gem5/src/mem/comm_monitor.cc
Geoffrey Blake 1d403960af mem: Enable CommMonitor to output traces in atomic mode
The CommMonitor by default only allows memory traces to be gathered in
timing mode. This patch allows memory traces to be gathered in atomic
mode if all one needs is a functional trace of memory addresses used
and timing information is of a secondary concern.
2015-03-19 04:06:10 -04:00

631 lines
20 KiB
C++

/*
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* Authors: Thomas Grass
* Andreas Hansson
*/
#include "base/callback.hh"
#include "base/output.hh"
#include "base/trace.hh"
#include "debug/CommMonitor.hh"
#include "mem/comm_monitor.hh"
#include "proto/packet.pb.h"
#include "sim/stats.hh"
CommMonitor::CommMonitor(Params* params)
: MemObject(params),
masterPort(name() + "-master", *this),
slavePort(name() + "-slave", *this),
samplePeriodicEvent(this),
samplePeriodTicks(params->sample_period),
readAddrMask(params->read_addr_mask),
writeAddrMask(params->write_addr_mask),
stats(params),
stackDistCalc(params->stack_dist_calc),
traceStream(NULL),
system(params->system)
{
// If we are using a trace file, then open the file
if (params->trace_enable) {
std::string filename;
if (params->trace_file != "") {
// If the trace file is not specified as an absolute path,
// append the current simulation output directory
filename = simout.resolve(params->trace_file);
std::string suffix = ".gz";
// If trace_compress has been set, check the suffix. Append
// accordingly.
if (params->trace_compress &&
filename.compare(filename.size() - suffix.size(), suffix.size(),
suffix) != 0)
filename = filename + suffix;
} else {
// Generate a filename from the name of the SimObject. Append .trc
// and .gz if we want compression enabled.
filename = simout.resolve(name() + ".trc" +
(params->trace_compress ? ".gz" : ""));
}
traceStream = new ProtoOutputStream(filename);
// Create a protobuf message for the header and write it to
// the stream
ProtoMessage::PacketHeader header_msg;
header_msg.set_obj_id(name());
header_msg.set_tick_freq(SimClock::Frequency);
traceStream->write(header_msg);
// Register a callback to compensate for the destructor not
// being called. The callback forces the stream to flush and
// closes the output file.
Callback* cb = new MakeCallback<CommMonitor,
&CommMonitor::closeStreams>(this);
registerExitCallback(cb);
}
// keep track of the sample period both in ticks and absolute time
samplePeriod.setTick(params->sample_period);
DPRINTF(CommMonitor,
"Created monitor %s with sample period %d ticks (%f ms)\n",
name(), samplePeriodTicks, samplePeriod.msec());
}
CommMonitor::~CommMonitor()
{
// if not already done, close the stream
closeStreams();
}
void
CommMonitor::closeStreams()
{
if (traceStream != NULL)
delete traceStream;
}
CommMonitor*
CommMonitorParams::create()
{
return new CommMonitor(this);
}
void
CommMonitor::init()
{
// make sure both sides of the monitor are connected
if (!slavePort.isConnected() || !masterPort.isConnected())
fatal("Communication monitor is not connected on both sides.\n");
if (traceStream != NULL) {
// Check the memory mode. We only record something when in
// timing mode. Warn accordingly.
if (!system->isTimingMode())
warn("%s: Not in timing mode. No trace will be recorded.", name());
}
}
BaseMasterPort&
CommMonitor::getMasterPort(const std::string& if_name, PortID idx)
{
if (if_name == "master") {
return masterPort;
} else {
return MemObject::getMasterPort(if_name, idx);
}
}
BaseSlavePort&
CommMonitor::getSlavePort(const std::string& if_name, PortID idx)
{
if (if_name == "slave") {
return slavePort;
} else {
return MemObject::getSlavePort(if_name, idx);
}
}
void
CommMonitor::recvFunctional(PacketPtr pkt)
{
masterPort.sendFunctional(pkt);
}
void
CommMonitor::recvFunctionalSnoop(PacketPtr pkt)
{
slavePort.sendFunctionalSnoop(pkt);
}
Tick
CommMonitor::recvAtomic(PacketPtr pkt)
{
// do stack distance calculations if enabled
if (stackDistCalc)
stackDistCalc->update(pkt->cmd, pkt->getAddr());
// if tracing enabled, store the packet information
// to the trace stream
if (traceStream != NULL) {
ProtoMessage::Packet pkt_msg;
pkt_msg.set_tick(curTick());
pkt_msg.set_cmd(pkt->cmdToIndex());
pkt_msg.set_flags(pkt->req->getFlags());
pkt_msg.set_addr(pkt->getAddr());
pkt_msg.set_size(pkt->getSize());
traceStream->write(pkt_msg);
}
return masterPort.sendAtomic(pkt);
}
Tick
CommMonitor::recvAtomicSnoop(PacketPtr pkt)
{
return slavePort.sendAtomicSnoop(pkt);
}
bool
CommMonitor::recvTimingReq(PacketPtr pkt)
{
// should always see a request
assert(pkt->isRequest());
// Store relevant fields of packet, because packet may be modified
// or even deleted when sendTiming() is called.
