scheduler.cc revision 12995:3421144dd03e
12391SN/A/* 28931Sandreas.hansson@arm.com * Copyright 2018 Google, Inc. 38931Sandreas.hansson@arm.com * 48931Sandreas.hansson@arm.com * Redistribution and use in source and binary forms, with or without 58931Sandreas.hansson@arm.com * modification, are permitted provided that the following conditions are 68931Sandreas.hansson@arm.com * met: redistributions of source code must retain the above copyright 78931Sandreas.hansson@arm.com * notice, this list of conditions and the following disclaimer; 88931Sandreas.hansson@arm.com * redistributions in binary form must reproduce the above copyright 98931Sandreas.hansson@arm.com * notice, this list of conditions and the following disclaimer in the 108931Sandreas.hansson@arm.com * documentation and/or other materials provided with the distribution; 118931Sandreas.hansson@arm.com * neither the name of the copyright holders nor the names of its 128931Sandreas.hansson@arm.com * contributors may be used to endorse or promote products derived from 132391SN/A * this software without specific prior written permission. 142391SN/A * 152391SN/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 162391SN/A * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 172391SN/A * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 182391SN/A * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 192391SN/A * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 202391SN/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 212391SN/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 222391SN/A * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 232391SN/A * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 242391SN/A * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 252391SN/A * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 262391SN/A * 272391SN/A * Authors: Gabe Black 282391SN/A */ 292391SN/A 302391SN/A#include "systemc/core/scheduler.hh" 312391SN/A 322391SN/A#include "base/fiber.hh" 332391SN/A#include "base/logging.hh" 342391SN/A#include "sim/eventq.hh" 352391SN/A#include "systemc/core/kernel.hh" 362665Ssaidi@eecs.umich.edu#include "systemc/ext/core/sc_main.hh" 378931Sandreas.hansson@arm.com 382391SN/Anamespace sc_gem5 392391SN/A{ 402391SN/A 412391SN/AScheduler::Scheduler() : 422391SN/A eq(nullptr), readyEvent(this, false, ReadyPriority), 439235Sandreas.hansson@arm.com pauseEvent(this, false, PausePriority), 449293Sandreas.hansson@arm.com stopEvent(this, false, StopPriority), 459293Sandreas.hansson@arm.com scMain(nullptr), 469293Sandreas.hansson@arm.com starvationEvent(this, false, StarvationPriority), 479293Sandreas.hansson@arm.com _started(false), _paused(false), _stopped(false), 489293Sandreas.hansson@arm.com maxTickEvent(this, false, MaxTickPriority), 499293Sandreas.hansson@arm.com _numCycles(0), _current(nullptr), initReady(false) 504762Snate@binkert.org{} 518931Sandreas.hansson@arm.com 528931Sandreas.hansson@arm.comvoid 538931Sandreas.hansson@arm.comScheduler::prepareForInit() 548931Sandreas.hansson@arm.com{ 559293Sandreas.hansson@arm.com for (Process *p = toFinalize.getNext(); p; p = toFinalize.getNext()) { 569293Sandreas.hansson@arm.com p->finalize(); 579293Sandreas.hansson@arm.com p->popListNode(); 589293Sandreas.hansson@arm.com } 599293Sandreas.hansson@arm.com 609293Sandreas.hansson@arm.com for (Process *p = initList.getNext(); p; p = initList.getNext()) { 619293Sandreas.hansson@arm.com p->finalize(); 629293Sandreas.hansson@arm.com p->ready(); 639293Sandreas.hansson@arm.com } 649293Sandreas.hansson@arm.com 659293Sandreas.hansson@arm.com for (auto ets: eventsToSchedule) 668931Sandreas.hansson@arm.com eq->schedule(ets.first, ets.second); 679293Sandreas.hansson@arm.com eventsToSchedule.clear(); 682391SN/A 692413SN/A if (_started) 702391SN/A eq->schedule(&maxTickEvent, maxTick); 712391SN/A 729293Sandreas.hansson@arm.com initReady = true; 739293Sandreas.hansson@arm.com} 749293Sandreas.hansson@arm.com 758931Sandreas.hansson@arm.comvoid 769235Sandreas.hansson@arm.comScheduler::reg(Process *p) 773170Sstever@eecs.umich.edu{ 788931Sandreas.hansson@arm.com if (initReady) { 799235Sandreas.hansson@arm.com // If we're past initialization, finalize static sensitivity. 