From owner-freebsd-hackers  Thu Dec 18 14:42:29 1997
Return-Path: <owner-freebsd-hackers>
Received: (from root@localhost)
          by hub.freebsd.org (8.8.7/8.8.7) id OAA29237
          for hackers-outgoing; Thu, 18 Dec 1997 14:42:29 -0800 (PST)
          (envelope-from owner-freebsd-hackers)
Received: from word.smith.net.au (ppp3.portal.net.au [202.12.71.103])
          by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id OAA28618
          for <freebsd-hackers@FreeBSD.ORG>; Thu, 18 Dec 1997 14:35:44 -0800 (PST)
          (envelope-from mike@word.smith.net.au)
Received: from word (localhost [127.0.0.1])
	by word.smith.net.au (8.8.8/8.8.5) with ESMTP id JAA01661;
	Fri, 19 Dec 1997 09:00:03 +1030 (CST)
Message-Id: <199712182230.JAA01661@word.smith.net.au>
X-Mailer: exmh version 2.0zeta 7/24/97
To: John-Mark Gurney <gurney_j@resnet.uoregon.edu>
cc: Darren Reed <avalon@coombs.anu.edu.au>, freebsd-hackers@FreeBSD.ORG
Subject: Re: converting drivers to dynamic memory... 
In-reply-to: Your message of "Thu, 18 Dec 1997 06:51:07 -0800."
             <19971218065107.10999@hydrogen.nike.efn.org> 
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Fri, 19 Dec 1997 09:00:02 +1030
From: Mike Smith <mike@smith.net.au>
Sender: owner-freebsd-hackers@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

> 
> yep, I think that would be a great addition...  IMO, once devfs has
> finally been completed, we will still need a minor number of the void *
> (I happen to like the name dev_info_t), the minor so that we know what
> part of the device driver we are accessing...  else we would need to
> allocate a bunch of small structs like:
> struct {
> 	int option;
> 	struct devicedata data;
> }
> 
> which would be really wasteful of precious memory resources...

No.  I take your point about wanting to have multiple DEVFS entries 
referencing a single softc structure though; you might want to have 
something like:

struct devfs_softc_reference
{
	void	*softc;
	int	token;
}

inside the devfs_node structure.

Forget the btree model; it's not going to fly in the face of a direct 
reference approach. 

mike