#include <stride.hh>

Inheritance diagram for gem5::prefetch::Stride:

Classes
struct	PCTableInfo
	Information used to create a new PC table. More...

struct	StrideEntry
	Tagged by hashed PCs. More...

Public Member Functions
	Stride (const StridePrefetcherParams &p)

void	calculatePrefetch (const PrefetchInfo &pfi, std::vector< AddrPriority > &addresses, const CacheAccessor &cache) override

Public Member Functions inherited from gem5::prefetch::Queued
	Queued (const QueuedPrefetcherParams &p)

virtual	~Queued ()

void	notify (const CacheAccessProbeArg &acc, const PrefetchInfo &pfi) override
	Notify prefetcher of cache access (may be any access or just misses, depending on cache parameters.)

void	insert (const PacketPtr &pkt, PrefetchInfo &new_pfi, int32_t priority, const CacheAccessor &cache)

PacketPtr	getPacket () override

Tick	nextPrefetchReadyTime () const override

void	printQueue (const std::list< DeferredPacket > &queue) const

Public Member Functions inherited from gem5::prefetch::Base
	Base (const BasePrefetcherParams &p)

virtual	~Base ()=default

virtual void	setParentInfo (System sys, ProbeManager pm, unsigned blk_size)

virtual void	notifyFill (const CacheAccessProbeArg &acc)
	Notify prefetcher of cache fill.

virtual void	notifyEvict (const EvictionInfo &info)
	Notify prefetcher of cache eviction.

void	prefetchUnused ()

void	incrDemandMhsrMisses ()

void	pfHitInCache ()

void	pfHitInMSHR ()

void	pfHitInWB ()

void	regProbeListeners () override
	Register probe points for this object.

void	probeNotify (const CacheAccessProbeArg &acc, bool miss)
	Process a notification event from the ProbeListener.

void	addEventProbe (SimObject obj, const char name)
	Add a SimObject and a probe name to listen events from.

void	addMMU (BaseMMU *mmu)
	Add a BaseMMU object to be used whenever a translation is needed.

Public Member Functions inherited from gem5::ClockedObject
	ClockedObject (const ClockedObjectParams &p)

void	serialize (CheckpointOut &cp) const override
	Serialize an object.

void	unserialize (CheckpointIn &cp) override
	Unserialize an object.

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.

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

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

virtual void	regProbePoints ()
	Register probe points for this object.

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

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

virtual void	startup ()
	startup() is the final initialization call before simulation.

DrainState	drain () override
	Provide a default implementation of the drain interface for objects that don't need draining.

virtual void	memWriteback ()
	Write back dirty buffers to memory using functional writes.

virtual void	memInvalidate ()
	Invalidate the contents of memory buffers.

void	serialize (CheckpointOut &cp) const override
	Serialize an object.

void	unserialize (CheckpointIn &cp) override
	Unserialize an object.

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.

void	setCurTick (Tick newVal)

	EventManager (EventManager &em)
	Event manger manages events in the event queue.

	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.

void	serializeSection (CheckpointOut &cp, const std::string &name) const

void	unserializeSection (CheckpointIn &cp, const char *name)
	Unserialize an a child object.

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.

virtual void	notifyFork ()
	Notify a child process of a fork.

Public Member Functions inherited from gem5::statistics::Group
	Group (Group parent, const char name=nullptr)
	Construct a new statistics group.

virtual	~Group ()

virtual void	regStats ()
	Callback to set stat parameters.

virtual void	resetStats ()
	Callback to reset stats.

virtual void	preDumpStats ()
	Callback before stats are dumped.

void	addStat (statistics::Info *info)
	Register a stat with this group.

const std::map< std::string, Group * > &	getStatGroups () const
	Get all child groups associated with this object.

const std::vector< Info * > &	getStats () const
	Get all stats associated with this object.

void	addStatGroup (const char name, Group block)
	Add a stat block as a child of this block.

const Info *	resolveStat (std::string name) const
	Resolve a stat by its name within this group.

void	mergeStatGroup (Group *block)
	Merge the contents (stats & children) of a block to this block.

	Group ()=delete

	Group (const Group &)=delete

Group &	operator= (const Group &)=delete

Public Member Functions inherited from gem5::Named
	Named (std::string_view 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.

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.

Cycles	curCycle () const
	Determine the current cycle, corresponding to a tick aligned to a clock edge.

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.

uint64_t	frequency () const

Tick	clockPeriod () const

double	voltage () const

Cycles	ticksToCycles (Tick t) const

Tick	cyclesToTicks (Cycles c) const

Protected Types
using	PCTable = AssociativeCache<StrideEntry>

Protected Types inherited from gem5::prefetch::Queued
using	const_iterator = std::list<DeferredPacket>::const_iterator

using	iterator = std::list<DeferredPacket>::iterator

Protected Member Functions
PCTable &	findTable (int context)
	Try to find a table of entries for the given context.

PCTable &	allocateNewContext (int context)
	Create a PC table for the given context.

