Re: need pointer to Understand how to use IBV_WR_RDMA_WRITE_WITH_IMM

[Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>]

On Tue, Jun 07, 2011 at 07:18:14AM -0700, Steven Dake wrote:
> On 06/07/2011 05:23 AM, Benoit Hudzia wrote:
> > I am uncertain if this is the correct place for such email, please
> > point me to an appropriate mailing list place if not.
> > 
> > I would like to use IBV_WR_RDMA_WRITE_WITH_IMM , however I am facing
> > difficulty to find documentation or example on how to use such
> > feature.  The idea would be to do an RDMA write and wake up the peer
> > upon reception in order to process the received data.
> > 
> > What I understand from IBV_WR_RDMA_WRITE_WITH_IMM:
> 
> I would recommend against using IMM modes.  I believe they are not
> supported on non-infiniband hardware, which limits your application from
> being used on Ethernet rdma systems.

There is some talk of fixing that in iWarp, the IMM stuff is much more
efficient than a RDMA + SEND combo.

If you are going to use it, and care about iWarp then you should
design a fall back into your protocol to use RDMA + SEND.. I have some
stuff that works like this.

Jason
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