traffic_gen.cc revision 10128
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 (!updateEvent.scheduled()) { 123 // no event has been scheduled yet (e.g. switched from atomic mode) 124 return 0; 125 } 126 127 if (retryPkt == NULL) { 128 // shut things down 129 nextPacketTick = MaxTick; 130 nextTransitionTick = MaxTick; 131 deschedule(updateEvent); 132 return 0; 133 } else { 134 drainManager = dm; 135 return 1; 136 } 137} 138 139void 140TrafficGen::serialize(ostream &os) 141{ 142 DPRINTF(Checkpoint, "Serializing TrafficGen\n"); 143 144 // save ticks of the graph event if it is scheduled 145 Tick nextEvent = updateEvent.scheduled() ? updateEvent.when() : 0; 146 147 DPRINTF(TrafficGen, "Saving nextEvent=%llu\n", nextEvent); 148 149 SERIALIZE_SCALAR(nextEvent); 150 151 SERIALIZE_SCALAR(nextTransitionTick); 152 153 SERIALIZE_SCALAR(nextPacketTick); 154 155 SERIALIZE_SCALAR(currState); 156} 157 158void 159TrafficGen::unserialize(Checkpoint* cp, const string& section) 160{ 161 // restore scheduled events 162 Tick nextEvent; 163 UNSERIALIZE_SCALAR(nextEvent); 164 if (nextEvent != 0) { 165 schedule(updateEvent, nextEvent); 166 } 167 168 UNSERIALIZE_SCALAR(nextTransitionTick); 169 170 UNSERIALIZE_SCALAR(nextPacketTick); 171 172 // @todo In the case of a stateful generator state such as the 173 // trace player we would also have to restore the position in the 174 // trace playback and the tick offset 175 UNSERIALIZE_SCALAR(currState); 176} 177 178void 179TrafficGen::update() 180{ 181 // if we have reached the time for the next state transition, then 182 // perform the transition 183 if (curTick() >= nextTransitionTick) { 184 transition(); 185 } else { 186 assert(curTick() >= nextPacketTick); 187 // get the next packet and try to send it 188 PacketPtr pkt = states[currState]->getNextPacket(); 189 numPackets++; 190 if (!port.sendTimingReq(pkt)) { 191 retryPkt = pkt; 192 retryPktTick = curTick(); 193 } 194 } 195 196 // if we are waiting for a retry, do not schedule any further 197 // events, in the case of a transition or a successful send, go 198 // ahead and determine when the next update should take place 199 if (retryPkt == NULL) { 200 // schedule next update event based on either the next execute 201 // tick or the next transition, which ever comes first 202 nextPacketTick = states[currState]->nextPacketTick(elasticReq, 0); 203 Tick nextEventTick = std::min(nextPacketTick, nextTransitionTick); 204 DPRINTF(TrafficGen, "Next event scheduled at %lld\n", nextEventTick); 205 schedule(updateEvent, nextEventTick); 206 } 207} 208 209void 210TrafficGen::parseConfig() 211{ 212 // keep track of the transitions parsed to create the matrix when 213 // done 214 vector<Transition> transitions; 215 216 // open input file 217 ifstream infile; 218 infile.open(configFile.c_str(), ifstream::in); 219 if (!infile.is_open()) { 220 fatal("Traffic generator %s config file not found at %s\n", 221 name(), configFile); 222 } 223 224 bool init_state_set = false; 225 226 // read line by line and determine the action based on the first 227 // keyword 228 string keyword; 229 string line; 230 231 while (getline(infile, line).good()) { 232 // see if this line is a comment line, and if so skip it 233 if (line.find('#') != 1) { 234 // create an input stream for the tokenization 235 istringstream is(line); 236 237 // determine the keyword 238 is >> keyword; 239 240 if (keyword == "STATE") { 241 // parse the behaviour of this state 242 uint32_t id; 243 Tick duration; 244 string mode; 245 246 is >> id >> duration >> mode; 247 248 if (mode == "TRACE") { 249 string traceFile; 250 Addr addrOffset; 251 252 is >> traceFile >> addrOffset; 253 254 states[id] = new TraceGen(name(), masterID, duration, 255 traceFile, addrOffset); 256 DPRINTF(TrafficGen, "State: %d TraceGen\n", id); 257 } else if (mode == "IDLE") { 258 states[id] = new IdleGen(name(), masterID, duration); 259 DPRINTF(TrafficGen, "State: %d IdleGen\n", id); 260 } else if (mode == "LINEAR" || mode == "RANDOM") { 261 uint32_t read_percent; 262 Addr start_addr; 263 Addr end_addr; 264 Addr blocksize; 265 Tick min_period; 266 Tick max_period; 267 Addr data_limit; 268 269 is >> read_percent >> start_addr >> end_addr >> 270 blocksize >> min_period >> max_period >> data_limit; 271 272 DPRINTF(TrafficGen, "%s, addr %x to %x, size %d," 273 " period %d to %d, %d%% reads\n", 274 mode, start_addr, end_addr, blocksize, min_period, 275 max_period, read_percent); 276 277 278 if (blocksize > system->cacheLineSize()) 279 fatal("TrafficGen %s block size (%d) is larger than " 280 "system block size (%d)\n", name(), 281 blocksize, system->cacheLineSize()); 282 283 if (read_percent > 100) 284 