DVFS Handler class, maintains a list of all the domains it can handle. More...

#include <dvfs_handler.hh>

Inheritance diagram for gem5::DVFSHandler:

Classes
struct	UpdateEvent
	Update performance level event, encapsulates all the required information for a future call to change a domain's performance level. More...

Public Types
typedef DVFSHandlerParams	Params

typedef SrcClockDomain::DomainID	DomainID

typedef SrcClockDomain::PerfLevel	PerfLevel

Public Types inherited from gem5::SimObject
typedef SimObjectParams	Params

Public Member Functions
	DVFSHandler (const Params &p)

uint32_t	numDomains () const
	Get the number of domains assigned to this DVFS handler. More...

DomainID	domainID (uint32_t index) const
	Get the n-th domain ID, from the domains managed by this handler. More...

bool	validDomainID (DomainID domain_id) const
	Check whether a domain ID is known to the handler or not. More...

Tick	transLatency () const
	Get transition latency to switch between performance levels. More...

bool	perfLevel (DomainID domain_id, PerfLevel perf_level)
	Set a new performance level for the specified domain. More...

PerfLevel	perfLevel (DomainID domain_id) const
	Get the current performance level of a domain. More...

Tick	clkPeriodAtPerfLevel (DomainID domain_id, PerfLevel perf_level) const
	Read the clock period of the specified domain at the specified performance level. More...

double	voltageAtPerfLevel (DomainID domain_id, PerfLevel perf_level) const
	Read the voltage of the specified domain at the specified performance level. More...

PerfLevel	numPerfLevels (PerfLevel domain_id) const
	Get the total number of available performance levels. More...

bool	isEnabled () const
	Check enable status of the DVFS handler, when the handler is disabled, no request should be sent to the handler. 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::SimObject
const Params &	params () const

	SimObject (const Params &p)

virtual	~SimObject ()

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

virtual void	loadState (CheckpointIn &cp)
	loadState() is called on each SimObject when restoring from a checkpoint. More...

virtual void	initState ()
	initState() is called on each SimObject when not 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...

ProbeManager *	getProbeManager ()
	Get the probe manager for this object. More...

virtual Port &	getPort (const std::string &if_name, PortID idx=InvalidPortID)
	Get a port with a given name and index. 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
EventQueue *	eventQueue () 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 Info *	resolveStat (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

Group &	operator= (const Group &)=delete

Public Member Functions inherited from gem5::Named
	Named (const std::string &name_)

virtual	~Named ()=default

virtual std::string	name () const

Private Types
typedef std::map< DomainID, SrcClockDomain * >	Domains

typedef std::map< DomainID, UpdateEvent >	UpdatePerfLevelEvents

Private Member Functions
SrcClockDomain *	findDomain (DomainID domain_id) const
	Search for a domain based on the domain ID. More...

Private Attributes
Domains	domains

std::vector< DomainID >	domainIDList
	List of IDs avaiable in the domain list. More...

SrcClockDomain *	sysClkDomain
	Clock domain of the system the handler is instantiated. More...

bool	enableHandler
	Disabling the DVFS handler ensures that all the DVFS migration requests are ignored. More...

const Tick	_transLatency
	This corresponds to the maximum transition latency associated with the hardware transitioning from a particular performance level to the other. More...

UpdatePerfLevelEvents	updatePerfLevelEvents
	Map from domain IDs -> perf level update events, records in-flight change requests per domain ID. More...

Additional Inherited Members
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 SimObject *	find (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 SimObjectResolver *	getSimObjectResolver ()
	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...

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 Attributes inherited from gem5::SimObject
const SimObjectParams &	_params
	Cached copy of the object parameters. More...

Protected Attributes inherited from gem5::EventManager
EventQueue *	eventq
	A pointer to this object's event queue. More...

Detailed Description

DVFS Handler class, maintains a list of all the domains it can handle.

Each entry of that list is an object of the DomainConfig class, and the handler uses the methods provided by that class to get access to the configuration of each domain. The handler is responsible for setting/getting clock periods and voltages from clock/voltage domains. The handler acts the bridge between software configurable information for each domain as provided to the controller and the hardware implementation details for those domains.

Definition at line 74 of file dvfs_handler.hh.

Member Typedef Documentation

◆ DomainID

typedef SrcClockDomain::DomainID gem5::DVFSHandler::DomainID

Definition at line 80 of file dvfs_handler.hh.

◆ Domains

typedef std::map<DomainID, SrcClockDomain*> gem5::DVFSHandler::Domains

private

Definition at line 184 of file dvfs_handler.hh.

◆ Params

typedef DVFSHandlerParams gem5::DVFSHandler::Params

Definition at line 77 of file dvfs_handler.hh.

◆ PerfLevel

typedef SrcClockDomain::PerfLevel gem5::DVFSHandler::PerfLevel

Definition at line 81 of file dvfs_handler.hh.

