From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: need pointer to Understand how to use IBV_WR_RDMA_WRITE_WITH_IMM Date: Tue, 7 Jun 2011 10:31:11 -0600 Message-ID: <20110607163111.GA24005@obsidianresearch.com> References: <4DEE3326.9050105@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4DEE3326.9050105-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Steven Dake Cc: Benoit Hudzia , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.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 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html