From owner-freebsd-current@FreeBSD.ORG Sun Jul 6 17:48:13 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5960B37B401 for ; Sun, 6 Jul 2003 17:48:13 -0700 (PDT) Received: from mail.gmx.net (pop.gmx.net [213.165.64.20]) by mx1.FreeBSD.org (Postfix) with SMTP id F262243FDD for ; Sun, 6 Jul 2003 17:48:11 -0700 (PDT) (envelope-from mdcki@gmx.net) Received: (qmail 4039 invoked by uid 65534); 7 Jul 2003 00:48:10 -0000 Received: from cvpn012.gwdg.de (EHLO gmx.net) (134.76.22.12) by mail.gmx.net (mp001) with SMTP; 07 Jul 2003 02:48:10 +0200 Message-ID: <3F08C369.8080207@gmx.net> Date: Mon, 07 Jul 2003 02:48:41 +0200 From: Marcin Dalecki User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.4) Gecko/20030701 X-Accept-Language: en-us, en, pl, ru MIME-Version: 1.0 To: dickey@herndon4.his.com References: <3F08B199.3050409@comcast.net> <3F08B79B.2040805@gmx.net> <20030707001443.GA1530@invisible-island.net> In-Reply-To: <20030707001443.GA1530@invisible-island.net> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit cc: "Myron J. Mayfield" cc: current@freebsd.org Subject: Re: /dev/shm X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Jul 2003 00:48:13 -0000 Thomas Dickey wrote: > On Mon, Jul 07, 2003 at 01:58:19AM +0200, Marcin Dalecki wrote: > >>Myron J. Mayfield wrote: >> >>>I attempted to install the linux java sapgui on FreeBSD 5.0, but the jar >>>file only unpacked part of it. I then copied the files from my Redhat 9 >>>machine. I linked up all the linux libraries needed and attempted to >>>start it. It gives me an error saying cant find /dev/shm. I tried >>>adding this to /dev but was unable to. Does anyone have any >>>information? Thank you. I am somewhat new to FreeBSD but have used >>>linux for Many years. >> >>For some unexcused reason there is the trend in Linux to represent >>everything as kind of a wired half finished pseudo file system. /proc pipe >>devicefs sysctl and so on... The list is really long. Even shared memmory is >>mapped to ehrm.... a filesystem. This is "expected" to be mounted at >>/dev/shm by the system. You can't expect FreeBSD to follow this path... > > > Linux isn't the only system that does this (learn a little, criticize less). There is a great span between everything and some things where it makes sense. Just please compare the devfs *implementations* between FreeBSD and Linux to see the difference. Some examples: /etc/rc.d/init.d# cat /proc/meminfo total: used: free: shared: buffers: cached: Mem: 526184448 515764224 10420224 0 43528192 353251328 Swap: 536862720 0 536862720 MemTotal: 513852 kB MemFree: 10176 kB MemShared: 0 kB Buffers: 42508 kB Cached: 344972 kB SwapCached: 0 kB Active: 332328 kB ActiveAnon: 79088 kB ActiveCache: 253240 kB Inact_dirty: 8932 kB Inact_laundry: 0 kB Inact_clean: 125308 kB Inact_target: 93312 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 513852 kB LowFree: 10176 kB SwapTotal: 524280 kB SwapFree: 524280 kB /etc/rc.d/init.d# Wonderfull well tought out conscise and dense design isn't it? Or maybe: /etc/rc.d/init.d# cat /proc/filesystems nodev rootfs nodev bdev nodev proc nodev sockfs nodev tmpfs nodev shm nodev pipefs ext2 nodev ramfs iso9660 nodev devpts ext3 nodev usbdevfs nodev usbfs nodev binfmt_misc /etc/rc.d/init.d# And this is 2.4 kernel not the "upcomming" 2.6 Oh and I know well about the motivation behing /dev/shm - the excuse is called "POSIX shm semantics". Which are broken in first place and never got over the "standard" draft state.