gem5  v21.1.0.2
policy_pf.cc
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37 
38 #include "mem/qos/policy_pf.hh"
39 
40 #include <algorithm>
41 
42 #include "base/logging.hh"
43 #include "params/QoSPropFairPolicy.hh"
44 
45 namespace gem5
46 {
47 
48 namespace memory
49 {
50 
52 namespace qos
53 {
54 
56  : Policy(p), weight(p.weight)
57 {
58  fatal_if(weight < 0 || weight > 1,
59  "weight must be a value between 0 and 1");
60 }
61 
63 {}
64 
65 template <typename Requestor>
66 void
67 PropFairPolicy::initRequestor(const Requestor requestor, const double score)
68 {
69  RequestorID id = memCtrl->system()->lookupRequestorId(requestor);
70 
71  assert(id != Request::invldRequestorId);
72 
73  // Setting the Initial score for the selected requestor.
74  history.push_back(std::make_pair(id, score));
75 
77  "Policy's maximum number of requestors is currently dictated "
78  "by the maximum number of priorities\n");
79 }
80 
81 void
82 PropFairPolicy::initRequestorName(const std::string requestor, const double score)
83 {
84  initRequestor(requestor, score);
85 }
86 
87 void
88 PropFairPolicy::initRequestorObj(const SimObject* requestor, const double score)
89 {
90  initRequestor(requestor, score);
91 }
92 
93 double
95  const double old_score, const uint64_t served_bytes) const
96 {
97  return ((1.0 - weight) * old_score) + (weight * served_bytes);
98 }
99 
100 uint8_t
101 PropFairPolicy::schedule(const RequestorID pkt_id, const uint64_t pkt_size)
102 {
103  auto sort_pred =
104  [] (const RequestorHistory& lhs, const RequestorHistory& rhs)
105  { return lhs.second > rhs.second; };
106 
107  // Sorting in reverse in base of personal history:
108  // First elements have higher history/score -> lower priority.
109  // The qos priority is the position in the sorted vector.
110  std::sort(history.begin(), history.end(), sort_pred);
111 
112  const double served_bytes = static_cast<double>(pkt_size);
113 
114  uint8_t pkt_priority = 0;
115  for (auto m_hist = history.begin(); m_hist != history.end(); m_hist++) {
116 
117  RequestorID curr_id = m_hist->first;
118  double& curr_score = m_hist->second;
119 
120  if (curr_id == pkt_id) {
121  // The qos priority is the position in the sorted vector.
122  pkt_priority = std::distance(history.begin(), m_hist);
123 
124  curr_score = updateScore(curr_score, served_bytes);
125  } else {
126  curr_score = updateScore(curr_score, 0);
127  }
128  }
129 
130  return pkt_priority;
131 }
132 
133 } // namespace qos
134 } // namespace memory
135 } // namespace gem5
gem5::memory::qos::Policy::memCtrl
MemCtrl * memCtrl
Pointer to parent memory controller implementing the policy.
Definition: policy.hh:124
gem5::System::lookupRequestorId
RequestorID lookupRequestorId(const SimObject *obj) const
Looks up the RequestorID for a given SimObject returns an invalid RequestorID (invldRequestorId) if n...
Definition: system.cc:543
gem5::memory::qos::Policy
QoS Policy base class.
Definition: policy.hh:71
memory
Definition: mem.h:38
gem5::memory::qos::PropFairPolicy::~PropFairPolicy
virtual ~PropFairPolicy()
Definition: policy_pf.cc:62
policy_pf.hh
gem5::memory::GEM5_DEPRECATED_NAMESPACE
GEM5_DEPRECATED_NAMESPACE(QoS, qos)
gem5::memory::qos::PropFairPolicy::weight
const double weight
PF Policy weight.
Definition: policy_pf.hh:117
gem5::MipsISA::p
Bitfield< 0 > p
Definition: pra_constants.hh:326
gem5::memory::qos::PropFairPolicy::updateScore
double updateScore(const double old_score, const uint64_t served_bytes) const
Definition: policy_pf.cc:94
gem5::memory::qos::PropFairPolicy::schedule
virtual uint8_t schedule(const RequestorID id, const uint64_t pkt_size) override
Schedules a packet based on proportional fair configuration.
Definition: policy_pf.cc:101
gem5::memory::qos::MemCtrl::system
System * system() const
read the system pointer
Definition: mem_ctrl.hh:371
gem5::memory::qos::Policy::Params
QoSPolicyParams Params
Definition: policy.hh:74
gem5::SimObject
Abstract superclass for simulation objects.
Definition: sim_object.hh:146
std::pair
STL pair class.
Definition: stl.hh:58
gem5::memory::qos::PropFairPolicy::initRequestor
void initRequestor(const Requestor requestor, const double score)
Definition: policy_pf.cc:67
gem5::memory::qos::PropFairPolicy::initRequestorName
void initRequestorName(const std::string requestor, const double score)
Initialize the requestor's score by providing the requestor's name and initial score value.
Definition: policy_pf.cc:82
gem5::memory::qos::MemCtrl::numPriorities
uint8_t numPriorities() const
Gets the total number of priority levels in the QoS memory controller.
Definition: mem_ctrl.hh:367
gem5::memory::qos::PropFairPolicy::PropFairPolicy
PropFairPolicy(const Params &)
Definition: policy_pf.cc:55
logging.hh
gem5::RequestorID
uint16_t RequestorID
Definition: request.hh:95
gem5::memory::qos::PropFairPolicy::initRequestorObj
void initRequestorObj(const SimObject *requestor, const double score)
Initialize the requestor's score by providing the requestor's SimObject pointer and initial score val...
Definition: policy_pf.cc:88
gem5::memory::qos::PropFairPolicy::history
std::vector< RequestorHistory > history
Definition: policy_pf.hh:121
fatal_if
#define fatal_if(cond,...)
Conditional fatal macro that checks the supplied condition and only causes a fatal error if the condi...
Definition: logging.hh:225
gem5
Reference material can be found at the JEDEC website: UFS standard http://www.jedec....
Definition: decoder.cc:40
gem5::Request::invldRequestorId
@ invldRequestorId
Invalid requestor id for assertion checking only.
Definition: request.hh:267

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