Re: [ewg] [PATCH v4] IB Core: RAW ETH support

Steve Wise
2010-06-16T14:09:59Z

Roland Dreier wrote:
> > I tested it before on the Roland tree ( iboe branch ) and it fails,
> > because it writen in the way suitable for OFED. If adapt the patch to
> > the Roland tree, then appling Mellanox OFED patches will fail, because
> > it changes the same functions in the code.
> > Here is one example:
> > Look at __mlx4_ib_modify_qp at the Roland tree - there is no RAW_ETY
> > support. But in the OFED version of the same function this support is
> > present.
> > RAW_ETH patch modify this function and looking for RAW_ETY word and
> > without this RAW_ETH Mellanox patch will fail.
>
> Don't take this too personally -- I picked a semi-random email in this
> thread to reply to; this is pretty broadly targeted.
>
> <rant>
>
> What the hell is the thinking behind introducing IB_QPT_RAW_ETH? You're
> inserting an enum value before IB_QPT_RAW_ETY, so any old userspace
> passing in IB_QPT_RAW_ETY will silently get different behavior depending
> on the kernel version. And you're creating two constands that differ in
> a single letter (IB_QPT_RAW_ETY vs. IB_QPT_RAW_ETH). How are you going
> to explain that to users? How is anyone ever going to get it right?
> For that matter, what exactly does IB_QPT_RAW_ETH mean?
>
> This all seems to be a symptom of how broken our development process
> is. Yes, unfortunately I can't spend as much time reviewing and
> applying patches as I might like, and I apologize for that. But if we
> have all the RDMA developers piling up shit in their little area and
> then sending it on to be merged as soon as it kind of works, without
> thinking about design or maintainability and without ever doing any
> review, then I'm always going to have an expanding review backlog.
>
> And then we have OFED compounding problems -- "Oh that's a nice pile of
> shit you've built there. We better ship it to users while it's still
> steaming." How about if OFED developers take a little time to think
> things through?
>
> </rant>
>
> In other words, can someone explain the plan for this raw QP stuff to me?
>
> - R.
>

It doesn't even look like this patch and the mlx4 patch were ever posted
to linux-rdma. Only to the EWG list.

Granted our dev process may not be documented, but I always assumed the
general idea was to get changes accepted upstream, then pull into ofed.
OFED is just a mechanism to make top-of-tree linux work on distro
kernels. There are some exceptions, but this stuff shouldn't be an
exception.

We should all follow this "upstream first" process IMO.

Steve.