From owner-freebsd-hackers@FreeBSD.ORG Mon Nov 14 20:39:23 2005 Return-Path: X-Original-To: freebsd-hackers@freebsd.org 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 320DB16A41F for ; Mon, 14 Nov 2005 20:39:23 +0000 (GMT) (envelope-from John.Giacomoni@colorado.edu) Received: from serl.cs.colorado.edu (serl.cs.colorado.edu [128.138.207.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id BDA0743D49 for ; Mon, 14 Nov 2005 20:39:22 +0000 (GMT) (envelope-from John.Giacomoni@colorado.edu) Received: from [IPv6???1] (localhost [127.0.0.1]) by serl.cs.colorado.edu (Postfix) with ESMTP id 922907B0B22 for ; Mon, 14 Nov 2005 13:40:12 -0700 (MST) Mime-Version: 1.0 (Apple Message framework v746.2) Content-Transfer-Encoding: 7bit Message-Id: Content-Type: text/plain; charset=US-ASCII; format=flowed To: freebsd-hackers@freebsd.org From: John Giacomoni Date: Mon, 14 Nov 2005 13:39:19 -0700 X-Mailer: Apple Mail (2.746.2) Subject: Sharing the same VM address space between Kernel and UserSpace X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Nov 2005 20:39:23 -0000 I am in need of a way to share memory between kernel space and possibly multiple different user-space processes for an extended period of time. This memory would need to be a single unpageable region. I am using the vm routines as cribbed from mmap, however I'd like the address spaces to be viewed as the same regardless of which process I'm in to avoid swizzling pointers as I'm storing data structures in the shared memory region. I imagine I'd need to find a way to expose part of the kernel address space to user space to accomplish this. Is there a way to do this? thanks John G -- John.Giacomoni@colorado.edu University of Colorado at Boulder Department of Computer Science Engineering Center, ECCR 1B05 430 UCB Boulder, CO 80303-0430 USA