gem5  v21.1.0.2
stack_dist.cc
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2015 ARM Limited
3  * All rights reserved
4  *
5  * The license below extends only to copyright in the software and shall
6  * not be construed as granting a license to any other intellectual
7  * property including but not limited to intellectual property relating
8  * to a hardware implementation of the functionality of the software
9  * licensed hereunder. You may use the software subject to the license
10  * terms below provided that you ensure that this notice is replicated
11  * unmodified and in its entirety in all distributions of the software,
12  * modified or unmodified, in source code or in binary form.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions are
16  * met: redistributions of source code must retain the above copyright
17  * notice, this list of conditions and the following disclaimer;
18  * redistributions in binary form must reproduce the above copyright
19  * notice, this list of conditions and the following disclaimer in the
20  * documentation and/or other materials provided with the distribution;
21  * neither the name of the copyright holders nor the names of its
22  * contributors may be used to endorse or promote products derived from
23  * this software without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include "mem/probes/stack_dist.hh"
39 
40 #include "params/StackDistProbe.hh"
41 #include "sim/system.hh"
42 
43 namespace gem5
44 {
45 
46 StackDistProbe::StackDistProbe(const StackDistProbeParams &p)
47  : BaseMemProbe(p),
48  lineSize(p.line_size),
49  disableLinearHists(p.disable_linear_hists),
50  disableLogHists(p.disable_log_hists),
51  calc(p.verify),
52  stats(this)
53 {
54  fatal_if(p.system->cacheLineSize() > p.line_size,
55  "The stack distance probe must use a cache line size that is "
56  "larger or equal to the system's cahce line size.");
57 }
58 
60  StackDistProbe *parent)
61  : statistics::Group(parent),
62  ADD_STAT(readLinearHist, statistics::units::Count::get(),
63  "Reads linear distribution"),
64  ADD_STAT(readLogHist, statistics::units::Ratio::get(),
65  "Reads logarithmic distribution"),
66  ADD_STAT(writeLinearHist, statistics::units::Count::get(),
67  "Writes linear distribution"),
68  ADD_STAT(writeLogHist, statistics::units::Ratio::get(),
69  "Writes logarithmic distribution"),
70  ADD_STAT(infiniteSD, statistics::units::Count::get(),
71  "Number of requests with infinite stack distance")
72 {
73  using namespace statistics;
74 
75  const StackDistProbeParams &p =
76  dynamic_cast<const StackDistProbeParams &>(parent->params());
77 
79  .init(p.linear_hist_bins)
80  .flags(parent->disableLinearHists ? nozero : pdf);
81 
83  .init(p.log_hist_bins)
84  .flags(parent->disableLogHists ? nozero : pdf);
85 
87  .init(p.linear_hist_bins)
88  .flags(parent->disableLinearHists ? nozero : pdf);
89 
91  .init(p.log_hist_bins)
92  .flags(parent->disableLogHists ? nozero : pdf);
93 
95  .flags(nozero);
96 }
97 
98 void
100 {
101  // only capturing read and write requests (which allocate in the
102  // cache)
103  if (!pkt_info.cmd.isRead() && !pkt_info.cmd.isWrite())
104  return;
105 
106  // Align the address to a cache line size
107  const Addr aligned_addr(roundDown(pkt_info.addr, lineSize));
108 
109  // Calculate the stack distance
110  const uint64_t sd(calc.calcStackDistAndUpdate(aligned_addr).first);
111  if (sd == StackDistCalc::Infinity) {
112  stats.infiniteSD++;
113  return;
114  }
115 
116  // Sample the stack distance of the address in linear bins
117  if (!disableLinearHists) {
118  if (pkt_info.cmd.isRead())
119  stats.readLinearHist.sample(sd);
120  else
121  stats.writeLinearHist.sample(sd);
122  }
123 
124  if (!disableLogHists) {
125  int sd_lg2 = sd == 0 ? 1 : floorLog2(sd);
126 
127  // Sample the stack distance of the address in log bins
128  if (pkt_info.cmd.isRead())
129  stats.readLogHist.sample(sd_lg2);
130  else
131  stats.writeLogHist.sample(sd_lg2);
132  }
133 }
134 
135 } // namespace gem5
gem5::StackDistProbe::StackDistProbeStats::infiniteSD
statistics::Scalar infiniteSD
Definition: stack_dist.hh:89
system.hh
gem5::StackDistCalc::Infinity
static constexpr uint64_t Infinity
A convenient way of refering to infinity.
