A fully associative LRU cache. More...

#include <fa_lru.hh>

Inheritance diagram for FALRU:

Public Types
typedef FALRUBlk	BlkType
	Typedef the block type used in this class. More...

typedef FALRUParams	Params

Public Types inherited from BaseTags
typedef BaseTagsParams	Params

Public Types inherited from ClockedObject
typedef ClockedObjectParams	Params
	Parameters of ClockedObject. More...

Public Types inherited from SimObject
typedef SimObjectParams	Params

Public Member Functions
	FALRU (const Params *p)
	Construct and initialize this cache tagstore. More...

	~FALRU ()

void	regStats () override
	Register the stats for this object. More...

void	invalidate (CacheBlk *blk) override
	Invalidate a cache block. More...

CacheBlk *	accessBlock (Addr addr, bool is_secure, Cycles &lat, int *inCache)
	Access block and update replacement data. More...

CacheBlk *	accessBlock (Addr addr, bool is_secure, Cycles &lat) override
	Just a wrapper of above function to conform with the base interface. More...

CacheBlk *	findBlock (Addr addr, bool is_secure) const override
	Find the block in the cache, do not update the replacement data. More...

CacheBlk *	findVictim (Addr addr) override
	Find a replacement block for the address provided. More...

void	insertBlock (PacketPtr pkt, CacheBlk *blk) override

CacheBlk *	findBlockBySetAndWay (int set, int way) const override
	Find the cache block given set and way. More...

Addr	extractTag (Addr addr) const override
	Generate the tag from the addres. More...

int	extractSet (Addr addr) const override
	Return the set of an address. More...

Addr	regenerateBlkAddr (Addr tag, unsigned set) const override
	Regenerate the block address from the tag and the set. More...

virtual std::string	print () const override

void	forEachBlk (CacheBlkVisitor &visitor) override
	Visit each block in the tag store and apply a visitor to the block. More...

Public Member Functions inherited from BaseTags
	BaseTags (const Params *p)

virtual	~BaseTags ()
	Destructor. More...

void	setCache (BaseCache *_cache)
	Set the parent cache back pointer. More...

virtual void	cleanupRefs ()
	Average in the reference count for valid blocks when the simulation exits. More...

virtual void	computeStats ()
	Computes stats just prior to dump event. More...

Addr	blkAlign (Addr addr) const
	Align an address to the block size. More...

int	extractBlkOffset (Addr addr) const
	Calculate the block offset of an address. More...

virtual void	setWayAllocationMax (int ways)
	Limit the allocation for the cache ways. More...

virtual int	getWayAllocationMax () const
	Get the way allocation mask limit. More...

Public Member Functions inherited from ClockedObject
	ClockedObject (const ClockedObjectParams *p)

const Params *	params () const

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

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

Enums::PwrState	pwrState () const

std::string	pwrStateName () const

std::vector< double >	pwrStateWeights () const
	Returns the percentage residency for each power state. More...

void	computeStats ()
	Record stats values like state residency by computing the time difference from previous update. More...

void	pwrState (Enums::PwrState)

void	regStats () override
	Register statistics for this object. More...

Public Member Functions inherited from SimObject
const Params *	params () const

	SimObject (const Params *_params)

virtual	~SimObject ()

virtual const std::string	name () const

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	resetStats ()
	Reset statistics associated with this object. 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 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 EventManager
	EventManager (EventManager &em)

	EventManager (EventManager *em)

	EventManager (EventQueue *eq)

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)

void	setCurTick (Tick newVal)

Public Member Functions inherited from 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 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 Clocked
void	updateClockPeriod () const
	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 Types
typedef std::unordered_map < Addr, FALRUBlk *, std::hash < Addr > >	hash_t
	Hash table type mapping addresses to cache block pointers. More...

typedef hash_t::const_iterator	tagIterator
	Iterator into the address hash table. More...

Protected Member Functions
FALRUBlk *	hashLookup (Addr addr) const
	Find the cache block for the given address. More...

void	moveToHead (FALRUBlk *blk)
	Move a cache block to the MRU position. More...

bool	check ()
	Check to make sure all the cache boundaries are still where they should be. More...

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

	Clocked (Clocked &)=delete

Clocked &	operator= (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...

Protected Attributes
FALRUBlk **	cacheBoundaries
	Array of pointers to blocks at the cache size boundaries. More...

int	cacheMask
	A mask for the FALRUBlk::inCache bits. More...

unsigned	numCaches
	The number of different size caches being tracked. More...