bool is_read = pkt->isRead();
bool is_write = pkt->isWrite();
MemCmd cmd = pkt->cmd;
int cmd_idx = pkt->cmdToIndex();
Request::FlagsType req_flags = pkt->req->getFlags();
unsigned size = pkt->getSize();
Addr addr = pkt->getAddr();
bool expects_response = pkt->needsResponse() && !pkt->memInhibitAsserted();
// If a cache miss is served by a cache, a monitor near the memory
// would see a request which needs a response, but this response
// would be inhibited and not come back from the memory. Therefore
// we additionally have to check the inhibit flag.
if (expects_response && !stats.disableLatencyHists) {
pkt->pushSenderState(new CommMonitorSenderState(curTick()));
}
// Attempt to send the packet (always succeeds for inhibited
// packets)
bool successful = masterPort.sendTimingReq(pkt);
// If not successful, restore the sender state
if (!successful && expects_response && !stats.disableLatencyHists) {
delete pkt->popSenderState();
}
// If successful and we are calculating stack distances, update
// the calculator
if (successful && stackDistCalc)
stackDistCalc->update(cmd, addr);
if (successful && traceStream != NULL) {
// Create a protobuf message representing the
// packet. Currently we do not preserve the flags in the
// trace.
ProtoMessage::Packet pkt_msg;
pkt_msg.set_tick(curTick());
pkt_msg.set_cmd(cmd_idx);
pkt_msg.set_flags(req_flags);
pkt_msg.set_addr(addr);
pkt_msg.set_size(size);
traceStream->write(pkt_msg);
}
if (successful && is_read) {
DPRINTF(CommMonitor, "Forwarded read request\n");
// Increment number of observed read transactions
if (!stats.disableTransactionHists) {
++stats.readTrans;
}
// Get sample of burst length
if (!stats.disableBurstLengthHists) {
stats.readBurstLengthHist.sample(size);
}
// Sample the masked address
if (!stats.disableAddrDists) {
stats.readAddrDist.sample(addr & readAddrMask);
}
// If it needs a response increment number of outstanding read
// requests
if (!stats.disableOutstandingHists && expects_response) {
++stats.outstandingReadReqs;
}
if (!stats.disableITTDists) {
// Sample value of read-read inter transaction time
if (stats.timeOfLastRead != 0) {
stats.ittReadRead.sample(curTick() - stats.timeOfLastRead);
}
stats.timeOfLastRead = curTick();
// Sample value of req-req inter transaction time
if (stats.timeOfLastReq != 0) {
stats.ittReqReq.sample(curTick() - stats.timeOfLastReq);
}
stats.timeOfLastReq = curTick();
}
} else if (successful && is_write) {
DPRINTF(CommMonitor, "Forwarded write request\n");
// Same as for reads
if (!stats.disableTransactionHists) {
++stats.writeTrans;
}
if (!stats.disableBurstLengthHists) {
stats.writeBurstLengthHist.sample(size);
}
// Update the bandwidth stats on the request
if (!stats.disableBandwidthHists) {
stats.writtenBytes += size;
stats.totalWrittenBytes += size;
}
// Sample the masked write address
if (!stats.disableAddrDists) {
stats.writeAddrDist.sample(addr & writeAddrMask);
}
if (!stats.disableOutstandingHists && expects_response) {
++stats.outstandingWriteReqs;
}
if (!stats.disableITTDists) {
// Sample value of write-to-write inter transaction time
if (stats.timeOfLastWrite != 0) {
stats.ittWriteWrite.sample(curTick() - stats.timeOfLastWrite);
}
stats.timeOfLastWrite = curTick();
// Sample value of req-to-req inter transaction time
if (stats.timeOfLastReq != 0) {
stats.ittReqReq.sample(curTick() - stats.timeOfLastReq);
}
stats.timeOfLastReq = curTick();
}
} else if (successful) {
DPRINTF(CommMonitor, "Forwarded non read/write request\n");
}
return successful;
}
bool
CommMonitor::recvTimingResp(PacketPtr pkt)
{
// should always see responses
assert(pkt->isResponse());
// Store relevant fields of packet, because packet may be modified
// or even deleted when sendTiming() is called.
