gem5  v21.2.1.1
weighted_lru_rp.cc
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31 
33 
34 #include <cassert>
35 
36 #include "params/WeightedLRURP.hh"
37 #include "sim/cur_tick.hh"
38 
39 namespace gem5
40 {
41 
42 GEM5_DEPRECATED_NAMESPACE(ReplacementPolicy, replacement_policy);
43 namespace replacement_policy
44 {
45 
47  : LRU(p)
48 {
49 }
50 
51 void
52 WeightedLRU::touch(const std::shared_ptr<ReplacementData>& replacement_data,
53  int occupancy) const
54 {
55  LRU::touch(replacement_data);
56  std::static_pointer_cast<WeightedLRUReplData>(replacement_data)->
57  last_occ_ptr = occupancy;
58 }
59 
62 {
63  assert(candidates.size() > 0);
64 
65  ReplaceableEntry* victim = candidates[0];
66  // Use weight (last_occ_ptr) to find victim.
67  // Evict the block that has the smallest weight.
68  // If two blocks have the same weight, evict the oldest one.
69  for (const auto& candidate : candidates) {
70  // candidate's replacement_data
71  std::shared_ptr<WeightedLRUReplData> candidate_replacement_data =
72  std::static_pointer_cast<WeightedLRUReplData>(
73  candidate->replacementData);
74  // victim's replacement_data
75  std::shared_ptr<WeightedLRUReplData> victim_replacement_data =
76  std::static_pointer_cast<WeightedLRUReplData>(
77  victim->replacementData);
78 
79  if (candidate_replacement_data->last_occ_ptr <
80  victim_replacement_data->last_occ_ptr) {
81  victim = candidate;
82  } else if (candidate_replacement_data->last_occ_ptr ==
83  victim_replacement_data->last_occ_ptr) {
84  // Evict the block with a smaller tick.
85  Tick time = candidate_replacement_data->lastTouchTick;
86  if (time < victim_replacement_data->lastTouchTick) {
87  victim = candidate;
88  }
89  }
90  }
91  return victim;
92 }
93 
94 std::shared_ptr<ReplacementData>
96 {
97  return std::shared_ptr<ReplacementData>(new WeightedLRUReplData);
98 }
99 
100 } // namespace replacement_policy
101 } // namespace gem5
weighted_lru_rp.hh
gem5::replacement_policy::Base::Params
BaseReplacementPolicyParams Params
Definition: base.hh:58
gem5::replacement_policy::WeightedLRU::getVictim
ReplaceableEntry * getVictim(const ReplacementCandidates &candidates) const override
Find replacement victim using weight.
Definition: weighted_lru_rp.cc:61
cur_tick.hh
gem5::replacement_policy::WeightedLRU::instantiateEntry
std::shared_ptr< ReplacementData > instantiateEntry() override
Instantiate a replacement data entry.
Definition: weighted_lru_rp.cc:95
std::vector
STL vector class.
Definition: stl.hh:37
gem5::MipsISA::p
Bitfield< 0 > p
Definition: pra_constants.hh:326
gem5::Tick
uint64_t Tick
Tick count type.
Definition: types.hh:58
gem5::replacement_policy::WeightedLRU::touch
void touch(const std::shared_ptr< ReplacementData > &replacement_data, int occupancy) const
Definition: weighted_lru_rp.cc:52
gem5::GEM5_DEPRECATED_NAMESPACE
GEM5_DEPRECATED_NAMESPACE(GuestABI, guest_abi)
gem5::replacement_policy::WeightedLRU::WeightedLRUReplData
Weighted LRU implementation of replacement data.
Definition: weighted_lru_rp.hh:53
gem5::replacement_policy::LRU::touch
void touch(const std::shared_ptr< ReplacementData > &replacement_data) const override
Touch an entry to update its replacement data.
Definition: lru_rp.cc:58
gem5::ReplaceableEntry
A replaceable entry is a basic entry in a 2d table-like structure that needs to have replacement func...
Definition: replaceable_entry.hh:63
gem5::replacement_policy::LRU
Definition: lru_rp.hh:49
gem5::ReplaceableEntry::replacementData
std::shared_ptr< replacement_policy::ReplacementData > replacementData
Replacement data associated to this entry.
Definition: replaceable_entry.hh:84
gem5
Reference material can be found at the JEDEC website: UFS standard http://www.jedec....
Definition: tlb.cc:60
gem5::replacement_policy::WeightedLRU::WeightedLRU
WeightedLRU(const Params &p)
Definition: weighted_lru_rp.cc:46

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