gem5
v20.1.0.0
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A non-coherent cache. More...
#include <noncoherent_cache.hh>
Public Member Functions | |
NoncoherentCache (const NoncoherentCacheParams *p) | |
Public Member Functions inherited from BaseCache | |
void | regProbePoints () override |
Registers probes. More... | |
BaseCache (const BaseCacheParams *p, unsigned blk_size) | |
~BaseCache () | |
void | init () override |
init() is called after all C++ SimObjects have been created and all ports are connected. More... | |
Port & | getPort (const std::string &if_name, PortID idx=InvalidPortID) override |
Get a port with a given name and index. More... | |
unsigned | getBlockSize () const |
Query block size of a cache. More... | |
const AddrRangeList & | getAddrRanges () const |
MSHR * | allocateMissBuffer (PacketPtr pkt, Tick time, bool sched_send=true) |
void | allocateWriteBuffer (PacketPtr pkt, Tick time) |
bool | isBlocked () const |
Returns true if the cache is blocked for accesses. More... | |
void | setBlocked (BlockedCause cause) |
Marks the access path of the cache as blocked for the given cause. More... | |
void | clearBlocked (BlockedCause cause) |
Marks the cache as unblocked for the given cause. More... | |
void | schedMemSideSendEvent (Tick time) |
Schedule a send event for the memory-side port. More... | |
bool | inCache (Addr addr, bool is_secure) const |
bool | hasBeenPrefetched (Addr addr, bool is_secure) const |
bool | inMissQueue (Addr addr, bool is_secure) const |
void | incMissCount (PacketPtr pkt) |
void | incHitCount (PacketPtr pkt) |
bool | coalesce () const |
Checks if the cache is coalescing writes. More... | |
void | writebackVisitor (CacheBlk &blk) |
Cache block visitor that writes back dirty cache blocks using functional writes. More... | |
void | invalidateVisitor (CacheBlk &blk) |
Cache block visitor that invalidates all blocks in the cache. More... | |
virtual bool | sendMSHRQueuePacket (MSHR *mshr) |
Take an MSHR, turn it into a suitable downstream packet, and send it out. More... | |
bool | sendWriteQueuePacket (WriteQueueEntry *wq_entry) |
Similar to sendMSHR, but for a write-queue entry instead. More... | |
void | serialize (CheckpointOut &cp) const override |
Serialize the state of the caches. More... | |
void | unserialize (CheckpointIn &cp) override |
Unserialize an object. 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... | |
Public Member Functions inherited from SimObject | |
const Params * | params () const |
SimObject (const Params *_params) | |
virtual | ~SimObject () |
virtual const std::string | name () const |
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 | 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... | |
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 | |
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 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 Stats::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 (Stats::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... | |
Group ()=delete | |
Group (const Group &)=delete | |
Group & | operator= (const Group &)=delete |
Public Member Functions inherited from 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 |
Protected Member Functions | |
bool | access (PacketPtr pkt, CacheBlk *&blk, Cycles &lat, PacketList &writebacks) override |
Does all the processing necessary to perform the provided request. More... | |
void | handleTimingReqMiss (PacketPtr pkt, CacheBlk *blk, Tick forward_time, Tick request_time) override |
void | recvTimingReq (PacketPtr pkt) override |
Performs the access specified by the request. More... | |
void | doWritebacks (PacketList &writebacks, Tick forward_time) override |
Insert writebacks into the write buffer. More... | |
void | doWritebacksAtomic (PacketList &writebacks) override |
Send writebacks down the memory hierarchy in atomic mode. More... | |
void | serviceMSHRTargets (MSHR *mshr, const PacketPtr pkt, CacheBlk *blk) override |
Service non-deferred MSHR targets using the received response. More... | |
void | recvTimingResp (PacketPtr pkt) override |
Handles a response (cache line fill/write ack) from the bus. More... | |
void | recvTimingSnoopReq (PacketPtr pkt) override |
Snoops bus transactions to maintain coherence. More... | |
void | recvTimingSnoopResp (PacketPtr pkt) override |
Handle a snoop response. More... | |
