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author | Andreas Sandberg <andreas.sandberg@arm.com> | 2018-04-26 18:16:53 +0100 |
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committer | Andreas Sandberg <andreas.sandberg@arm.com> | 2018-07-13 09:26:23 +0000 |
commit | 0793a1bbdc190a7bd41b7ed81ef8291ceaeb722e (patch) | |
tree | d86192c9d5d2dfecdee71bd731a92d09494f04b5 /src/cpu/testers/traffic_gen/base.cc | |
parent | c9dd86a5cd6f26a2ba776d0adb60d4e18c553b8b (diff) | |
download | gem5-0793a1bbdc190a7bd41b7ed81ef8291ceaeb722e.tar.xz |
cpu: Split the traffic generator into two classes
The traffic generator currently assumes that it is always driven from
a configuration file. Split it into a base class (BaseTrafficGen) that
handles basic packet generation and a derived class that implements
the config handling (TrafficGen).
Change-Id: I9407f04c40ad7e40a263c8d1ef29d37ff8e6f1b4
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/11515
Diffstat (limited to 'src/cpu/testers/traffic_gen/base.cc')
-rw-r--r-- | src/cpu/testers/traffic_gen/base.cc | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/src/cpu/testers/traffic_gen/base.cc b/src/cpu/testers/traffic_gen/base.cc new file mode 100644 index 000000000..9ea6c9398 --- /dev/null +++ b/src/cpu/testers/traffic_gen/base.cc @@ -0,0 +1,306 @@ +/* + * Copyright (c) 2012-2013, 2016-2018 ARM Limited + * All rights reserved + * + * The license below extends only to copyright in the software and shall + * not be construed as granting a license to any other intellectual + * property including but not limited to intellectual property relating + * to a hardware implementation of the functionality of the software + * licensed hereunder. You may use the software subject to the license + * terms below provided that you ensure that this notice is replicated + * unmodified and in its entirety in all distributions of the software, + * modified or unmodified, in source code or in binary form. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Thomas Grass + * Andreas Hansson + * Sascha Bischoff + */ +#include "cpu/testers/traffic_gen/base.hh" + +#include <sstream> + +#include "base/intmath.hh" +#include "base/random.hh" +#include "cpu/testers/traffic_gen/base_gen.hh" +#include "debug/Checkpoint.hh" +#include "debug/TrafficGen.hh" +#include "params/BaseTrafficGen.hh" +#include "sim/sim_exit.hh" +#include "sim/stats.hh" +#include "sim/system.hh" + +using namespace std; + +BaseTrafficGen::BaseTrafficGen(const BaseTrafficGenParams* p) + : MemObject(p), + system(p->system), + elasticReq(p->elastic_req), + progressCheck(p->progress_check), + noProgressEvent([this]{ noProgress(); }, name()), + nextTransitionTick(0), + nextPacketTick(0), + port(name() + ".port", *this), + retryPkt(NULL), + retryPktTick(0), + updateEvent([this]{ update(); }, name()), + numSuppressed(0), + masterID(system->getMasterId(this)) +{ +} + +BaseMasterPort& +BaseTrafficGen::getMasterPort(const string& if_name, PortID idx) +{ + if (if_name == "port") { + return port; + } else { + return MemObject::getMasterPort(if_name, idx); + } +} + +void +BaseTrafficGen::init() +{ + MemObject::init(); + + if (!port.isConnected()) + fatal("The port of %s is not connected!\n", name()); +} + +DrainState +BaseTrafficGen::drain() +{ + if (!updateEvent.scheduled()) { + // no event has been scheduled yet (e.g. switched from atomic mode) + return DrainState::Drained; + } + + if (retryPkt == NULL) { + // shut things down + nextPacketTick = MaxTick; + nextTransitionTick = MaxTick; + deschedule(updateEvent); + return DrainState::Drained; + } else { + return DrainState::Draining; + } +} + +void +BaseTrafficGen::serialize(CheckpointOut &cp) const +{ + DPRINTF(Checkpoint, "Serializing BaseTrafficGen\n"); + + // save ticks of the graph event if it is scheduled + Tick nextEvent = updateEvent.scheduled() ? updateEvent.when() : 0; + + DPRINTF(TrafficGen, "Saving nextEvent=%llu\n", nextEvent); + + SERIALIZE_SCALAR(nextEvent); + + SERIALIZE_SCALAR(nextTransitionTick); + + SERIALIZE_SCALAR(nextPacketTick); +} + +void +BaseTrafficGen::unserialize(CheckpointIn &cp) +{ + // restore scheduled events + Tick nextEvent; + UNSERIALIZE_SCALAR(nextEvent); + if (nextEvent != 