gem5  v21.2.1.1
Classes | Public Member Functions | Private Types | Private Member Functions | Private Attributes | List of all members
gem5::prefetch::BOP Class Reference

#include <bop.hh>

Inheritance diagram for gem5::prefetch::BOP:
gem5::prefetch::Queued gem5::prefetch::Base gem5::ClockedObject gem5::SimObject gem5::Clocked gem5::EventManager gem5::Serializable gem5::Drainable gem5::statistics::Group gem5::Named

Classes

struct  DelayQueueEntry
 In a first implementation of the BO prefetcher, both banks of the RR were written simultaneously when a prefetched line is inserted into the cache. More...
 

Public Member Functions

 BOP (const BOPPrefetcherParams &p)
 
 ~BOP ()=default
 
void calculatePrefetch (const PrefetchInfo &pfi, std::vector< AddrPriority > &addresses) override
 
- Public Member Functions inherited from gem5::prefetch::Queued
 Queued (const QueuedPrefetcherParams &p)
 
virtual ~Queued ()
 
void notify (const PacketPtr &pkt, const PrefetchInfo &pfi) override
 Notify prefetcher of cache access (may be any access or just misses, depending on cache parameters.) More...
 
void insert (const PacketPtr &pkt, PrefetchInfo &new_pfi, int32_t priority)
 
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 setCache (BaseCache *_cache)
 
void prefetchUnused ()
 
void incrDemandMhsrMisses ()
 
void pfHitInCache ()
 
void pfHitInMSHR ()
 
void pfHitInWB ()
 
void regProbeListeners () override
 Register probe points for this object. More...
 
void probeNotify (const PacketPtr &pkt, bool miss)
 Process a notification event from the ProbeListener. More...
 
void addEventProbe (SimObject *obj, const char *name)
 Add a SimObject and a probe name to listen events from. More...
 
void addTLB (BaseTLB *tlb)
 Add a BaseTLB object to be used whenever a translation is needed. More...
 
- 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 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...
 
ProbeManagergetProbeManager ()
 Get the probe manager for this object. More...
 
virtual PortgetPort (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
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
 

Private Types

enum  RRWay { Left, Right }
 
typedef std::pair< int16_t, uint8_t > OffsetListEntry
 Structure to save the offset and the score. More...
 

Private Member Functions

void delayQueueEventWrapper ()
 Event to handle the delay queue processing. More...
 
unsigned int hash (Addr addr, unsigned int way) const
 Generate a hash for the specified address to index the RR table. More...
 
void insertIntoRR (Addr addr, unsigned int way)
 Insert the specified address into the RR table. More...
 
void insertIntoDelayQueue (Addr addr)
 Insert the specified address into the delay queue. More...
 
void resetScores ()
 Reset all the scores from the offset list. More...
 
Addr tag (Addr addr) const
 Generate the tag for the specified address based on the tag bits and the block size. More...
 
bool testRR (Addr) const
 Test if @X-O is hitting in the RR table to update the offset score. More...
 
void bestOffsetLearning (Addr)
 Learning phase of the BOP. More...
 
void notifyFill (const PacketPtr &pkt) override
 Update the RR right table after a prefetch fill. More...
 

Private Attributes

const unsigned int scoreMax
 Learning phase parameters. More...
 
const unsigned int roundMax
 
const unsigned int badScore
 
const unsigned int rrEntries
 Recent requests table parameteres. More...
 
const unsigned int tagMask
 
const bool delayQueueEnabled
 Delay queue parameters. More...
 
const unsigned int delayQueueSize
 
const unsigned int delayTicks
 
std::vector< AddrrrLeft
 
std::vector< AddrrrRight
 
std::vector< OffsetListEntryoffsetsList
 
std::deque< DelayQueueEntrydelayQueue
 
EventFunctionWrapper delayQueueEvent
 
bool issuePrefetchRequests
 Hardware prefetcher enabled. More...
 
Addr bestOffset
 Current best offset to issue prefetches. More...
 