803170Sstever@eecs.umich.edu p->finalize(); 818931Sandreas.hansson@arm.com // Mark the process as ready. 828931Sandreas.hansson@arm.com p->ready(); 833170Sstever@eecs.umich.edu } else { 848931Sandreas.hansson@arm.com // Otherwise, record that this process should be initialized once we 858931Sandreas.hansson@arm.com // get there. 863170Sstever@eecs.umich.edu initList.pushLast(p); 879293Sandreas.hansson@arm.com } 889293Sandreas.hansson@arm.com} 899293Sandreas.hansson@arm.com 909293Sandreas.hansson@arm.comvoid 918931Sandreas.hansson@arm.comScheduler::dontInitialize(Process *p) 928931Sandreas.hansson@arm.com{ 933170Sstever@eecs.umich.edu if (initReady) { 948931Sandreas.hansson@arm.com // Pop this process off of the ready list. 958931Sandreas.hansson@arm.com p->popListNode(); 968719SAli.Saidi@ARM.com } else { 979293Sandreas.hansson@arm.com // Push this process onto the list of processes which still need 989293Sandreas.hansson@arm.com // their static sensitivity to be finalized. That implicitly pops it 999293Sandreas.hansson@arm.com // off the list of processes to be initialized/marked ready. 1009293Sandreas.hansson@arm.com toFinalize.pushLast(p); 1019293Sandreas.hansson@arm.com } 1029293Sandreas.hansson@arm.com} 1039293Sandreas.hansson@arm.com 1049293Sandreas.hansson@arm.comvoid 1059293Sandreas.hansson@arm.comScheduler::yield() 1069293Sandreas.hansson@arm.com{ 1079293Sandreas.hansson@arm.com _current = readyList.getNext(); 1082391SN/A if (!_current) { 1092391SN/A // There are no more processes, so return control to evaluate. 1108931Sandreas.hansson@arm.com Fiber::primaryFiber()->run(); 1118931Sandreas.hansson@arm.com } else { 1128931Sandreas.hansson@arm.com _current->popListNode(); 1139293Sandreas.hansson@arm.com // Switch to whatever Fiber is supposed to run this process. All 1149293Sandreas.hansson@arm.com // Fibers which aren't running should be parked at this line. 1152391SN/A _current->fiber()->run(); 1168931Sandreas.hansson@arm.com // If the current process needs to be manually started, start it. 1179293Sandreas.hansson@arm.com if (_current && _current->needsStart()) 1188931Sandreas.hansson@arm.com _current->run(); 1199293Sandreas.hansson@arm.com } 1209293Sandreas.hansson@arm.com if (_current && _current->excWrapper) { 1219293Sandreas.hansson@arm.com // Make sure this isn't a method process. 1229293Sandreas.hansson@arm.com assert(!_current->needsStart()); 1239293Sandreas.hansson@arm.com auto ew = _current->excWrapper; 1249293Sandreas.hansson@arm.com _current->excWrapper = nullptr; 1259293Sandreas.hansson@arm.com ew->throw_it(); 1264762Snate@binkert.org } 1278931Sandreas.hansson@arm.com} 1288931Sandreas.hansson@arm.com 1298931Sandreas.hansson@arm.comvoid 1308931Sandreas.hansson@arm.comScheduler::ready(Process *p) 1318931Sandreas.hansson@arm.com{ 1328931Sandreas.hansson@arm.com // Clump methods together to minimize context switching. 1338931Sandreas.hansson@arm.com if (p->procKind() == ::sc_core::SC_METHOD_PROC_) 1348931Sandreas.hansson@arm.com readyList.pushFirst(p); 1352391SN/A else 1368931Sandreas.hansson@arm.com readyList.pushLast(p); 1378931Sandreas.hansson@arm.com 1389413Sandreas.hansson@arm.com scheduleReadyEvent(); 1399413Sandreas.hansson@arm.com} 1409413Sandreas.hansson@arm.com 1418931Sandreas.hansson@arm.comvoid 1428931Sandreas.hansson@arm.comScheduler::requestUpdate(Channel *c) 1438931Sandreas.hansson@arm.com{ 1448931Sandreas.hansson@arm.com updateList.pushLast(c); 1458923Sandreas.hansson@arm.com scheduleReadyEvent(); 1468931Sandreas.hansson@arm.com} 1478931Sandreas.hansson@arm.com 1488931Sandreas.hansson@arm.comvoid 1498931Sandreas.hansson@arm.comScheduler::scheduleReadyEvent() 1508931Sandreas.hansson@arm.com{ 1518931Sandreas.hansson@arm.com // Schedule the evaluate and update phases. 1528923Sandreas.hansson@arm.com if (!readyEvent.scheduled()) { 1539293Sandreas.hansson@arm.com panic_if(!eq, "Need to schedule ready, but no event manager.\n"); 1549293Sandreas.hansson@arm.com eq->schedule(&readyEvent, eq->getCurTick()); 1559293Sandreas.hansson@arm.com if (starvationEvent.scheduled()) 1569293Sandreas.hansson@arm.com eq->deschedule(&starvationEvent); 1579293Sandreas.hansson@arm.com } 1589293Sandreas.hansson@arm.com} 1599293Sandreas.hansson@arm.com 1609293Sandreas.hansson@arm.comvoid 1619293Sandreas.hansson@arm.comScheduler::scheduleStarvationEvent() 1629293Sandreas.hansson@arm.com{ 1639293Sandreas.hansson@arm.com if (!starvationEvent.scheduled()) { 1649293Sandreas.hansson@arm.com panic_if(!eq, "Need to schedule starvation event, " 1659293Sandreas.hansson@arm.com "but no event manager.