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{
| 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{
|
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
| 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
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