Addr phaseBestOffset
 Current best offset found in the learning phase. More...
 
std::vector< OffsetListEntry >::iterator offsetsListIterator
 Current test offset index. More...
 
unsigned int bestScore
 Max score found so far. More...
 
unsigned int round
 Current round. More...
 

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. 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 Types inherited from gem5::prefetch::Queued
using const_iterator = std::list< DeferredPacket >::const_iterator
 
using iterator = std::list< DeferredPacket >::iterator
 
- Protected Member Functions inherited from gem5::prefetch::Base
bool observeAccess (const PacketPtr &pkt, bool miss) const
 Determine if this access should be observed. More...
 
bool inCache (Addr addr, bool is_secure) const
 Determine if address is in cache. More...
 
bool inMissQueue (Addr addr, bool is_secure) const
 Determine if address is in cache miss queue. More...
 
bool hasBeenPrefetched (Addr addr, bool is_secure) const
 
bool samePage (Addr a, Addr b) const
 Determine if addresses are on the same page. More...
 
Addr blockAddress (Addr a) const
 Determine the address of the block in which a lays. More...
 
Addr blockIndex (Addr a) const
 Determine the address of a at block granularity. More...
 
Addr pageAddress (Addr a) const
 Determine the address of the page in which a lays. More...
 
Addr pageOffset (Addr a) const
 Determine the page-offset of a
More...
 
Addr pageIthBlockAddress (Addr page, uint32_t i) const
 Build the address of the i-th block inside the page. 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 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...
 
- Protected Attributes inherited from gem5::prefetch::Queued
std::list< DeferredPacketpfq
 
std::list< DeferredPacketpfqMissingTranslation
 
const unsigned queueSize
 Maximum size of the prefetch queue. More...
 
const unsigned missingTranslationQueueSize
 Maximum size of the queue holding prefetch requests with missing address translations. More...
 
const Cycles latency
 Cycles after generation when a prefetch can first be issued. More...
 
const bool queueSquash
 Squash queued prefetch if demand access observed. More...
 
const bool queueFilter
 Filter prefetches if already queued. More...
 
const bool cacheSnoop
 Snoop the cache before generating prefetch (cheating basically) More...
 
const bool tagPrefetch
 Tag prefetch with PC of generating access? More...
 
const unsigned int throttleControlPct
 Percentage of requests that can be throttled. More...
 
gem5::prefetch::Queued::QueuedStats statsQueued
 
- Protected Attributes inherited from gem5::prefetch::Base
BaseCachecache
 Pointr to the parent cache. More...
 
unsigned blkSize
 The block size of the parent cache. More...
 
unsigned lBlkSize
 log_2(block size of the parent cache). More...
 
const bool onMiss
 Only consult prefetcher on cache misses? More...
 
const bool onRead
 Consult prefetcher on reads? More...
 
const bool onWrite
 Consult prefetcher on reads? More...
 
const bool onData
 Consult prefetcher on data accesses? More...
 
const bool onInst
 Consult prefetcher on instruction accesses? More...
 
const RequestorID requestorId
 Request id for prefetches. More...
 
const Addr pageBytes
 
const bool prefetchOnAccess
 Prefetch on every access, not just misses. More...
 
const bool prefetchOnPfHit
 Prefetch on hit on prefetched lines. More...
 
const bool useVirtualAddresses
 Use Virtual Addresses for prefetching. More...
 
gem5::prefetch::Base::StatGroup prefetchStats
 
uint64_t issuedPrefetches
 Total prefetches issued. More...
 
uint64_t usefulPrefetches
 Total prefetches that has been useful. More...
 
BaseTLBtlb
 Registered tlb for address translations. 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

Definition at line 53 of file bop.hh.

Member Typedef Documentation

◆ OffsetListEntry

typedef std::pair<int16_t, uint8_t> gem5::prefetch::BOP::OffsetListEntry
private

Structure to save the offset and the score.

Definition at line 79 of file bop.hh.

Member Enumeration Documentation

◆ RRWay

Enumerator
Left 
Right 

Definition at line 57 of file bop.hh.