fatal("%s cannot have more than 100% reads", name()); 285 286 if (min_period > max_period) 287 fatal("%s cannot have min_period > max_period", name()); 288 289 if (mode == "LINEAR") { 290 states[id] = new LinearGen(name(), masterID, 291 duration, start_addr, 292 end_addr, blocksize, 293 min_period, max_period, 294 read_percent, data_limit); 295 DPRINTF(TrafficGen, "State: %d LinearGen\n", id); 296 } else if (mode == "RANDOM") { 297 states[id] = new RandomGen(name(), masterID, 298 duration, start_addr, 299 end_addr, blocksize, 300 min_period, max_period, 301 read_percent, data_limit); 302 DPRINTF(TrafficGen, "State: %d RandomGen\n", id); 303 } 304 } else { 305 fatal("%s: Unknown traffic generator mode: %s", 306 name(), mode); 307 } 308 } else if (keyword == "TRANSITION") { 309 Transition transition; 310 311 is >> transition.from >> transition.to >> transition.p; 312 313 transitions.push_back(transition); 314 315 DPRINTF(TrafficGen, "Transition: %d -> %d\n", transition.from, 316 transition.to); 317 } else if (keyword == "INIT") { 318 // set the initial state as the active state 319 is >> currState; 320 321 init_state_set = true; 322 323 DPRINTF(TrafficGen, "Initial state: %d\n", currState); 324 } 325 } 326 } 327 328 if (!init_state_set) 329 fatal("%s: initial state not specified (add 'INIT <id>' line " 330 "to the config file)\n", name()); 331 332 // resize and populate state transition matrix 333 transitionMatrix.resize(states.size()); 334 for (size_t i = 0; i < states.size(); i++) { 335 transitionMatrix[i].resize(states.size()); 336 } 337 338 for (vector<Transition>::iterator t = transitions.begin(); 339 t != transitions.end(); ++t) { 340 transitionMatrix[t->from][t->to] = t->p; 341 } 342 343 // ensure the egress edges do not have a probability larger than 344 // one 345 for (size_t i = 0; i < states.size(); i++) { 346 double sum = 0; 347 for (size_t j = 0; j < states.size(); j++) { 348 sum += transitionMatrix[i][j]; 349 } 350 351 // avoid comparing floating point numbers 352 if (abs(sum - 1.0) > 0.001) 353 fatal("%s has transition probability != 1 for state %d\n", 354 name(), i); 355 } 356 357 // close input file 358 infile.close(); 359} 360 361void 362TrafficGen::transition() 363{ 364 // exit the current state 365 states[currState]->exit(); 366 367 // determine next state 368 double p = random_mt.gen_real1(); 369 assert(currState < transitionMatrix.size()); 370 double cumulative = 0.0; 371 size_t i = 0; 372 do { 373 cumulative += transitionMatrix[currState][i]; 374 ++i; 375 } while (cumulative < p && i < transitionMatrix[currState].size()); 376 377 enterState(i - 1); 378} 379 380void 381TrafficGen::enterState(uint32_t newState) 382{ 383 DPRINTF(TrafficGen, "Transition to state %d\n", newState); 384 385 currState = newState; 386 // we could have been delayed and not transitioned on the exact 387 // tick when we were supposed to (due to back pressure when 388 // sending a packet) 389 nextTransitionTick = curTick() + states[currState]->duration; 390 states[currState]->enter(); 391} 392 393void 394TrafficGen::recvRetry() 395{ 396 assert(retryPkt != NULL); 397 398 DPRINTF(TrafficGen, "Received retry\n"); 399 numRetries++; 400 // attempt to send the packet, and if we are successful start up 401 // the machinery again 402 if (port.sendTimingReq(retryPkt)) { 403 retryPkt = NULL; 404 // remember how much delay was incurred due to back-pressure 405 // when sending the request, we also use this to derive 406 // the tick for the next packet 407 Tick delay = curTick() - retryPktTick; 408 retryPktTick = 0; 409 retryTicks += delay; 410 411 if (drainManager == NULL) { 412 // packet is sent, so find out when the next one is due 413 nextPacketTick = states[currState]->nextPacketTick(elasticReq, 414 delay); 415 Tick nextEventTick = std::min(nextPacketTick, nextTransitionTick); 416 schedule(updateEvent, std::max(curTick(), nextEventTick)); 417 } else { 418 // shut things down 419 nextPacketTick = MaxTick; 420 nextTransitionTick = MaxTick; 421 drainManager->signalDrainDone(); 422 // Clear the drain event once we're done with it. 423 drainManager = NULL; 424 } 425 } 426} 427 428void 429TrafficGen::regStats() 430{ 431 // Initialise all the stats 432 using namespace Stats; 433 434 numPackets 435 .name(name() + ".numPackets") 436 .desc("Number of packets generated"); 437 438 numRetries 439 .name(name() + ".numRetries") 440 .desc("Number of retries"); 441 442 retryTicks 443 .name(name() + ".retryTicks") 444 .desc("Time spent waiting due to back-pressure (ticks)"); 445} 446 447bool 448TrafficGen::TrafficGenPort::recvTimingResp(PacketPtr pkt) 449{ 450 delete pkt->req; 451 delete pkt; 452 453 return true; 454} 455