gem5  v21.1.0.2
mshr_queue.cc
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40 
45 #include "mem/cache/mshr_queue.hh"
46 
47 #include <cassert>
48 
49 #include "debug/MSHR.hh"
50 #include "mem/cache/mshr.hh"
51 
52 namespace gem5
53 {
54 
55 MSHRQueue::MSHRQueue(const std::string &_label,
56  int num_entries, int reserve,
57  int demand_reserve, std::string cache_name = "")
58  : Queue<MSHR>(_label, num_entries, reserve, cache_name + ".mshr_queue"),
59  demandReserve(demand_reserve)
60 {}
61 
62 MSHR *
63 MSHRQueue::allocate(Addr blk_addr, unsigned blk_size, PacketPtr pkt,
64  Tick when_ready, Counter order, bool alloc_on_fill)
65 {
66  assert(!freeList.empty());
67  MSHR *mshr = freeList.front();
68  assert(mshr->getNumTargets() == 0);
69  freeList.pop_front();
70 
71  DPRINTF(MSHR, "Allocating new MSHR. Number in use will be %lu/%lu\n",
72  allocatedList.size() + 1, numEntries);
73 
74  mshr->allocate(blk_addr, blk_size, pkt, when_ready, order, alloc_on_fill);
75  mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
76  mshr->readyIter = addToReadyList(mshr);
77 
78  allocated += 1;
79  return mshr;
80 }
81 
82 void
84 {
85 
86  DPRINTF(MSHR, "Deallocating all targets: %s", mshr->print());
88  DPRINTF(MSHR, "MSHR deallocated. Number in use: %lu/%lu\n",
89  allocatedList.size(), numEntries);
90 }
91 
92 
93 void
95 {
96  if (!mshr->inService) {
97  assert(mshr == *(mshr->readyIter));
98  readyList.erase(mshr->readyIter);
99  mshr->readyIter = readyList.insert(readyList.begin(), mshr);
100  }
101 }
102 
103 void
104 MSHRQueue::delay(MSHR *mshr, Tick delay_ticks)
105 {
106  mshr->delay(delay_ticks);
107  auto it = std::find_if(mshr->readyIter, readyList.end(),
108  [mshr] (const MSHR* _mshr) {
109  return mshr->readyTime >= _mshr->readyTime;
110  });
111  readyList.splice(it, readyList, mshr->readyIter);
112 }
113 
114 void
115 MSHRQueue::markInService(MSHR *mshr, bool pending_modified_resp)
116 {
117  mshr->markInService(pending_modified_resp);
118  readyList.erase(mshr->readyIter);
119  _numInService += 1;
120 }
121 
122 void
124 {
125  assert(mshr->inService);
126  mshr->inService = false;
127  --_numInService;
132  mshr->readyIter = addToReadyList(mshr);
133 }
134 
135 bool
137 {
138  bool was_full = isFull();
139  assert(mshr->hasTargets());
140  // Pop the prefetch off of the target list
141  mshr->popTarget();
142  // Delete mshr if no remaining targets
143  if (!mshr->hasTargets() && !mshr->promoteDeferredTargets()) {
144  deallocate(mshr);
145  }
146 
147  // Notify if MSHR queue no longer full
148  return was_full && !isFull();
149 }
150 
151 } // namespace gem5
gem5::MSHR::print
void print(std::ostream &os, int verbosity=0, const std::string &prefix="") const override
Prints the contents of this MSHR for debugging.
Definition: mshr.cc:712
gem5::MSHR
Miss Status and handling Register.
Definition: mshr.hh:74
gem5::MSHRQueue::moveToFront
void moveToFront(MSHR *mshr)
Moves the MSHR to the front of the pending list if it is not in service.
Definition: mshr_queue.cc:94
mshr.hh
gem5::MSHR::promoteDeferredTargets
bool promoteDeferredTargets()
Definition: mshr.cc:581
gem5::Queue< MSHR >::readyList
MSHR ::List readyList
Holds pointers to entries that haven't been sent downstream.
Definition: queue.hh:100
gem5::MSHRQueue::delay
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 t...
