Topology.cc revision 9117:49116b947194
1/* 2 * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#include <cassert> 30 31#include "debug/RubyNetwork.hh" 32#include "mem/protocol/MachineType.hh" 33#include "mem/ruby/common/NetDest.hh" 34#include "mem/ruby/network/BasicLink.hh" 35#include "mem/ruby/network/BasicRouter.hh" 36#include "mem/ruby/network/Network.hh" 37#include "mem/ruby/network/Topology.hh" 38#include "mem/ruby/slicc_interface/AbstractController.hh" 39 40using namespace std; 41 42const int INFINITE_LATENCY = 10000; // Yes, this is a big hack 43 44class BasicRouter; 45 46// Note: In this file, we use the first 2*m_nodes SwitchIDs to 47// represent the input and output endpoint links. These really are 48// not 'switches', as they will not have a Switch object allocated for 49// them. The first m_nodes SwitchIDs are the links into the network, 50// the second m_nodes set of SwitchIDs represent the the output queues 51// of the network. 52 53// Helper functions based on chapter 29 of Cormen et al. 54void extend_shortest_path(Matrix& current_dist, Matrix& latencies, 55 Matrix& inter_switches); 56Matrix shortest_path(const Matrix& weights, Matrix& latencies, 57 Matrix& inter_switches); 58bool link_is_shortest_path_to_node(SwitchID src, SwitchID next, 59 SwitchID final, const Matrix& weights, const Matrix& dist); 60NetDest shortest_path_to_node(SwitchID src, SwitchID next, 61 const Matrix& weights, const Matrix& dist); 62 63Topology::Topology(const Params *p) 64 : SimObject(p) 65{ 66 m_print_config = p->print_config; 67 m_number_of_switches = p->routers.size(); 68 69 // initialize component latencies record 70 m_component_latencies.resize(0); 71 m_component_inter_switches.resize(0); 72 73 // Total nodes/controllers in network 74 // Must make sure this is called after the State Machine constructors 75 m_nodes = MachineType_base_number(MachineType_NUM); 76 assert(m_nodes > 1); 77 78 if (m_nodes != params()->ext_links.size() && 79 m_nodes != params()->ext_links.size()) { 80 fatal("m_nodes (%d) != ext_links vector length (%d)\n", 81 m_nodes, params()->ext_links.size()); 82 } 83 84 // analyze both the internal and external links, create data structures 85 // Note that the python created links are bi-directional, but that the 86 // topology and networks utilize uni-directional links. Thus each 87 // BasicLink is converted to two calls to add link, on for each direction 88 for (vector<BasicExtLink*>::const_iterator i = params()->ext_links.begin(); 89 i != params()->ext_links.end(); ++i) { 90 BasicExtLink *ext_link = (*i); 91 AbstractController *abs_cntrl = ext_link->params()->ext_node; 92 BasicRouter *router = ext_link->params()->int_node; 93 94 // Store the controller and ExtLink pointers for later 95 m_controller_vector.push_back(abs_cntrl); 96 m_ext_link_vector.push_back(ext_link); 97 98 int ext_idx1 = abs_cntrl->params()->cntrl_id; 99 int ext_idx2 = ext_idx1 + m_nodes; 100 int int_idx = router->params()->router_id + 2*m_nodes; 101 102 // create the internal uni-directional links in both directions 103 // the first direction is marked: In 104 addLink(ext_idx1, int_idx, ext_link, LinkDirection_In); 105 // the first direction is marked: Out 106 addLink(int_idx, ext_idx2, ext_link, LinkDirection_Out); 107 } 108 109 for (vector<BasicIntLink*>::const_iterator i = params()->int_links.begin(); 110 i != params()->int_links.end(); ++i) { 111 BasicIntLink *int_link = (*i); 112 BasicRouter *router_a = int_link->params()->node_a; 113 BasicRouter *router_b = int_link->params()->node_b; 114 115 // Store the IntLink pointers for later 116 m_int_link_vector.push_back(int_link); 117 118 int a = router_a->params()->router_id + 2*m_nodes; 119 int b = router_b->params()->router_id + 2*m_nodes; 120 121 // create the internal uni-directional links in both directions 122 // the first direction is marked: In 123 