src/mem/comm_monitor.hh

   1 /*
   2  * Copyright (c) 2012-2013, 2015, 2018 ARM Limited
   3  * Copyright (c) 2016 Google Inc.
   4  * Copyright (c) 2017, Centre National de la Recherche Scientifique
   5  * All rights reserved.
   6  *
   7  * The license below extends only to copyright in the software and shall
   8  * not be construed as granting a license to any other intellectual
   9  * property including but not limited to intellectual property relating
  10  * to a hardware implementation of the functionality of the software
  11  * licensed hereunder.  You may use the software subject to the license
  12  * terms below provided that you ensure that this notice is replicated
  13  * unmodified and in its entirety in all distributions of the software,
  14  * modified or unmodified, in source code or in binary form.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions are
  18  * met: redistributions of source code must retain the above copyright
  19  * notice, this list of conditions and the following disclaimer;
  20  * redistributions in binary form must reproduce the above copyright
  21  * notice, this list of conditions and the following disclaimer in the
  22  * documentation and/or other materials provided with the distribution;
  23  * neither the name of the copyright holders nor the names of its
  24  * contributors may be used to endorse or promote products derived from
  25  * this software without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  38  *
  39  * Authors: Thomas Grass
  40  *          Andreas Hansson
  41  *          Rahul Thakur
  42  *          Pierre-Yves Peneau
  43  */
  44
  45 #ifndef __MEM_COMM_MONITOR_HH__
  46 #define __MEM_COMM_MONITOR_HH__
  47
  48 #include "base/statistics.hh"
  49 #include "mem/mem_object.hh"
  50 #include "params/CommMonitor.hh"
  51 #include "sim/probe/mem.hh"
  52
  53 /**
  54  * The communication monitor is a MemObject which can monitor statistics of
  55  * the communication happening between two ports in the memory system.
  56  *
  57  * Currently the following stats are implemented: Histograms of read/write
  58  * transactions, read/write burst lengths, read/write bandwidth,
  59  * outstanding read/write requests, read latency and inter transaction time
  60  * (read-read, write-write, read/write-read/write). Furthermore it allows
  61  * to capture the number of accesses to an address over time ("heat map").
  62  * All stats can be disabled from Python.
  63  */
  64 class CommMonitor : public MemObject
  65 {
  66
  67   public: // Construction & SimObject interfaces
  68
  69     /** Parameters of communication monitor */
  70     typedef CommMonitorParams Params;
  71     const Params* params() const
  72     { return reinterpret_cast<const Params*>(_params); }
  73
  74     /**
  75      * Constructor based on the Python params
  76      *
  77      * @param params Python parameters
  78      */
  79     CommMonitor(Params* params);
  80
  81     void init() override;
  82     void regStats() override;
  83     void startup() override;
  84     void regProbePoints() override;
  85
  86   public: // MemObject interfaces
  87     Port &getPort(const std::string &if_name,
  88                   PortID idx=InvalidPortID) override;
  89
  90   private:
  91
  92     /**
  93      * Sender state class for the monitor so that we can annotate
  94      * packets with a transmit time and receive time.
  95      */
  96     class CommMonitorSenderState : public Packet::SenderState
  97     {
  98
  99       public:
 100
 101         /**
 102          * Construct a new sender state and store the time so we can
 103          * calculate round-trip latency.
 104          *
 105          * @param _transmitTime Time of packet transmission
 106          */
 107         CommMonitorSenderState(Tick _transmitTime)
 108             : transmitTime(_transmitTime)
 109         { }
 110
 111         /** Destructor */
 112         ~CommMonitorSenderState() { }
 113
 114         /** Tick when request is transmitted */
 115         Tick transmitTime;
 116
 117     };
 118
 119     /**
 120      * This is the master port of the communication monitor. All recv
 121      * functions call a function in CommMonitor, where the
 122      * send function of the slave port is called. Besides this, these
 123      * functions can also perform actions for capturing statistics.
