traffic_gen.cc revision 9722
1/* 2 * Copyright (c) 2012-2013 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions are 16 * met: redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer; 18 * redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution; 21 * neither the name of the copyright holders nor the names of its 22 * contributors may be used to endorse or promote products derived from 23 * this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 * 37 * Authors: Thomas Grass 38 * Andreas Hansson 39 * Sascha Bischoff 40 */ 41 42#include <sstream> 43 44#include "base/random.hh" 45#include "cpu/testers/traffic_gen/traffic_gen.hh" 46#include "debug/Checkpoint.hh" 47#include "debug/TrafficGen.hh" 48#include "sim/stats.hh" 49#include "sim/system.hh" 50 51using namespace std; 52 53TrafficGen::TrafficGen(const TrafficGenParams* p) 54 : MemObject(p), 55 system(p->system), 56 masterID(system->getMasterId(name())), 57 configFile(p->config_file), 58 elasticReq(p->elastic_req), 59 nextTransitionTick(0), 60 nextPacketTick(0), 61 port(name() + ".port", *this), 62 retryPkt(NULL), 63 retryPktTick(0), 64 updateEvent(this), 65 drainManager(NULL) 66{ 67} 68 69TrafficGen* 70TrafficGenParams::create() 71{ 72 return new TrafficGen(this); 73} 74 75BaseMasterPort& 76TrafficGen::getMasterPort(const string& if_name, PortID idx) 77{ 78 if (if_name == "port") { 79 return port; 80 } else { 81 return MemObject::getMasterPort(if_name, idx); 82 } 83} 84 85void 86TrafficGen::init() 87{ 88 if (!port.isConnected()) 89 fatal("The port of %s is not connected!\n", name()); 90 91 // if the system is in timing mode active the request generator 92 if (system->isTimingMode()) { 93 DPRINTF(TrafficGen, "Timing mode, activating request generator\n"); 94 95 parseConfig(); 96 97 // enter initial state 98 enterState(currState); 99 } else { 100 DPRINTF(TrafficGen, 101 "Traffic generator is only active in timing mode\n"); 102 } 103} 104 105void 106TrafficGen::initState() 107{ 108 // when not restoring from a checkpoint, make sure we kick things off 109 if (system->isTimingMode()) { 110 // call nextPacketTick on the state to advance it 111 nextPacketTick = states[currState]->nextPacketTick(elasticReq, 0); 112 schedule(updateEvent, std::min(nextPacketTick, nextTransitionTick)); 113 } else { 114 DPRINTF(TrafficGen, 115 "Traffic generator is only active in timing mode\n"); 116 } 117} 118 119unsigned int 120TrafficGen::drain(DrainManager *dm) 121{ 122 if (retryPkt == NULL) { 123 // shut things down 124 nextPacketTick = MaxTick; 125 nextTransitionTick = MaxTick; 126 deschedule(updateEvent); 127 return 0; 128 } else { 129 drainManager = dm; 130 return 1; 131 } 132} 133 134void 135TrafficGen::serialize(ostream &os) 136{ 137 DPRINTF(Checkpoint, "Serializing TrafficGen\n"); 138 139 // save ticks of the graph event if it is scheduled 140 Tick nextEvent = updateEvent.scheduled() ? updateEvent.when() : 0; 141 142 DPRINTF(TrafficGen, "Saving nextEvent=%llu\n", nextEvent); 143 144 SERIALIZE_SCALAR(nextEvent); 145 146 SERIALIZE_SCALAR(nextTransitionTick); 147 148 SERIALIZE_SCALAR(nextPacketTick); 149 150 SERIALIZE_SCALAR(currState); 151} 152 153void 154TrafficGen::unserialize(Checkpoint* cp, const string& section) 155{ 156 // restore scheduled events 157 Tick nextEvent; 158 UNSERIALIZE_SCALAR(nextEvent); 159 if (nextEvent != 0) { 160 schedule(updateEvent, nextEvent); 161 } 162 163 UNSERIALIZE_SCALAR(nextTransitionTick); 164 165 UNSERIALIZE_SCALAR(nextPacketTick); 166 167 // @todo In the case of a stateful generator state such as the 168 // trace player we would also have to restore the position in the 169 // trace playback and the tick offset 170 UNSERIALIZE_SCALAR(currState); 171} 172 173void 174TrafficGen::update() 175{ 176 // if we have reached the time for the next state transition, then 