scheduler.cc revision 13145
112953Sgabeblack@google.com/* 212953Sgabeblack@google.com * Copyright 2018 Google, Inc. 312953Sgabeblack@google.com * 412953Sgabeblack@google.com * Redistribution and use in source and binary forms, with or without 512953Sgabeblack@google.com * modification, are permitted provided that the following conditions are 612953Sgabeblack@google.com * met: redistributions of source code must retain the above copyright 712953Sgabeblack@google.com * notice, this list of conditions and the following disclaimer; 812953Sgabeblack@google.com * redistributions in binary form must reproduce the above copyright 912953Sgabeblack@google.com * notice, this list of conditions and the following disclaimer in the 1012953Sgabeblack@google.com * documentation and/or other materials provided with the distribution; 1112953Sgabeblack@google.com * neither the name of the copyright holders nor the names of its 1212953Sgabeblack@google.com * contributors may be used to endorse or promote products derived from 1312953Sgabeblack@google.com * this software without specific prior written permission. 1412953Sgabeblack@google.com * 1512953Sgabeblack@google.com * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 1612953Sgabeblack@google.com * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 1712953Sgabeblack@google.com * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 1812953Sgabeblack@google.com * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 1912953Sgabeblack@google.com * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 2012953Sgabeblack@google.com * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 2112953Sgabeblack@google.com * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2212953Sgabeblack@google.com * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2312953Sgabeblack@google.com * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2412953Sgabeblack@google.com * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 2512953Sgabeblack@google.com * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2612953Sgabeblack@google.com * 2712953Sgabeblack@google.com * Authors: Gabe Black 2812953Sgabeblack@google.com */ 2912953Sgabeblack@google.com 3012953Sgabeblack@google.com#include "systemc/core/scheduler.hh" 3112953Sgabeblack@google.com 3212953Sgabeblack@google.com#include "base/fiber.hh" 3312954Sgabeblack@google.com#include "base/logging.hh" 3412954Sgabeblack@google.com#include "sim/eventq.hh" 3512982Sgabeblack@google.com#include "systemc/core/kernel.hh" 3612982Sgabeblack@google.com#include "systemc/ext/core/sc_main.hh" 3712953Sgabeblack@google.com 3812953Sgabeblack@google.comnamespace sc_gem5 3912953Sgabeblack@google.com{ 4012953Sgabeblack@google.com 4112954Sgabeblack@google.comScheduler::Scheduler() : 4212962Sgabeblack@google.com eq(nullptr), readyEvent(this, false, ReadyPriority), 4312961Sgabeblack@google.com pauseEvent(this, false, PausePriority), 4412961Sgabeblack@google.com stopEvent(this, false, StopPriority), 4512987Sgabeblack@google.com scMain(nullptr), 4612987Sgabeblack@google.com starvationEvent(this, false, StarvationPriority), 4712987Sgabeblack@google.com _started(false), _paused(false), _stopped(false), 4812961Sgabeblack@google.com maxTickEvent(this, false, MaxTickPriority), 4913140Sgabeblack@google.com _numCycles(0), _changeStamp(0), _current(nullptr), initDone(false), 5013061Sgabeblack@google.com runOnce(false) 5112954Sgabeblack@google.com{} 5212953Sgabeblack@google.com 5313072Sgabeblack@google.comScheduler::~Scheduler() 5413072Sgabeblack@google.com{ 5513072Sgabeblack@google.com // Clear out everything that belongs to us to make sure nobody tries to 5613072Sgabeblack@google.com // clear themselves out after the scheduler goes away. 5713076Sgabeblack@google.com clear(); 5813076Sgabeblack@google.com} 5913072Sgabeblack@google.com 6013076Sgabeblack@google.comvoid 6113076Sgabeblack@google.comScheduler::clear() 6213076Sgabeblack@google.com{ 6313072Sgabeblack@google.com // Delta notifications. 