◆ UpdatePerfLevelEvents

typedef std::map<DomainID, UpdateEvent> gem5::DVFSHandler::UpdatePerfLevelEvents

private

Definition at line 260 of file dvfs_handler.hh.

Constructor & Destructor Documentation

◆ DVFSHandler()

gem5::DVFSHandler::DVFSHandler ( const Params & p )

Definition at line 58 of file dvfs_handler.cc.

References gem5::ArmISA::d, gem5::ArmISA::dit, domainIDList, domains, gem5::DVFSHandler::UpdateEvent::dvfsHandler, gem5::SrcClockDomain::emptyDomainID, fatal_if, gem5::VegaISA::p, sysClkDomain, and updatePerfLevelEvents.

Member Function Documentation

◆ clkPeriodAtPerfLevel()

Tick gem5::DVFSHandler::clkPeriodAtPerfLevel	(	DomainID	domain_id,
		PerfLevel	perf_level
	)		const

inline

Read the clock period of the specified domain at the specified performance level.

Parameters

domain_id	Domain ID to query
perf_level	Performance level of interest

Returns: Clock period in ticks for the requested performance level of the respective domain

Definition at line 138 of file dvfs_handler.hh.

References gem5::ArmISA::d, findDomain(), gem5::ArmISA::n, gem5::Named::name(), and warn.

Referenced by gem5::EnergyCtrl::read().

◆ domainID()

DVFSHandler::DomainID gem5::DVFSHandler::domainID ( uint32_t index ) const

Get the n-th domain ID, from the domains managed by this handler.

Returns: Domain ID

Definition at line 94 of file dvfs_handler.cc.

References domainIDList, domains, fatal_if, gem5::MipsISA::index, and numDomains().

Referenced by gem5::EnergyCtrl::read().

◆ findDomain()

SrcClockDomain* gem5::DVFSHandler::findDomain ( DomainID domain_id ) const

inlineprivate

Search for a domain based on the domain ID.

Parameters

domain_id Domain ID to search for

Returns: Pointer to the source clock domain with matching ID.

Definition at line 203 of file dvfs_handler.hh.

References domains, and panic_if.

Referenced by clkPeriodAtPerfLevel(), numPerfLevels(), perfLevel(), gem5::DVFSHandler::UpdateEvent::updatePerfLevel(), and voltageAtPerfLevel().

◆ isEnabled()

bool gem5::DVFSHandler::isEnabled ( ) const

inline

Check enable status of the DVFS handler, when the handler is disabled, no request should be sent to the handler.

Returns: True, if the handler is enabled

Definition at line 178 of file dvfs_handler.hh.

References enableHandler.

Referenced by perfLevel(), gem5::EnergyCtrl::read(), gem5::EnergyCtrl::startup(), validDomainID(), and gem5::EnergyCtrl::write().

◆ numDomains()

uint32_t gem5::DVFSHandler::numDomains ( ) const

inline

Get the number of domains assigned to this DVFS handler.

Returns: Number of domains

Definition at line 87 of file dvfs_handler.hh.

References domainIDList.

Referenced by domainID(), and gem5::EnergyCtrl::read().

◆ numPerfLevels()

PerfLevel gem5::DVFSHandler::numPerfLevels ( PerfLevel domain_id ) const

inline

Get the total number of available performance levels.

Parameters

domain_id Domain ID to query

Returns: Number of performance levels that where configured for the respective domain

Definition at line 168 of file dvfs_handler.hh.

References findDomain(), and gem5::SrcClockDomain::numPerfLevels().

Referenced by gem5::EnergyCtrl::read().

◆ perfLevel() [1/2]

PerfLevel gem5::DVFSHandler::perfLevel ( DomainID domain_id ) const

inline

Get the current performance level of a domain.

While a change request is in-flight, will return the current (i.e. old, unmodified) value.

Parameters

domain_id Domain ID to query

Returns: Current performance level of the specified domain

Definition at line 125 of file dvfs_handler.hh.

References findDomain(), isEnabled(), and gem5::SrcClockDomain::perfLevel().

◆ perfLevel() [2/2]

bool gem5::DVFSHandler::perfLevel	(	DomainID	domain_id,
		PerfLevel	perf_level
	)

Set a new performance level for the specified domain.

The actual update will be delayed by transLatency().

Parameters

domain_id	Software visible ID of the domain to be configured
perf_level	Requested performance level (0 - fast, >0 slower)

Returns: status whether the setting was successful

Definition at line 118 of file dvfs_handler.cc.

References _transLatency, gem5::curTick(), gem5::ArmISA::d, gem5::EventManager::deschedule(), DPRINTF, findDomain(), isEnabled(), gem5::DVFSHandler::UpdateEvent::perfLevelToSet, gem5::EventManager::schedule(), gem5::Event::scheduled(), updatePerfLevelEvents, and warn.

Referenced by gem5::EnergyCtrl::read(), and gem5::EnergyCtrl::write().

