From owner-freebsd-hackers@FreeBSD.ORG Sun Oct 26 10:06:59 2003 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DAA9716A4B3 for ; Sun, 26 Oct 2003 10:06:59 -0800 (PST) Received: from mail.speakeasy.net (mail10.speakeasy.net [216.254.0.210]) by mx1.FreeBSD.org (Postfix) with ESMTP id E78DA43F93 for ; Sun, 26 Oct 2003 10:06:58 -0800 (PST) (envelope-from jmg@hydrogen.funkthat.com) Received: (qmail 14816 invoked from network); 26 Oct 2003 18:06:58 -0000 Received: from unknown (HELO hydrogen.funkthat.com) ([69.17.45.168]) (envelope-sender ) by mail10.speakeasy.net (qmail-ldap-1.03) with SMTP for ; 26 Oct 2003 18:06:58 -0000 Received: from hydrogen.funkthat.com (yvwfgj@localhost.funkthat.com [127.0.0.1])h9QI6mgP066726; Sun, 26 Oct 2003 10:06:48 -0800 (PST) (envelope-from jmg@hydrogen.funkthat.com) Received: (from jmg@localhost) by hydrogen.funkthat.com (8.12.10/8.12.10/Submit) id h9QI6lnL066725; Sun, 26 Oct 2003 10:06:47 -0800 (PST) Date: Sun, 26 Oct 2003 10:06:47 -0800 From: John-Mark Gurney To: Sean Hamilton Message-ID: <20031026180647.GD558@funkthat.com> Mail-Followup-To: Sean Hamilton , freebsd-hackers@freebsd.org References: <005b01c398ed$87070080$0300000a@antalus> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <005b01c398ed$87070080$0300000a@antalus> User-Agent: Mutt/1.4.1i X-Operating-System: FreeBSD 4.2-RELEASE i386 X-PGP-Fingerprint: B7 EC EF F8 AE ED A7 31 96 7A 22 B3 D8 56 36 F4 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ X-Resume: http://resnet.uoregon.edu/~gurney_j/resume.html cc: freebsd-hackers@freebsd.org Subject: Re: Passthrough block device X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: John-Mark Gurney List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 26 Oct 2003 18:07:00 -0000 Sean Hamilton wrote this message on Wed, Oct 22, 2003 at 15:40 -0700: > Does FreeBSD support a device that will allow for the passing of all reads > and writes on it to a userland application? I wish to handle swapping > myself, preferably without any kernel hacking. Take a look at geom_gate from Pawel Dawidek. You could probably very easily modify the client side to do your own code, instead of passing it over the network to the server. http://garage.freebsd.pl/geom_gate.README > What would happen if the kernel decided to swap out such a process? Probably a deadlock... you could partially avoid this by using mlock to prevent your process from swapping. It may still be possible to dead lock due to the stack of the process being able to be swapped out.. some one better versed in the process/VM interaction should answer that. -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."