FALRUBlk *	blks
	The cache blocks. More...

FALRUBlk *	head
	The MRU block. More...

FALRUBlk *	tail
	The LRU block. More...

hash_t	tagHash
	The address hash table. More...

Stats::Vector	hits
	Hits in each cache size >= 128K. More...

Stats::Vector	misses
	Misses in each cache size >= 128K. More...

Stats::Scalar	accesses
	Total number of accesses. More...

Protected Attributes inherited from BaseTags
const unsigned	blkSize
	The block size of the cache. More...

const Addr	blkMask
	Mask out all bits that aren't part of the block offset. More...

const unsigned	size
	The size of the cache. More...

const Cycles	lookupLatency
	The tag lookup latency of the cache. More...

const Cycles	accessLatency
	The total access latency of the cache. More...

BaseCache *	cache
	Pointer to the parent cache. More...

int	warmupBound
	The number of tags that need to be touched to meet the warmup percentage. More...

bool	warmedUp
	Marked true when the cache is warmed up. More...

unsigned	numBlocks
	the number of blocks in the cache More...

Stats::Vector	replacements
	Number of replacements of valid blocks per thread. More...

Stats::Average	tagsInUse
	Per cycle average of the number of tags that hold valid data. More...

Stats::Scalar	totalRefs
	The total number of references to a block before it is replaced. More...

Stats::Scalar	sampledRefs
	The number of reference counts sampled. More...

Stats::Formula	avgRefs
	Average number of references to a block before is was replaced. More...

Stats::Scalar	warmupCycle
	The cycle that the warmup percentage was hit. More...

Stats::AverageVector	occupancies
	Average occupancy of each requestor using the cache. More...

Stats::Formula	avgOccs
	Average occ % of each requestor using the cache. More...

Stats::Vector	occupanciesTaskId
	Occupancy of each context/cpu using the cache. More...

Stats::Vector2d	ageTaskId
	Occupancy of each context/cpu using the cache. More...

Stats::Formula	percentOccsTaskId
	Occ % of each context/cpu using the cache. More...

Stats::Scalar	tagAccesses
	Number of tags consulted over all accesses. More...

Stats::Scalar	dataAccesses
	Number of data blocks consulted over all accesses. More...

Protected Attributes inherited from ClockedObject
Enums::PwrState	_currPwrState
	To keep track of the current power state. More...

Tick	prvEvalTick

Stats::Scalar	numPwrStateTransitions

Stats::Distribution	pwrStateClkGateDist

Stats::Vector	pwrStateResidencyTicks

Protected Attributes inherited from SimObject
const SimObjectParams *	_params
	Cached copy of the object parameters. More...

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

Additional Inherited Members
Static Public Member Functions inherited from SimObject
static void	serializeAll (CheckpointOut &cp)
	Serialize 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 Public Member Functions inherited from Serializable
static const std::string &	currentSection ()
	Get the fully-qualified name of the active section. More...

static void	serializeAll (const std::string &cpt_dir)

static void	unserializeGlobals (CheckpointIn &cp)

Static Public Attributes inherited from Serializable
static int	ckptCount = 0

static int	ckptMaxCount = 0

static int	ckptPrevCount = -1

Detailed Description

A fully associative LRU cache.

Keeps statistics for accesses to a number of cache sizes at once.

Definition at line 88 of file fa_lru.hh.

Member Typedef Documentation

typedef FALRUBlk FALRU::BlkType

Typedef the block type used in this class.

Definition at line 92 of file fa_lru.hh.

typedef std::unordered_map<Addr, FALRUBlk *, std::hash<Addr> > FALRU::hash_t

protected

Hash table type mapping addresses to cache block pointers.

Definition at line 111 of file fa_lru.hh.

typedef FALRUParams FALRU::Params

Definition at line 158 of file fa_lru.hh.

typedef hash_t::const_iterator FALRU::tagIterator

protected

Iterator into the address hash table.

Definition at line 113 of file fa_lru.hh.

Constructor & Destructor Documentation

FALRU::FALRU ( const Params * p )

Construct and initialize this cache tagstore.

Definition at line 58 of file fa_lru.cc.