◆ serialize()

void gem5::DVFSHandler::serialize ( CheckpointOut & cp ) const

overridevirtual

Serialize an object.

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

Parameters

cp	Checkpoint state

Implements gem5::Serializable.

Definition at line 197 of file dvfs_handler.cc.

References enableHandler, gem5::MipsISA::event, SERIALIZE_CONTAINER, SERIALIZE_SCALAR, and updatePerfLevelEvents.

◆ transLatency()

Tick gem5::DVFSHandler::transLatency ( ) const

inline

Get transition latency to switch between performance levels.

Returns: Transition latency

Definition at line 106 of file dvfs_handler.hh.

References _transLatency.

Referenced by gem5::EnergyCtrl::read(), and gem5::EnergyCtrl::write().

◆ unserialize()

void gem5::DVFSHandler::unserialize ( CheckpointIn & cp )

overridevirtual

Unserialize an object.

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

Parameters

cp	Checkpoint state

Implements gem5::Serializable.

Definition at line 224 of file dvfs_handler.cc.

References gem5::DVFSHandler::UpdateEvent::dvfsHandler, enableHandler, gem5::MipsISA::event, gem5::ArmISA::i, gem5::EventManager::schedule(), UNSERIALIZE_CONTAINER, UNSERIALIZE_SCALAR, updatePerfLevelEvents, and warn.

◆ validDomainID()

bool gem5::DVFSHandler::validDomainID ( DomainID domain_id ) const

Check whether a domain ID is known to the handler or not.

Parameters

domain_id Domain ID to check

Returns: Domain ID known to handler?

Definition at line 105 of file dvfs_handler.cc.

References domains, isEnabled(), and warn.

Referenced by gem5::EnergyCtrl::write().

◆ voltageAtPerfLevel()

double gem5::DVFSHandler::voltageAtPerfLevel	(	DomainID	domain_id,
		PerfLevel	perf_level
	)		const

Read the voltage of the specified domain at the specified performance level.

Parameters

domain_id	Domain ID to query
perf_level	Performance level of interest

Returns: Voltage for the requested performance level of the respective domain

Definition at line 173 of file dvfs_handler.cc.

References gem5::ArmISA::d, DPRINTF, findDomain(), gem5::ArmISA::n, gem5::Named::name(), gem5::ClockDomain::voltageDomain(), and warn.

Referenced by gem5::EnergyCtrl::read().

Member Data Documentation

◆ _transLatency

const Tick gem5::DVFSHandler::_transLatency

private

This corresponds to the maximum transition latency associated with the hardware transitioning from a particular performance level to the other.

Definition at line 221 of file dvfs_handler.hh.

Referenced by perfLevel(), and transLatency().

◆ domainIDList

std::vector<DomainID> gem5::DVFSHandler::domainIDList

private

List of IDs avaiable in the domain list.

Definition at line 190 of file dvfs_handler.hh.

Referenced by domainID(), DVFSHandler(), and numDomains().

◆ domains

Domains gem5::DVFSHandler::domains

private

Definition at line 185 of file dvfs_handler.hh.

Referenced by domainID(), DVFSHandler(), findDomain(), and validDomainID().

◆ enableHandler

bool gem5::DVFSHandler::enableHandler

private

Disabling the DVFS handler ensures that all the DVFS migration requests are ignored.

Domains remain at their default frequency and voltage.

Definition at line 214 of file dvfs_handler.hh.

Referenced by isEnabled(), serialize(), and unserialize().

◆ sysClkDomain

SrcClockDomain* gem5::DVFSHandler::sysClkDomain

private

Clock domain of the system the handler is instantiated.

Definition at line 195 of file dvfs_handler.hh.

Referenced by DVFSHandler().

◆ updatePerfLevelEvents

UpdatePerfLevelEvents gem5::DVFSHandler::updatePerfLevelEvents

private

Map from domain IDs -> perf level update events, records in-flight change requests per domain ID.

Definition at line 265 of file dvfs_handler.hh.

Referenced by DVFSHandler(), perfLevel(), serialize(), and unserialize().

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

sim/dvfs_handler.hh
sim/dvfs_handler.cc

Classes

Public Types

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ DomainID

◆ Domains

◆ Params

◆ PerfLevel

◆ UpdatePerfLevelEvents

Constructor & Destructor Documentation

◆ DVFSHandler()

Member Function Documentation

◆ clkPeriodAtPerfLevel()

◆ domainID()

◆ findDomain()

◆ isEnabled()

◆ numDomains()

◆ numPerfLevels()

◆ perfLevel() [1/2]

◆ perfLevel() [2/2]

◆ serialize()

◆ transLatency()

◆ unserialize()

◆ validDomainID()

◆ voltageAtPerfLevel()

Member Data Documentation

◆ _transLatency

◆ domainIDList

◆ domains

◆ enableHandler

◆ sysClkDomain

◆ updatePerfLevelEvents