From: dws@cseg03.uark.edu (David W. Summers) Subject: Re: What causes these Zombie processes? Date: Sun, 10 Jan 1993 20:57:19 GMT
In comp.os.linux you write:
>After running for a few days, my Linux system ends up with quite a
>few 'Zombie' processes. I can't kill them off, even with kill -9 and
>the only way to get rid of them is with a reboot. This is a typical
>'ps -aux' screen after a few days.
>
>USER PID %CPU %MEM SIZE RSS TT STAT START TIME COMMAND
>root 1 0.0 3.3 32 136 ? S 23:39 0:00 init
>root 600 0.2 10.7 300 440 a1 S 10:06 0:07 -sh (sh)
>root 3 0.1 0.9 2 40 ? S 23:39 0:55 /etc/update
>root 376 0.0 2.8 48 116 a2 S 09:30 0:00 /etc/getty 9600 tty2
>root 322 0.0 0.0 48 0 a3 SW 08:45 0:00 (getty)
>root 323 0.0 0.0 48 0 a4 SW 08:45 0:00 (getty)
>root 22 0.0 2.9 80 120 ? S 23:39 0:00 /usr/etc/inet/portmap
>root 24 0.1 4.3 56 180 ? S 23:39 0:50 /usr/etc/inet/inetd
>lee 26 0.0 0.0 112 0 ? SW 23:39 0:29 (nfsd)
>root 28 0.0 3.4 80 140 ? S 23:39 0:00 /usr/etc/inet/mountd
>root 318 0.0 0.0 96 0 ? Z 08:21 0:00 <defunct>
>root 319 0.0 0.0 96 0 ? Z 08:44 0:00 <defunct>
>root 341 0.0 0.0 96 0 ? Z 08:58 0:00 <defunct>
>root 622 0.0 8.1 268 332 a1 S 10:10 0:01 sh /usr/bin/X11/startx
>root 463 0.0 0.0 96 0 ? Z 09:41 0:00 <defunct>
>
>Notice that the processes are all 96k in size. The process number still
>shows up in the /proc partition, but I don't know how to get any info
>from that. I'm open to suggestions and advice.
>
>I'm running mostly SLS 0.98p5 with a 0.99p2 kernel, netbin0.1, X11, and
>smtp smail. The system also mounts and serves up NFS partitions.
>
>Thanks
>
>--
>Seng-Poh Lee <splee@pd.org>
The problem is probably the 'inetd' daemon. I was having the same problem
and found out that everytime after I did a 'finger' of my Linux machine
that another <defunct> process would appear. I put debugging code in
the 'inetd.c' file and found out that the first time the SIGCHLD signal
was being sent the inetd program was catching it but none thereafter.
I put a 'signal( SIGCHLD, reapchild);' at the end of the reapchild
subroutine and that fixed it.
- David Summers
--
"Never under-estimate the bandwidth of a station-wagon
David Summers full of tapes, hurtling down the highway."
dws@engr.uark.edu - Tanenbaum, "Computer Networks"