A Class for maintaining a list of pending and allocated memory requests. More...

#include <mshr_queue.hh>

Inheritance diagram for gem5::MSHRQueue:

Public Member Functions
	MSHRQueue (const std::string &_label, int num_entries, int reserve, int demand_reserve, std::string cache_name)
	Create a queue with a given number of entries.

MSHR *	allocate (Addr blk_addr, unsigned blk_size, PacketPtr pkt, Tick when_ready, Counter order, bool alloc_on_fill)
	Allocates a new MSHR for the request and size.

void	deallocate (MSHR *mshr) override
	Deallocate a MSHR and its targets.

void	moveToFront (MSHR *mshr)
	Moves the MSHR to the front of the pending list if it is not in service.

void	delay (MSHR *mshr, Tick delay_ticks)
	Adds a delay to the provided MSHR and moves MSHRs that will be ready earlier than this entry to the top of the list.

void	markInService (MSHR *mshr, bool pending_modified_resp)
	Mark the given MSHR as in service.

void	markPending (MSHR *mshr)
	Mark an in service entry as pending, used to resend a request.

bool	forceDeallocateTarget (MSHR *mshr)
	Deallocate top target, possibly freeing the MSHR.

bool	havePending () const
	Returns true if the pending list is not empty.

bool	canPrefetch () const
	Returns true if sufficient mshrs for prefetch.

Public Member Functions inherited from gem5::Queue< MSHR >
	Queue (const std::string &_label, int num_entries, int reserve, const std::string &name)
	Create a queue with a given number of entries.

bool	isEmpty () const

bool	isFull () const

int	numInService () const

MSHR *	findMatch (Addr blk_addr, bool is_secure, bool ignore_uncacheable=true) const
	Find the first entry that matches the provided address.

bool	trySatisfyFunctional (PacketPtr pkt)

MSHR *	findPending (const QueueEntry *entry) const
	Find any pending requests that overlap the given request of a different queue.

MSHR *	getNext () const
	Returns the WriteQueueEntry at the head of the readyList.

Tick	nextReadyTime () const

virtual void	deallocate (MSHR *entry)
	Removes the given entry from the queue.

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.

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::Named
	Named (const std::string &name_)

virtual	~Named ()=default

virtual std::string	name () const

Private Attributes
const int	demandReserve
	The number of entries to reserve for future demand accesses.

Additional Inherited Members
Protected Member Functions inherited from gem5::Queue< MSHR >
Entry::Iterator	addToReadyList (MSHR *entry)

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

virtual	~Drainable ()

virtual DrainState	drain ()=0
	Draining is the process of clearing out the states of SimObjects.These are the SimObjects that are partially executed or are partially in flight.

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

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

Protected Attributes inherited from gem5::Queue< MSHR >
const std::string	label
	Local label (for functional print requests)

const int	numEntries
	The total number of entries in this queue.

const int	numReserve
	The number of entries to hold as a temporary overflow space.

std::vector< MSHR >	entries
	Actual storage.

Entry::List	allocatedList
	Holds pointers to all allocated entries.

Entry::List	readyList
	Holds pointers to entries that haven't been sent downstream.

Entry::List	freeList
	Holds non allocated entries.

int	_numInService
	The number of entries that are in service.

int	allocated
	The number of currently allocated entries.

Detailed Description

A Class for maintaining a list of pending and allocated memory requests.

Definition at line 61 of file mshr_queue.hh.

Constructor & Destructor Documentation

◆ MSHRQueue()

gem5::MSHRQueue::MSHRQueue	(	const std::string &	_label,
		int	num_entries,
		int	reserve,
		int	demand_reserve,
		std::string	cache_name = `""`
	)

Create a queue with a given number of entries.

Parameters

num_entrys	The number of entries in this queue.
reserve	The minimum number of entries needed to satisfy any access.
demand_reserve	The minimum number of entries needed to satisfy demand accesses.

Definition at line 55 of file mshr_queue.cc.

Member Function Documentation

◆ allocate()

MSHR * gem5::MSHRQueue::allocate	(	Addr	blk_addr,
		unsigned	blk_size,
		PacketPtr	pkt,
		Tick	when_ready,
		Counter	order,
		bool	alloc_on_fill
	)

Allocates a new MSHR for the request and size.

This places the request as the first target in the MSHR.

Parameters

blk_addr	The address of the block.
blk_size	The number of bytes to request.
pkt	The original miss.
when_ready	When should the MSHR be ready to act upon.
order	The logical order of this MSHR
alloc_on_fill	Should the cache allocate a block on fill