Cycles | handleAtomicReqMiss (PacketPtr pkt, CacheBlk *&blk, PacketList &writebacks) override |
Handle a request in atomic mode that missed in this cache. More... | |
Tick | recvAtomic (PacketPtr pkt) override |
Performs the access specified by the request. More... | |
Tick | recvAtomicSnoop (PacketPtr pkt) override |
Snoop for the provided request in the cache and return the estimated time taken. More... | |
void | functionalAccess (PacketPtr pkt, bool from_cpu_side) override |
Performs the access specified by the request. More... | |
void | satisfyRequest (PacketPtr pkt, CacheBlk *blk, bool deferred_response=false, bool pending_downgrade=false) override |
Perform any necessary updates to the block and perform any data exchange between the packet and the block. More... | |
PacketPtr | createMissPacket (PacketPtr cpu_pkt, CacheBlk *blk, bool needs_writable, bool is_whole_line_write) const override |
Create an appropriate downstream bus request packet. More... | |
M5_NODISCARD PacketPtr | evictBlock (CacheBlk *blk) override |
Evict a cache block. More... | |
Protected Member Functions inherited from BaseCache | |
void | markInService (MSHR *mshr, bool pending_modified_resp) |
Mark a request as in service (sent downstream in the memory system), effectively making this MSHR the ordering point. More... | |
void | markInService (WriteQueueEntry *entry) |
bool | allocOnFill (MemCmd cmd) const |
Determine whether we should allocate on a fill or not. More... | |
Addr | regenerateBlkAddr (CacheBlk *blk) |
Regenerate block address using tags. More... | |
Cycles | calculateTagOnlyLatency (const uint32_t delay, const Cycles lookup_lat) const |
Calculate latency of accesses that only touch the tag array. More... | |
Cycles | calculateAccessLatency (const CacheBlk *blk, const uint32_t delay, const Cycles lookup_lat) const |
Calculate access latency in ticks given a tag lookup latency, and whether access was a hit or miss. More... | |
virtual void | handleTimingReqHit (PacketPtr pkt, CacheBlk *blk, Tick request_time) |
void | handleTimingReqMiss (PacketPtr pkt, MSHR *mshr, CacheBlk *blk, Tick forward_time, Tick request_time) |
void | handleUncacheableWriteResp (PacketPtr pkt) |
Handling the special case of uncacheable write responses to make recvTimingResp less cluttered. More... | |
void | cmpAndSwap (CacheBlk *blk, PacketPtr pkt) |
Handle doing the Compare and Swap function for SPARC. More... | |
QueueEntry * | getNextQueueEntry () |
Return the next queue entry to service, either a pending miss from the MSHR queue, a buffered write from the write buffer, or something from the prefetcher. More... | |
void | writebackTempBlockAtomic () |
Send the outstanding tempBlock writeback. More... | |
bool | updateCompressionData (CacheBlk *blk, const uint64_t *data, PacketList &writebacks) |
When a block is overwriten, its compression information must be updated, and it may need to be recompressed. More... | |
void | maintainClusivity (bool from_cache, CacheBlk *blk) |
Maintain the clusivity of this cache by potentially invalidating a block. More... | |
bool | handleEvictions (std::vector< CacheBlk * > &evict_blks, PacketList &writebacks) |
Try to evict the given blocks. More... | |
CacheBlk * | handleFill (PacketPtr pkt, CacheBlk *blk, PacketList &writebacks, bool allocate) |
Handle a fill operation caused by a received packet. More... | |
CacheBlk * | allocateBlock (const PacketPtr pkt, PacketList &writebacks) |
Allocate a new block and perform any necessary writebacks. More... | |
void | evictBlock (CacheBlk *blk, PacketList &writebacks) |
Evict a cache block. More... | |
void | invalidateBlock (CacheBlk *blk) |
Invalidate a cache block. More... | |
PacketPtr | writebackBlk (CacheBlk *blk) |
Create a writeback request for the given block. More... | |
PacketPtr | writecleanBlk (CacheBlk *blk, Request::Flags dest, PacketId id) |
Create a writeclean request for the given block. More... | |
virtual void | memWriteback () override |
Write back dirty blocks in the cache using functional accesses. More... | |
virtual void | memInvalidate () override |
Invalidates all blocks in the cache. More... | |
bool | isDirty () const |
Determine if there are any dirty blocks in the cache. More... | |
bool | inRange (Addr addr) const |
Determine if an address is in the ranges covered by this cache. More... | |
Tick | nextQueueReadyTime () const |
Find next request ready time from among possible sources. 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... | |
