[openib-general] Re: [PATCH] sockaddr_ll change for IPoIB interface

[Tom Duffy]

On Aug 12, 2005, at 7:51 AM, Roland Dreier wrote:

>     Tom> Do we need backward compatibility?
>
>     Hal> I'm not sure but I think this was a recommendation from
>     Hal> Roland.
>
> Yes, of course we need backward compatibility.  We can't put a change
> into the kernel that breaks userspace binaries.
>
> For example, the old Fedora binary of arping has to continue to work,
> even if you use a new kernel.

But, Fedora will rebuild their binary once this change is in.  If the  
Linux developers cared about this sort of thing, it would version all  
its kernel structs and put padding at the end to ensure new fields  
could be added.  It has opted for the cleaner (technical) solution of  
having all the apps recompile.  Sure there will be a little bit of  
growing pain, but in the end, it won't have all kinds of backwards  
compatibility cruft lying around.

-tduffy