bool is_read = pkt->isRead();
bool is_write = pkt->isWrite();
unsigned size = pkt->getSize();
Tick latency = 0;
CommMonitorSenderState* received_state =
dynamic_cast<CommMonitorSenderState*>(pkt->senderState);
if (!stats.disableLatencyHists) {
// Restore initial sender state
if (received_state == NULL)
panic("Monitor got a response without monitor sender state\n");
// Restore the sate
pkt->senderState = received_state->predecessor;
}
// Attempt to send the packet
bool successful = slavePort.sendTimingResp(pkt);
if (!stats.disableLatencyHists) {
// If packet successfully send, sample value of latency,
// afterwards delete sender state, otherwise restore state
if (successful) {
latency = curTick() - received_state->transmitTime;
DPRINTF(CommMonitor, "Latency: %d\n", latency);
delete received_state;
} else {
// Don't delete anything and let the packet look like we
// did not touch it
pkt->senderState = received_state;
}
}
if (successful && is_read) {
// Decrement number of outstanding read requests
DPRINTF(CommMonitor, "Received read response\n");
if (!stats.disableOutstandingHists) {
assert(stats.outstandingReadReqs != 0);
--stats.outstandingReadReqs;
}
if (!stats.disableLatencyHists) {
stats.readLatencyHist.sample(latency);
}
// Update the bandwidth stats based on responses for reads
if (!stats.disableBandwidthHists) {
stats.readBytes += size;
stats.totalReadBytes += size;
}
} else if (successful && is_write) {
// Decrement number of outstanding write requests
DPRINTF(CommMonitor, "Received write response\n");
if (!stats.disableOutstandingHists) {
assert(stats.outstandingWriteReqs != 0);
--stats.outstandingWriteReqs;
}
if (!stats.disableLatencyHists) {
stats.writeLatencyHist.sample(latency);
}
} else if (successful) {
DPRINTF(CommMonitor, "Received non read/write response\n");
}
return successful;
}
void
CommMonitor::recvTimingSnoopReq(PacketPtr pkt)
{
slavePort.sendTimingSnoopReq(pkt);
}
bool
CommMonitor::recvTimingSnoopResp(PacketPtr pkt)
{
return masterPort.sendTimingSnoopResp(pkt);
}
bool
CommMonitor::isSnooping() const
{
// check if the connected master port is snooping
return slavePort.isSnooping();
}
AddrRangeList
CommMonitor::getAddrRanges() const
{
// get the address ranges of the connected slave port
return masterPort.getAddrRanges();
}
void
CommMonitor::recvReqRetry()
{
slavePort.sendRetryReq();
}
void
CommMonitor::recvRespRetry()
{
masterPort.sendRetryResp();
}
void
CommMonitor::recvRangeChange()
{
slavePort.sendRangeChange();
}
void
CommMonitor::regStats()
{
// Initialise all the monitor stats
using namespace Stats;
stats.readBurstLengthHist
.init(params()->burst_length_bins)
.name(name() + ".readBurstLengthHist")
.desc("Histogram of burst lengths of transmitted packets")
.flags(stats.disableBurstLengthHists ? nozero : pdf);
stats.writeBurstLengthHist
.init(params()->burst_length_bins)
.name(name() + ".writeBurstLengthHist")
.desc("Histogram of burst lengths of transmitted packets")
.flags(stats.disableBurstLengthHists ? nozero : pdf);
// Stats based on received responses
stats.readBandwidthHist
.init(params()->bandwidth_bins)
.name(name() + ".readBandwidthHist")
.desc("Histogram of read bandwidth per sample period (bytes/s)")
.flags(stats.disableBandwidthHists ? nozero : pdf);
stats.averageReadBW
.name(name() + ".averageReadBandwidth")
.desc("Average read bandwidth (bytes/s)")
.flags(stats.disableBandwidthHists ? nozero : pdf);
stats.totalReadBytes
.name(name() + ".totalReadBytes")
.desc("Number of bytes read")
.flags(stats.disableBandwidthHists ? nozero : pdf);
stats.averageReadBW = stats.totalReadBytes / simSeconds;
// Stats based on successfully sent requests
stats.writeBandwidthHist
.init(params()->bandwidth_bins)
.name(name() + ".writeBandwidthHist")