\n"); 1669293Sandreas.hansson@arm.com eq->schedule(&starvationEvent, eq->getCurTick()); 1679293Sandreas.hansson@arm.com if (readyEvent.scheduled()) 1688931Sandreas.hansson@arm.com eq->deschedule(&readyEvent); 1699293Sandreas.hansson@arm.com } 1709293Sandreas.hansson@arm.com} 1719293Sandreas.hansson@arm.com 1728931Sandreas.hansson@arm.comvoid 1739293Sandreas.hansson@arm.comScheduler::runReady() 1748719SAli.Saidi@ARM.com{ 1758931Sandreas.hansson@arm.com bool empty = readyList.empty(); 1769293Sandreas.hansson@arm.com 1779293Sandreas.hansson@arm.com // The evaluation phase. 1789293Sandreas.hansson@arm.com do { 1799293Sandreas.hansson@arm.com yield(); 1809293Sandreas.hansson@arm.com } while (!readyList.empty()); 1819293Sandreas.hansson@arm.com 1829293Sandreas.hansson@arm.com if (!empty) 1839293Sandreas.hansson@arm.com _numCycles++; 1849293Sandreas.hansson@arm.com 1858931Sandreas.hansson@arm.com // The update phase. 1869293Sandreas.hansson@arm.com update(); 1879293Sandreas.hansson@arm.com 1889293Sandreas.hansson@arm.com if (starved() && !runToTime) 1899293Sandreas.hansson@arm.com scheduleStarvationEvent(); 1909293Sandreas.hansson@arm.com 1919293Sandreas.hansson@arm.com // The delta phase will happen naturally through the event queue. 1929293Sandreas.hansson@arm.com} 1939293Sandreas.hansson@arm.com 1949293Sandreas.hansson@arm.comvoid 1959293Sandreas.hansson@arm.comScheduler::update() 1969293Sandreas.hansson@arm.com{ 1979293Sandreas.hansson@arm.com Channel *channel = updateList.getNext(); 1989293Sandreas.hansson@arm.com while (channel) { 1999293Sandreas.hansson@arm.com channel->popListNode(); 2009293Sandreas.hansson@arm.com channel->update(); 2019293Sandreas.hansson@arm.com channel = updateList.getNext(); 2029293Sandreas.hansson@arm.com } 2039293Sandreas.hansson@arm.com} 2049293Sandreas.hansson@arm.com 2059293Sandreas.hansson@arm.comvoid 2069293Sandreas.hansson@arm.comScheduler::pause() 2079293Sandreas.hansson@arm.com{ 2089293Sandreas.hansson@arm.com _paused = true; 2099293Sandreas.hansson@arm.com kernel->status(::sc_core::SC_PAUSED); 2109293Sandreas.hansson@arm.com scMain->run(); 2119293Sandreas.hansson@arm.com} 2129293Sandreas.hansson@arm.com 2139293Sandreas.hansson@arm.comvoid 2149293Sandreas.hansson@arm.comScheduler::stop() 2159293Sandreas.hansson@arm.com{ 2169293Sandreas.hansson@arm.com _stopped = true; 2179293Sandreas.hansson@arm.com kernel->stop(); 2189293Sandreas.hansson@arm.com scMain->run(); 2192391SN/A} 2202391SN/A 2212391SN/Avoid 222Scheduler::start(Tick max_tick, bool run_to_time) 223{ 224 // We should be running from sc_main. Keep track of that Fiber to return 225 // to later. 226 scMain = Fiber::currentFiber(); 227 228 _started = true; 229 _paused = false; 230 _stopped = false; 231 runToTime = run_to_time; 232 233 maxTick = max_tick; 234 235 if (starved() && !runToTime) 236 return; 237 238 if (initReady) { 239 kernel->status(::sc_core::SC_RUNNING); 240 eq->schedule(&maxTickEvent, maxTick); 241 } 242 243 // Return to gem5 to let it run events, etc. 244 Fiber::primaryFiber()->run(); 245 246 if (pauseEvent.scheduled()) 247 eq->deschedule(&pauseEvent); 248 if (stopEvent.scheduled()) 249 eq->deschedule(&stopEvent); 250 if (maxTickEvent.scheduled()) 251 eq->deschedule(&maxTickEvent); 252 if (starvationEvent.scheduled()) 253 eq->deschedule(&starvationEvent); 254} 255 256void 257Scheduler::schedulePause() 258{ 259 if (pauseEvent.scheduled()) 260 return; 261 262 eq->schedule(&pauseEvent, eq->getCurTick()); 263} 264 265void 266Scheduler::scheduleStop(bool finish_delta) 267{ 268 if (stopEvent.scheduled()) 269 return; 270 271 if (!finish_delta) { 272 // If we're not supposed to finish the delta cycle, flush the list 273 // of ready processes and scheduled updates. 274 Process *p; 275 while ((p = readyList.getNext())) 276 p->popListNode(); 277 Channel *c; 278 while ((c = updateList.getNext())) 279 c->popListNode(); 280 } 281 eq->schedule(&stopEvent, eq->getCurTick()); 282} 283 284Scheduler scheduler; 285 286} // namespace sc_gem5 287