Re: [PATCH] IB/mlx4: Allow to always block UD multicast loopback

Doug Ledford
2014-05-01T15:34:16Z

----- Original Message -----
> On 01/05/2014 02:28, Doug Ledford wrote:
> > This seems like driving a thumb tack with a sledge hammer. No
> > doubt
> > the correct path here is to get the proper flag added to verbs
> > multicast
> > attach command. Or, do you still have a patch that does this the
> > right way? Did the one from 2008 do it the right way or this way?
>
> Doug, as I commented earlier on this thread, the correct way here is
> to
> carry out the task is to repeat the QP creation flags which we have
> in
> the kernel verbs API for years (see
> IB_QP_CREATE_BLOCK_MULTICAST_LOOPBACK in ib_verbs.h and usage in
> IPoIB)

I'm curious why this is done at QP creation time. Should this not
be done at multicast join time? A single QP can be a member of more
than one MC group, would it not seem more correct to you that the
loopback should be specified on a per group basis and not a per QP
basis?

> for the user space verbs API. The patch I provided to Christophand CO
> was a band-aid to bring up a whole system on upstream and mlx4 where
> this (avoiding multicast loopback) was the only/major missing piece.
>
> The patch posted back in 2008 is proper, but it added a whole new
> uverb
> call/structure, where I think we can get along here with just
> re-using a
> reserved field in the existing uverbs API, see my other post on this
> thread.
>
> Or.
>
> Or.
>

--
Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
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