.desc("Histogram of write bandwidth (bytes/s)")
.flags(stats.disableBandwidthHists ? (pdf | nozero) : pdf);
stats.averageWriteBW
.name(name() + ".averageWriteBandwidth")
.desc("Average write bandwidth (bytes/s)")
.flags(stats.disableBandwidthHists ? nozero : pdf);
stats.totalWrittenBytes
.name(name() + ".totalWrittenBytes")
.desc("Number of bytes written")
.flags(stats.disableBandwidthHists ? nozero : pdf);
stats.averageWriteBW = stats.totalWrittenBytes / simSeconds;
stats.readLatencyHist
.init(params()->latency_bins)
.name(name() + ".readLatencyHist")
.desc("Read request-response latency")
.flags(stats.disableLatencyHists ? nozero : pdf);
stats.writeLatencyHist
.init(params()->latency_bins)
.name(name() + ".writeLatencyHist")
.desc("Write request-response latency")
.flags(stats.disableLatencyHists ? nozero : pdf);
stats.ittReadRead
.init(1, params()->itt_max_bin, params()->itt_max_bin /
params()->itt_bins)
.name(name() + ".ittReadRead")
.desc("Read-to-read inter transaction time")
.flags(stats.disableITTDists ? nozero : pdf);
stats.ittWriteWrite
.init(1, params()->itt_max_bin, params()->itt_max_bin /
params()->itt_bins)
.name(name() + ".ittWriteWrite")
.desc("Write-to-write inter transaction time")
.flags(stats.disableITTDists ? nozero : pdf);
stats.ittReqReq
.init(1, params()->itt_max_bin, params()->itt_max_bin /
params()->itt_bins)
.name(name() + ".ittReqReq")
.desc("Request-to-request inter transaction time")
.flags(stats.disableITTDists ? nozero : pdf);
stats.outstandingReadsHist
.init(params()->outstanding_bins)
.name(name() + ".outstandingReadsHist")
.desc("Outstanding read transactions")
.flags(stats.disableOutstandingHists ? nozero : pdf);
stats.outstandingWritesHist
.init(params()->outstanding_bins)
.name(name() + ".outstandingWritesHist")
.desc("Outstanding write transactions")
.flags(stats.disableOutstandingHists ? nozero : pdf);
stats.readTransHist
.init(params()->transaction_bins)
.name(name() + ".readTransHist")
.desc("Histogram of read transactions per sample period")
.flags(stats.disableTransactionHists ? nozero : pdf);
stats.writeTransHist
.init(params()->transaction_bins)
.name(name() + ".writeTransHist")
.desc("Histogram of read transactions per sample period")
.flags(stats.disableTransactionHists ? nozero : pdf);
stats.readAddrDist
.init(0)
.name(name() + ".readAddrDist")
.desc("Read address distribution")
.flags(stats.disableAddrDists ? nozero : pdf);
stats.writeAddrDist
.init(0)
.name(name() + ".writeAddrDist")
.desc("Write address distribution")
.flags(stats.disableAddrDists ? nozero : pdf);
}
void
CommMonitor::samplePeriodic()
{
// the periodic stats update runs on the granularity of sample
// periods, but in combination with this there may also be a
// external resets and dumps of the stats (through schedStatEvent)
// causing the stats themselves to capture less than a sample
// period
// only capture if we have not reset the stats during the last
// sample period
if (simTicks.value() >= samplePeriodTicks) {
if (!stats.disableTransactionHists) {
stats.readTransHist.sample(stats.readTrans);
stats.writeTransHist.sample(stats.writeTrans);
}
if (!stats.disableBandwidthHists) {
stats.readBandwidthHist.sample(stats.readBytes / samplePeriod);
stats.writeBandwidthHist.sample(stats.writtenBytes / samplePeriod);
}
if (!stats.disableOutstandingHists) {
stats.outstandingReadsHist.sample(stats.outstandingReadReqs);
stats.outstandingWritesHist.sample(stats.outstandingWriteReqs);
}
}
// reset the sampled values
stats.readTrans = 0;
stats.writeTrans = 0;
stats.readBytes = 0;
stats.writtenBytes = 0;
schedule(samplePeriodicEvent, curTick() + samplePeriodTicks);
}
void
CommMonitor::startup()
{
schedule(samplePeriodicEvent, curTick() + samplePeriodTicks);
}