal
>>handler for SIGCHLD to IGNORE. BTW, this is UNIX not AIX.
>>
>>DEFUNCTs which stay in the process list are a programing error. Identify
>
> the
>
>>parent process with ps -ef and send the programer the man pages for wait()
>
> and
>
>>waitpid() :-)
>>
>>Johannes
>>
>>
>
> Hallo folks,
>
> Pedds, from your screen output I would think that you have a 4-processor
> server that is running a wait process for every cpu. Whenever the cpu is
> idle the wait process kicks in an will appear to use the cpu. However these
> wait processes run at the lowest priority possible and will NOT affect any
> other program/application. Hence no need to kill them ;-)
>
> Johannes, full marks for the effort but I doubt that the wait processes can
> be explained the way you did. Btw. most zombies I have seen so far relate to
> shell scripts that spawn off other processes without handling them properly
> (i.e. not closing them again / waiting for them to close). And AIX 5L
> improved to a great extend when it comes to zombies. While with 4.3 zombies
> almost never disappeard without a reboot 5L will almost always manage to get
> rid of those zombies within a reasonable time.
>
> Regards,
> Andreas
>
>

Thanking you all so very much in helping me out with these idle
processes...have a great weekend!

Cheers

Pedds : )
"Jurjen Oskam" <joskam@quadpro.stupendous.org> wrote in message
news:slrnciokt9.340.joskam@calvin.stupendous.org.. .
> On 2004-08-24, connect <pamato@ultradata.com.au> wrote:
>
> > I have a client running AIX 5.1 and have found a couple of defunct
processes
> > chewing up CPU usage.
>
> Those are not defunct processes. Defunct processes by definition cannot
eat
> processor time, they only occupy an entry in the process table. Defunct
> processes appear as "<defunct>" in the ps listing. They are also known as
> "zombies".
>
> > the processes are still there. Can you tell me how to get rid of these
or if
> > they are part of the unix kernal....
>
> You can't kill these. You don't want to kill these, either. :-) Each
processor
> has a "wait" process that runs when there is nothing else to run. It is
the
> "idle process", so to speak.
>
> --
> Jurjen Oskam
> "I often reflect that if "privileges" had been called "responsibilities"
or
> "duties", I would have saved thousands of hours explaining to people why
> they were only gonna get them over my dead body." - Lee K. Gleason, VMS
sysadmin