addLink(a, b, int_link, LinkDirection_In); 124 // the second direction is marked: Out 125 addLink(b, a, int_link, LinkDirection_Out); 126 } 127} 128 129void 130Topology::init() 131{ 132} 133 134 135void 136Topology::initNetworkPtr(Network* net_ptr) 137{ 138 for (vector<BasicExtLink*>::const_iterator i = params()->ext_links.begin(); 139 i != params()->ext_links.end(); ++i) { 140 BasicExtLink *ext_link = (*i); 141 AbstractController *abs_cntrl = ext_link->params()->ext_node; 142 abs_cntrl->initNetworkPtr(net_ptr); 143 } 144} 145 146void 147Topology::createLinks(Network *net, bool isReconfiguration) 148{ 149 // Find maximum switchID 150 SwitchID max_switch_id = 0; 151 for (LinkMap::const_iterator i = m_link_map.begin(); 152 i != m_link_map.end(); ++i) { 153 std::pair<int, int> src_dest = (*i).first; 154 max_switch_id = max(max_switch_id, src_dest.first); 155 max_switch_id = max(max_switch_id, src_dest.second); 156 } 157 158 // Initialize weight, latency, and inter switched vectors 159 Matrix topology_weights; 160 int num_switches = max_switch_id+1; 161 topology_weights.resize(num_switches); 162 m_component_latencies.resize(num_switches); 163 m_component_inter_switches.resize(num_switches); 164 165 for (int i = 0; i < topology_weights.size(); i++) { 166 topology_weights[i].resize(num_switches); 167 m_component_latencies[i].resize(num_switches); 168 m_component_inter_switches[i].resize(num_switches); 169 170 for (int j = 0; j < topology_weights[i].size(); j++) { 171 topology_weights[i][j] = INFINITE_LATENCY; 172 173 // initialize to invalid values 174 m_component_latencies[i][j] = -1; 175 176 // initially assume direct connections / no intermediate 177 // switches between components 178 m_component_inter_switches[i][j] = 0; 179 } 180 } 181 182 // Set identity weights to zero 183 for (int i = 0; i < topology_weights.size(); i++) { 184 topology_weights[i][i] = 0; 185 } 186 187 // Fill in the topology weights and bandwidth multipliers 188 for (LinkMap::const_iterator i = m_link_map.begin(); 189 i != m_link_map.end(); ++i) { 190 std::pair<int, int> src_dest = (*i).first; 191 BasicLink* link = (*i).second.link; 192 int src = src_dest.first; 193 int dst = src_dest.second; 194 m_component_latencies[src][dst] = link->m_latency; 195 topology_weights[src][dst] = link->m_weight; 196 } 197 198 // Walk topology and hookup the links 199 Matrix dist = shortest_path(topology_weights, m_component_latencies, 200 m_component_inter_switches); 201 for (int i = 0; i < topology_weights.size(); i++) { 202 for (int j = 0; j < topology_weights[i].size(); j++) { 203 int weight = topology_weights[i][j]; 204 if (weight > 0 && weight != INFINITE_LATENCY) { 205 NetDest destination_set = shortest_path_to_node(i, j, 206 topology_weights, dist); 207 makeLink(net, i, j, destination_set, isReconfiguration); 208 } 209 } 210 } 211} 212 213void 214Topology::addLink(SwitchID src, SwitchID dest, BasicLink* link, 215 LinkDirection dir) 216{ 217 assert(src <= m_number_of_switches+m_nodes+m_nodes); 218 assert(dest <= m_number_of_switches+m_nodes+m_nodes); 219 220 std::pair<int, int> src_dest_pair; 221 LinkEntry link_entry; 222 223 src_dest_pair.first = src; 224 src_dest_pair.second = dest; 225 link_entry.direction = dir; 226 link_entry.link = link; 227 m_link_map[src_dest_pair] = link_entry; 228} 229 230void 231Topology::makeLink(Network *net, SwitchID src, SwitchID dest, 232 const NetDest& routing_table_entry, bool isReconfiguration) 233{ 234 // Make sure we're not trying to connect two end-point nodes 235 // directly together 236 assert(src >= 2 * m_nodes || dest >= 2 * m_nodes); 237 238 std::pair<int, int> src_dest; 239 LinkEntry link_entry; 240 241 if (src < m_nodes) { 242 src_dest.first = src; 243 src_dest.second = dest; 244 link_entry = m_link_map[src_dest]; 245 net->makeInLink(src, dest - (2 * m_nodes), link_entry.link, 246 