Topology.cc revision 9593:9441ca79f3c8
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 "base/trace.hh" 32#include "debug/RubyNetwork.hh" 33#include "mem/protocol/MachineType.hh" 34#include "mem/ruby/common/NetDest.hh" 35#include "mem/ruby/network/BasicLink.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 44// Note: In this file, we use the first 2*m_nodes SwitchIDs to 45// represent the input and output endpoint links. These really are 46// not 'switches', as they will not have a Switch object allocated for 47// them. The first m_nodes SwitchIDs are the links into the network, 48// the second m_nodes set of SwitchIDs represent the the output queues 49// of the network. 50 51// Helper functions based on chapter 29 of Cormen et al. 52void extend_shortest_path(Matrix& current_dist, Matrix& latencies, 53 Matrix& inter_switches); 54Matrix shortest_path(const Matrix& weights, Matrix& latencies, 55 Matrix& inter_switches); 56bool link_is_shortest_path_to_node(SwitchID src, SwitchID next, 57 SwitchID final, const Matrix& weights, const Matrix& dist); 58NetDest shortest_path_to_node(SwitchID src, SwitchID next, 59 const Matrix& weights, const Matrix& dist); 60 61Topology::Topology(const Params *p) 62 : SimObject(p) 63{ 64 m_number_of_switches = p->num_routers; 65 66 // initialize component latencies record 67 m_component_latencies.resize(0); 68 m_component_inter_switches.resize(0); 69 70 // Total nodes/controllers in network 71 // Must make sure this is called after the State Machine constructors 72 m_nodes = MachineType_base_number(MachineType_NUM); 73 assert(m_nodes > 1); 74 75 if (m_nodes != params()->ext_links.size() && 76 m_nodes != params()->ext_links.size()) { 77 fatal("m_nodes (%d) != ext_links vector length (%d)\n", 78 m_nodes, params()->ext_links.size()); 79 } 80 81 // analyze both the internal and external links, create data structures 82 // Note that the python created links are bi-directional, but that the 83 // topology and networks utilize uni-directional links. Thus each 84 // BasicLink is converted to two calls to add link, on for each direction 85 for (vector<BasicExtLink*>::const_iterator i = params()->ext_links.begin(); 86 i != params()->ext_links.end(); ++i) { 87 BasicExtLink *ext_link = (*i); 88 AbstractController *abs_cntrl = ext_link->params()->ext_node; 89 BasicRouter *router = ext_link->params()->int_node; 90 91 // Store the ExtLink pointers for later 92 m_ext_link_vector.push_back(ext_link); 93 94 int ext_idx1 = abs_cntrl->params()->cntrl_id; 95 int ext_idx2 = ext_idx1 + m_nodes; 96 int int_idx = router->params()->router_id + 2*m_nodes; 97 98 // create the internal uni-directional links in both directions 99 // the first direction is marked: In 100 addLink(ext_idx1, int_idx, ext_link, LinkDirection_In); 101 // the first direction is marked: Out 102 addLink(int_idx, ext_idx2, ext_link, LinkDirection_Out); 103 } 104 105 for (vector<BasicIntLink*>::const_iterator i = params()->int_links.begin(); 106 i != params()->int_links.end(); ++i) { 107 BasicIntLink *int_link = (*i); 108 BasicRouter *router_a = int_link->params()->node_a; 109 BasicRouter *router_b = int_link->params()->node_b; 110 111 // Store the IntLink pointers for later 112 m_int_link_vector.push_back(int_link); 113 114 int a = router_a->params()->router_id + 2*m_nodes; 115 int b = router_b->params()->router_id + 2*m_nodes; 116 117 // create the internal uni-directional links in both directions 118 // the first direction is marked: In 119 addLink(a, b, int_link, LinkDirection_In); 120 // the second direction is marked: Out 121 addLink(b, a, int_link, LinkDirection_Out); 