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/*
* Copyright (c) 2013-2015 Advanced Micro Devices, Inc.
* All rights reserved.
*
* For use for simulation and test purposes only
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. 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.
*
* 3. Neither the name of the copyright holder 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 HOLDER 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.
*/
#include "mem/ruby/system/GPUCoalescer.hh"
#include "base/compiler.hh"
#include "base/logging.hh"
#include "base/str.hh"
#include "cpu/testers/rubytest/RubyTester.hh"
#include "debug/GPUCoalescer.hh"
#include "debug/MemoryAccess.hh"
#include "debug/ProtocolTrace.hh"
#include "debug/RubyPort.hh"
#include "debug/RubyStats.hh"
#include "gpu-compute/shader.hh"
#include "mem/packet.hh"
#include "mem/ruby/common/DataBlock.hh"
#include "mem/ruby/common/SubBlock.hh"
#include "mem/ruby/network/MessageBuffer.hh"
#include "mem/ruby/profiler/Profiler.hh"
#include "mem/ruby/slicc_interface/AbstractController.hh"
#include "mem/ruby/slicc_interface/RubyRequest.hh"
#include "mem/ruby/structures/CacheMemory.hh"
#include "mem/ruby/system/RubySystem.hh"
#include "params/RubyGPUCoalescer.hh"
namespace gem5
{
namespace ruby
{
UncoalescedTable::UncoalescedTable(GPUCoalescer *gc)
: coalescer(gc)
{
}
void
UncoalescedTable::insertPacket(PacketPtr pkt)
{
uint64_t seqNum = pkt->req->getReqInstSeqNum();
instMap[seqNum].push_back(pkt);
DPRINTF(GPUCoalescer, "Adding 0x%X seqNum %d to map. (map %d vec %d)\n",
pkt->getAddr(), seqNum, instMap.size(), instMap[seqNum].size());
}
bool
UncoalescedTable::packetAvailable()
{
return !instMap.empty();
}
void
UncoalescedTable::initPacketsRemaining(InstSeqNum seqNum, int count)
{
if (!instPktsRemaining.count(seqNum)) {
instPktsRemaining[seqNum] = count;
}
}
int
UncoalescedTable::getPacketsRemaining(InstSeqNum seqNum)
{
return instPktsRemaining[seqNum];
}
void
UncoalescedTable::setPacketsRemaining(InstSeqNum seqNum, int count)
{
instPktsRemaining[seqNum] = count;
}
PerInstPackets*
UncoalescedTable::getInstPackets(int offset)
{
if (offset >= instMap.size()) {
return nullptr;
}
auto instMapIter = instMap.begin();
std::advance(instMapIter, offset);
return &(instMapIter->second);
}
void
UncoalescedTable::updateResources()
{
for (auto iter = instMap.begin(); iter != instMap.end(); ) {
InstSeqNum seq_num = iter->first;
DPRINTF(GPUCoalescer, "%s checking remaining pkts for %d\n",
coalescer->name().c_str(), seq_num);
assert(instPktsRemaining.count(seq_num));
if (instPktsRemaining[seq_num] == 0) {
assert(iter->second.empty());
// Remove from both maps
instMap.erase(iter++);
instPktsRemaining.erase(seq_num);
// Release the token
DPRINTF(GPUCoalescer, "Returning token seqNum %d\n", seq_num);
coalescer->getGMTokenPort().sendTokens(1);
} else {
++iter;
}
}
}
bool
UncoalescedTable::areRequestsDone(const uint64_t instSeqNum) {
// iterate the instructions held in UncoalescedTable to see whether there
// are more requests to issue; if yes, not yet done; otherwise, done
for (auto& inst : instMap) {
DPRINTF(GPUCoalescer, "instSeqNum= %d, pending packets=%d\n"
,inst.first, inst.second.size());
if (inst.first == instSeqNum) { return false; }
}
return true;
}
void
UncoalescedTable::printRequestTable(std::stringstream& ss)
{
ss << "Listing pending packets from " << instMap.size() << " instructions";
for (auto& inst : instMap) {
ss << "\tAddr: " << printAddress(inst.first) << " with "
<< inst.second.size() << " pending packets" << std::endl;
}
}
void
UncoalescedTable::checkDeadlock(Tick threshold)
{
Tick current_time = curTick();
for (auto &it : instMap) {
for (auto &pkt : it.second) {
if (current_time - pkt->req->time() > threshold) {