177 // perform the transition 178 if (curTick() >= nextTransitionTick) { 179 transition(); 180 } else { 181 assert(curTick() >= nextPacketTick); 182 // get the next packet and try to send it 183 PacketPtr pkt = states[currState]->getNextPacket(); 184 numPackets++; 185 if (!port.sendTimingReq(pkt)) { 186 retryPkt = pkt; 187 retryPktTick = curTick(); 188 } 189 } 190 191 // if we are waiting for a retry, do not schedule any further 192 // events, in the case of a transition or a successful send, go 193 // ahead and determine when the next update should take place 194 if (retryPkt == NULL) { 195 // schedule next update event based on either the next execute 196 // tick or the next transition, which ever comes first 197 nextPacketTick = states[currState]->nextPacketTick(elasticReq, 0); 198 Tick nextEventTick = std::min(nextPacketTick, nextTransitionTick); 199 DPRINTF(TrafficGen, "Next event scheduled at %lld\n", nextEventTick); 200 schedule(updateEvent, nextEventTick); 201 } 202} 203 204void 205TrafficGen::parseConfig() 206{ 207 // keep track of the transitions parsed to create the matrix when 208 // done 209 vector<Transition> transitions; 210 211 // open input file 212 ifstream infile; 213 infile.open(configFile.c_str(), ifstream::in); 214 if (!infile.is_open()) { 215 fatal("Traffic generator %s config file not found at %s\n", 216 name(), configFile); 217 } 218 219 // read line by line and determine the action based on the first 220 // keyword 221 string keyword; 222 string line; 223 224 while (getline(infile, line).good()) { 225 // see if this line is a comment line, and if so skip it 226 if (line.find('#') != 1) { 227 // create an input stream for the tokenization 228 istringstream is(line); 229 230 // determine the keyword 231 is >> keyword; 232 233 if (keyword == "STATE") { 234 // parse the behaviour of this state 235 uint32_t id; 236 Tick duration; 237 string mode; 238 239 is >> id >> duration >> mode; 240 241 if (mode == "TRACE") { 242 string traceFile; 243 Addr addrOffset; 244 245 is >> traceFile >> addrOffset; 246 247 states[id] = new TraceGen(name(), masterID, duration, 248 traceFile, addrOffset); 249 DPRINTF(TrafficGen, "State: %d TraceGen\n", id); 250 } else if (mode == "IDLE") { 251 states[id] = new IdleGen(name(), masterID, duration); 252 DPRINTF(TrafficGen, "State: %d IdleGen\n", id); 253 } else if (mode == "LINEAR" || mode == "RANDOM") { 254 uint32_t read_percent; 255 Addr start_addr; 256 Addr end_addr; 257 Addr blocksize; 258 Tick min_period; 259 Tick max_period; 260 Addr data_limit; 261 262 is >> read_percent >> start_addr >> end_addr >> 263 blocksize >> min_period >> max_period >> data_limit; 264 265 DPRINTF(TrafficGen, "%s, addr %x to %x, size %d," 266 " period %d to %d, %d%% reads\n", 267 mode, start_addr, end_addr, blocksize, min_period, 268 max_period, read_percent); 269 270 271 if (port.deviceBlockSize() && 272 blocksize > port.deviceBlockSize()) 273 fatal("TrafficGen %s block size (%d) is larger than " 274 "port block size (%d)\n", name(), 275 blocksize, port.deviceBlockSize()); 276 277 if (read_percent > 100) 278 fatal("%s cannot have more than 100% reads", name()); 279 280 if (min_period > max_period) 281 fatal("%s cannot have min_period > max_period", name()); 282 283 if (mode == "LINEAR") { 284 states[id] = new LinearGen(name(), masterID, 285 duration, start_addr, 286 end_addr, blocksize, 287 min_period, max_period, 288 read_percent, data_limit); 289 DPRINTF(TrafficGen, "State: %d LinearGen\n", id); 290 } else if (mode == "RANDOM") { 291 states[id] = new RandomGen(name(), masterID, 292 duration, start_addr, 293 end_addr, blocksize, 294 min_period, max_period, 295 read_percent, data_limit); 296 DPRINTF(TrafficGen, "State: %d RandomGen\n", id); 297 } 298 } else { 299 fatal("%s: Unknown traffic generator