Constructor & Destructor Documentation

◆ BOP()

gem5::prefetch::BOP::BOP ( const BOPPrefetcherParams &  p)

Definition at line 41 of file bop.cc.

References delayQueueEventWrapper().

◆ ~BOP()

gem5::prefetch::BOP::~BOP ( )
default

Member Function Documentation

◆ bestOffsetLearning()

void gem5::prefetch::BOP::bestOffsetLearning ( Addr  x)
private

Learning phase of the BOP.

Update the intermediate values of the round and update the best offset if found

Definition at line 189 of file bop.cc.

References badScore, bestOffset, bestScore, DPRINTF, issuePrefetchRequests, offsetsList, offsetsListIterator, phaseBestOffset, resetScores(), round, roundMax, scoreMax, testRR(), and gem5::RiscvISA::x.

Referenced by calculatePrefetch().

◆ calculatePrefetch()

void gem5::prefetch::BOP::calculatePrefetch ( const PrefetchInfo pfi,
std::vector< AddrPriority > &  addresses 
)
overridevirtual

◆ delayQueueEventWrapper()

void gem5::prefetch::BOP::delayQueueEventWrapper ( )
private

Event to handle the delay queue processing.

Definition at line 101 of file bop.cc.

References gem5::curTick(), delayQueue, delayQueueEvent, insertIntoRR(), and gem5::EventManager::schedule().

Referenced by BOP().

◆ hash()

unsigned int gem5::prefetch::BOP::hash ( Addr  addr,
unsigned int  way 
) const
private

Generate a hash for the specified address to index the RR table.

Parameters
addraddress to hash
wayRR table to which is addressed (left/right)

Definition at line 118 of file bop.cc.

References gem5::X86ISA::addr, gem5::floorLog2(), and rrEntries.

Referenced by insertIntoRR().

◆ insertIntoDelayQueue()

void gem5::prefetch::BOP::insertIntoDelayQueue ( Addr  addr)
private

Insert the specified address into the delay queue.

This will trigger an event after the delay cycles pass

Parameters
addraddress to insert into the delay queue

Definition at line 139 of file bop.cc.

References gem5::curTick(), delayQueue, delayQueueEvent, delayQueueSize, delayTicks, gem5::EventManager::schedule(), gem5::Event::scheduled(), and gem5::RiscvISA::x.

Referenced by calculatePrefetch().

◆ insertIntoRR()

void gem5::prefetch::BOP::insertIntoRR ( Addr  addr,
unsigned int  way 
)
private

Insert the specified address into the RR table.

Parameters
addraddress to insert
wayRR table to which the address will be inserted

Definition at line 126 of file bop.cc.

References gem5::X86ISA::addr, hash(), rrLeft, and rrRight.

Referenced by calculatePrefetch(), delayQueueEventWrapper(), and notifyFill().

◆ notifyFill()

void gem5::prefetch::BOP::notifyFill ( const PacketPtr pkt)
overrideprivatevirtual

Update the RR right table after a prefetch fill.

Reimplemented from gem5::prefetch::Base.

Definition at line 256 of file bop.cc.

References bestOffset, gem5::Packet::cmd, gem5::Packet::getAddr(), insertIntoRR(), gem5::MemCmd::isHWPrefetch(), issuePrefetchRequests, and tag().

◆ resetScores()

void gem5::prefetch::BOP::resetScores ( )
private

Reset all the scores from the offset list.

Definition at line 157 of file bop.cc.

References offsetsList.

Referenced by bestOffsetLearning().

◆ tag()

Addr gem5::prefetch::BOP::tag ( Addr  addr) const
inlineprivate

Generate the tag for the specified address based on the tag bits and the block size.

Parameters
addraddress to get the tag from

Definition at line 165 of file bop.cc.

References gem5::X86ISA::addr, gem5::prefetch::Base::blkSize, and tagMask.

Referenced by calculatePrefetch(), and notifyFill().

◆ testRR()

bool gem5::prefetch::BOP::testRR ( Addr  addr) const
private

Test if @X-O is hitting in the RR table to update the offset score.

Definition at line 171 of file bop.cc.

