From mboxrd@z Thu Jan 1 00:00:00 1970 From: Or Gerlitz Subject: Re: QoS in local SA entity Date: Sun, 08 Nov 2009 08:25:55 +0200 Message-ID: <4AF66473.2050303@voltaire.com> References: <4AF2C00A.4040808@voltaire.com> <9BF1CEFA7F6F44F5B5641065C4914EB5@amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <9BF1CEFA7F6F44F5B5641065C4914EB5-Zpru7NauK7drdx17CPfAsdBPR1lH4CV8@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sean Hefty Cc: linux-rdma List-Id: linux-rdma@vger.kernel.org Sean Hefty wrote: > 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 excellent... still, this is dependent on how the ACM MGIDs are constructed, I'll take a look on the code. > 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. fail-enough, I believe that my suggestion is doable also without circular dependency, e.g as you indicated below or with a fairly small enhancement of librdmacm, see next > 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 I assume you are referring to an IP local to the system where ACM runs on correct? this would work well for applications calling rdma_bind and/or rdma_resolve_address while specifying a source address. To support also the case of application which do neither of these two, that is call rdma_resolve_addr with dest address only, I suggest to enhance librdmacm-calling-ACM flow and resolve the source address using route lookup from user space, next the librdmacm can issue rdma_bind on behalf of this ID and you have the triplet at your hand so now the ACM call can be made form librdmacm. Writing this, I realized that better(should) be done also for apps _resove_addr with src ip specified. This way you have unified flow for the ACM use in librdmacm for either of apps A,B,C below A.1 rdma_bind(src=X) A.2 rdma_resolve_addr(src=null, dst=Y) B.1 rdma_resolve_addr(src=null, dst=Y) C.1 rdma_resolve_addr(src=X, dst=Y) where librdmacm calling-ACM flow is L1. compute source address L2. issue kernel rdma_bind to source address and resolve L3. issue ACM address (DGID) resolution call using (, dest-ip) makes sense? if yes, what's the need in the address configuration file? Or. -- 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