From owner-freebsd-current@FreeBSD.ORG Tue Jan 25 15:26:00 2005 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 1120116A4CE; Tue, 25 Jan 2005 15:26:00 +0000 (GMT) Received: from critter.freebsd.dk (f170.freebsd.dk [212.242.86.170]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5AAF043D2F; Tue, 25 Jan 2005 15:25:59 +0000 (GMT) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.13.1/8.13.1) with ESMTP id j0PFPXqR086405; Tue, 25 Jan 2005 16:25:33 +0100 (CET) (envelope-from phk@critter.freebsd.dk) To: Robert Watson From: "Poul-Henning Kamp" In-Reply-To: Your message of "Tue, 25 Jan 2005 15:22:37 GMT." Date: Tue, 25 Jan 2005 16:25:33 +0100 Message-ID: <86404.1106666733@critter.freebsd.dk> Sender: phk@critter.freebsd.dk cc: pete@altadena.net cc: current@freebsd.org cc: "M. Warner Losh" Subject: Re: Devd event from GEOM? 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: Tue, 25 Jan 2005 15:26:00 -0000 In message , Robert Watson writes: >The interesting question becomes how you map between levels of >abstraction: many consumers of device event information don't really care >about the device and the route by which messages get to it from the CPU. >They care about the abstraction layered over the device, and the events >that occur in relating one object in an abstraction to another object, >perhaps involving topologies that have little to do with the physical >device topology. This raise the questions as to whether the newbus >topology is really the most useful place to expose information like GEOM >slicing, volume management of disk devices, and ethernet bonding for >devices that may be physically discovered using newbus. GEOM already has its own mechanism, and given the diversity of what geom classes can do, I don't think trying to shoehorn it into a newbus like view makes sense. >One appealing thing to the current devd protocol design is that different >abstraction layers (classes) can define their own event name spaces, and >each abstraction layer can declare the events it knows about. newbus >announces "I found a route to a physical device", GEOM shouts "And I found >some storage space on it", etc. Right. IMO we just need devfs to add "And here is a thing you can access". -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.