*BSD News Article 16866


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Newsgroups: comp.os.386bsd.questions
Path: sserve!newshost.anu.edu.au!munnari.oz.au!uunet!mcsun!fuug!ajake
From: ajake@muncca.fi (Jarkko Aitti)
Subject: Re: Strange problem with pseudo-tty
Message-ID: <1993Jun7.002714.886@fuug.fi>
Sender: usenet@fuug.fi (USENET News System)
Nntp-Posting-Host: snafu.muncca.fi
Organization: MyBBS ry
References: <C87Jwq.2qG@veda.is>
Date: Mon, 7 Jun 1993 00:27:14 GMT
Lines: 51

In article <C87Jwq.2qG@veda.is> adam@veda.is (Adam David) writes:
>Has anyone seen this, or know why it happens?
>
>When a user hangs up abnormally from a session, active programs remain
>attached to their ptys and the next person to get that pty (next person
>to login or open a window) whether that person is the same one or someone
>else, ends up attached to both the hung process and the new session at
>the same time. This happens with any number of programs, but it might
>only affect sessions which use iScreen (I have only seen it there, but
>this is not necessarily the cause).
>
>Any such hung program uses lots of CPU. It is random whether the input
>and output streams are talking to the old process or the new process,
>so some pretty strange effects occur.
......
>--
>adam@veda.is

I've been wondering why i haven't heard about this before, while i'm having
same kind of promlems too!

Well, nothing gets messed up with next logins like that, but when users here
get disconnected for some reason their leftovers sometime start eating as
much cpu they can get! (until machine reboots or they get killed)
(it is actual cpu, i sometimes notice it while wondering why everything
slows down)

First i suspected screen too, but after removing it we noticed that it didn't
help too much. (well, did help some because with screen it is so easy to left
more prosesses hanging around;-)

So now i'm suspecting that prosesses which lose their ttyp? gets crazy
sometimes... (should i say pty's ?)

SOME INFO:
All users are connected thru ethernet connection.
(using terminal server here)

This is happening with 386bsd+patchkit and netbsd.
(both a month old "patch levels")

Hardware: two different brand of 486 machines with also different ESDI
controllers on both, (don't remember brand of ethercards;-), etc...

So i'm very interested if someone got any solution to this so that i don't
have to sit and watch every prosess 24h a day:)

Ps. i'm kinda unix newbie so forgive possible errors in this article, or if
this blows up your machine, it's my first post with this 'home compiled' trn;-)

ajake@snafu.muncca.fi