6413144Sgabeblack@google.com while (!deltas.empty()) 6513144Sgabeblack@google.com deltas.front()->deschedule(); 6613072Sgabeblack@google.com 6713072Sgabeblack@google.com // Timed notifications. 6813076Sgabeblack@google.com for (auto &tsp: timeSlots) { 6913076Sgabeblack@google.com TimeSlot *&ts = tsp.second; 7013144Sgabeblack@google.com while (!ts->events.empty()) 7113144Sgabeblack@google.com ts->events.front()->deschedule(); 7213088Sgabeblack@google.com deschedule(ts); 7313072Sgabeblack@google.com } 7413076Sgabeblack@google.com timeSlots.clear(); 7513072Sgabeblack@google.com 7613072Sgabeblack@google.com // gem5 events. 7713072Sgabeblack@google.com if (readyEvent.scheduled()) 7813088Sgabeblack@google.com deschedule(&readyEvent); 7913072Sgabeblack@google.com if (pauseEvent.scheduled()) 8013088Sgabeblack@google.com deschedule(&pauseEvent); 8113072Sgabeblack@google.com if (stopEvent.scheduled()) 8213088Sgabeblack@google.com deschedule(&stopEvent); 8313072Sgabeblack@google.com if (starvationEvent.scheduled()) 8413088Sgabeblack@google.com deschedule(&starvationEvent); 8513072Sgabeblack@google.com if (maxTickEvent.scheduled()) 8613088Sgabeblack@google.com deschedule(&maxTickEvent); 8713072Sgabeblack@google.com 8813072Sgabeblack@google.com Process *p; 8913072Sgabeblack@google.com while ((p = toFinalize.getNext())) 9013072Sgabeblack@google.com p->popListNode(); 9113072Sgabeblack@google.com while ((p = initList.getNext())) 9213072Sgabeblack@google.com p->popListNode(); 9313072Sgabeblack@google.com while ((p = readyList.getNext())) 9413072Sgabeblack@google.com p->popListNode(); 9513072Sgabeblack@google.com 9613072Sgabeblack@google.com Channel *c; 9713072Sgabeblack@google.com while ((c = updateList.getNext())) 9813072Sgabeblack@google.com c->popListNode(); 9913072Sgabeblack@google.com} 10013072Sgabeblack@google.com 10112953Sgabeblack@google.comvoid 10213067Sgabeblack@google.comScheduler::initPhase() 10312953Sgabeblack@google.com{ 10412957Sgabeblack@google.com for (Process *p = toFinalize.getNext(); p; p = toFinalize.getNext()) { 10512957Sgabeblack@google.com p->finalize(); 10612957Sgabeblack@google.com p->popListNode(); 10712957Sgabeblack@google.com } 10812957Sgabeblack@google.com 10912957Sgabeblack@google.com for (Process *p = initList.getNext(); p; p = initList.getNext()) { 11012957Sgabeblack@google.com p->finalize(); 11112996Sgabeblack@google.com p->popListNode(); 11212959Sgabeblack@google.com p->ready(); 11312957Sgabeblack@google.com } 11412957Sgabeblack@google.com 11513067Sgabeblack@google.com update(); 11613067Sgabeblack@google.com 11713144Sgabeblack@google.com while (!deltas.empty()) 11813144Sgabeblack@google.com deltas.front()->run(); 11913067Sgabeblack@google.com 12012985Sgabeblack@google.com for (auto ets: eventsToSchedule) 12112985Sgabeblack@google.com eq->schedule(ets.first, ets.second); 12212985Sgabeblack@google.com eventsToSchedule.clear(); 12312985Sgabeblack@google.com 12413068Sgabeblack@google.com if (_started) { 12513096Sgabeblack@google.com if (!runToTime && starved()) 12613068Sgabeblack@google.com scheduleStarvationEvent(); 12713069Sgabeblack@google.com kernel->status(::sc_core::SC_RUNNING); 12813068Sgabeblack@google.com } 12912961Sgabeblack@google.com 13013067Sgabeblack@google.com initDone = true; 13112957Sgabeblack@google.com} 13212957Sgabeblack@google.com 13312957Sgabeblack@google.comvoid 13412957Sgabeblack@google.comScheduler::reg(Process *p) 13512957Sgabeblack@google.com{ 13613067Sgabeblack@google.com if (initDone) { 13712957Sgabeblack@google.com // If we're past initialization, finalize static sensitivity. 13812957Sgabeblack@google.com p->finalize(); 13912957Sgabeblack@google.com // Mark the process as ready. 14012959Sgabeblack@google.com p->ready(); 14112957Sgabeblack@google.com } else { 14212957Sgabeblack@google.com // Otherwise, record that this process should be initialized once we 14312957Sgabeblack@google.com // get there. 