[ofa-general] Re: [PATCHv4 RFC] Scalable Reliable Connection: API and documentation

[Jack Morgenstein]

On Tuesday 14 August 2007 00:37, Roland Dreier wrote:
> Yes, in fact I think we might be able to get away with not breaking
> the user-kernel ABI.  If I understand things correctly, XRC QPs do not
> have an SRQ attached to them, so we could overload the srq_handle
> member of struct ib_uverbs_create_qp to hold the xrc_domain_handle
> when creating an XRC QP.
Only caveat -- I'll need to put a comment in the code regarding the
overloading (to avoid confusion).

> Then if we're OK with having create_xrc_srq be a separate operation
> from create_srq, I think everything else doesn't break the ABI.
I've checked -- everything else seems OK.

> Does that seem like a good plan?  The only ugly thing is making the
> interface a little fatter than it needs to be with the duplicated
> create_xrc_srq and create_srq operations; but we save the pain of
> bumping the ABI and avoid the ugliness of putting generic objects into
> the driver-specific data (which would force us to export the lookup of
> XRC objects from the uverbs module, etc).

I think its the only reasonable plan -- all the other options were
much nastier.

I'll implement this as described above.

- Jack