References blks, BaseTags::blkSize, cacheBoundaries, cacheMask, fatal, floorLog2(), head, ArmISA::i, FALRUBlk::inCache, MipsISA::index, isPowerOf2(), FALRUBlk::isTouched, ArmISA::j, FALRUBlk::next, BaseTags::numBlocks, numCaches, FALRUBlk::prev, CacheBlk::set, BaseTags::size, tail, ULL, BaseTags::warmupBound, and CacheBlk::way.

FALRU::~FALRU ( )

Definition at line 113 of file fa_lru.cc.

References blks, cacheBoundaries, and numCaches.

Member Function Documentation

CacheBlk * FALRU::accessBlock	(	Addr	addr,
		bool	is_secure,
		Cycles &	lat,
		int *	inCache
	)

Access block and update replacement data.

May not succeed, in which case nullptr pointer is returned. This has all the implications of a cache access and should only be used as such. Returns the access latency and inCache flags as a side effect.

Parameters

addr	The address to look for.
is_secure	True if the target memory space is secure.
lat	The latency of the access.
inCache	The FALRUBlk::inCache flags.

Returns: Pointer to the cache block.

Definition at line 180 of file fa_lru.cc.

References accesses, BaseTags::accessLatency, BaseTags::blkAlign(), BaseTags::cache, curTick(), hashLookup(), head, hits, ArmISA::i, FALRUBlk::inCache, CacheBlk::isValid(), BaseTags::lookupLatency, misses, moveToHead(), numCaches, CacheBlk::tag, Clocked::ticksToCycles(), and CacheBlk::whenReady.

Referenced by accessBlock().

CacheBlk * FALRU::accessBlock	(	Addr	addr,
		bool	is_secure,
		Cycles &	lat
	)

overridevirtual

Just a wrapper of above function to conform with the base interface.

Implements BaseTags.

Definition at line 174 of file fa_lru.cc.

References accessBlock().

bool FALRU::check ( )

protected

Check to make sure all the cache boundaries are still where they should be.

Used for debugging.

Returns: True if everything is correct.

Definition at line 306 of file fa_lru.cc.

References BaseTags::blkSize, cacheBoundaries, cacheMask, head, FALRUBlk::inCache, ArmISA::j, FALRUBlk::next, and tail.

int FALRU::extractSet ( Addr addr ) const

inlineoverridevirtual

Return the set of an address.

Only one set in a fully associative cache.

Parameters

addr	The address to get the set from.

Returns: 0.

Implements BaseTags.

Definition at line 239 of file fa_lru.hh.

Addr FALRU::extractTag ( Addr addr ) const

inlineoverridevirtual

Generate the tag from the addres.

For fully associative this is just the block address.

Parameters

addr	The address to get the tag from.

Returns: The tag.

Implements BaseTags.

Definition at line 229 of file fa_lru.hh.

References BaseTags::blkAlign().

CacheBlk * FALRU::findBlock	(	Addr	addr,
		bool	is_secure
	)		const

overridevirtual

Find the block in the cache, do not update the replacement data.

Parameters

addr	The address to look for.
is_secure	True if the target memory space is secure.
asid	The address space ID.

Returns: Pointer to the cache block.

Implements BaseTags.

Definition at line 229 of file fa_lru.cc.

References BaseTags::blkAlign(), hashLookup(), CacheBlk::isValid(), and CacheBlk::tag.

CacheBlk * FALRU::findBlockBySetAndWay	(	int	set,
		int	way
	)		const

overridevirtual

Find the cache block given set and way.

Parameters

set	The set of the block.
way	The way of the block.

Returns: The cache block.

Implements BaseTags.

Definition at line 243 of file fa_lru.cc.

References blks.

CacheBlk * FALRU::findVictim ( Addr addr )

overridevirtual

Find a replacement block for the address provided.

Parameters

pkt	The request to a find a replacement candidate for.

Returns: The block to place the replacement in.

Implements BaseTags.

Definition at line 250 of file fa_lru.cc.

References BaseTags::blkAlign(), curTick(), FALRUBlk::inCache, FALRUBlk::isTouched, CacheBlk::isValid(), moveToHead(), BaseTags::replacements, CacheBlk::tag, tagHash, BaseTags::tagsInUse, tail, Stats::ScalarBase< Derived, Stor >::value(), BaseTags::warmedUp, BaseTags::warmupBound, and BaseTags::warmupCycle.

void FALRU::forEachBlk ( CacheBlkVisitor & visitor )

inlineoverridevirtual

Visit each block in the tag store and apply a visitor to the block.

