Subject: Re: Cardbus
To: Lennart Augustsson <lennart@augustsson.net>
From: Chris G. Demetriou <cgd@netbsd.org>
List: tech-kern
Date: 12/28/1999 16:01:58
Lennart Augustsson <lennart@augustsson.net> writes:
> itojun@iijlab.net wrote:
>
> > Traditionally UNIX assumes there will be no changes made to device
> > attach/detach during its runtime. Because of it UNIX do not really
> > have a good way to notify of changes to the userland programs, and
> > not many userland programs are designed to be adaptable to those
> > changes. I think that we may need to hide those dynamic changes to
> > network devices (interface removal, pcmcia slot power down and
> > other things) from the userland programs to "preserve" traditional,
> > not-too-many-changes-to-list-of-devices view from uesrland.
>
> I think we need to bite the bullet. Devices that come and go are here.
> We can try and hide it a little, but they are still here. I'd rather see some
> mechanism to notify userland about changes so we can cope with these
> things.
I agree.
The "things never change" may well have been good in the 70s and 80s,
but it's been a while since devices have been hot-pluggable in
commodity hardware (PCs) (even discounting hot-pluggable SCSI devices
which have been been kinda-supported for varying levels of 'kinda' for
years in various systems).
PCMCIA/CardBus, USB, ... it's only going to get worse. UNIX-like
systems are going to have to cope, unless they want to be relegated to
running only in static-configuration server-ish environments. (Can't
even really do workstations, thanks to USB's pluggability and users'
whims...)
cgd
--
Chris Demetriou - cgd@netbsd.org - http://www.netbsd.org/People/Pages/cgd.html
Disclaimer: Not speaking for NetBSD, just expressing my own opinion.