mode: %s", 300 name(), mode); 301 } 302 } else if (keyword == "TRANSITION") { 303 Transition transition; 304 305 is >> transition.from >> transition.to >> transition.p; 306 307 transitions.push_back(transition); 308 309 DPRINTF(TrafficGen, "Transition: %d -> %d\n", transition.from, 310 transition.to); 311 } else if (keyword == "INIT") { 312 // set the initial state as the active state 313 is >> currState; 314 315 DPRINTF(TrafficGen, "Initial state: %d\n", currState); 316 } 317 } 318 } 319 320 // resize and populate state transition matrix 321 transitionMatrix.resize(states.size()); 322 for (size_t i = 0; i < states.size(); i++) { 323 transitionMatrix[i].resize(states.size()); 324 } 325 326 for (vector<Transition>::iterator t = transitions.begin(); 327 t != transitions.end(); ++t) { 328 transitionMatrix[t->from][t->to] = t->p; 329 } 330 331 // ensure the egress edges do not have a probability larger than 332 // one 333 for (size_t i = 0; i < states.size(); i++) { 334 double sum = 0; 335 for (size_t j = 0; j < states.size(); j++) { 336 sum += transitionMatrix[i][j]; 337 } 338 339 // avoid comparing floating point numbers 340 if (abs(sum - 1.0) > 0.001) 341 fatal("%s has transition probability != 1 for state %d\n", 342 name(), i); 343 } 344 345 // close input file 346 infile.close(); 347} 348 349void 350TrafficGen::transition() 351{ 352 // exit the current state 353 states[currState]->exit(); 354 355 // determine next state 356 double p = random_mt.gen_real1(); 357 assert(currState < transitionMatrix.size()); 358 double cumulative = 0.0; 359 size_t i = 0; 360 do { 361 cumulative += transitionMatrix[currState][i]; 362 ++i; 363 } while (cumulative < p && i < transitionMatrix[currState].size()); 364 365 enterState(i - 1); 366} 367 368void 369TrafficGen::enterState(uint32_t newState) 370{ 371 DPRINTF(TrafficGen, "Transition to state %d\n", newState); 372 373 currState = newState; 374 // we could have been delayed and not transitioned on the exact 375 // tick when we were supposed to (due to back pressure when 376 // sending a packet) 377 nextTransitionTick = curTick() + states[currState]->duration; 378 states[currState]->enter(); 379} 380 381void 382TrafficGen::recvRetry() 383{ 384 assert(retryPkt != NULL); 385 386 DPRINTF(TrafficGen, "Received retry\n"); 387 numRetries++; 388 // attempt to send the packet, and if we are successful start up 389 // the machinery again 390 if (port.sendTimingReq(retryPkt)) { 391 retryPkt = NULL; 392 // remember how much delay was incurred due to back-pressure 393 // when sending the request, we also use this to derive 394 // the tick for the next packet 395 Tick delay = curTick() - retryPktTick; 396 retryPktTick = 0; 397 retryTicks += delay; 398 399 if (drainManager == NULL) { 400 // packet is sent, so find out when the next one is due 401 nextPacketTick = states[currState]->nextPacketTick(elasticReq, 402 delay); 403 Tick nextEventTick = std::min(nextPacketTick, nextTransitionTick); 404 schedule(updateEvent, std::max(curTick(), nextEventTick)); 405 } else { 406 // shut things down 407 nextPacketTick = MaxTick; 408 nextTransitionTick = MaxTick; 409 drainManager->signalDrainDone(); 410 // Clear the drain event once we're done with it. 411 drainManager = NULL; 412 } 413 } 414} 415 416void 417TrafficGen::regStats() 418{ 419 // Initialise all the stats 420 using namespace Stats; 421 422 numPackets 423 .name(name() + ".numPackets") 424 .desc("Number of packets generated"); 425 426 numRetries 427 .name(name() + ".numRetries") 428 .desc("Number of retries"); 429 430 retryTicks 431 .name(name() + ".retryTicks") 432 .desc("Time spent waiting due to back-pressure (ticks)"); 433} 434 435bool 436TrafficGen::TrafficGenPort::recvTimingResp(PacketPtr pkt) 437{ 438 delete pkt->req; 439 delete pkt; 440 441 return true; 442} 443