Definition: mshr_queue.cc:104
gem5::MSHRQueue::markInService
void markInService(MSHR *mshr, bool pending_modified_resp)
Mark the given MSHR as in service.
Definition: mshr_queue.cc:115
gem5::MSHR::markInService
void markInService(bool pending_modified_resp)
Definition: mshr.cc:343
gem5::MSHR::allocIter
Iterator allocIter
Pointer to this MSHR on the allocated list.
Definition: mshr.hh:375
gem5::Queue< MSHR >::freeList
MSHR ::List freeList
Holds non allocated entries.
Definition: queue.hh:102
gem5::Queue< MSHR >::isFull
bool isFull() const
Definition: queue.hh:150
gem5::MSHR::readyIter
Iterator readyIter
Pointer to this MSHR on the ready list.
Definition: mshr.hh:369
gem5::Queue< MSHR >::numEntries
const int numEntries
The total number of entries in this queue.
Definition: queue.hh:85
DPRINTF
#define DPRINTF(x,...)
Definition: trace.hh:186
gem5::Packet
A Packet is used to encapsulate a transfer between two objects in the memory system (e....
Definition: packet.hh:283
gem5::MSHR::popTarget
void popTarget()
Pop first target.
Definition: mshr.hh:466
gem5::Tick
uint64_t Tick
Tick count type.
Definition: types.hh:58
gem5::Queue< MSHR >::allocatedList
MSHR ::List allocatedList
Holds pointers to all allocated entries.
Definition: queue.hh:98
gem5::MSHRQueue::allocate
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.
Definition: mshr_queue.cc:63
gem5::Queue
A high-level queue interface, to be used by both the MSHR queue and the write buffer.
Definition: queue.hh:70
gem5::MSHRQueue::forceDeallocateTarget
bool forceDeallocateTarget(MSHR *mshr)
Deallocate top target, possibly freeing the MSHR.
Definition: mshr_queue.cc:136
gem5::Addr
uint64_t Addr
Address type This will probably be moved somewhere else in the near future.
Definition: types.hh:147
gem5::Queue::deallocate
virtual void deallocate(Entry *entry)
Removes the given entry from the queue.
Definition: queue.hh:241
gem5::MSHRQueue::markPending
void markPending(MSHR *mshr)
Mark an in service entry as pending, used to resend a request.
Definition: mshr_queue.cc:123
gem5::MSHRQueue::deallocate
void deallocate(MSHR *mshr) override
Deallocate a MSHR and its targets.
Definition: mshr_queue.cc:83
gem5::MSHRQueue::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.
Definition: mshr_queue.cc:55
gem5::Queue< MSHR >::addToReadyList
MSHR ::Iterator addToReadyList(MSHR *entry)
Definition: queue.hh:104
gem5::MSHR::getNumTargets
int getNumTargets() const
Returns the current number of allocated targets.
Definition: mshr.hh:430
gem5::statistics::Counter
double Counter
All counters are of 64-bit values.
Definition: types.hh:47
gem5::MSHR::allocate
void allocate(Addr blk_addr, unsigned blk_size, PacketPtr pkt, Tick when_ready, Counter _order, bool alloc_on_fill)
Allocate a miss to this MSHR.
Definition: mshr.cc:303
gem5::MSHR::hasTargets
bool hasTargets() const
Returns true if there are targets left.
Definition: mshr.hh:451
mshr_queue.hh
gem5::Queue< MSHR >::_numInService
int _numInService
The number of entries that are in service.
Definition: queue.hh:120
gem5::Queue< MSHR >::allocated
int allocated
The number of currently allocated entries.
Definition: queue.hh:123
gem5
Reference material can be found at the JEDEC website: UFS standard http://www.jedec....
Definition: decoder.cc:40
gem5::MSHR::delay
void delay(Tick delay_ticks)
Adds a delay relative to the current tick to the current MSHR.
Definition: mshr.hh:500
gem5::QueueEntry::inService
bool inService
True if the entry has been sent downstream.
Definition: queue_entry.hh:110

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