std::stringstream ss;
printRequestTable(ss);
panic("Possible Deadlock detected. Aborting!\n"
"version: %d request.paddr: 0x%x uncoalescedTable: %d "
"current time: %u issue_time: %d difference: %d\n"
"Request Tables:\n\n%s", coalescer->getId(),
pkt->getAddr(), instMap.size(), current_time,
pkt->req->time(), current_time - pkt->req->time(),
ss.str());
}
}
}
}
GPUCoalescer::GPUCoalescer(const Params &p)
: RubyPort(p),
issueEvent([this]{ completeIssue(); }, "Issue coalesced request",
false, Event::Progress_Event_Pri),
uncoalescedTable(this),
deadlockCheckEvent([this]{ wakeup(); }, "GPUCoalescer deadlock check"),
gmTokenPort(name() + ".gmTokenPort", this)
{
m_store_waiting_on_load_cycles = 0;
m_store_waiting_on_store_cycles = 0;
m_load_waiting_on_store_cycles = 0;
m_load_waiting_on_load_cycles = 0;
m_outstanding_count = 0;
coalescingWindow = p.max_coalesces_per_cycle;
m_max_outstanding_requests = 0;
m_instCache_ptr = nullptr;
m_dataCache_ptr = nullptr;
m_instCache_ptr = p.icache;
m_dataCache_ptr = p.dcache;
m_max_outstanding_requests = p.max_outstanding_requests;
m_deadlock_threshold = p.deadlock_threshold;
assert(m_max_outstanding_requests > 0);
assert(m_deadlock_threshold > 0);
assert(m_instCache_ptr);
assert(m_dataCache_ptr);
m_runningGarnetStandalone = p.garnet_standalone;
// These statistical variables are not for display.
// The profiler will collate these across different
// coalescers and display those collated statistics.
m_outstandReqHist.init(10);
m_latencyHist.init(10);
m_missLatencyHist.init(10);
for (int i = 0; i < RubyRequestType_NUM; i++) {
m_typeLatencyHist.push_back(new statistics::Histogram());
m_typeLatencyHist[i]->init(10);
m_missTypeLatencyHist.push_back(new statistics::Histogram());
m_missTypeLatencyHist[i]->init(10);
}
for (int i = 0; i < MachineType_NUM; i++) {
m_missMachLatencyHist.push_back(new statistics::Histogram());
m_missMachLatencyHist[i]->init(10);
m_IssueToInitialDelayHist.push_back(new statistics::Histogram());
m_IssueToInitialDelayHist[i]->init(10);
m_InitialToForwardDelayHist.push_back(new statistics::Histogram());
m_InitialToForwardDelayHist[i]->init(10);
m_ForwardToFirstResponseDelayHist.push_back(
new statistics::Histogram());
m_ForwardToFirstResponseDelayHist[i]->init(10);
m_FirstResponseToCompletionDelayHist.push_back(
new statistics::Histogram());
m_FirstResponseToCompletionDelayHist[i]->init(10);
}
for (int i = 0; i < RubyRequestType_NUM; i++) {
m_missTypeMachLatencyHist.push_back(
std::vector<statistics::Histogram *>());
for (int j = 0; j < MachineType_NUM; j++) {
m_missTypeMachLatencyHist[i].push_back(
new statistics::Histogram());
m_missTypeMachLatencyHist[i][j]->init(10);
}
}
}
GPUCoalescer::~GPUCoalescer()
{
}
Port &
GPUCoalescer::getPort(const std::string &if_name, PortID idx)
{
if (if_name == "gmTokenPort") {
return gmTokenPort;
}
// delgate to RubyPort otherwise
return RubyPort::getPort(if_name, idx);
}
void
GPUCoalescer::wakeup()
{
Cycles current_time = curCycle();
for (auto& requestList : coalescedTable) {
for (auto& req : requestList.second) {
if (current_time - req->getIssueTime() > m_deadlock_threshold) {
std::stringstream ss;
printRequestTable(ss);
warn("GPUCoalescer %d Possible deadlock detected!\n%s\n",
m_version, ss.str());
panic("Aborting due to deadlock!\n");
}
}
}
Tick tick_threshold = cyclesToTicks(m_deadlock_threshold);
uncoalescedTable.checkDeadlock(tick_threshold);
if (m_outstanding_count > 0) {
schedule(deadlockCheckEvent,
m_deadlock_threshold * clockPeriod() +
curTick());
}
}
void
GPUCoalescer::printRequestTable(std::stringstream& ss)
{
ss << "Printing out " << coalescedTable.size()
<< " outstanding requests in the coalesced table\n";
for (auto& requestList : coalescedTable) {
for (auto& request : requestList.second) {
