1 /* Copyright (c) 2014-2016. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #ifndef SIMGRID_ROUTING_CLUSTER_FAT_TREE_HPP_
7 #define SIMGRID_ROUTING_CLUSTER_FAT_TREE_HPP_
9 #include "src/surf/AsCluster.hpp"
14 class XBT_PRIVATE FatTreeLink;
16 /** \brief A node in a fat tree (@ref AsClusterFatTree).
17 * A FatTreeNode can either be a switch or a processing node. Switches are
18 * identified by a negative ID. This class is closely related to fat
20 class XBT_PRIVATE FatTreeNode {
22 /** Unique ID which identifies every node. */
24 /* Level into the tree, with 0 being the leafs.
27 /* \brief Position into the level, starting from 0.
29 unsigned int position;
30 /** In order to link nodes between them, each one must be assigned a label,
31 * consisting of l integers, l being the levels number of the tree. Each label
32 * is unique in the level, and the way it is generated allows the construction
33 * of a fat tree which fits the desired topology.
35 std::vector<unsigned int> label;
37 /** Links to the lower level, where the position in the vector corresponds to
40 std::vector<FatTreeLink*> children;
41 /** Links to the upper level, where the position in the vector corresponds to
44 std::vector<FatTreeLink*> parents;
46 /** Virtual link standing for the node global capacity.
49 /** If present, communications from this node to this node will pass through it
50 * instead of passing by an upper level switch.
53 FatTreeNode(sg_platf_cluster_cbarg_t cluster, int id, int level, int position);
58 /** \brief Link in a fat tree (@ref AsClusterFatTree).
60 * Represents a single, duplex link in a fat tree. This is necessary to have a tree.
61 * It is equivalent to a physical link.
65 FatTreeLink(sg_platf_cluster_cbarg_t cluster, FatTreeNode *source, FatTreeNode *destination);
66 /** Link going up in the tree */
68 /** Link going down in the tree */
70 /** Upper end of the link */
72 /** Lower end of the link */
73 FatTreeNode *downNode;
77 * \class AsClusterFatTree
79 * \brief Fat tree representation and routing.
81 * Generate fat trees according to the topology asked for, according to:
82 * Eitan Zahavi, D-Mod-K Routing Providing Non-Blocking Traffic for Shift
83 * Permutations on Real Life Fat Trees (2010).
85 * RLFT are PGFT with some restrictions to address real world constraints,
86 * which are not currently enforced.
88 * The exact topology is described in the mandatory topo_parameters
89 * field, and follow the "h ; m_h, ..., m_1 ; w_h, ..., w_1 ; p_h, ..., p_1" format.
90 * h stands for the switches levels number, i.e. the fat tree is of height h,
91 * without the processing nodes. m_i stands for the number of lower level nodes
92 * connected to a node in level i. w_i stands for the number of upper levels
93 * nodes connected to a node in level i-1. p_i stands for the number of
94 * parallel links connecting two nodes between level i and i - 1. Level h is
95 * the topmost switch level, level 1 is the lowest switch level, and level 0
96 * represents the processing nodes. The number of provided nodes must be exactly
97 * the number of processing nodes required to fit the topology, which is the
98 * product of the m_i's.
100 * Routing is made using a destination-mod-k scheme.
102 class XBT_PRIVATE AsClusterFatTree : public AsCluster {
104 explicit AsClusterFatTree(const char*name);
105 ~AsClusterFatTree() override;
106 void getRouteAndLatency(NetCard *src, NetCard *dst,
107 sg_platf_route_cbarg_t into,
108 double *latency) override;
110 /** \brief Generate the fat tree
112 * Once all processing nodes have been added, this will make sure the fat
113 * tree is generated by calling generateLabels(), generateSwitches() and
114 * then connection all nodes between them, using their label.
116 void seal() override;
117 /** \brief Read the parameters in topo_parameters field.
119 * It will also store the cluster for future use.
121 void parse_specific_arguments(sg_platf_cluster_cbarg_t cluster) override;
122 void addProcessingNode(int id);
123 void generateDotFile(const std::string& filename = "fatTree.dot") const;
127 //description of a PGFT (TODO : better doc)
128 unsigned int levels_ = 0;
129 std::vector<unsigned int> lowerLevelNodesNumber_; // number of children by node
130 std::vector<unsigned int> upperLevelNodesNumber_; // number of parents by node
131 std::vector<unsigned int> lowerLevelPortsNumber_; // ports between each level l and l-1
133 std::map<int, FatTreeNode*> computeNodes_;
134 std::vector<FatTreeNode*> nodes_;
135 std::vector<FatTreeLink*> links_;
136 std::vector<unsigned int> nodesByLevel_;
138 sg_platf_cluster_cbarg_t cluster_;
140 void addLink(FatTreeNode *parent, unsigned int parentPort,
141 FatTreeNode *child, unsigned int childPort);
142 int getLevelPosition(const unsigned int level);
143 void generateLabels();
144 void generateSwitches();
145 int connectNodeToParents(FatTreeNode *node);
146 bool areRelated(FatTreeNode *parent, FatTreeNode *child);
147 bool isInSubTree(FatTreeNode *root, FatTreeNode *node);