122 } 123} 124 125void 126Topology::init() 127{ 128} 129 130 131void 132Topology::initNetworkPtr(Network* net_ptr) 133{ 134 for (vector<BasicExtLink*>::const_iterator i = params()->ext_links.begin(); 135 i != params()->ext_links.end(); ++i) { 136 BasicExtLink *ext_link = (*i); 137 AbstractController *abs_cntrl = ext_link->params()->ext_node; 138 abs_cntrl->initNetworkPtr(net_ptr); 139 } 140} 141 142void 143Topology::createLinks(Network *net, bool isReconfiguration) 144{ 145 // Find maximum switchID 146 SwitchID max_switch_id = 0; 147 for (LinkMap::const_iterator i = m_link_map.begin(); 148 i != m_link_map.end(); ++i) { 149 std::pair<int, int> src_dest = (*i).first; 150 max_switch_id = max(max_switch_id, src_dest.first); 151 max_switch_id = max(max_switch_id, src_dest.second); 152 } 153 154 // Initialize weight, latency, and inter switched vectors 155 Matrix topology_weights; 156 int num_switches = max_switch_id+1; 157 topology_weights.resize(num_switches); 158 m_component_latencies.resize(num_switches); 159 m_component_inter_switches.resize(num_switches); 160 161 for (int i = 0; i < topology_weights.size(); i++) { 162 topology_weights[i].resize(num_switches); 163 m_component_latencies[i].resize(num_switches); 164 m_component_inter_switches[i].resize(num_switches); 165 166 for (int j = 0; j < topology_weights[i].size(); j++) { 167 topology_weights[i][j] = INFINITE_LATENCY; 168 169 // initialize to invalid values 170 m_component_latencies[i][j] = -1; 171 172 // initially assume direct connections / no intermediate 173 // switches between components 174 m_component_inter_switches[i][j] = 0; 175 } 176 } 177 178 // Set identity weights to zero 179 for (int i = 0; i < topology_weights.size(); i++) { 180 topology_weights[i][i] = 0; 181 } 182 183 // Fill in the topology weights and bandwidth multipliers 184 for (LinkMap::const_iterator i = m_link_map.begin(); 185 i != m_link_map.end(); ++i) { 186 std::pair<int, int> src_dest = (*i).first; 187 BasicLink* link = (*i).second.link; 188 int src = src_dest.first; 189 int dst = src_dest.second; 190 m_component_latencies[src][dst] = link->m_latency; 191 topology_weights[src][dst] = link->m_weight; 192 } 193 194 // Walk topology and hookup the links 195 Matrix dist = shortest_path(topology_weights, m_component_latencies, 196 m_component_inter_switches); 197 for (int i = 0; i < topology_weights.size(); i++) { 198 for (int j = 0; j < topology_weights[i].size(); j++) { 199 int weight = topology_weights[i][j]; 200 if (weight > 0 && weight != INFINITE_LATENCY) { 201 NetDest destination_set = shortest_path_to_node(i, j, 202 topology_weights, dist); 203 makeLink(net, i, j, destination_set, isReconfiguration); 204 } 205 } 206 } 207} 208 209void 210Topology::addLink(SwitchID src, SwitchID dest, BasicLink* link, 211 LinkDirection dir) 212{ 213 assert(src <= m_number_of_switches+m_nodes+m_nodes); 214 assert(dest <= m_number_of_switches+m_nodes+m_nodes); 215 216 std::pair<int, int> src_dest_pair; 217 LinkEntry link_entry; 218 219 src_dest_pair.first = src; 220 src_dest_pair.second = dest; 221 link_entry.direction = dir; 222 link_entry.link = link; 223 m_link_map[src_dest_pair] = link_entry; 224} 225 226void 227Topology::makeLink(Network *net, SwitchID src, SwitchID dest, 228 const NetDest& routing_table_entry, bool isReconfiguration) 229{ 230 // Make sure we're not trying to connect two end-point nodes 231 // directly together 232 assert(src >= 2 * m_nodes || dest >= 2 * m_nodes); 233 234 std::pair<int, int> src_dest; 235 LinkEntry link_entry; 236 237 if (src < m_nodes) { 238 src_dest.first = src; 239 src_dest.second = dest; 240 link_entry = m_link_map[src_dest]; 241 net->makeInLink(src, dest - (2 * m_nodes), link_entry.link, 242 link_entry.direction, 243 routing_table_entry, 244 isReconfiguration); 245 } else if (dest < 2*m_nodes) { 246 assert(dest >= m_nodes); 247 NodeID node = dest - m_nodes; 248 src_dest.first = src; 249 src_dest.second = dest; 250 link_entry = m_link_map[src_dest]; 251 net->makeOutLink(src - (2 * m_nodes), node, link_entry.link, 252 link_entry.direction, 253 routing_table_entry, 254 isReconfiguration); 255 } else { 256 assert((src >= 2 * m_nodes) && (dest >= 2 * m_nodes)); 257 src_dest.first = src; 258 src_dest.second = dest; 259 link_entry = m_link_map[src_dest]; 260 net->makeInternalLink(src - (2 * m_nodes), dest - (2 * m_nodes), 261 link_entry.link, link_entry.direction, 262 routing_table_entry, isReconfiguration); 263 } 264} 265 266// The following all-pairs shortest path algorithm is based on the 267// discussion from Cormen et al., Chapter 26.1. 268void 269extend_shortest_path(Matrix& current_dist, Matrix& latencies, 270 Matrix& inter_switches) 271{ 272 bool change = true; 273 int nodes = current_dist.size(); 274 275 while (change) { 276 change = false; 277 for (int i = 0; i < nodes; i++) { 278 for (int j = 0; j < nodes; j++) { 279 int minimum = current_dist[i][j]; 280 int previous_minimum = minimum; 281 int intermediate_switch = -1; 282 for (int k = 0; k < nodes; k++) { 283 minimum = min(minimum, 284 current_dist[i][k] + current_dist[k][j]); 285 if (previous_minimum != minimum) { 286 intermediate_switch = k; 287 inter_switches[i][j] = 288 inter_switches[i][k] + 289 inter_switches[k][j] + 1; 290 } 291 previous_minimum = minimum; 292 } 293 if (current_dist[i][j] != minimum) { 294 change = true; 295 current_dist[i][j] = minimum; 296 assert(intermediate_switch >= 0); 297 assert(intermediate_switch < latencies[i].size()); 298 latencies[i][j] = latencies[i][intermediate_switch] + 299 latencies[intermediate_switch][j]; 300 } 301 } 302 } 303 } 304} 305 306Matrix 307shortest_path(const Matrix& weights, Matrix& latencies, Matrix& inter_switches) 308{ 309 Matrix dist = weights; 310 extend_shortest_path(dist, latencies, inter_switches); 311 return dist; 312} 313 314bool 315link_is_shortest_path_to_node(SwitchID src, SwitchID next, SwitchID final, 316 const Matrix& weights, const Matrix& dist) 317{ 318 return weights[src][next] + dist[next][final] == dist[src][final]; 319} 320 321NetDest 322shortest_path_to_node(SwitchID src, SwitchID next, const Matrix& weights, 323 const Matrix& dist) 324{ 325 NetDest result; 326 int d = 0; 327 int machines; 328 int max_machines; 329 330 machines = MachineType_NUM; 331 max_machines = MachineType_base_number(MachineType_NUM); 332 333 for (int m = 0; m < machines; m++) { 334 for (int i = 0; i < MachineType_base_count((MachineType)m); i++) { 335 // we use "d+max_machines" below since the "destination" 336 // switches for the machines are numbered 337 // [MachineType_base_number(MachineType_NUM)... 338 // 2*MachineType_base_number(MachineType_NUM)-1] for the 339 // component network 340 if (link_is_shortest_path_to_node(src, next, d + max_machines, 341 weights, dist)) { 342 MachineID mach = {(MachineType)m, i}; 343 result.add(mach); 344 } 345 d++; 346 } 347 } 348 349 DPRINTF(RubyNetwork, "Returning shortest path\n" 350 "(src-(2*max_machines)): %d, (next-(2*max_machines)): %d, " 351 "src: %d, next: %d, result: %s\n", 352 (src-(2*max_machines)), (next-(2*max_machines)), 353 src, next, result); 354 355 return result; 356} 357 358Topology * 359TopologyParams::create() 360{ 361 return new Topology(this); 362} 363 364