How do I kill this?

[Dave Platt]

In article <2150 at brchh104.bnr.ca> mferrare at physics.adelaide.edu.au (Mark Ferraretto) writes:

>How do I kill this process?
>
>root      6585  0.0  0.0   48    0 je S    15:47   0:00 <exiting>
>
>I've already tried
>kill -[1-9] 6585
>especially kill -9 6585
>
>The process used to be a getty.
>I'm running SunOS4.0.3 on a Sun 4/280.
>Terminal is connected to ALMII Board

Welcome to the "Dead gettys society", Mark.  I've seen hung getty
processes of this sort on 4.0.3 and 4.1.1, on both an ALM-II and on CPU
serial ports, on a 4/280, 3/60, a Sparc-1.  Quite a few other people have
seen this problem as well.  I never saw it on SunOS 3.5, and so I suspect
that the problem was introduced with SunOS 4.0.

The dead gettys seem to crop up when an outbound phone call (e.g.  uucico)
closes the secondary aspect of a dual-direction serial port (e.g. the call
was made on /dev/cua, and there was a getty camped on /dev/ttya).  Most of
the people who have mentioned this problem seem to be running Telebit
modems in PEP mode.  I don't know whether the problem is related to the
Telebits, or whether the Telebits are simply the most popular modem in use
on bidirectional ports.

My suspicion is as follows: when uucico terminates, it closes the
secondary port descriptor.  This causes DTR to be deasserted for a second
or so.  The Telebit modems take a second or so to deassert the CD (carrier
detect) line after they see DTR go away... and in some cases, DTR comes
back up before CD is deasserted..  I believe that the hung getty may
appear if the getty process is allowed to open the port after DTR comes
back up and before the modem drops CD.  This allows the getty to start
configuring the port... and if CD then drops before the configuration is
completed, one of getty's ioctl() calls hangs up somehow.

I've installed the latest Sun serial-port patch (100225-02), which was
apparently supposed to fix some hung-serial-port problems.  It does not
appear to have eliminated the hung-getty problem... I had one occur
yesterday.

Oh... per your original question... when a really-hung getty process shows
up, the only way I know of to kill the process and get the port back into
use is to reboot the machine.  The only way I know of to entirely avoid
the problem is to use your modems for dialin or dialout, but not both.

Dave Platt                                                VOICE: (415) 813-8917
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