ss << "\tAddr: " << printAddress(requestList.first) << "\n"
<< "\tInstruction sequence number: "
<< request->getSeqNum() << "\n"
<< "\t\tType: "
<< RubyRequestType_to_string(request->getRubyType()) << "\n"
<< "\t\tNumber of associated packets: "
<< request->getPackets().size() << "\n"
<< "\t\tIssue time: "
<< request->getIssueTime() * clockPeriod() << "\n"
<< "\t\tDifference from current tick: "
<< (curCycle() - request->getIssueTime()) * clockPeriod();
}
}
// print out packets waiting to be issued in uncoalesced table
uncoalescedTable.printRequestTable(ss);
}
void
GPUCoalescer::resetStats()
{
m_latencyHist.reset();
m_missLatencyHist.reset();
for (int i = 0; i < RubyRequestType_NUM; i++) {
m_typeLatencyHist[i]->reset();
m_missTypeLatencyHist[i]->reset();
for (int j = 0; j < MachineType_NUM; j++) {
m_missTypeMachLatencyHist[i][j]->reset();
}
}
for (int i = 0; i < MachineType_NUM; i++) {
m_missMachLatencyHist[i]->reset();
m_IssueToInitialDelayHist[i]->reset();
m_InitialToForwardDelayHist[i]->reset();
m_ForwardToFirstResponseDelayHist[i]->reset();
m_FirstResponseToCompletionDelayHist[i]->reset();
}
}
void
GPUCoalescer::printProgress(std::ostream& out) const
{
}
// sets the kernelEndList
void
GPUCoalescer::insertKernel(int wavefront_id, PacketPtr pkt)
{
// Don't know if this will happen or is possible
// but I just want to be careful and not have it become
// simulator hang in the future
DPRINTF(GPUCoalescer, "inserting wf: %d to kernelEndlist\n", wavefront_id);
assert(kernelEndList.count(wavefront_id) == 0);
kernelEndList[wavefront_id] = pkt;
DPRINTF(GPUCoalescer, "kernelEndList->size() = %d\n",
kernelEndList.size());
}
void
GPUCoalescer::writeCallback(Addr address, DataBlock& data)
{
writeCallback(address, MachineType_NULL, data);
}
void
GPUCoalescer::writeCallback(Addr address,
MachineType mach,
DataBlock& data)
{
writeCallback(address, mach, data, Cycles(0), Cycles(0), Cycles(0));
}
void
GPUCoalescer::writeCallback(Addr address,
MachineType mach,
DataBlock& data,
Cycles initialRequestTime,
Cycles forwardRequestTime,
Cycles firstResponseTime)
{
writeCallback(address, mach, data,
initialRequestTime, forwardRequestTime, firstResponseTime,
false);
}
void
GPUCoalescer::writeCallback(Addr address,
MachineType mach,
DataBlock& data,
Cycles initialRequestTime,
Cycles forwardRequestTime,
Cycles firstResponseTime,
bool isRegion)
{
assert(address == makeLineAddress(address));
assert(coalescedTable.count(address));
auto crequest = coalescedTable.at(address).front();
hitCallback(crequest, mach, data, true, crequest->getIssueTime(),
forwardRequestTime, firstResponseTime, isRegion);
// remove this crequest in coalescedTable
delete crequest;
coalescedTable.at(address).pop_front();
if (coalescedTable.at(address).empty()) {
coalescedTable.erase(address);
} else {
auto nextRequest = coalescedTable.at(address).front();
issueRequest(nextRequest);
}
}
void
GPUCoalescer::writeCompleteCallback(Addr address,
uint64_t instSeqNum,
MachineType mach)
{
DPRINTF(GPUCoalescer, "writeCompleteCallback for address 0x%x"
" instSeqNum = %d\n", address, instSeqNum);
assert(pendingWriteInsts.count(instSeqNum) == 1);
PendingWriteInst& inst = pendingWriteInsts[instSeqNum];
// check the uncoalescedTable to see whether all requests for the inst
// have been issued or not
bool reqsAllIssued = uncoalescedTable.areRequestsDone(instSeqNum);
DPRINTF(GPUCoalescer, "instSeqNum = %d, pendingStores=%d, "
"reqsAllIssued=%d\n", reqsAllIssued,
inst.getNumPendingStores()-1, reqsAllIssued);
if (inst.receiveWriteCompleteAck() && reqsAllIssued ) {
// if the pending write instruction has received all write completion
// callbacks for its issued Ruby requests, we can now start respond
// the requesting CU in one response packet.