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... | |
Additional Inherited Members | |
Public Types inherited from BaseCache | |
enum | BlockedCause { Blocked_NoMSHRs = MSHRQueue_MSHRs, Blocked_NoWBBuffers = MSHRQueue_WriteBuffer, Blocked_NoTargets, NUM_BLOCKED_CAUSES } |
Reasons for caches to be blocked. More... | |
Public Types inherited from ClockedObject | |
typedef ClockedObjectParams | Params |
Parameters of ClockedObject. More... | |
Public Types inherited from SimObject | |
typedef SimObjectParams | Params |
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 () |
Gets the fully-qualified name of the active section. More... | |
static void | serializeAll (const std::string &cpt_dir) |
Serializes all the SimObjects. More... | |
static void | unserializeGlobals (CheckpointIn &cp) |
Public Attributes inherited from BaseCache | |
System * | system |
System we are currently operating in. More... | |
BaseCache::CacheStats | stats |
Public Attributes inherited from ClockedObject | |
PowerState * | powerState |
Protected Types inherited from BaseCache | |
enum | MSHRQueueIndex { MSHRQueue_MSHRs, MSHRQueue_WriteBuffer } |
Indexes to enumerate the MSHR queues. More... | |
Protected Attributes inherited from BaseCache | |
CpuSidePort | cpuSidePort |
MemSidePort | memSidePort |
MSHRQueue | mshrQueue |
Miss status registers. More... | |
WriteQueue | writeBuffer |
Write/writeback buffer. More... | |
BaseTags * | tags |
Tag and data Storage. More... | |
Compressor::Base * | compressor |
Compression method being used. More... | |
Prefetcher::Base * | prefetcher |
Prefetcher. More... | |
ProbePointArg< PacketPtr > * | ppHit |
To probe when a cache hit occurs. More... | |
ProbePointArg< PacketPtr > * | ppMiss |
To probe when a cache miss occurs. More... | |
ProbePointArg< PacketPtr > * | ppFill |
To probe when a cache fill occurs. More... | |
WriteAllocator *const | writeAllocator |
The writeAllocator drive optimizations for streaming writes. More... | |
TempCacheBlk * | tempBlock |
Temporary cache block for occasional transitory use. More... | |
std::unique_ptr< Packet > | pendingDelete |
Upstream caches need this packet until true is returned, so hold it for deletion until a subsequent call. More... | |
const bool | writebackClean |
Determine if clean lines should be written back or not. More... | |
PacketPtr | tempBlockWriteback |
Writebacks from the tempBlock, resulting on the response path in atomic mode, must happen after the call to recvAtomic has finished (for the right ordering of the packets). More... | |
EventFunctionWrapper | writebackTempBlockAtomicEvent |
An event to writeback the tempBlock after recvAtomic finishes. More... | |
const unsigned | blkSize |
Block size of this cache. More... | |
const Cycles | lookupLatency |
The latency of tag lookup of a cache. More... | |
const Cycles | dataLatency |
The latency of data access of a cache. More... | |
const Cycles | forwardLatency |
This is the forward latency of the cache. More... | |
const Cycles | fillLatency |
The latency to fill a cache block. More... | |
const Cycles | responseLatency |
The latency of sending reponse to its upper level cache/core on a linefill. More... | |
const bool | sequentialAccess |
Whether tags and data are accessed sequentially. More... | |
const int | numTarget |
The number of targets for each MSHR. More... | |
bool | forwardSnoops |
Do we forward snoops from mem side port through to cpu side port? More... | |
const Enums::Clusivity | clusivity |
Clusivity with respect to the upstream cache, determining if we fill into both this cache and the cache above on a miss. More... | |
const bool | isReadOnly |
Is this cache read only, for example the instruction cache, or table-walker cache. More... | |
uint8_t | blocked |
Bit vector of the blocking reasons for the access path. More... | |
uint64_t | order |
Increasing order number assigned to each incoming request. More... | |
Cycles | blockedCycle |
Stores time the cache blocked for statistics. More... | |
MSHR * | noTargetMSHR |
Pointer to the MSHR that has no targets. More... | |
Counter | missCount |
The number of misses to trigger an exit event. More... | |
const AddrRangeList | addrRanges |
The address range to which the cache responds on the CPU side. More... | |
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... | |
A non-coherent cache.
Definition at line 64 of file noncoherent_cache.hh.
NoncoherentCache::NoncoherentCache | ( | const NoncoherentCacheParams * | p | ) |
Definition at line 59 of file noncoherent_cache.cc.
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overrideprotectedvirtual |
Does all the processing necessary to perform the provided request.
pkt | The memory request to perform. |
blk | The cache block to be updated. |
lat | The latency of the access. |
writebacks | List for any writebacks that need to be performed. |
Reimplemented from BaseCache.
Definition at line 75 of file noncoherent_cache.cc.
References BaseCache::access(), BlkWritable, Packet::cmd, CacheBlk::isValid(), Packet::isWriteback(), CacheBlk::status, and MemCmd::WriteClean.
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overrideprotectedvirtual |
Create an appropriate downstream bus request packet.
Creates a new packet with the request to be send to the memory below, or nullptr if the current request in cpu_pkt should just be forwarded on.
cpu_pkt | The miss packet that needs to be satisfied. |
blk | The referenced block, can be nullptr. |
needs_writable | Indicates that the block must be writable even if the request in cpu_pkt doesn't indicate that. |
is_whole_line_write | True if there are writes for the whole line |
Implements BaseCache.
Definition at line 142 of file noncoherent_cache.cc.
References Packet::allocate(), BaseCache::blkSize, DPRINTF, Packet::getAddr(), Packet::getBlockAddr(), CacheBlk::isValid(), Packet::needsResponse(), Packet::print(), MemCmd::ReadReq, and Packet::req.
Referenced by handleAtomicReqMiss().
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overrideprotectedvirtual |
Insert writebacks into the write buffer.
Implements BaseCache.
Definition at line 93 of file noncoherent_cache.cc.
References BaseCache::allocateWriteBuffer().
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overrideprotectedvirtual |
Send writebacks down the memory hierarchy in atomic mode.
Implements BaseCache.
Definition at line 103 of file noncoherent_cache.cc.
References BaseCache::memSidePort, and RequestPort::sendAtomic().
Evict a cache block.
Performs a writeback if necesssary and invalidates the block
blk | Block to invalidate |
Implements BaseCache.
Definition at line 330 of file noncoherent_cache.cc.
References BaseCache::invalidateBlock(), CacheBlk::isDirty(), BaseCache::writebackBlk(), and BaseCache::writebackClean.
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overrideprotectedvirtual |
Performs the access specified by the request.
pkt | The request to perform. |
fromCpuSide | from the CPU side port or the memory side port |
Reimplemented from BaseCache.
Definition at line 228 of file noncoherent_cache.cc.
References BaseCache::functionalAccess(), and panic_if.
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overrideprotectedvirtual |
Handle a request in atomic mode that missed in this cache.
Creates a downstream request, sends it to the memory below and handles the response. As we are in atomic mode all operations are performed immediately.
pkt | The packet with the requests |
blk | The referenced block |
writebacks | A list with packets for any performed writebacks |
Implements BaseCache.
Definition at line 166 of file noncoherent_cache.cc.
References BaseCache::allocOnFill(), BaseCache::blkSize, Packet::cmd, Packet::copyError(), createMissPacket(), DPRINTF, Packet::getAddr(), BaseCache::handleFill(), Packet::hasSharers(), Packet::isError(), Packet::isInvalidate(), Packet::isRead(), Packet::isResponse(), Packet::isWholeLineWrite(), Packet::isWriteback(), BaseCache::maintainClusivity(), Packet::makeAtomicResponse(), BaseCache::memSidePort, Packet::needsResponse(), Packet::print(), satisfyRequest(), RequestPort::sendAtomic(), Clocked::ticksToCycles(), MemCmd::UpgradeResp, and MemCmd::WriteClean.
