From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bang Nguyen Subject: Re: APM support for IPoIB Date: Thu, 04 Oct 2012 09:06:46 -0700 Message-ID: <506DB416.6030304@oracle.com> References: <506A17EA.8080400@oracle.com> <20121001235303.GH22342@obsidianresearch.com> <506A2F01.8000605@oracle.com> <506B8365.9010507@oracle.com> <1828884A29C6694DAF28B7E6B8A8237346A98B11@FMSMSX151.amr.corp.intel.com> <506BBDE3.3010904@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <506BBDE3.3010904-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Hefty, Sean" Cc: Tziporet Koren , Roland Dreier , Jason Gunthorpe , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Richard Frank , Eli Cohen , Jack Morgenstein List-Id: linux-rdma@vger.kernel.org I'm experimenting with trying to model IPoIB-CM APM after RDMA-CM APM, particularly the protocol for loading/re-loading of the alternate path and will see how it goes.. Thanks, --Bang. On 10/2/2012 9:24 PM, Bang Nguyen wrote: > Here is the presentation on RDMA-CM APM > > https://www.openfabrics.org/ofa-documents/presentations/doc_download/516-rdmacm-amp.html > > > On 10/2/2012 8:03 PM, Hefty, Sean wrote: >>> Just a crazy thought but IPoIB could use RDMA-CM for all of its >>> connection management stuff..this way it can leverage the APM >>> support in >>> RDMA-CM.. >>> >>> comments?... >> ipoib predates the rdma cm, which is why it's written to the ib_cm >> directly. Communication setup with the rdma cm follows these 3 steps. >> >> 1. address resolution - The rdma cm indirectly ends up using ipoib >> for this. With ipoib, this step isn't necessary. I think having >> AF_IB support would help this by avoiding this step, plus it >> restricts the rdma cm to using IB devices. >> 2. route resolution (aka path record query) - Ipoib maintains its own >> path record cache. It can set the rdma cm paths manually, or there >> would need to be some sort of rework. >> 3. connection setup - formats the ib cm private data and exchanges >> messages. The rdma cm would need to know the ipoib private data format. >> >> Sooo... ipoib wouldn't use address resolution. It maintains its own >> path record cache, which is a significant piece of supporting APM. >> Ipoib probably doesn't need to maintain its own cache, but there's no >> decent alternative for kernel clients currently. And connection >> setup using the rdma cm is only slightly easier than using the ib >> cm. (I have no idea what APM support in the rdma cm looks like.) >> >> - Sean > -- 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