gem5  v20.1.0.0
stack_dist.cc
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37 
38 #include "mem/probes/stack_dist.hh"
39 
40 #include "params/StackDistProbe.hh"
41 #include "sim/system.hh"
42 
43 StackDistProbe::StackDistProbe(StackDistProbeParams *p)
44  : BaseMemProbe(p),
45  lineSize(p->line_size),
46  disableLinearHists(p->disable_linear_hists),
47  disableLogHists(p->disable_log_hists),
48  calc(p->verify)
49 {
50  fatal_if(p->system->cacheLineSize() > p->line_size,
51  "The stack distance probe must use a cache line size that is "
52  "larger or equal to the system's cahce line size.");
53 }
54 
55 void
57 {
59 
60  const StackDistProbeParams *p(
61  dynamic_cast<const StackDistProbeParams *>(params()));
62  assert(p);
63 
64  using namespace Stats;
65 
67  .init(p->linear_hist_bins)
68  .name(name() + ".readLinearHist")
69  .desc("Reads linear distribution")
71 
73  .init(p->log_hist_bins)
74  .name(name() + ".readLogHist")
75  .desc("Reads logarithmic distribution")
77 
79  .init(p->linear_hist_bins)
80  .name(name() + ".writeLinearHist")
81  .desc("Writes linear distribution")
83 
85  .init(p->log_hist_bins)
86  .name(name() + ".writeLogHist")
87  .desc("Writes logarithmic distribution")
89 
91  .name(name() + ".infinity")
92  .desc("Number of requests with infinite stack distance")
93  .flags(nozero);
94 }
95 
96 void
98 {
99  // only capturing read and write requests (which allocate in the
100  // cache)
101  if (!pkt_info.cmd.isRead() && !pkt_info.cmd.isWrite())
102  return;
103 
104  // Align the address to a cache line size
105  const Addr aligned_addr(roundDown(pkt_info.addr, lineSize));
106 
107  // Calculate the stack distance
108  const uint64_t sd(calc.calcStackDistAndUpdate(aligned_addr).first);
109  if (sd == StackDistCalc::Infinity) {
110  infiniteSD++;
111  return;
112  }
113 
114  // Sample the stack distance of the address in linear bins
115  if (!disableLinearHists) {
116  if (pkt_info.cmd.isRead())
118  else
120  }
121 
122  if (!disableLogHists) {
123  int sd_lg2 = sd == 0 ? 1 : floorLog2(sd);
124 
125  // Sample the stack distance of the address in log bins
126  if (pkt_info.cmd.isRead())
127  readLogHist.sample(sd_lg2);
128  else
129  writeLogHist.sample(sd_lg2);
130  }
131 }
132 
133 
135 StackDistProbeParams::create()
136 {
137  return new StackDistProbe(this);
138 }
StackDistProbe::StackDistProbe
StackDistProbe(StackDistProbeParams *params)
Definition: stack_dist.cc:43
Stats::Group::regStats
virtual void regStats()
Callback to set stat parameters.
Definition: group.cc:64
roundDown
T roundDown(const T &val, const U &align)
This function is used to align addresses in memory.
Definition: intmath.hh:150
ProbePoints::PacketInfo::addr
Addr addr
Definition: mem.hh:55
system.hh
StackDistProbe::regStats
void regStats() override
Callback to set stat parameters.
Definition: stack_dist.cc:56
StackDistProbe::disableLogHists
const bool disableLogHists
Definition: stack_dist.hh:66
StackDistProbe::readLinearHist
Stats::Histogram readLinearHist
Definition: stack_dist.hh:70
floorLog2
std::enable_if< std::is_integral< T >::value, int >::type floorLog2(T x)
Definition: intmath.hh:63
StackDistProbe
Definition: stack_dist.hh:48
Stats::DataWrap::flags
Derived & flags(Flags _flags)
Set the flags and marks this stat to print at the end of simulation.
Definition: statistics.hh:331
MemCmd::isRead
bool isRead() const
Definition: packet.hh:199
StackDistProbe::readLogHist
Stats::SparseHistogram readLogHist
Definition: stack_dist.hh:73
ArmISA::sd
Bitfield< 4 > sd
Definition: miscregs_types.hh:768
StackDistCalc::calcStackDistAndUpdate
std::pair< uint64_t, bool > calcStackDistAndUpdate(const Addr r_address, bool addNewNode=true)
Process the given address:
Definition: stack_dist_calc.cc:357
Addr
uint64_t Addr
Address type This will probably be moved somewhere else in the near future.
Definition: types.hh:142
Stats::DataWrap::name
Derived & name(const std::string &name)
Set the name and marks this stat to print at the end of simulation.
Definition: statistics.hh:274
SimObject::params
const Params * params() const
Definition: sim_object.hh:119
Stats::nozero
const FlagsType nozero
Don't print if this is zero.
Definition: info.hh:57
StackDistProbe::writeLinearHist
Stats::Histogram writeLinearHist
Definition: stack_dist.hh:76
StackDistCalc::Infinity
static constexpr uint64_t Infinity
A convenient way of refering to infinity.
Definition: stack_dist_calc.hh:312
SimObject::name
virtual const std::string name() const
Definition: sim_object.hh:133
Stats::SparseHistBase::sample
void sample(const U &v, int n=1)
Add a value to the distribtion n times.
Definition: statistics.hh:2902
StackDistProbe::disableLinearHists
const bool disableLinearHists
Definition: stack_dist.hh:63
ProbePoints::PacketInfo::cmd
MemCmd cmd
Definition: mem.hh:54
stack_dist.hh
Stats::pdf
const FlagsType pdf
Print the percent of the total that this entry represents.
Definition: info.hh:51
Stats::DistBase::sample
void sample(const U &v, int n=1)
Add a value to the distribtion n times.
Definition: statistics.hh:1924
StackDistProbe::calc
StackDistCalc calc
Definition: stack_dist.hh:85
Stats
Definition: statistics.cc:61
Stats::SparseHistogram::init
SparseHistogram & init(size_type size)
Set the parameters of this histogram.
Definition: statistics.hh:3022
StackDistProbe::lineSize
const unsigned lineSize
Definition: stack_dist.hh:60
Stats::Histogram::init
Histogram & init(size_type size)
Set the parameters of this histogram.
Definition: statistics.hh:2669
StackDistProbe::handleRequest
void handleRequest(const ProbePoints::PacketInfo &pkt_info) override
Callback to analyse intercepted Packets.
Definition: stack_dist.cc:97
MipsISA::p
Bitfield< 0 > p
Definition: pra_constants.hh:323
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:219
Stats::DataWrap::desc
Derived & desc(const std::string &_desc)
Set the description and marks this stat to print at the end of simulation.
Definition: statistics.hh:307
ProbePoints::PacketInfo
A struct to hold on to the essential fields from a packet, so that the packet and underlying request ...
Definition: mem.hh:53
MemCmd::isWrite
bool isWrite() const
Definition: packet.hh:200
StackDistProbe::writeLogHist
Stats::SparseHistogram writeLogHist
Definition: stack_dist.hh:79
StackDistProbe::infiniteSD
Stats::Scalar infiniteSD
Definition: stack_dist.hh:82
BaseMemProbe
Base class for memory system probes accepting Packet instances.
Definition: base.hh:61

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