14412957Sgabeblack@google.com initList.pushLast(p); 14512957Sgabeblack@google.com } 14612957Sgabeblack@google.com} 14712957Sgabeblack@google.com 14812957Sgabeblack@google.comvoid 14912957Sgabeblack@google.comScheduler::dontInitialize(Process *p) 15012957Sgabeblack@google.com{ 15113067Sgabeblack@google.com if (initDone) { 15212957Sgabeblack@google.com // Pop this process off of the ready list. 15312957Sgabeblack@google.com p->popListNode(); 15412957Sgabeblack@google.com } else { 15512957Sgabeblack@google.com // Push this process onto the list of processes which still need 15612957Sgabeblack@google.com // their static sensitivity to be finalized. That implicitly pops it 15712957Sgabeblack@google.com // off the list of processes to be initialized/marked ready. 15812957Sgabeblack@google.com toFinalize.pushLast(p); 15912957Sgabeblack@google.com } 16012953Sgabeblack@google.com} 16112953Sgabeblack@google.com 16212953Sgabeblack@google.comvoid 16312953Sgabeblack@google.comScheduler::yield() 16412953Sgabeblack@google.com{ 16512953Sgabeblack@google.com _current = readyList.getNext(); 16612953Sgabeblack@google.com if (!_current) { 16712953Sgabeblack@google.com // There are no more processes, so return control to evaluate. 16812953Sgabeblack@google.com Fiber::primaryFiber()->run(); 16912953Sgabeblack@google.com } else { 17012953Sgabeblack@google.com _current->popListNode(); 17112953Sgabeblack@google.com // Switch to whatever Fiber is supposed to run this process. All 17212953Sgabeblack@google.com // Fibers which aren't running should be parked at this line. 17312953Sgabeblack@google.com _current->fiber()->run(); 17412961Sgabeblack@google.com // If the current process needs to be manually started, start it. 17513093Sgabeblack@google.com if (_current && _current->needsStart()) { 17613093Sgabeblack@google.com _current->needsStart(false); 17712953Sgabeblack@google.com _current->run(); 17813093Sgabeblack@google.com } 17912953Sgabeblack@google.com } 18012995Sgabeblack@google.com if (_current && _current->excWrapper) { 18112995Sgabeblack@google.com // Make sure this isn't a method process. 18212995Sgabeblack@google.com assert(!_current->needsStart()); 18312995Sgabeblack@google.com auto ew = _current->excWrapper; 18412995Sgabeblack@google.com _current->excWrapper = nullptr; 18512995Sgabeblack@google.com ew->throw_it(); 18612995Sgabeblack@google.com } 18712953Sgabeblack@google.com} 18812953Sgabeblack@google.com 18912953Sgabeblack@google.comvoid 19012954Sgabeblack@google.comScheduler::ready(Process *p) 19112953Sgabeblack@google.com{ 19212954Sgabeblack@google.com // Clump methods together to minimize context switching. 19313145Sgabeblack@google.com static bool cluster_methods = false; 19413145Sgabeblack@google.com 19513145Sgabeblack@google.com if (cluster_methods && p->procKind() == ::sc_core::SC_METHOD_PROC_) 19612954Sgabeblack@google.com readyList.pushFirst(p); 19712954Sgabeblack@google.com else 19812954Sgabeblack@google.com readyList.pushLast(p); 19912953Sgabeblack@google.com 20012954Sgabeblack@google.com scheduleReadyEvent(); 20112954Sgabeblack@google.com} 20212954Sgabeblack@google.com 20312954Sgabeblack@google.comvoid 20413133Sgabeblack@google.comScheduler::resume(Process *p) 20513133Sgabeblack@google.com{ 20613133Sgabeblack@google.com if (initDone) 20713133Sgabeblack@google.com ready(p); 20813133Sgabeblack@google.com else 20913133Sgabeblack@google.com initList.pushLast(p); 21013133Sgabeblack@google.com} 21113133Sgabeblack@google.com 21213133Sgabeblack@google.combool 21313133Sgabeblack@google.comScheduler::suspend(Process *p) 21413133Sgabeblack@google.com{ 21513133Sgabeblack@google.com if (initDone) { 21613133Sgabeblack@google.com // After initialization, the only list we can be on is the ready list. 21713133Sgabeblack@google.com bool was_ready = (p->nextListNode != nullptr); 21813133Sgabeblack@google.com p->popListNode(); 21913133Sgabeblack@google.com return was_ready; 22013133Sgabeblack@google.com } else { 22113133Sgabeblack@google.com bool was_ready = false; 22213133Sgabeblack@google.com // Check the ready list to see if we find this process. 