Re: [PATCH 1/3] ifb: make device count build-time configurable

From: Stephen Hemminger <stephen@networkplumber.org>
Date: Tue, 12 Jan 2016 10:44:37 -0800

On Tue, 12 Jan 2016 07:55:22 -0500
Jamal Hadi Salim [off-list ref] wrote:

quoted

On 16-01-12 06:56 AM, Lubomir Rintel wrote:

quoted

The devices can be created at run-time for quite some time already and the
load-time device creation collides with attempts to create the device of
the same name:

   # rmmod ifb
   # ip link add ifb0 type ifb
   RTNETLINK answers: File exists

This is pretty much the same situation as was with the block loop devices
which was solved by adding a build-time configuration that the
distributions could use as they deem fit while keeping the default for
compatibility.

Let's do that here as well.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>

I guess module options are frowned upon. so:

I would prefer that this were done with a module parameter, the same as dummy.
Only developers build their own configured kernels. Having the value set later
at module load time is preferable.

I like this even less, it means tools behave significantly differently
based upon what module options were passed to the kernel.

Module options really should not change kernel behavior like this..