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overrideprotectedvirtual |
Implements BaseCache.
Definition at line 114 of file noncoherent_cache.cc.
References BaseCache::blkSize, Queue< Entry >::findMatch(), Packet::getBlockAddr(), BaseCache::handleTimingReqMiss(), Packet::isSecure(), CacheBlk::isValid(), and BaseCache::mshrQueue.
Performs the access specified by the request.
pkt | The request to perform. |
Reimplemented from BaseCache.
Definition at line 215 of file noncoherent_cache.cc.
References Packet::cacheResponding(), Packet::isRead(), Packet::isWrite(), panic_if, and BaseCache::recvAtomic().
Snoop for the provided request in the cache and return the estimated time taken.
pkt | The memory request to snoop |
Implements BaseCache.
Definition at line 99 of file noncoherent_cache.hh.
References panic, and Packet::print().
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overrideprotectedvirtual |
Performs the access specified by the request.
pkt | The request to perform. |
Reimplemented from BaseCache.
Definition at line 130 of file noncoherent_cache.cc.
References Packet::cacheResponding(), Packet::isRead(), Packet::isWrite(), panic_if, and BaseCache::recvTimingReq().
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overrideprotectedvirtual |
Handles a response (cache line fill/write ack) from the bus.
pkt | The response packet |
Reimplemented from BaseCache.
Definition at line 312 of file noncoherent_cache.cc.
References Packet::cmd, Packet::hasSharers(), Packet::isInvalidate(), Packet::isRead(), Packet::isResponse(), BaseCache::recvTimingResp(), and MemCmd::UpgradeResp.
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inlineoverrideprotectedvirtual |
Snoops bus transactions to maintain coherence.
pkt | The current bus transaction. |
Implements BaseCache.
Definition at line 86 of file noncoherent_cache.hh.
References panic, and Packet::print().
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inlineoverrideprotectedvirtual |
Handle a snoop response.
pkt | Snoop response packet |
Implements BaseCache.
Definition at line 90 of file noncoherent_cache.hh.
References panic, and Packet::print().
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overrideprotectedvirtual |
Perform any necessary updates to the block and perform any data exchange between the packet and the block.
The flags of the packet are also set accordingly.
pkt | Request packet from upstream that hit a block |
blk | Cache block that the packet hit |
deferred_response | Whether this request originally missed |
pending_downgrade | Whether the writable flag is to be removed |
Reimplemented from BaseCache.
Definition at line 65 of file noncoherent_cache.cc.
References Packet::isRead(), Packet::isWrite(), and BaseCache::satisfyRequest().
Referenced by handleAtomicReqMiss(), and serviceMSHRTargets().
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overrideprotectedvirtual |
Service non-deferred MSHR targets using the received response.
Iterates through the list of targets that can be serviced with the current response.
mshr | The MSHR that corresponds to the reponse |
pkt | The response packet |
blk | The reference block |
Implements BaseCache.
Definition at line 237 of file noncoherent_cache.cc.
References BlkHWPrefetched, BaseCache::blkSize, Clocked::clockEdge(), Packet::cmd, BaseCache::CacheStats::cmdStats(), Packet::copyError(), BaseCache::cpuSidePort, MSHR::extractServiceableTargets(), MSHR::Target::FromCPU, MSHR::Target::FromPrefetcher, MSHR::getNumTargets(), Packet::getOffset(), MSHR::getTarget(), MemCmd::HardPFReq, Packet::headerDelay, Packet::isError(), Packet::makeTimingResponse(), System::maxRequestors(), BaseCache::CacheCmdStats::missLatency, panic, Packet::payloadDelay, QueueEntry::Target::pkt, Packet::req, BaseCache::responseLatency, satisfyRequest(), QueuedResponsePort::schedTimingResp(), BaseCache::stats, CacheBlk::status, and BaseCache::system.