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From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: net.rumor
Subject: Re: Re: Computer Horror Stories
Message-ID: <823@kitty.UUCP>
Date: Thu, 20-Feb-86 08:58:13 EST
Article-I.D.: kitty.823
Posted: Thu Feb 20 08:58:13 1986
Date-Received: Mon, 24-Feb-86 05:03:41 EST
References: <14700001@hplabsb.UUCP> <476@mmm.UUCP> <672@amiga.amiga.UUCP> <404@ccivax.UUCP> <389@watdragon.UUCP> <1036@burl.UUCP>
Organization: Recognition Research Corp., Clarence, NY
Lines: 26

> There is a great way to bring any Unix system (that I know of, anyway) to
> its knees for quite some time (last time I did it it was almost 10 minutes)
> with a simple 4-5 line C program.  This works regardless of system load;
> the machine goes completely catatonic (except for separate processors
> that don't need the main machine for a while, like tty driver boards).
> 
> If you kick off a shell that infinitely forks these babies, the only way
> to kill the system in less than about 3 days is to drop it on the floor.

	It works.  It happened to me once when one of my first application
programs screwed up, resulting in the failure of forked processes to be
killed.  The application program was running okay, but the system kept getting
slower and slowerrrr (the only thing wrong was the failure to kill completed
processes).  Finally I did a ps, and was horrified to discover the nature of
the problem.  The processes were forking faster than I could kill 'em, the
process table overflowed, and I couldn't even do a ps anymore.  Since the
parent process was owned by root and spawned by crontab, logging out would
not solve the problem.  Going to single user mode would not work because the
process table had overflowed.  Powerdown time...

==>  Larry Lippman @ Recognition Research Corp., Clarence, New York        <==
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