22313133Sgabeblack@google.com ListNode *n = readyList.nextListNode; 22413133Sgabeblack@google.com while (n != &readyList) { 22513133Sgabeblack@google.com if (n == p) { 22613133Sgabeblack@google.com was_ready = true; 22713133Sgabeblack@google.com break; 22813133Sgabeblack@google.com } 22913133Sgabeblack@google.com } 23013133Sgabeblack@google.com if (was_ready) 23113133Sgabeblack@google.com toFinalize.pushLast(p); 23213133Sgabeblack@google.com return was_ready; 23313133Sgabeblack@google.com } 23413133Sgabeblack@google.com} 23513133Sgabeblack@google.com 23613133Sgabeblack@google.comvoid 23712954Sgabeblack@google.comScheduler::requestUpdate(Channel *c) 23812954Sgabeblack@google.com{ 23912954Sgabeblack@google.com updateList.pushLast(c); 24013069Sgabeblack@google.com scheduleReadyEvent(); 24112954Sgabeblack@google.com} 24212954Sgabeblack@google.com 24312954Sgabeblack@google.comvoid 24412954Sgabeblack@google.comScheduler::scheduleReadyEvent() 24512954Sgabeblack@google.com{ 24612954Sgabeblack@google.com // Schedule the evaluate and update phases. 24712954Sgabeblack@google.com if (!readyEvent.scheduled()) { 24813069Sgabeblack@google.com schedule(&readyEvent); 24912987Sgabeblack@google.com if (starvationEvent.scheduled()) 25013069Sgabeblack@google.com deschedule(&starvationEvent); 25112987Sgabeblack@google.com } 25212987Sgabeblack@google.com} 25312987Sgabeblack@google.com 25412987Sgabeblack@google.comvoid 25512987Sgabeblack@google.comScheduler::scheduleStarvationEvent() 25612987Sgabeblack@google.com{ 25712987Sgabeblack@google.com if (!starvationEvent.scheduled()) { 25813069Sgabeblack@google.com schedule(&starvationEvent); 25912987Sgabeblack@google.com if (readyEvent.scheduled()) 26013069Sgabeblack@google.com deschedule(&readyEvent); 26112954Sgabeblack@google.com } 26212954Sgabeblack@google.com} 26312954Sgabeblack@google.com 26412954Sgabeblack@google.comvoid 26512954Sgabeblack@google.comScheduler::runReady() 26612954Sgabeblack@google.com{ 26712954Sgabeblack@google.com bool empty = readyList.empty(); 26813140Sgabeblack@google.com lastReadyTick = getCurTick(); 26912954Sgabeblack@google.com 27012954Sgabeblack@google.com // The evaluation phase. 27112953Sgabeblack@google.com do { 27212953Sgabeblack@google.com yield(); 27312953Sgabeblack@google.com } while (!readyList.empty()); 27412954Sgabeblack@google.com 27513140Sgabeblack@google.com if (!empty) { 27612954Sgabeblack@google.com _numCycles++; 27713140Sgabeblack@google.com _changeStamp++; 27813140Sgabeblack@google.com } 27912954Sgabeblack@google.com 28012954Sgabeblack@google.com // The update phase. 28112954Sgabeblack@google.com update(); 28212954Sgabeblack@google.com 28313063Sgabeblack@google.com // The delta phase. 28413144Sgabeblack@google.com while (!deltas.empty()) 28513144Sgabeblack@google.com deltas.front()->run(); 28613061Sgabeblack@google.com 28713096Sgabeblack@google.com if (!runToTime && starved()) 28813096Sgabeblack@google.com scheduleStarvationEvent(); 28913096Sgabeblack@google.com 29013064Sgabeblack@google.com if (runOnce) 29113064Sgabeblack@google.com schedulePause(); 29212953Sgabeblack@google.com} 29312953Sgabeblack@google.com 29412953Sgabeblack@google.comvoid 29512953Sgabeblack@google.comScheduler::update() 29612953Sgabeblack@google.com{ 29712954Sgabeblack@google.com Channel *channel = updateList.getNext(); 29812954Sgabeblack@google.com while (channel) { 29912954Sgabeblack@google.com channel->popListNode(); 30012954Sgabeblack@google.com channel->update(); 30112954Sgabeblack@google.com channel = updateList.getNext(); 30212954Sgabeblack@google.com } 30312953Sgabeblack@google.com} 30412953Sgabeblack@google.com 30512961Sgabeblack@google.comvoid 30612961Sgabeblack@google.comScheduler::pause() 30712961Sgabeblack@google.com{ 30812961Sgabeblack@google.com _paused = true; 30912982Sgabeblack@google.com