inst.ackWriteCompletion(m_usingRubyTester);
DPRINTF(GPUCoalescer, "write inst %d completed at coalescer\n",
instSeqNum);
pendingWriteInsts.erase(instSeqNum);
}
}
void
GPUCoalescer::readCallback(Addr address, DataBlock& data)
{
readCallback(address, MachineType_NULL, data);
}
void
GPUCoalescer::readCallback(Addr address,
MachineType mach,
DataBlock& data)
{
readCallback(address, mach, data, Cycles(0), Cycles(0), Cycles(0));
}
void
GPUCoalescer::readCallback(Addr address,
MachineType mach,
DataBlock& data,
Cycles initialRequestTime,
Cycles forwardRequestTime,
Cycles firstResponseTime)
{
readCallback(address, mach, data,
initialRequestTime, forwardRequestTime, firstResponseTime,
false);
}
void
GPUCoalescer::readCallback(Addr address,
MachineType mach,
DataBlock& data,
Cycles initialRequestTime,
Cycles forwardRequestTime,
Cycles firstResponseTime,
bool isRegion)
{
assert(address == makeLineAddress(address));
assert(coalescedTable.count(address));
auto crequest = coalescedTable.at(address).front();
fatal_if(crequest->getRubyType() != RubyRequestType_LD,
"readCallback received non-read type response\n");
// Iterate over the coalesced requests to respond to as many loads as
// possible until another request type is seen. Models MSHR for TCP.
while (crequest->getRubyType() == RubyRequestType_LD) {
hitCallback(crequest, mach, data, true, crequest->getIssueTime(),
forwardRequestTime, firstResponseTime, isRegion);
delete crequest;
coalescedTable.at(address).pop_front();
if (coalescedTable.at(address).empty()) {
break;
}
crequest = coalescedTable.at(address).front();
}
if (coalescedTable.at(address).empty()) {
coalescedTable.erase(address);
} else {
auto nextRequest = coalescedTable.at(address).front();
issueRequest(nextRequest);
}
}
void
GPUCoalescer::hitCallback(CoalescedRequest* crequest,
MachineType mach,
DataBlock& data,
bool success,
Cycles initialRequestTime,
Cycles forwardRequestTime,
Cycles firstResponseTime,
bool isRegion)
{
PacketPtr pkt = crequest->getFirstPkt();
Addr request_address = pkt->getAddr();
[[maybe_unused]] Addr request_line_address =
makeLineAddress(request_address);
RubyRequestType type = crequest->getRubyType();
DPRINTF(GPUCoalescer, "Got hitCallback for 0x%X\n", request_line_address);
recordMissLatency(crequest, mach,
initialRequestTime,
forwardRequestTime,
firstResponseTime,
success, isRegion);
// update the data
//
// MUST AD DOING THIS FOR EACH REQUEST IN COALESCER
std::vector<PacketPtr> pktList = crequest->getPackets();
DPRINTF(GPUCoalescer, "Responding to %d packets for addr 0x%X\n",
pktList.size(), request_line_address);
for (auto& pkt : pktList) {
request_address = pkt->getAddr();
if (pkt->getPtr<uint8_t>()) {
if ((type == RubyRequestType_LD) ||
(type == RubyRequestType_ATOMIC) ||
(type == RubyRequestType_ATOMIC_RETURN) ||
(type == RubyRequestType_IFETCH) ||
(type == RubyRequestType_RMW_Read) ||
(type == RubyRequestType_Locked_RMW_Read) ||
(type == RubyRequestType_Load_Linked)) {
pkt->setData(
data.getData(getOffset(request_address), pkt->getSize()));
} else {
data.setData(pkt->getPtr<uint8_t>(),
getOffset(request_address), pkt->getSize());
}
} else {
DPRINTF(MemoryAccess,
"WARNING. Data not transfered from Ruby to M5 for type " \
"%s\n",
RubyRequestType_to_string(type));
}
}
m_outstanding_count--;
assert(m_outstanding_count >= 0);
completeHitCallback(pktList);
}
bool
GPUCoalescer::empty() const
{
return coalescedTable.empty();
}
RubyRequestType
GPUCoalescer::getRequestType(PacketPtr pkt)
{
RubyRequestType req_type = RubyRequestType_NULL;
// These types are not support or not used in GPU caches.