The visitor should be a function (or object that behaves like a function) that takes a cache block reference as its parameter and returns a bool. A visitor can request the traversal to be stopped by returning false, returning true causes it to be called for the next block in the tag store.

Parameters

visitor Visitor to call on each block.

Implements BaseTags.

Definition at line 272 of file fa_lru.hh.

References blks, ArmISA::i, and BaseTags::numBlocks.

FALRUBlk * FALRU::hashLookup ( Addr addr ) const

protected

Find the cache block for the given address.

Parameters

addr	The address to find.

Returns: The cache block of the address, if any.

Definition at line 157 of file fa_lru.cc.

References tagHash.

Referenced by accessBlock(), and findBlock().

void FALRU::insertBlock	(	PacketPtr	pkt,
		CacheBlk *	blk
	)

overridevirtual

Implements BaseTags.

Definition at line 272 of file fa_lru.cc.

void FALRU::invalidate ( CacheBlk * blk )

overridevirtual

Invalidate a cache block.

Parameters

blk	The block to invalidate.

Implements BaseTags.

Definition at line 167 of file fa_lru.cc.

References BaseTags::tagsInUse.

void FALRU::moveToHead ( FALRUBlk * blk )

protected

Move a cache block to the MRU position.

Parameters

blk	The block to promote.

Definition at line 277 of file fa_lru.cc.

References cacheBoundaries, cacheMask, head, ArmISA::i, FALRUBlk::inCache, FALRUBlk::next, numCaches, FALRUBlk::prev, and tail.

Referenced by accessBlock(), and findVictim().

virtual std::string FALRU::print ( ) const

inlineoverridevirtual

Todo:: Implement as in lru. Currently not used

Implements BaseTags.

Definition at line 258 of file fa_lru.hh.

Addr FALRU::regenerateBlkAddr	(	Addr	tag,
		unsigned	set
	)		const

inlineoverridevirtual

Regenerate the block address from the tag and the set.

Parameters

tag	The tag of the block.
set	The set the block belongs to.

Returns: the block address.

Implements BaseTags.

Definition at line 250 of file fa_lru.hh.

void FALRU::regStats ( )

overridevirtual

Register the stats for this object.

Parameters

name	The name to prepend to the stats name.

Reimplemented from BaseTags.

Definition at line 122 of file fa_lru.cc.

References accesses, Stats::DataWrap< Derived, InfoProxyType >::desc(), hits, ArmISA::i, Stats::VectorBase< Derived, Stor >::init(), misses, SimObject::name(), Stats::DataWrap< Derived, InfoProxyType >::name(), numCaches, BaseTags::regStats(), Stats::DataWrapVec< Derived, InfoProxyType >::subdesc(), and Stats::DataWrapVec< Derived, InfoProxyType >::subname().

Member Data Documentation

FALRUBlk* FALRU::blks

protected

The cache blocks.

Definition at line 103 of file fa_lru.hh.

Referenced by FALRU(), findBlockBySetAndWay(), forEachBlk(), and ~FALRU().

FALRUBlk** FALRU::cacheBoundaries

protected

Array of pointers to blocks at the cache size boundaries.

Definition at line 96 of file fa_lru.hh.

Referenced by check(), FALRU(), moveToHead(), and ~FALRU().

int FALRU::cacheMask

protected

A mask for the FALRUBlk::inCache bits.

Definition at line 98 of file fa_lru.hh.

Referenced by check(), FALRU(), and moveToHead().

FALRUBlk* FALRU::head

protected

The MRU block.

Definition at line 106 of file fa_lru.hh.

Referenced by accessBlock(), check(), FALRU(), and moveToHead().

unsigned FALRU::numCaches

protected

The number of different size caches being tracked.

Definition at line 100 of file fa_lru.hh.

Referenced by accessBlock(), FALRU(), moveToHead(), regStats(), and ~FALRU().

hash_t FALRU::tagHash

protected

The address hash table.

Definition at line 116 of file fa_lru.hh.

Referenced by findVictim(), and hashLookup().

FALRUBlk* FALRU::tail

protected

The LRU block.

Definition at line 108 of file fa_lru.hh.

Referenced by check(), FALRU(), findVictim(), and moveToHead().

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

mem/cache/tags/fa_lru.hh
mem/cache/tags/fa_lru.cc

Public Types

Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation