From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: WRITE_WITH_IMMEDIATE target semantic Date: Mon, 20 Sep 2010 11:23:47 -0600 Message-ID: <20100920172347.GA11157@obsidianresearch.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Bernard Metzler Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On Mon, Sep 20, 2010 at 06:32:05PM +0200, Bernard Metzler wrote: > while currently only supported by the InfiniBand transport, > the libibverbs define a IBV_WR_RDMA_WRITE_WITH_IMM work request. > Could someone please explain what the action at the peer side would be > if a WRITE with immediate data comes in? One possible action would be > to: I've used this feature and according to my notes this is broadly correct. A RWQE is consumed, the HCA doesn't use it for anything, and the WC has the imm_data set, and the wr_id corrisponds to the RWQE. The IBA notes the RWQE could be zero length. The app needs to check for: if (wc.opcode & IBV_WC_RECV) To see if the completion consumed a RWQE. > (3) set the WC's 'byte_len' to the received WRITE payload, Hmm, I'm surprised by this, but, yep! pg 632 of the IBA. 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