[openib-general] kDAPL: ready for gen2/trunk/ inclusion?

[Libor Michalek]

On Thu, Jul 14, 2005 at 02:04:52PM -0400, James Lentini wrote:
> On Wed, 13 Jul 2005, Christoph Hellwig wrote:
> > On Wed, Jul 13, 2005 at 10:18:41AM -0400, James Lentini wrote:
> >> In addition to the streamlined connection management interface, kDAPL
> >> also provides a unified event model. This is another feature that the
> >> verbs do not provide.
> >
> > It's probably the biggest mis-feature and would have to go aswell if
> > we mæssage what started as kdapl into the kernel rdma layer.
> 
> When the DAT Collaborative solicited requirements for their API, RDMA 
> consumers requested this feature. The idea is that a single 
> event source is a cleaner, simpler programming model.

  I'm not sure how it originally came to be, but it seems like a feature
that made sense in userspace and got moved to kernel space because of
the, in my opinion, misguided desire to have a unified kernel/userspace
API. Having written to the userspace DAPL, and kerel verbs/cm APIs, I would
not want to use the proposed event model in the kernel. Getting the locking
correct and good performance is difficult enough without your APIs hiding 
the source of your events.


-Libor