 124      */
 125     class MonitorMasterPort : public MasterPort
 126     {
 127
 128       public:
 129
 130         MonitorMasterPort(const std::string& _name, CommMonitor& _mon)
 131             : MasterPort(_name, &_mon), mon(_mon)
 132         { }
 133
 134       protected:
 135
 136         void recvFunctionalSnoop(PacketPtr pkt)
 137         {
 138             mon.recvFunctionalSnoop(pkt);
 139         }
 140
 141         Tick recvAtomicSnoop(PacketPtr pkt)
 142         {
 143             return mon.recvAtomicSnoop(pkt);
 144         }
 145
 146         bool recvTimingResp(PacketPtr pkt)
 147         {
 148             return mon.recvTimingResp(pkt);
 149         }
 150
 151         void recvTimingSnoopReq(PacketPtr pkt)
 152         {
 153             mon.recvTimingSnoopReq(pkt);
 154         }
 155
 156         void recvRangeChange()
 157         {
 158             mon.recvRangeChange();
 159         }
 160
 161         bool isSnooping() const
 162         {
 163             return mon.isSnooping();
 164         }
 165
 166         void recvReqRetry()
 167         {
 168             mon.recvReqRetry();
 169         }
 170
 171         void recvRetrySnoopResp()
 172         {
 173             mon.recvRetrySnoopResp();
 174         }
 175
 176       private:
 177
 178         CommMonitor& mon;
 179
 180     };
 181
 182     /** Instance of master port, facing the memory side */
 183     MonitorMasterPort masterPort;
 184
 185     /**
 186      * This is the slave port of the communication monitor. All recv
 187      * functions call a function in CommMonitor, where the
 188      * send function of the master port is called. Besides this, these
 189      * functions can also perform actions for capturing statistics.
 190      */
 191     class MonitorSlavePort : public SlavePort
 192     {
 193
 194       public:
 195
 196         MonitorSlavePort(const std::string& _name, CommMonitor& _mon)
 197             : SlavePort(_name, &_mon), mon(_mon)
 198         { }
 199
 200       protected:
 201
 202         void recvFunctional(PacketPtr pkt)
 203         {
 204             mon.recvFunctional(pkt);
 205         }
 206
 207         Tick recvAtomic(PacketPtr pkt)
 208         {
 209             return mon.recvAtomic(pkt);
 210         }
 211
 212         bool recvTimingReq(PacketPtr pkt)
 213         {
 214             return mon.recvTimingReq(pkt);
 215         }
 216
 217         bool recvTimingSnoopResp(PacketPtr pkt)
 218         {
 219             return mon.recvTimingSnoopResp(pkt);
 220         }
 221
 222         AddrRangeList getAddrRanges() const
 223         {
 224             return mon.getAddrRanges();
 225         }
 226
 227         void recvRespRetry()
 228         {
 229             mon.recvRespRetry();
 230         }
 231
 232         bool tryTiming(PacketPtr pkt)
 233         {
 234             return mon.tryTiming(pkt);
 235         }
 236
 237       private:
 238
 239         CommMonitor& mon;
 240
 241     };
 242
 243     /** Instance of slave port, i.e. on the CPU side */
 244     MonitorSlavePort slavePort;
 245
 246     void recvFunctional(PacketPtr pkt);
 247
 248     void recvFunctionalSnoop(PacketPtr pkt);
 249
 250     Tick recvAtomic(PacketPtr pkt);
 251
 252     Tick recvAtomicSnoop(PacketPtr pkt);
 253
 254     bool recvTimingReq(PacketPtr pkt);
 255
 256     bool recvTimingResp(PacketPtr pkt);
 257
 258     void recvTimingSnoopReq(PacketPtr pkt);
 259
 260     bool recvTimingSnoopResp(PacketPtr pkt);
 261
 262     void recvRetrySnoopResp();
 263
 264     AddrRangeList getAddrRanges() const;
 265
 266     bool isSnooping() const;
 267
 268     void recvReqRetry();
 269
 270     void recvRespRetry();
 271
 272     void recvRangeChange();
 273
 274     bool tryTiming(PacketPtr pkt);
 275
 276     /** Stats declarations, all in a struct for convenience. */
 277     struct MonitorStats
 278     {
 279
 280         /** Disable flag for burst length histograms **/
 281         bool disableBurstLengthHists;
 282
 283         /** Histogram of read burst lengths */
 284         Stats::Histogram readBurstLengthHist;
 285
 286         /** Histogram of write burst lengths */
 287         Stats::Histogram writeBurstLengthHist;
 288
 289         /** Disable flag for the bandwidth histograms */
 290         bool disableBandwidthHists;
 291
 292         /**
 293          * Histogram for read bandwidth per sample window. The
 294          * internal counter is an unsigned int rather than a stat.
