From owner-freebsd-hackers Sun Sep 30 1: 9:25 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from elvis.mu.org (elvis.mu.org [216.33.66.196]) by hub.freebsd.org (Postfix) with ESMTP id B9D6C37B40C for ; Sun, 30 Sep 2001 01:09:22 -0700 (PDT) Received: by elvis.mu.org (Postfix, from userid 1192) id 8214581D01; Sun, 30 Sep 2001 03:09:22 -0500 (CDT) Date: Sun, 30 Sep 2001 03:09:22 -0500 From: Alfred Perlstein To: Matt Dillon Cc: Vladimir Dozen , Wilko Bulte , hackers@FreeBSD.ORG Subject: Re: VM: dynamic swap remapping (patch) Message-ID: <20010930030922.F59854@elvis.mu.org> References: <20010929155941.A291@eix.do-labs.spb.ru> <20010929071024.Q59854@elvis.mu.org> <20010929141349.A80876@freebie.xs4all.nl> <200109291653.f8TGrRR37689@earth.backplane.com> <20010929232953.B341@eix.do-labs.spb.ru> <200109300752.f8U7qsj41649@earth.backplane.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <200109300752.f8U7qsj41649@earth.backplane.com>; from dillon@earth.backplane.com on Sun, Sep 30, 2001 at 12:52:54AM -0700 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Matt Dillon [010930 02:53] wrote: > > : Second, application not always grows to 1G, most of the time it keeps > : as small as 500M ;). Why should we precommit 1G for 500M data? Doing > : multi-mmap memory management is additional pain. > > Why not? Disk space is cheap. For a problem like this I would simply > throw in two 30G+ hard drives and partition them with 16G of swap each, > giving me 32G of swap for the machine. If you needed to do it cheaply > you could even use IDE, though personally I would use SCSI for > reliability. Depending on the amount of real memory in the machine > you might have to tweek a few kernel options (like matching NSWAP to > the actual number of swap devices), but basically it should just work. > > Even using file-backed memory is fairly trivial. You don't need to > do multi-mmap memory management or do any kernel tweaking. Just > reserve 1G and use a single mmap() and file per process. What he needs is a system to inform him that things aren't looking so good, check my email for what I think is a pretty good solution. -- -Alfred Perlstein [alfred@freebsd.org] 'Instead of asking why a piece of software is using "1970s technology," start asking why software is ignoring 30 years of accumulated wisdom.' To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message