gem5  v21.1.0.2
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gem5::TrafficGen Class Reference

The traffic generator is a module that generates stimuli for the memory system, based on a collection of simple behaviours that are either probabilistic or based on traces. More...

#include <traffic_gen.hh>

Inheritance diagram for gem5::TrafficGen:
gem5::BaseTrafficGen gem5::ClockedObject gem5::SimObject gem5::Clocked gem5::EventManager gem5::Serializable gem5::Drainable gem5::statistics::Group gem5::Named

Classes

struct  Transition
 Struct to represent a probabilistic transition during parsing. More...
 

Public Member Functions

 TrafficGen (const TrafficGenParams &p)
 
 ~TrafficGen ()
 
void init () override
 init() is called after all C++ SimObjects have been created and all ports are connected. More...
 
void initState () override
 initState() is called on each SimObject when not restoring from a checkpoint. More...
 
void serialize (CheckpointOut &cp) const override
 Serialize an object. More...
 
void unserialize (CheckpointIn &cp) override
 Unserialize an object. More...
 
- Public Member Functions inherited from gem5::BaseTrafficGen
 BaseTrafficGen (const BaseTrafficGenParams &p)
 
 ~BaseTrafficGen ()
 
PortgetPort (const std::string &if_name, PortID idx=InvalidPortID) override
 Get a port with a given name and index. More...
 
DrainState drain () override
 Draining is the process of clearing out the states of SimObjects.These are the SimObjects that are partially executed or are partially in flight. More...
 
std::shared_ptr< BaseGencreateIdle (Tick duration)
 
std::shared_ptr< BaseGencreateExit (Tick duration)
 
std::shared_ptr< BaseGencreateLinear (Tick duration, Addr start_addr, Addr end_addr, Addr blocksize, Tick min_period, Tick max_period, uint8_t read_percent, Addr data_limit)
 
std::shared_ptr< BaseGencreateRandom (Tick duration, Addr start_addr, Addr end_addr, Addr blocksize, Tick min_period, Tick max_period, uint8_t read_percent, Addr data_limit)
 
std::shared_ptr< BaseGencreateDram (Tick duration, Addr start_addr, Addr end_addr, Addr blocksize, Tick min_period, Tick max_period, uint8_t read_percent, Addr data_limit, unsigned int num_seq_pkts, unsigned int page_size, unsigned int nbr_of_banks, unsigned int nbr_of_banks_util, enums::AddrMap addr_mapping, unsigned int nbr_of_ranks)
 
std::shared_ptr< BaseGencreateDramRot (Tick duration, Addr start_addr, Addr end_addr, Addr blocksize, Tick min_period, Tick max_period, uint8_t read_percent, Addr data_limit, unsigned int num_seq_pkts, unsigned int page_size, unsigned int nbr_of_banks, unsigned int nbr_of_banks_util, enums::AddrMap addr_mapping, unsigned int nbr_of_ranks, unsigned int max_seq_count_per_rank)
 
std::shared_ptr< BaseGencreateHybrid (Tick duration, Addr start_addr_dram, Addr end_addr_dram, Addr blocksize_dram, Addr start_addr_nvm, Addr end_addr_nvm, Addr blocksize_nvm, Tick min_period, Tick max_period, uint8_t read_percent, Addr data_limit, unsigned int num_seq_pkts_dram, unsigned int page_size_dram, unsigned int nbr_of_banks_dram, unsigned int nbr_of_banks_util_dram, unsigned int num_seq_pkts_nvm, unsigned int buffer_size_nvm, unsigned int nbr_of_banks_nvm, unsigned int nbr_of_banks_util_nvm, enums::AddrMap addr_mapping, unsigned int nbr_of_ranks_dram, unsigned int nbr_of_ranks_nvm, uint8_t nvm_percent)
 
std::shared_ptr< BaseGencreateNvm (Tick duration, Addr start_addr, Addr end_addr, Addr blocksize, Tick min_period, Tick max_period, uint8_t read_percent, Addr data_limit, unsigned int num_seq_pkts, unsigned int buffer_size, unsigned int nbr_of_banks, unsigned int nbr_of_banks_util, enums::AddrMap addr_mapping, unsigned int nbr_of_ranks)
 
std::shared_ptr< BaseGencreateStrided (Tick duration, Addr start_addr, Addr end_addr, Addr blocksize, Addr stride_size, int gen_id, Tick min_period, Tick max_period, uint8_t read_percent, Addr data_limit)
 
std::shared_ptr< BaseGencreateTrace (Tick duration, const std::string &trace_file, Addr addr_offset)
 
- Public Member Functions inherited from gem5::ClockedObject
 ClockedObject (const ClockedObjectParams &p)
 
void serialize (CheckpointOut &cp) const override
 Serialize an object. More...
 
void unserialize (CheckpointIn &cp) override
 Unserialize an object. More...
 