Protected Member Functions inherited from gem5::prefetch::Base
bool	observeAccess (const PacketPtr &pkt, bool miss, bool prefetched) const
	Determine if this access should be observed.

bool	samePage (Addr a, Addr b) const
	Determine if addresses are on the same page.

Addr	blockAddress (Addr a) const
	Determine the address of the block in which a lays.

Addr	blockIndex (Addr a) const
	Determine the address of a at block granularity.

Addr	pageAddress (Addr a) const
	Determine the address of the page in which a lays.

Addr	pageOffset (Addr a) const
	Determine the page-offset of a.

Addr	pageIthBlockAddress (Addr page, uint32_t i) const
	Build the address of the i-th block inside the page.

Protected Member Functions inherited from gem5::Drainable
	Drainable ()

virtual	~Drainable ()

virtual void	drainResume ()
	Resume execution after a successful drain.

void	signalDrainDone () const
	Signal that an object is drained.

Protected Member Functions inherited from gem5::Clocked
	Clocked (ClockDomain &clk_domain)
	Create a clocked object and set the clock domain based on the parameters.

	Clocked (Clocked &)=delete

Clocked &	operator= (Clocked &)=delete

virtual	~Clocked ()
	Virtual destructor due to inheritance.

void	resetClock () const
	Reset the object's clock using the current global tick value.

virtual void	clockPeriodUpdated ()
	A hook subclasses can implement so they can do any extra work that's needed when the clock rate is changed.

Protected Attributes
const SatCounter8	initConfidence
	Initial confidence counter value for the pc tables.

const double	threshConf
	Confidence threshold for prefetch generation.

const bool	useRequestorId

const int	degree

const int	distance
	How far ahead of the demand stream to start prefetching.

const struct gem5::prefetch::Stride::PCTableInfo	pcTableInfo

std::unordered_map< int, std::unique_ptr< PCTable > >	pcTables

const bool	useCachelineAddr
	If this parameter is set to true, then the prefetcher will operate at the granularity of cache line.

Protected Attributes inherited from gem5::prefetch::Queued
std::list< DeferredPacket >	pfq

std::list< DeferredPacket >	pfqMissingTranslation

const unsigned	queueSize
	Maximum size of the prefetch queue.

const unsigned	missingTranslationQueueSize
	Maximum size of the queue holding prefetch requests with missing address translations.

const Cycles	latency
	Cycles after generation when a prefetch can first be issued.

const bool	queueSquash
	Squash queued prefetch if demand access observed.

const bool	queueFilter
	Filter prefetches if already queued.

const bool	cacheSnoop
	Snoop the cache before generating prefetch (cheating basically)

const bool	tagPrefetch
	Tag prefetch with PC of generating access?

const unsigned int	throttleControlPct
	Percentage of requests that can be throttled.

gem5::prefetch::Queued::QueuedStats	statsQueued

Protected Attributes inherited from gem5::prefetch::Base
System *	system
	Pointer to the parent system.

ProbeManager *	probeManager
	Pointer to the parent cache's probe manager.

unsigned	blkSize
	The block size of the parent cache.

unsigned	lBlkSize
	log_2(block size of the parent cache).

const bool	onMiss
	Only consult prefetcher on cache misses?

const bool	onRead
	Consult prefetcher on reads?

const bool	onWrite
	Consult prefetcher on reads?

const bool	onData
	Consult prefetcher on data accesses?

const bool	onInst
	Consult prefetcher on instruction accesses?

const RequestorID	requestorId
	Request id for prefetches.

const Addr	pageBytes

const bool	prefetchOnAccess
	Prefetch on every access, not just misses.

const bool	prefetchOnPfHit
	Prefetch on hit on prefetched lines.

const bool	useVirtualAddresses
	Use Virtual Addresses for prefetching.

gem5::prefetch::Base::StatGroup	prefetchStats

uint64_t	issuedPrefetches
	Total prefetches issued.

uint64_t	usefulPrefetches
	Total prefetches that has been useful.

BaseMMU *	mmu
	Registered mmu for address translations.

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

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

Additional Inherited Members
Public Types inherited from gem5::prefetch::Queued
using	AddrPriority = std::pair<Addr, int32_t>

Public Types inherited from gem5::ClockedObject
using	Params = ClockedObjectParams
	Parameters of ClockedObject.

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.

static SimObject *	find (const char *name)
	Find the SimObject with the given name and return a pointer to it.

static void	setSimObjectResolver (SimObjectResolver *resolver)
	There is a single object name resolver, and it is only set when simulation is restoring from checkpoints.

static SimObjectResolver *	getSimObjectResolver ()
	There is a single object name resolver, and it is only set when simulation is restoring from checkpoints.

Static Public Member Functions inherited from gem5::Serializable
static const std::string &	currentSection ()
	Gets the fully-qualified name of the active section.

static void	generateCheckpointOut (const std::string &cpt_dir, std::ofstream &outstream)
	Generate a checkpoint file so that the serialization can be routed to it.

Public Attributes inherited from gem5::ClockedObject
PowerState *	powerState

Detailed Description

Definition at line 95 of file stride.hh.

