From owner-freebsd-stable@FreeBSD.ORG Thu Jul 24 16:48:01 2003 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 36A9C37B401 for ; Thu, 24 Jul 2003 16:48:01 -0700 (PDT) Received: from gw.catspoiler.org (217-ip-163.nccn.net [209.79.217.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9770743FAF for ; Thu, 24 Jul 2003 16:48:00 -0700 (PDT) (envelope-from truckman@FreeBSD.org) Received: from FreeBSD.org (mousie.catspoiler.org [192.168.101.2]) by gw.catspoiler.org (8.12.9/8.12.9) with ESMTP id h6ONlqM7055640; Thu, 24 Jul 2003 16:47:56 -0700 (PDT) (envelope-from truckman@FreeBSD.org) Message-Id: <200307242347.h6ONlqM7055640@gw.catspoiler.org> Date: Thu, 24 Jul 2003 16:47:52 -0700 (PDT) From: Don Lewis To: b.j.casavant@ieee.org In-Reply-To: MIME-Version: 1.0 Content-Type: TEXT/plain; charset=us-ascii cc: freebsd-stable@FreeBSD.org Subject: Re: malloc does not return null when out of memory 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, 24 Jul 2003 23:48:01 -0000 On 24 Jul, Brent Casavant wrote: > [hopefully I didn't mess up the attribution, replying to a digest sucks] > > On Thu, 24 Jul 2003, Jamie Bowden wrote: > >> On Wed, 23 Jul 2003, Don Lewis wrote: >> >> > On 23 Jul, Brooks Davis wrote: >> >> > > No there isn't. Overcommit is a fundamental design feature of the BSD >> > > VM. If you don't like it, find an OS that doesn't do it. The only one >> > > I can think of off the top of my head in Irix where I've found it to be >> > > a serious pain in the ass. >> >> Irix allows for use of what it calls 'vswap' as well, which is just a file >> that lives on a normal filesystem that the system can fall back on when >> actual RAM and swap are exhausted. It allows for extremely large commits >> on memory limited systems while guaranteeing that it has somewhere to page >> out to if necessary. The poster above may not like Irix, but I do. >> There's a lot of good stuff in there, but SGI aren't the best at telling >> people it exists and how to use it. > > Almost. Having actually worked on the IRIX VM system, and on vswap > issues in particular... > > Don is correct in that IRIX doesn't overcommit. But that is only > the default swap configuration. I didn't say this, Jamie did.