- Public Member Functions inherited from gem5::SimObject
const Paramsparams () const
 
 SimObject (const Params &p)
 
virtual ~SimObject ()
 
virtual void loadState (CheckpointIn &cp)
 loadState() is called on each SimObject when restoring from a checkpoint. More...
 
virtual void regProbePoints ()
 Register probe points for this object. More...
 
virtual void regProbeListeners ()
 Register probe listeners for this object. More...
 
ProbeManagergetProbeManager ()
 Get the probe manager for this object. More...
 
virtual void startup ()
 startup() is the final initialization call before simulation. More...
 
DrainState drain () override
 Provide a default implementation of the drain interface for objects that don't need draining. More...
 
virtual void memWriteback ()
 Write back dirty buffers to memory using functional writes. More...
 
virtual void memInvalidate ()
 Invalidate the contents of memory buffers. More...
 
void serialize (CheckpointOut &cp) const override
 Serialize an object. More...
 
void unserialize (CheckpointIn &cp) override
 Unserialize an object. More...
 
- Public Member Functions inherited from gem5::EventManager
EventQueueeventQueue () const
 
void schedule (Event &event, Tick when)
 
void deschedule (Event &event)
 
void reschedule (Event &event, Tick when, bool always=false)
 
void schedule (Event *event, Tick when)
 
void deschedule (Event *event)
 
void reschedule (Event *event, Tick when, bool always=false)
 
void wakeupEventQueue (Tick when=(Tick) -1)
 This function is not needed by the usual gem5 event loop but may be necessary in derived EventQueues which host gem5 on other schedulers. More...
 
void setCurTick (Tick newVal)
 
 EventManager (EventManager &em)
 Event manger manages events in the event queue. More...
 
 EventManager (EventManager *em)
 
 EventManager (EventQueue *eq)
 
- Public Member Functions inherited from gem5::Serializable
 Serializable ()
 
virtual ~Serializable ()
 
void serializeSection (CheckpointOut &cp, const char *name) const
 Serialize an object into a new section. More...
 
void serializeSection (CheckpointOut &cp, const std::string &name) const
 
void unserializeSection (CheckpointIn &cp, const char *name)
 Unserialize an a child object. More...
 
void unserializeSection (CheckpointIn &cp, const std::string &name)
 
- Public Member Functions inherited from gem5::Drainable
DrainState drainState () const
 Return the current drain state of an object. More...
 
virtual void notifyFork ()
 Notify a child process of a fork. More...
 
- Public Member Functions inherited from gem5::statistics::Group
 Group (Group *parent, const char *name=nullptr)
 Construct a new statistics group. More...
 
virtual ~Group ()
 
virtual void regStats ()
 Callback to set stat parameters. More...
 
virtual void resetStats ()
 Callback to reset stats. More...
 
virtual void preDumpStats ()
 Callback before stats are dumped. More...
 
void addStat (statistics::Info *info)
 Register a stat with this group. More...
 
const std::map< std::string, Group * > & getStatGroups () const
 Get all child groups associated with this object. More...
 
const std::vector< Info * > & getStats () const
 Get all stats associated with this object. More...
 
void addStatGroup (const char *name, Group *block)
 Add a stat block as a child of this block. More...
 
const InforesolveStat (std::string name) const
 Resolve a stat by its name within this group. More...
 
void mergeStatGroup (Group *block)
 Merge the contents (stats & children) of a block to this block. More...
 
 Group ()=delete
 
 Group (const Group &)=delete
 
Groupoperator= (const Group &)=delete
 
- Public Member Functions inherited from gem5::Named
 Named (const std::string &name_)
 
virtual ~Named ()=default
 
virtual std::string name () const
 
- Public Member Functions inherited from gem5::Clocked
void updateClockPeriod ()
 Update the tick to the current tick. More...
 
Tick clockEdge (Cycles cycles=Cycles(0)) const
 Determine the tick when a cycle begins, by default the current one, but the argument also enables the caller to determine a future cycle. More...
 
Cycles curCycle () const
 Determine the current cycle, corresponding to a tick aligned to a clock edge. More...
 
