From patchwork Tue Jul 5 11:33:20 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hal Rosenstock X-Patchwork-Id: 944472 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p65BWQRh000552 for ; Tue, 5 Jul 2011 11:33:25 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932231Ab1GELdZ (ORCPT ); Tue, 5 Jul 2011 07:33:25 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:64943 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932176Ab1GELdY (ORCPT ); Tue, 5 Jul 2011 07:33:24 -0400 Received: by mail-ww0-f44.google.com with SMTP id 5so5837014wwe.1 for ; Tue, 05 Jul 2011 04:33:24 -0700 (PDT) Received: by 10.216.237.32 with SMTP id x32mr705224weq.20.1309865603681; Tue, 05 Jul 2011 04:33:23 -0700 (PDT) Received: from [192.168.1.100] (c-71-192-10-85.hsd1.ma.comcast.net [71.192.10.85]) by mx.google.com with ESMTPS id fn12sm1668258wbb.21.2011.07.05.04.33.21 (version=SSLv3 cipher=OTHER); Tue, 05 Jul 2011 04:33:22 -0700 (PDT) Message-ID: <4E12F680.5040404@dev.mellanox.co.il> Date: Tue, 05 Jul 2011 07:33:20 -0400 From: Hal Rosenstock User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.18) Gecko/20110616 Thunderbird/3.1.11 MIME-Version: 1.0 To: Alex Netes CC: "linux-rdma@vger.kernel.org" Subject: [PATCH] opensm/current-routing.txt: Add DnUp description Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Tue, 05 Jul 2011 11:33:25 +0000 (UTC) Signed-off-by: Hal Rosenstock --- -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/doc/current-routing.txt b/doc/current-routing.txt index 5048c55..ac00d13 100644 --- a/doc/current-routing.txt +++ b/doc/current-routing.txt @@ -1,7 +1,7 @@ Current OpenSM Routing -10/9/09 +7/4/11 -OpenSM offers six routing engines: +OpenSM offers seven routing engines: 1. Min Hop Algorithm - based on the minimum hops to each node where the path length is optimized. @@ -11,24 +11,28 @@ node, but it is constrained to ranking rules. This algorithm should be chosen if the subnet is not a pure Fat Tree, and deadlock may occur due to a loop in the subnet. -3. Fat-tree Unicast routing algorithm - this algorithm optimizes routing +3. DNUP Unicast routing algorithm - similar to UPDN but allows routing in +fabrics which have some CA nodes attached closer to the roots than some switch +nodes. + +4. Fat-tree Unicast routing algorithm - this algorithm optimizes routing of fat-trees for congestion-free "shift" communication pattern. It should be chosen if a subnet is a symmetrical fat-tree. Similar to UPDN routing, Fat-tree routing is credit-loop-free. -4. LASH unicast routing algorithm - uses Infiniband virtual layers +5. LASH unicast routing algorithm - uses Infiniband virtual layers (SL) to provide deadlock-free shortest-path routing while also distributing the paths between layers. LASH is an alternative deadlock-free topology-agnostic routing algorithm to the non-minimal UPDN algorithm avoiding the use of a potentially congested root node. -5. DOR Unicast routing algorithm - based on the Min Hop algorithm, but +6. DOR Unicast routing algorithm - based on the Min Hop algorithm, but avoids port equalization except for redundant links between the same two switches. This provides deadlock free routes for hypercubes when the fabric is cabled as a hypercube and for meshes when cabled as a mesh (see details below). -6. Torus-2QoS unicast routing algorithm - a DOR-based routing algorithm +7. Torus-2QoS unicast routing algorithm - a DOR-based routing algorithm specialized for 2D/3D torus topologies. Torus-2QoS provides deadlock-free routing while supporting two quality of service (QoS) levels. In addition it is able to route around multiple failed fabric links or a single failed @@ -192,6 +196,20 @@ To learn more about deadlock-free routing, see the article by William J Dally and Charles L Seitz (1985). +Purpose of DNUP Algorithm + +The DNUP algorithm is designed to serve a similar purpose to UPDN. However +it is intended to work in network topologies which are unsuited to +UPDN due to nodes being connected closer to the roots than some of +the switches. An example would be a fabric which contains nodes and +uplinks connected to the same switch. The operation of DNUP is the +same as UPDN with the exception of the ranking process. In DNUP all +switch nodes are ranked based solely on their distance from CA Nodes, +all switch nodes directly connected to at least one CA are assigned a +value of 1 all other switch nodes are assigned a value of one more than +the minimum rank of all neighbor switch nodes. + + Fat-tree Routing Algorithm --------------------------