Definition: stack_dist_calc.hh:315
gem5::StackDistProbe::calc
StackDistCalc calc
Definition: stack_dist.hh:70
gem5::statistics::nozero
const FlagsType nozero
Don't print if this is zero.
Definition: info.hh:68
gem5::StackDistProbe::StackDistProbeStats::writeLogHist
statistics::SparseHistogram writeLogHist
Definition: stack_dist.hh:86
gem5::probing::PacketInfo::addr
Addr addr
Definition: mem.hh:61
gem5::MemCmd::isWrite
bool isWrite() const
Definition: packet.hh:218
gem5::BaseMemProbe
Base class for memory system probes accepting Packet instances.
Definition: base.hh:64
gem5::statistics::pdf
const FlagsType pdf
Print the percent of the total that this entry represents.
Definition: info.hh:62
gem5::StackDistProbe::disableLinearHists
const bool disableLinearHists
Definition: stack_dist.hh:64
gem5::probing::PacketInfo::cmd
MemCmd cmd
Definition: mem.hh:60
gem5::statistics::SparseHistogram::init
SparseHistogram & init(size_type size)
Set the parameters of this histogram.
Definition: statistics.hh:2521
gem5::StackDistProbe::disableLogHists
const bool disableLogHists
Definition: stack_dist.hh:67
gem5::StackDistProbe::StackDistProbeStats::readLinearHist
statistics::Histogram readLinearHist
Definition: stack_dist.hh:77
gem5::SimObject::params
const Params & params() const
Definition: sim_object.hh:176
ADD_STAT
#define ADD_STAT(n,...)
Convenience macro to add a stat to a statistics group.
Definition: group.hh:75
gem5::StackDistCalc::calcStackDistAndUpdate
std::pair< uint64_t, bool > calcStackDistAndUpdate(const Addr r_address, bool addNewNode=true)
Process the given address:
Definition: stack_dist_calc.cc:361
gem5::MipsISA::p
Bitfield< 0 > p
Definition: pra_constants.hh:326
gem5::StackDistProbe::lineSize
const unsigned lineSize
Definition: stack_dist.hh:61
gem5::roundDown
static constexpr T roundDown(const T &val, const U &align)
This function is used to align addresses in memory.
Definition: intmath.hh:279
gem5::StackDistProbe::StackDistProbeStats::writeLinearHist
statistics::Histogram writeLinearHist
Definition: stack_dist.hh:83
gem5::Addr
uint64_t Addr
Address type This will probably be moved somewhere else in the near future.
Definition: types.hh:147
gem5::statistics::Histogram::init
Histogram & init(size_type size)
Set the parameters of this histogram.
Definition: statistics.hh:2151
gem5::StackDistProbe::handleRequest
void handleRequest(const probing::PacketInfo &pkt_info) override
Callback to analyse intercepted Packets.
Definition: stack_dist.cc:99
stack_dist.hh
gem5::StackDistProbe::StackDistProbe
StackDistProbe(const StackDistProbeParams &params)
Definition: stack_dist.cc:46
gem5::StackDistProbe::StackDistProbeStats::readLogHist
statistics::SparseHistogram readLogHist
Definition: stack_dist.hh:80
gem5::floorLog2
static constexpr std::enable_if_t< std::is_integral< T >::value, int > floorLog2(T x)
Definition: intmath.hh:59
gem5::StackDistProbe::StackDistProbeStats::StackDistProbeStats
StackDistProbeStats(StackDistProbe *parent)
Definition: stack_dist.cc:59
gem5::statistics::Group
Statistics container.
Definition: group.hh:93
gem5::statistics::Group::stats
std::vector< Info * > stats
Definition: group.hh:221
gem5::ArmISA::sd
Bitfield< 4 > sd
Definition: misc_types.hh:774
gem5::statistics::DataWrap::flags
Derived & flags(Flags _flags)
Set the flags and marks this stat to print at the end of simulation.
Definition: statistics.hh:355
gem5::StackDistProbe
Definition: stack_dist.hh:51
gem5::probing::PacketInfo
A struct to hold on to the essential fields from a packet, so that the packet and underlying request ...
Definition: mem.hh:58
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::MemCmd::isRead
bool isRead() const
Definition: packet.hh:217

Generated on Tue Sep 21 2021 12:25:34 for gem5 by doxygen 1.8.17