assert(!pkt->req->isLLSC());
assert(!pkt->req->isLockedRMW());
assert(!pkt->req->isInstFetch());
assert(!pkt->isFlush());
if (pkt->req->isAtomicReturn()) {
req_type = RubyRequestType_ATOMIC_RETURN;
} else if (pkt->req->isAtomicNoReturn()) {
req_type = RubyRequestType_ATOMIC_NO_RETURN;
} else if (pkt->isRead()) {
req_type = RubyRequestType_LD;
} else if (pkt->isWrite()) {
req_type = RubyRequestType_ST;
} else {
panic("Unsupported ruby packet type\n");
}
return req_type;
}
// Places an uncoalesced packet in uncoalescedTable. If the packet is a
// special type (MemFence, scoping, etc), it is issued immediately.
RequestStatus
GPUCoalescer::makeRequest(PacketPtr pkt)
{
// all packets must have valid instruction sequence numbers
assert(pkt->req->hasInstSeqNum());
if (pkt->cmd == MemCmd::MemSyncReq) {
// issue mem_sync requests immediately to the cache system without
// going through uncoalescedTable like normal LD/ST/Atomic requests
issueMemSyncRequest(pkt);
} else {
// otherwise, this must be either read or write command
assert(pkt->isRead() || pkt->isWrite());
InstSeqNum seq_num = pkt->req->getReqInstSeqNum();
// in the case of protocol tester, there is one packet per sequence
// number. The number of packets during simulation depends on the
// number of lanes actives for that vmem request (i.e., the popcnt
// of the exec_mask.
int num_packets = 1;
if (!m_usingRubyTester) {
num_packets = 0;
for (int i = 0; i < TheGpuISA::NumVecElemPerVecReg; i++) {
num_packets += getDynInst(pkt)->getLaneStatus(i);
}
}
// the pkt is temporarily stored in the uncoalesced table until
// it's picked for coalescing process later in this cycle or in a
// future cycle. Packets remaining is set to the number of excepted
// requests from the instruction based on its exec_mask.
uncoalescedTable.insertPacket(pkt);
uncoalescedTable.initPacketsRemaining(seq_num, num_packets);
DPRINTF(GPUCoalescer, "Put pkt with addr 0x%X to uncoalescedTable\n",
pkt->getAddr());
// we schedule an issue event here to process the uncoalesced table
// and try to issue Ruby request to cache system
if (!issueEvent.scheduled()) {
DPRINTF(GPUCoalescer, "Scheduled issueEvent for seqNum %d\n",
seq_num);
schedule(issueEvent, curTick());
}
}
// we always return RequestStatus_Issued in this coalescer
// b/c the coalescer's resouce was checked ealier and the coalescer is
// queueing up aliased requets in its coalesced table
return RequestStatus_Issued;
}
template <class KEY, class VALUE>
std::ostream &
operator<<(std::ostream &out, const std::unordered_map<KEY, VALUE> &map)
{
out << "[";
for (auto i = map.begin(); i != map.end(); ++i)
out << " " << i->first << "=" << i->second;
out << " ]";
return out;
}
void
GPUCoalescer::print(std::ostream& out) const
{
out << "[GPUCoalescer: " << m_version
<< ", outstanding requests: " << m_outstanding_count
<< "]";
}
GPUDynInstPtr
GPUCoalescer::getDynInst(PacketPtr pkt) const
{
RubyPort::SenderState* ss =
safe_cast<RubyPort::SenderState*>(pkt->senderState);
ComputeUnit::DataPort::SenderState* cu_state =
safe_cast<ComputeUnit::DataPort::SenderState*>
(ss->predecessor);
return cu_state->_gpuDynInst;
}
bool
GPUCoalescer::coalescePacket(PacketPtr pkt)
{
uint64_t seqNum = pkt->req->getReqInstSeqNum();
Addr line_addr = makeLineAddress(pkt->getAddr());
// If the packet has the same line address as a request already in the
// coalescedTable and has the same sequence number, it can be coalesced.
