From owner-freebsd-stable@FreeBSD.ORG Thu Apr 14 03:18:48 2005 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 60FA216A4CF for ; Thu, 14 Apr 2005 03:18:48 +0000 (GMT) Received: from flake.decibel.org (flake.decibel.org [67.100.216.10]) by mx1.FreeBSD.org (Postfix) with ESMTP id D583F43D31 for ; Thu, 14 Apr 2005 03:18:47 +0000 (GMT) (envelope-from decibel@decibel.org) Received: by flake.decibel.org (Postfix, from userid 1001) id 31BC315447; Wed, 13 Apr 2005 22:18:46 -0500 (CDT) Date: Wed, 13 Apr 2005 22:18:45 -0500 From: "Jim C. Nasby" To: Matthias Buelow Message-ID: <20050414031845.GF58835@decibel.org> Mail-Followup-To: "Jim C. Nasby" , Matthias Buelow , Nick Barnes , Marc Olzheim , Vivek Khera , Dan Nelson , freebsd-stable@freebsd.org References: <52802.1113341617@thrush.ravenbrook.com> <200504122207.j3CM7BE7018595@drjekyll.mkbuelow.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200504122207.j3CM7BE7018595@drjekyll.mkbuelow.net> X-Operating-System: FreeBSD 4.11-RELEASE i386 X-Distributed: Join the Effort! http://www.distributed.net User-Agent: Mutt/1.5.8i cc: Marc Olzheim cc: Dan Nelson cc: freebsd-stable@freebsd.org cc: Vivek Khera Subject: Re: kernel killing processes when out of swap X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 Apr 2005 03:18:48 -0000 On Wed, Apr 13, 2005 at 12:07:11AM +0200, Matthias Buelow wrote: > Nick Barnes writes: > > >> This stuff has been discussed in the past. > >Indeed. For a couple of examples from the days before BSD systems got > >overcommit, see these threads from 1990 and 1991: > > > > >b658465/4c590978f1001507?q=overcommit&rnum=14#4c590978f1001507> > > > > >6d30eb1/e8c30f78c44a3f62?q=overcommit&rnum=12#e8c30f78c44a3f62> > > Apparently, it can be turned off on AIX, quoting from > http://tinyurl.com/4epc8: > > ``If the PSALLOC environment variable is set to early, then every > program started in that environment from that point on, but not > including currently running processes, runs in the early allocation > environment. In the early allocation environment, interfaces such as the > malloc subroutine and the brk subroutine will fail if sufficient paging > space cannot be reserved when the request is made. > Processes run in the early allocation environment mode are not sent the > SIGKILL signal if a low paging space condition occur.'' > > Googling showed that on Linux 2.6, overcommit can be disabled globally > through the vm.overcommit_memory sysctl. > > I hope that some day some mechanism to solve that problem will be > available in FreeBSD aswell. It's extremely disappointing that you can't turn this off. I've been bashing linux for months now about how they think it's OK to kill random processes. But at least they'll let you turn it off. -- Jim C. Nasby, Database Consultant decibel@decibel.org Give your computer some brain candy! www.distributed.net Team #1828 Windows: "Where do you want to go today?" Linux: "Where do you want to go tomorrow?" FreeBSD: "Are you guys coming, or what?"