kernel->status(::sc_core::SC_PAUSED); 31013061Sgabeblack@google.com runOnce = false; 31112961Sgabeblack@google.com scMain->run(); 31212961Sgabeblack@google.com} 31312961Sgabeblack@google.com 31412961Sgabeblack@google.comvoid 31512961Sgabeblack@google.comScheduler::stop() 31612961Sgabeblack@google.com{ 31712961Sgabeblack@google.com _stopped = true; 31812982Sgabeblack@google.com kernel->stop(); 31913074Sgabeblack@google.com 32013076Sgabeblack@google.com clear(); 32113074Sgabeblack@google.com 32213061Sgabeblack@google.com runOnce = false; 32312961Sgabeblack@google.com scMain->run(); 32412961Sgabeblack@google.com} 32512961Sgabeblack@google.com 32612961Sgabeblack@google.comvoid 32712961Sgabeblack@google.comScheduler::start(Tick max_tick, bool run_to_time) 32812961Sgabeblack@google.com{ 32912961Sgabeblack@google.com // We should be running from sc_main. Keep track of that Fiber to return 33012961Sgabeblack@google.com // to later. 33112961Sgabeblack@google.com scMain = Fiber::currentFiber(); 33212961Sgabeblack@google.com 33312961Sgabeblack@google.com _started = true; 33412961Sgabeblack@google.com _paused = false; 33512961Sgabeblack@google.com _stopped = false; 33612987Sgabeblack@google.com runToTime = run_to_time; 33712961Sgabeblack@google.com 33812961Sgabeblack@google.com maxTick = max_tick; 33913140Sgabeblack@google.com lastReadyTick = getCurTick(); 34012961Sgabeblack@google.com 34113067Sgabeblack@google.com if (initDone) { 34213096Sgabeblack@google.com if (!runToTime && starved()) 34313068Sgabeblack@google.com scheduleStarvationEvent(); 34412982Sgabeblack@google.com kernel->status(::sc_core::SC_RUNNING); 34512982Sgabeblack@google.com } 34612961Sgabeblack@google.com 34713069Sgabeblack@google.com schedule(&maxTickEvent, maxTick); 34813069Sgabeblack@google.com 34912961Sgabeblack@google.com // Return to gem5 to let it run events, etc. 35012961Sgabeblack@google.com Fiber::primaryFiber()->run(); 35112961Sgabeblack@google.com 35212961Sgabeblack@google.com if (pauseEvent.scheduled()) 35313088Sgabeblack@google.com deschedule(&pauseEvent); 35412961Sgabeblack@google.com if (stopEvent.scheduled()) 35513088Sgabeblack@google.com deschedule(&stopEvent); 35612961Sgabeblack@google.com if (maxTickEvent.scheduled()) 35713088Sgabeblack@google.com deschedule(&maxTickEvent); 35812987Sgabeblack@google.com if (starvationEvent.scheduled()) 35913088Sgabeblack@google.com deschedule(&starvationEvent); 36012961Sgabeblack@google.com} 36112961Sgabeblack@google.com 36212961Sgabeblack@google.comvoid 36313061Sgabeblack@google.comScheduler::oneCycle() 36413061Sgabeblack@google.com{ 36513061Sgabeblack@google.com runOnce = true; 36613095Sgabeblack@google.com scheduleReadyEvent(); 36713061Sgabeblack@google.com start(::MaxTick, false); 36813061Sgabeblack@google.com} 36913061Sgabeblack@google.com 37013061Sgabeblack@google.comvoid 37112961Sgabeblack@google.comScheduler::schedulePause() 37212961Sgabeblack@google.com{ 37312961Sgabeblack@google.com if (pauseEvent.scheduled()) 37412961Sgabeblack@google.com return; 37512961Sgabeblack@google.com 37613088Sgabeblack@google.com schedule(&pauseEvent); 37712961Sgabeblack@google.com} 37812961Sgabeblack@google.com 37912961Sgabeblack@google.comvoid 38012961Sgabeblack@google.comScheduler::scheduleStop(bool finish_delta) 38112961Sgabeblack@google.com{ 38212961Sgabeblack@google.com if (stopEvent.scheduled()) 38312961Sgabeblack@google.com return; 38412961Sgabeblack@google.com 38512961Sgabeblack@google.com if (!finish_delta) { 38613076Sgabeblack@google.com // If we're not supposed to finish the delta cycle, flush all 38713076Sgabeblack@google.com // pending activity. 38813076Sgabeblack@google.com clear(); 38912961Sgabeblack@google.com } 39013088Sgabeblack@google.com schedule(&stopEvent); 39112961Sgabeblack@google.com} 39212961Sgabeblack@google.com 39312953Sgabeblack@google.comScheduler scheduler; 39412953Sgabeblack@google.com 39512953Sgabeblack@google.com} // namespace sc_gem5 396