Re: [PATCH net-next-2.6] net: dummy: add auto_up module parameter

[David Miller <davem@davemloft.net>]

From: Octavian Purdila <opurdila@ixiacom.com>
Date: Tue, 30 Nov 2010 17:57:27 +0200

> Add auto_up module parameter to automatically bring up the created
> devices. This is useful when using the dummy driver for testing net
> device register / unregister performance.
> 
> Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>

Registering a new netdevice with IFF_UP set is an error.  You can't
set IFF_UP without also doing all of the other work, callbacks, and
state changes which are made by dev_open()'s code paths.

If, as you say, your interests are in testing register/unregister
performance, you can do that by making the appropriate calls in a loop
from userspace.

I honestly don't see what you hope to gain with this change, and
anyways since the registration state is basically illegal you'll need
to find another way to do this.