if (coalescedTable.count(line_addr)) {
// Search for a previous coalesced request with the same seqNum.
auto& creqQueue = coalescedTable.at(line_addr);
auto citer = std::find_if(creqQueue.begin(), creqQueue.end(),
[&](CoalescedRequest* c) { return c->getSeqNum() == seqNum; }
);
if (citer != creqQueue.end()) {
(*citer)->insertPacket(pkt);
return true;
}
}
if (m_outstanding_count < m_max_outstanding_requests) {
// This is an "aliased" or new request. Create a RubyRequest and
// append it to the list of "targets" in the coalescing table.
DPRINTF(GPUCoalescer, "Creating new or aliased request for 0x%X\n",
line_addr);
CoalescedRequest *creq = new CoalescedRequest(seqNum);
creq->insertPacket(pkt);
creq->setRubyType(getRequestType(pkt));
creq->setIssueTime(curCycle());
if (!coalescedTable.count(line_addr)) {
// If there is no outstanding request for this line address,
// create a new coalecsed request and issue it immediately.
auto reqList = std::deque<CoalescedRequest*> { creq };
coalescedTable.insert(std::make_pair(line_addr, reqList));
if (!coalescedReqs.count(seqNum)) {
coalescedReqs.insert(std::make_pair(seqNum, reqList));
} else {
coalescedReqs.at(seqNum).push_back(creq);
}
} else {
// The request is for a line address that is already outstanding
// but for a different instruction. Add it as a new request to be
// issued when the current outstanding request is completed.
coalescedTable.at(line_addr).push_back(creq);
DPRINTF(GPUCoalescer, "found address 0x%X with new seqNum %d\n",
line_addr, seqNum);
}
// In both cases, requests are added to the coalescing table and will
// be counted as outstanding requests.
m_outstanding_count++;
// We track all issued or to-be-issued Ruby requests associated with
// write instructions. An instruction may have multiple Ruby
// requests.
if (pkt->cmd == MemCmd::WriteReq) {
DPRINTF(GPUCoalescer, "adding write inst %d at line 0x%x to"
" the pending write instruction list\n", seqNum,
line_addr);
RubyPort::SenderState* ss =
safe_cast<RubyPort::SenderState*>(pkt->senderState);
// we need to save this port because it will be used to call
// back the requesting CU when we receive write
// complete callbacks for all issued Ruby requests of this
// instruction.
RubyPort::MemResponsePort* mem_response_port = ss->port;
GPUDynInstPtr gpuDynInst = nullptr;
if (!m_usingRubyTester) {
// If this coalescer is connected to a real CU, we need
// to save the corresponding gpu dynamic instruction.
// CU will use that instruction to decrement wait counters
// in the issuing wavefront.
// For Ruby tester, gpuDynInst == nullptr
gpuDynInst = getDynInst(pkt);
}
PendingWriteInst& inst = pendingWriteInsts[seqNum];
inst.addPendingReq(mem_response_port, gpuDynInst,
m_usingRubyTester);
}
return true;
}
// The maximum number of outstanding requests have been issued.
return false;
}
void
GPUCoalescer::completeIssue()
{
// Iterate over the maximum number of instructions we can coalesce
// per cycle (coalescingWindow).
for (int instIdx = 0; instIdx < coalescingWindow; ++instIdx) {
PerInstPackets *pkt_list =
uncoalescedTable.getInstPackets(instIdx);
// getInstPackets will return nullptr if no instruction
// exists at the current offset.
if (!pkt_list) {
break;
} else if (pkt_list->empty()) {
// Found something, but it has not been cleaned up by update
// resources yet. See if there is anything else to coalesce.
// Assume we can't check anymore if the coalescing window is 1.
continue;
} else {
// All packets in the list have the same seqNum, use first.