link_entry.direction, 247 routing_table_entry, 248 isReconfiguration); 249 } else if (dest < 2*m_nodes) { 250 assert(dest >= m_nodes); 251 NodeID node = dest - m_nodes; 252 src_dest.first = src; 253 src_dest.second = dest; 254 link_entry = m_link_map[src_dest]; 255 net->makeOutLink(src - (2 * m_nodes), node, link_entry.link, 256 link_entry.direction, 257 routing_table_entry, 258 isReconfiguration); 259 } else { 260 assert((src >= 2 * m_nodes) && (dest >= 2 * m_nodes)); 261 src_dest.first = src; 262 src_dest.second = dest; 263 link_entry = m_link_map[src_dest]; 264 net->makeInternalLink(src - (2 * m_nodes), dest - (2 * m_nodes), 265 link_entry.link, link_entry.direction, 266 routing_table_entry, isReconfiguration); 267 } 268} 269 270void 271Topology::printStats(std::ostream& out) const 272{ 273 for (int cntrl = 0; cntrl < m_controller_vector.size(); cntrl++) { 274 m_controller_vector[cntrl]->printStats(out); 275 } 276} 277 278void 279Topology::clearStats() 280{ 281 for (int cntrl = 0; cntrl < m_controller_vector.size(); cntrl++) { 282 m_controller_vector[cntrl]->clearStats(); 283 } 284} 285 286// The following all-pairs shortest path algorithm is based on the 287// discussion from Cormen et al., Chapter 26.1. 288void 289extend_shortest_path(Matrix& current_dist, Matrix& latencies, 290 Matrix& inter_switches) 291{ 292 bool change = true; 293 int nodes = current_dist.size(); 294 295 while (change) { 296 change = false; 297 for (int i = 0; i < nodes; i++) { 298 for (int j = 0; j < nodes; j++) { 299 int minimum = current_dist[i][j]; 300 int previous_minimum = minimum; 301 int intermediate_switch = -1; 302 for (int k = 0; k < nodes; k++) { 303 minimum = min(minimum, 304 current_dist[i][k] + current_dist[k][j]); 305 if (previous_minimum != minimum) { 306 intermediate_switch = k; 307 inter_switches[i][j] = 308 inter_switches[i][k] + 309 inter_switches[k][j] + 1; 310 } 311 previous_minimum = minimum; 312 } 313 if (current_dist[i][j] != minimum) { 314 change = true; 315 current_dist[i][j] = minimum; 316 assert(intermediate_switch >= 0); 317 assert(intermediate_switch < latencies[i].size()); 318 latencies[i][j] = latencies[i][intermediate_switch] + 319 latencies[intermediate_switch][j]; 320 } 321 } 322 } 323 } 324} 325 326Matrix 327shortest_path(const Matrix& weights, Matrix& latencies, Matrix& inter_switches) 328{ 329 Matrix dist = weights; 330 extend_shortest_path(dist, latencies, inter_switches); 331 return dist; 332} 333 334bool 335link_is_shortest_path_to_node(SwitchID src, SwitchID next, SwitchID final, 336 const Matrix& weights, const Matrix& dist) 337{ 338 return weights[src][next] + dist[next][final] == dist[src][final]; 339} 340 341NetDest 342shortest_path_to_node(SwitchID src, SwitchID next, const Matrix& weights, 343 const Matrix& dist) 344{ 345 NetDest result; 346 int d = 0; 347 int machines; 348 int max_machines; 349 350 machines = MachineType_NUM; 351 max_machines = MachineType_base_number(MachineType_NUM); 352 353 for (int m = 0; m < machines; m++) { 354 for (int i = 0; i < MachineType_base_count((MachineType)m); i++) { 355 // we use "d+max_machines" below since the "destination" 356 // switches for the machines are numbered 357 // [MachineType_base_number(MachineType_NUM)... 358 // 2*MachineType_base_number(MachineType_NUM)-1] for the 359 // component network 360 if (link_is_shortest_path_to_node(src, next, d + max_machines, 361 weights, dist)) { 362 MachineID mach = {(MachineType)m, i}; 363 result.add(mach); 364 } 365 d++; 366 } 367 } 368 369 DPRINTF(RubyNetwork, "Returning shortest path\n" 370 "(src-(2*max_machines)): %d, (next-(2*max_machines)): %d, " 371 "src: %d, next: %d, result: %s\n", 372 (src-(2*max_machines)), (next-(2*max_machines)), 373 src, next, result); 374 375 return result; 376} 377 378Topology * 379TopologyParams::create() 380{ 381 return new Topology(this); 382} 383 384