0) + schedule(updateEvent, nextEvent); + + UNSERIALIZE_SCALAR(nextTransitionTick); + + UNSERIALIZE_SCALAR(nextPacketTick); +} + +void +BaseTrafficGen::update() +{ + // shift our progress-tracking event forward + reschedule(noProgressEvent, curTick() + progressCheck, true); + + // if we have reached the time for the next state transition, then + // perform the transition + if (curTick() >= nextTransitionTick) { + transition(); + } else { + assert(curTick() >= nextPacketTick); + // get the next packet and try to send it + PacketPtr pkt = activeGenerator->getNextPacket(); + + // suppress packets that are not destined for a memory, such as + // device accesses that could be part of a trace + if (system->isMemAddr(pkt->getAddr())) { + numPackets++; + if (!port.sendTimingReq(pkt)) { + retryPkt = pkt; + retryPktTick = curTick(); + } + } else { + DPRINTF(TrafficGen, "Suppressed packet %s 0x%x\n", + pkt->cmdString(), pkt->getAddr()); + + ++numSuppressed; + if (numSuppressed % 10000) + warn("%s suppressed %d packets with non-memory addresses\n", + name(), numSuppressed); + + delete pkt; + pkt = nullptr; + } + } + + // if we are waiting for a retry, do not schedule any further + // events, in the case of a transition or a successful send, go + // ahead and determine when the next update should take place + if (retryPkt == NULL) { + nextPacketTick = activeGenerator->nextPacketTick(elasticReq, 0); + scheduleUpdate(); + } +} + +void +BaseTrafficGen::transition() +{ + if (activeGenerator) + activeGenerator->exit(); + + activeGenerator = nextGenerator(); + + if (activeGenerator) { + const Tick duration = activeGenerator->duration; + if (duration != MaxTick && duration != 0) { + // we could have been delayed and not transitioned on the + // exact tick when we were supposed to (due to back + // pressure when sending a packet) + nextTransitionTick = curTick() + duration; + } else { + nextTransitionTick = MaxTick; + } + + activeGenerator->enter(); + nextPacketTick = activeGenerator->nextPacketTick(elasticReq, 0); + } else { + nextPacketTick = MaxTick; + nextTransitionTick = MaxTick; + assert(!updateEvent.scheduled()); + } +} + +void +BaseTrafficGen::scheduleUpdate() +{ + // schedule next update event based on either the next execute + // tick or the next transition, which ever comes first + const Tick nextEventTick = std::min(nextPacketTick, nextTransitionTick); + if (nextEventTick == MaxTick) + return; + + DPRINTF(TrafficGen, "Next event scheduled at %lld\n", nextEventTick); + + // The next transition tick may be in the past if there was a + // retry, so ensure that we don't schedule anything in the past. + schedule(updateEvent, std::max(curTick(), nextEventTick)); +} + +void +BaseTrafficGen::start() +{ + transition(); + scheduleUpdate(); +} + +void +BaseTrafficGen::recvReqRetry() +{ + assert(retryPkt != NULL); + + DPRINTF(TrafficGen, "Received retry\n"); + numRetries++; + // attempt to send the packet, and if we are successful start up + // the machinery again + if (port.sendTimingReq(retryPkt)) { + retryPkt = NULL; + // remember how much delay was incurred due to back-pressure + // when sending the request, we also use this to derive + // the tick for the next packet + Tick delay = curTick() - retryPktTick; + retryPktTick = 0; + retryTicks += delay; + + if (drainState() != DrainState::Draining) { + // packet is sent, so find out when the next one is due + nextPacketTick = activeGenerator->nextPacketTick(elasticReq, + delay); + scheduleUpdate(); + } else { + // shut things down + nextPacketTick = MaxTick; + nextTransitionTick = MaxTick; + signalDrainDone(); + } + } +} + +void +BaseTrafficGen::noProgress() +{ + fatal("BaseTrafficGen %s spent %llu ticks without making progress", + name(), progressCheck); +} + +void +BaseTrafficGen::regStats() +{ + ClockedObject::regStats(); + + // Initialise all the stats + using namespace Stats; + + numPackets + .name(name() + ".numPackets") + .desc("Number of packets generated"); + + numRetries + .name(name() + ".numRetries") + .desc("Number of retries"); + + retryTicks + .name(name() + ".retryTicks") + .desc("Time spent waiting due to back-pressure (ticks)"); +} + +bool +BaseTrafficGen::TrafficGenPort::recvTimingResp(PacketPtr pkt) +{ + delete pkt; + + return true; +} |