InstSeqNum seq_num = pkt_list->front()->req->getReqInstSeqNum();
// The difference in list size before and after tells us the
// number of packets which were coalesced.
size_t pkt_list_size = pkt_list->size();
// Since we have a pointer to the list of packets in the inst,
// erase them from the list if coalescing is successful and
// leave them in the list otherwise. This aggressively attempts
// to coalesce as many packets as possible from the current inst.
pkt_list->remove_if(
[&](PacketPtr pkt) { return coalescePacket(pkt); }
);
if (coalescedReqs.count(seq_num)) {
auto& creqs = coalescedReqs.at(seq_num);
for (auto creq : creqs) {
DPRINTF(GPUCoalescer, "Issued req type %s seqNum %d\n",
RubyRequestType_to_string(creq->getRubyType()),
seq_num);
issueRequest(creq);
}
coalescedReqs.erase(seq_num);
}
assert(pkt_list_size >= pkt_list->size());
size_t pkt_list_diff = pkt_list_size - pkt_list->size();
int num_remaining = uncoalescedTable.getPacketsRemaining(seq_num);
num_remaining -= pkt_list_diff;
assert(num_remaining >= 0);
uncoalescedTable.setPacketsRemaining(seq_num, num_remaining);
DPRINTF(GPUCoalescer,
"Coalesced %d pkts for seqNum %d, %d remaining\n",
pkt_list_diff, seq_num, num_remaining);
}
}
// Clean up any instructions in the uncoalesced table that have had
// all of their packets coalesced and return a token for that column.
uncoalescedTable.updateResources();
// have Kernel End releases been issued this cycle
int len = newKernelEnds.size();
for (int i = 0; i < len; i++) {
kernelCallback(newKernelEnds[i]);
}
newKernelEnds.clear();
}
void
GPUCoalescer::evictionCallback(Addr address)
{
ruby_eviction_callback(address);
}
void
GPUCoalescer::kernelCallback(int wavefront_id)
{
assert(kernelEndList.count(wavefront_id));
ruby_hit_callback(kernelEndList[wavefront_id]);
kernelEndList.erase(wavefront_id);
}
void
GPUCoalescer::atomicCallback(Addr address,
MachineType mach,
const DataBlock& data)
{
assert(address == makeLineAddress(address));
assert(coalescedTable.count(address));
auto crequest = coalescedTable.at(address).front();
fatal_if((crequest->getRubyType() != RubyRequestType_ATOMIC &&
crequest->getRubyType() != RubyRequestType_ATOMIC_RETURN &&
crequest->getRubyType() != RubyRequestType_ATOMIC_NO_RETURN),
"atomicCallback saw non-atomic type response\n");
hitCallback(crequest, mach, (DataBlock&)data, true,
crequest->getIssueTime(), Cycles(0), Cycles(0), false);
delete crequest;
coalescedTable.at(address).pop_front();
if (coalescedTable.at(address).empty()) {
coalescedTable.erase(address);
} else {
auto nextRequest = coalescedTable.at(address).front();
issueRequest(nextRequest);
}
}
void
GPUCoalescer::completeHitCallback(std::vector<PacketPtr> & mylist)
{
for (auto& pkt : mylist) {
RubyPort::SenderState *ss =
safe_cast<RubyPort::SenderState *>(pkt->senderState);
MemResponsePort *port = ss->port;
assert(port != NULL);
pkt->senderState = ss->predecessor;
if (pkt->cmd != MemCmd::WriteReq) {
// for WriteReq, we keep the original senderState until
// writeCompleteCallback
delete ss;
}
port->hitCallback(pkt);
trySendRetries();
}
// We schedule an event in the same tick as hitCallback (similar to
// makeRequest) rather than calling completeIssue directly to reduce
// function calls to complete issue. This can only happen if the max
// outstanding requests is less than the number of slots in the
// uncoalesced table and makeRequest is not called again.
if (uncoalescedTable.packetAvailable() && !issueEvent.scheduled()) {
schedule(issueEvent, curTick());
}
testDrainComplete();
}
void
GPUCoalescer::recordMissLatency(CoalescedRequest* crequest,
MachineType mach,
Cycles initialRequestTime,
Cycles forwardRequestTime,
Cycles firstResponseTime,
bool success, bool isRegion)
{
}
} // namespace ruby
} // namespace gem5