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From: Duncan Sands <baldrick@wanadoo.fr>
To: Jeff Garzik <jgarzik@pobox.com>, "David S. Miller" <davem@redhat.com>
Subject: Re: SET_MODULE_OWNER
Date: Fri, 18 Jul 2003 09:31:39 +0200
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On Thursday 17 July 2003 22:22, Jeff Garzik wrote:
> David S. Miller wrote:
> > On Thu, 17 Jul 2003 12:00:58 -0400
> >
> > Jeff Garzik <jgarzik@pobox.com> wrote:
> >>David?  Does Rusty have a plan here or something?
> >
> > It just works how it works and that's it.
> >
> > Net devices are reference counted, anything more is superfluous.
> > They may be yanked out of the kernel whenever you want.
>
> (I'm obviously just realizing the implications of this... missed it
> completely during the earlier discussions)
>
> Object lifetime is just part of the story.
>
> This change is a major behavior change.  The whole point of removing a
> module is knowing its gone ;-)  And that is completely changed now.
> Modules are very often used by developers in a "modprobe ; test ; rmmod"
> cycle, and that's now impossible (you don't know when the net device,
> and thus your code, is really gone).  It's already breaking userland,
> which does sweeps for zero-refcount modules among other things.

Most USB drivers can be unloaded at any time, so this problem already
existed elsewhere.

Duncan.