References gem5::X86ISA::addr, rrLeft, and rrRight.

Referenced by bestOffsetLearning().

Member Data Documentation

◆ badScore

const unsigned int gem5::prefetch::BOP::badScore
private

Definition at line 66 of file bop.hh.

Referenced by bestOffsetLearning().

◆ bestOffset

Addr gem5::prefetch::BOP::bestOffset
private

Current best offset to issue prefetches.

Definition at line 106 of file bop.hh.

Referenced by bestOffsetLearning(), calculatePrefetch(), and notifyFill().

◆ bestScore

unsigned int gem5::prefetch::BOP::bestScore
private

Max score found so far.

Definition at line 112 of file bop.hh.

Referenced by bestOffsetLearning().

◆ delayQueue

std::deque<DelayQueueEntry> gem5::prefetch::BOP::delayQueue
private

Definition at line 97 of file bop.hh.

Referenced by delayQueueEventWrapper(), and insertIntoDelayQueue().

◆ delayQueueEnabled

const bool gem5::prefetch::BOP::delayQueueEnabled
private

Delay queue parameters.

Definition at line 71 of file bop.hh.

Referenced by calculatePrefetch().

◆ delayQueueEvent

EventFunctionWrapper gem5::prefetch::BOP::delayQueueEvent
private

Definition at line 101 of file bop.hh.

Referenced by delayQueueEventWrapper(), and insertIntoDelayQueue().

◆ delayQueueSize

const unsigned int gem5::prefetch::BOP::delayQueueSize
private

Definition at line 72 of file bop.hh.

Referenced by insertIntoDelayQueue().

◆ delayTicks

const unsigned int gem5::prefetch::BOP::delayTicks
private

Definition at line 73 of file bop.hh.

Referenced by insertIntoDelayQueue().

◆ issuePrefetchRequests

bool gem5::prefetch::BOP::issuePrefetchRequests
private

Hardware prefetcher enabled.

Definition at line 104 of file bop.hh.

Referenced by bestOffsetLearning(), calculatePrefetch(), and notifyFill().

◆ offsetsList

std::vector<OffsetListEntry> gem5::prefetch::BOP::offsetsList
private

Definition at line 80 of file bop.hh.

Referenced by bestOffsetLearning(), and resetScores().

◆ offsetsListIterator

std::vector<OffsetListEntry>::iterator gem5::prefetch::BOP::offsetsListIterator
private

Current test offset index.

Definition at line 110 of file bop.hh.

Referenced by bestOffsetLearning().

◆ phaseBestOffset

Addr gem5::prefetch::BOP::phaseBestOffset
private

Current best offset found in the learning phase.

Definition at line 108 of file bop.hh.

Referenced by bestOffsetLearning().

◆ round

unsigned int gem5::prefetch::BOP::round
private

Current round.

Definition at line 114 of file bop.hh.

Referenced by bestOffsetLearning().

◆ roundMax

const unsigned int gem5::prefetch::BOP::roundMax
private

Definition at line 65 of file bop.hh.

Referenced by bestOffsetLearning().

◆ rrEntries

const unsigned int gem5::prefetch::BOP::rrEntries
private

Recent requests table parameteres.

Definition at line 68 of file bop.hh.

Referenced by hash().

◆ rrLeft

std::vector<Addr> gem5::prefetch::BOP::rrLeft
private

Definition at line 75 of file bop.hh.

Referenced by insertIntoRR(), and testRR().

◆ rrRight

std::vector<Addr> gem5::prefetch::BOP::rrRight
private

Definition at line 76 of file bop.hh.

Referenced by insertIntoRR(), and testRR().

◆ scoreMax

const unsigned int gem5::prefetch::BOP::scoreMax
private

Learning phase parameters.

Definition at line 64 of file bop.hh.

Referenced by bestOffsetLearning().

◆ tagMask

const unsigned int gem5::prefetch::BOP::tagMask
private

Definition at line 69 of file bop.hh.

Referenced by tag().


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

Generated on Wed May 4 2022 12:15:49 for gem5 by doxygen 1.8.17