From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Sean Hefty" Subject: RE: QoS in local SA entity Date: Thu, 5 Nov 2009 08:40:55 -0800 Message-ID: <9BF1CEFA7F6F44F5B5641065C4914EB5@amr.corp.intel.com> References: <4AF2C00A.4040808@voltaire.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4AF2C00A.4040808-smomgflXvOZWk0Htik3J/w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: 'Or Gerlitz' , Roland Dreier Cc: linux-rdma , Jason Gunthorpe List-Id: linux-rdma@vger.kernel.org >I believe we can go also on a middle way, where the SA isn't contacted >directly using path query for each resolution, but rather "indirectly" >e.g using a dedicated multicast based protocol. Yes - I wasn't trying to limit how the SA could 'distribute' QoS information to the end nodes. ACM will obtain QoS information from the SA when it joins its multicast groups. >So assuming ACM supports AF_INET, using network stack route lookup on >the destination address / rdma_bind on the source address, etc as we >discussed, ACM can use the rdma-cm to resolve the pkey, then use this >pkey the MGID and a management software could tell the SA to use a >specific SL for MGIDs on this partition. Next, ACM can use this SL in >the path it generates for the IB connection, makes sense? ACM is intended to be a service that's used by the librdmacm to resolve address mappings and routes. Trying to have ACM use the librdmacm ends up with a circular dependency. That's the part I'm trying to avoid. ACM uses address mappings as defined in an address configuration file (IP -> device, port, pkey). The address file can be created using the provided ib_acme utility, which uses the current system configuration (in an ugly way, but it works). I think this provides QoS behavior similar to what you're describing. At some future point, the ib_acm service can be merged with ib_acme to respond to dynamic changes in ipoib address mappings, but that's a non-trivial amount of work and involves changes to the ACM multicast groups. - 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