Tick nextCycle () const
 Based on the clock of the object, determine the start tick of the first cycle that is at least one cycle in the future. More...
 
uint64_t frequency () const
 
Tick clockPeriod () const
 
double voltage () const
 
Cycles ticksToCycles (Tick t) const
 
Tick cyclesToTicks (Cycles c) const
 

Protected Member Functions

std::shared_ptr< BaseGennextGenerator () override
 
- Protected Member Functions inherited from gem5::BaseTrafficGen
void start ()
 
- Protected Member Functions inherited from gem5::Drainable
 Drainable ()
 
virtual ~Drainable ()
 
virtual void drainResume ()
 Resume execution after a successful drain. More...
 
void signalDrainDone () const
 Signal that an object is drained. More...
 
- Protected Member Functions inherited from gem5::Clocked
 Clocked (ClockDomain &clk_domain)
 Create a clocked object and set the clock domain based on the parameters. More...
 
 Clocked (Clocked &)=delete
 
Clockedoperator= (Clocked &)=delete
 
virtual ~Clocked ()
 Virtual destructor due to inheritance. More...
 
void resetClock () const
 Reset the object's clock using the current global tick value. More...
 
virtual void clockPeriodUpdated ()
 A hook subclasses can implement so they can do any extra work that's needed when the clock rate is changed. More...
 

Private Member Functions

std::string resolveFile (const std::string &name)
 Resolve a file path in the configuration file. More...
 
void parseConfig ()
 Parse the config file and build the state map and transition matrix. More...
 
size_t nextState ()
 Use the transition matrix to find the next state index. More...
 

Private Attributes

const std::string configFile
 The config file to parse. More...
 
std::vector< std::vector< double > > transitionMatrix
 State transition matrix. More...
 
uint32_t currState
 Index of the current state. More...
 
std::unordered_map< uint32_t, std::shared_ptr< BaseGen > > states
 Map of generator states. More...
 

Additional Inherited Members

- Public Types inherited from gem5::ClockedObject
using Params = ClockedObjectParams
 Parameters of ClockedObject. More...
 
- Public Types inherited from gem5::SimObject
typedef SimObjectParams Params
 
- Static Public Member Functions inherited from gem5::SimObject
static void serializeAll (const std::string &cpt_dir)
 Create a checkpoint by serializing all SimObjects in the system. More...
 
static SimObjectfind (const char *name)
 Find the SimObject with the given name and return a pointer to it. More...
 
static void setSimObjectResolver (SimObjectResolver *resolver)
 There is a single object name resolver, and it is only set when simulation is restoring from checkpoints. More...
 
static SimObjectResolvergetSimObjectResolver ()
 There is a single object name resolver, and it is only set when simulation is restoring from checkpoints. More...
 
- Static Public Member Functions inherited from gem5::Serializable
static const std::string & currentSection ()
 Gets the fully-qualified name of the active section. More...
 
static void generateCheckpointOut (const std::string &cpt_dir, std::ofstream &outstream)
 Generate a checkpoint file so that the serialization can be routed to it. More...
 
- Public Attributes inherited from gem5::ClockedObject
PowerStatepowerState
 
- Protected Attributes inherited from gem5::BaseTrafficGen
System *const system
 The system used to determine which mode we are currently operating in. More...
 
const bool elasticReq
 Determine whether to add elasticity in the request injection, thus responding to backpressure by slowing things down. More...
 
const Tick progressCheck
 Time to tolerate waiting for retries (not making progress), until we declare things broken. More...
 
std::unordered_map< RequestPtr, TickwaitingResp
 Reqs waiting for response. More...
 
gem5::BaseTrafficGen::StatGroup stats
 
const RequestorID requestorId
 RequestorID used in generated requests. More...
 
std::shared_ptr< BaseGenactiveGenerator
 Currently active generator. More...
 
std::unique_ptr< StreamGenstreamGenerator
 Stream/SubstreamID Generator. More...
 
- Protected Attributes inherited from gem5::SimObject
const SimObjectParams & _params
 Cached copy of the object parameters. More...
 
- Protected Attributes inherited from gem5::EventManager
EventQueueeventq
 A pointer to this object's event queue. More...
 

Detailed Description

The traffic generator is a module that generates stimuli for the memory system, based on a collection of simple behaviours that are either probabilistic or based on traces.

It can be used stand alone for creating test cases for interconnect and memory controllers, or function as a black-box replacement for system components that are not yet modelled in detail, e.g. a video engine or baseband subsystem in an SoC.

The traffic generator has a single request port that is used to send requests, independent of the specific behaviour. The behaviour of the traffic generator is specified in a configuration file, and this file describes a state transition graph where each state is a specific generator behaviour. Examples include idling, generating linear address sequences, random sequences and replay of captured traces. By describing these behaviours as states, it is straight forward to create very complex behaviours, simply by arranging them in graphs. The graph transitions can also be annotated with probabilities, effectively making it a Markov Chain.