Member Typedef Documentation

◆ PCTable

using gem5::prefetch::Stride::PCTable = AssociativeCache<StrideEntry>

protected

Definition at line 147 of file stride.hh.

Constructor & Destructor Documentation

◆ Stride()

gem5::prefetch::Stride::Stride ( const StridePrefetcherParams & p )

Definition at line 82 of file stride.cc.

References degree, distance, initConfidence, gem5::MipsISA::p, pcTableInfo, gem5::prefetch::Queued::Queued(), threshConf, useCachelineAddr, and useRequestorId.

Member Function Documentation

◆ allocateNewContext()

Stride::PCTable & gem5::prefetch::Stride::allocateNewContext ( int context )

protected

Create a PC table for the given context.

Parameters

context The context of the new PC table.

Returns: The new PC table

Definition at line 108 of file stride.cc.

References DPRINTF, gem5::genTagExtractor(), initConfidence, gem5::Named::name(), pcTableInfo, and pcTables.

Referenced by findTable().

◆ calculatePrefetch()

void gem5::prefetch::Stride::calculatePrefetch	(	const PrefetchInfo &	pfi,
		std::vector< AddrPriority > &	addresses,
		const CacheAccessor &	cache )

overridevirtual

Implements gem5::prefetch::Queued.

Definition at line 128 of file stride.cc.

References gem5::AssociativeCache< Entry >::accessEntry(), gem5::prefetch::Base::blkSize, gem5::prefetch::Base::blockAddress(), gem5::GenericSatCounter< T >::calcSaturation(), gem5::prefetch::Stride::StrideEntry::confidence, gem5::ArmISA::d, degree, distance, DPRINTF, gem5::AssociativeCache< Entry >::findEntry(), findTable(), gem5::AssociativeCache< Entry >::findVictim(), gem5::prefetch::Base::PrefetchInfo::getAddr(), gem5::prefetch::Base::PrefetchInfo::getPC(), gem5::prefetch::Base::PrefetchInfo::getRequestorId(), gem5::prefetch::Base::PrefetchInfo::hasPC(), gem5::AssociativeCache< Entry >::insertEntry(), gem5::prefetch::Base::PrefetchInfo::isSecure(), gem5::prefetch::Stride::StrideEntry::lastAddr, gem5::MipsISA::pc, gem5::prefetch::Stride::StrideEntry::stride, threshConf, useCachelineAddr, and useRequestorId.

◆ findTable()

Stride::PCTable & gem5::prefetch::Stride::findTable ( int context )

protected

Try to find a table of entries for the given context.

If none is found, a new table is created.

Parameters

context The context to be searched for.

Returns: The table corresponding to the given context.

Definition at line 96 of file stride.cc.

References allocateNewContext(), and pcTables.

Referenced by calculatePrefetch().

Member Data Documentation

◆ degree

const int gem5::prefetch::Stride::degree

protected

Definition at line 106 of file stride.hh.

Referenced by calculatePrefetch(), and Stride().

◆ distance

const int gem5::prefetch::Stride::distance

protected

How far ahead of the demand stream to start prefetching.

Skip this number of strides ahead of the first identified prefetch, then generate degree prefetches at stride intervals. A value of zero indicates no skip.

Definition at line 114 of file stride.hh.

Referenced by calculatePrefetch(), and Stride().

◆ initConfidence

const SatCounter8 gem5::prefetch::Stride::initConfidence

protected

Initial confidence counter value for the pc tables.

Definition at line 99 of file stride.hh.

Referenced by allocateNewContext(), and Stride().

◆ pcTableInfo

const struct gem5::prefetch::Stride::PCTableInfo gem5::prefetch::Stride::pcTableInfo

protected

Referenced by allocateNewContext(), and Stride().

◆ pcTables

std::unordered_map<int, std::unique_ptr<PCTable> > gem5::prefetch::Stride::pcTables

protected

Definition at line 148 of file stride.hh.

Referenced by allocateNewContext(), and findTable().

◆ threshConf

const double gem5::prefetch::Stride::threshConf

protected

Confidence threshold for prefetch generation.

Definition at line 102 of file stride.hh.

Referenced by calculatePrefetch(), and Stride().

◆ useCachelineAddr

const bool gem5::prefetch::Stride::useCachelineAddr

protected

If this parameter is set to true, then the prefetcher will operate at the granularity of cache line.

Otherwise it would operate on the granularity of word addresses

Definition at line 155 of file stride.hh.

Referenced by calculatePrefetch(), and Stride().

◆ useRequestorId

const bool gem5::prefetch::Stride::useRequestorId

protected

Definition at line 104 of file stride.hh.

Referenced by calculatePrefetch(), and Stride().

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

mem/cache/prefetch/stride.hh
mem/cache/prefetch/stride.cc

Classes

Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ PCTable

Constructor & Destructor Documentation

◆ Stride()

Member Function Documentation

◆ allocateNewContext()

◆ calculatePrefetch()

◆ findTable()

Member Data Documentation

◆ degree

◆ distance

◆ initConfidence

◆ pcTableInfo

◆ pcTables

◆ threshConf

◆ useCachelineAddr

◆ useRequestorId