Definition at line 70 of file traffic_gen.hh.

Constructor & Destructor Documentation

◆ TrafficGen()

gem5::TrafficGen::TrafficGen ( const TrafficGenParams &  p)

Definition at line 56 of file traffic_gen.cc.

◆ ~TrafficGen()

gem5::TrafficGen::~TrafficGen ( )
inline

Definition at line 129 of file traffic_gen.hh.

Member Function Documentation

◆ init()

void gem5::TrafficGen::init ( )
overridevirtual

init() is called after all C++ SimObjects have been created and all ports are connected.

Initializations that are independent of unserialization but rely on a fully instantiated and connected SimObject graph should be done here.

Reimplemented from gem5::BaseTrafficGen.

Definition at line 64 of file traffic_gen.cc.

References gem5::BaseTrafficGen::init(), and parseConfig().

◆ initState()

void gem5::TrafficGen::initState ( )
overridevirtual

initState() is called on each SimObject when not restoring from a checkpoint.

This provides a hook for state initializations that are only required for a "cold start".

Reimplemented from gem5::SimObject.

Definition at line 72 of file traffic_gen.cc.

References DPRINTF, gem5::SimObject::initState(), gem5::System::isTimingMode(), gem5::BaseTrafficGen::start(), and gem5::BaseTrafficGen::system.

◆ nextGenerator()

std::shared_ptr< BaseGen > gem5::TrafficGen::nextGenerator ( )
overrideprotectedvirtual

◆ nextState()

size_t gem5::TrafficGen::nextState ( )
private

Use the transition matrix to find the next state index.

Definition at line 349 of file traffic_gen.cc.

References currState, gem5::ArmISA::i, gem5::MipsISA::p, gem5::Random::random(), gem5::random_mt, and transitionMatrix.

Referenced by nextGenerator().

◆ parseConfig()

void gem5::TrafficGen::parseConfig ( )
private

◆ resolveFile()

std::string gem5::TrafficGen::resolveFile ( const std::string &  name)
private

Resolve a file path in the configuration file.

This method resolves a relative path to a file that has been referenced in the configuration file. It first tries to resolve the file relative to the configuration file's path. If that fails, it falls back to constructing a path relative to the current working directory.

Absolute paths are returned unmodified.

Parameters
namePath to resolve

Definition at line 106 of file traffic_gen.cc.

References configFile, gem5::csprintf(), and gem5::Named::name().

Referenced by parseConfig().

◆ serialize()

void gem5::TrafficGen::serialize ( CheckpointOut cp) const
overridevirtual

Serialize an object.

Output an object's state into the current checkpoint section.

Parameters
cpCheckpoint state

Reimplemented from gem5::BaseTrafficGen.

Definition at line 87 of file traffic_gen.cc.

References currState, gem5::BaseTrafficGen::serialize(), and SERIALIZE_SCALAR.

◆ unserialize()

void gem5::TrafficGen::unserialize ( CheckpointIn cp)
overridevirtual

Unserialize an object.

Read an object's state from the current checkpoint section.

Parameters
cpCheckpoint state

Reimplemented from gem5::BaseTrafficGen.

Definition at line 95 of file traffic_gen.cc.

References currState, gem5::BaseTrafficGen::unserialize(), and UNSERIALIZE_SCALAR.

Member Data Documentation

◆ configFile

const std::string gem5::TrafficGen::configFile
private

The config file to parse.

Definition at line 76 of file traffic_gen.hh.

Referenced by parseConfig(), and resolveFile().

◆ currState

uint32_t gem5::TrafficGen::currState
private

Index of the current state.

Definition at line 117 of file traffic_gen.hh.

Referenced by nextGenerator(), nextState(), parseConfig(), serialize(), and unserialize().

◆ states

std::unordered_map<uint32_t, std::shared_ptr<BaseGen> > gem5::TrafficGen::states
private

Map of generator states.

Definition at line 120 of file traffic_gen.hh.

Referenced by nextGenerator(), and parseConfig().

◆ transitionMatrix

std::vector<std::vector<double> > gem5::TrafficGen::transitionMatrix
private

State transition matrix.

Definition at line 114 of file traffic_gen.hh.

Referenced by nextState(), and parseConfig().


The documentation for this class was generated from the following files:

Generated on Tue Sep 21 2021 12:28:19 for gem5 by doxygen 1.8.17