 295          */
 296         unsigned int readBytes;
 297         Stats::Histogram readBandwidthHist;
 298         Stats::Formula averageReadBW;
 299         Stats::Scalar totalReadBytes;
 300
 301         /**
 302          * Histogram for write bandwidth per sample window. The
 303          * internal counter is an unsigned int rather than a stat.
 304          */
 305         unsigned int writtenBytes;
 306         Stats::Histogram writeBandwidthHist;
 307         Stats::Formula averageWriteBW;
 308         Stats::Scalar totalWrittenBytes;
 309
 310         /** Disable flag for latency histograms. */
 311         bool disableLatencyHists;
 312
 313         /** Histogram of read request-to-response latencies */
 314         Stats::Histogram readLatencyHist;
 315
 316         /** Histogram of write request-to-response latencies */
 317         Stats::Histogram writeLatencyHist;
 318
 319         /** Disable flag for ITT distributions. */
 320         bool disableITTDists;
 321
 322         /**
 323          * Inter transaction time (ITT) distributions. There are
 324          * histograms of the time between two read, write or arbitrary
 325          * accesses. The time of a request is the tick at which the
 326          * request is forwarded by the monitor.
 327          */
 328         Stats::Distribution ittReadRead;
 329         Stats::Distribution ittWriteWrite;
 330         Stats::Distribution ittReqReq;
 331         Tick timeOfLastRead;
 332         Tick timeOfLastWrite;
 333         Tick timeOfLastReq;
 334
 335         /** Disable flag for outstanding histograms. */
 336         bool disableOutstandingHists;
 337
 338         /**
 339          * Histogram of outstanding read requests. Counter for
 340          * outstanding read requests is an unsigned integer because
 341          * it should not be reset when stats are reset.
 342          */
 343         Stats::Histogram outstandingReadsHist;
 344         unsigned int outstandingReadReqs;
 345
 346         /**
 347          * Histogram of outstanding write requests. Counter for
 348          * outstanding write requests is an unsigned integer because
 349          * it should not be reset when stats are reset.
 350          */
 351         Stats::Histogram outstandingWritesHist;
 352         unsigned int outstandingWriteReqs;
 353
 354         /** Disable flag for transaction histograms. */
 355         bool disableTransactionHists;
 356
 357         /** Histogram of number of read transactions per time bin */
 358         Stats::Histogram readTransHist;
 359         unsigned int readTrans;
 360
 361         /** Histogram of number of timing write transactions per time bin */
 362         Stats::Histogram writeTransHist;
 363         unsigned int writeTrans;
 364
 365         /** Disable flag for address distributions. */
 366         bool disableAddrDists;
 367
 368         /** Address mask for sources of read accesses to be captured */
 369         const Addr readAddrMask;
 370
 371         /** Address mask for sources of write accesses to be captured */
 372         const Addr writeAddrMask;
 373
 374         /**
 375          * Histogram of number of read accesses to addresses over
 376          * time.
 377          */
 378         Stats::SparseHistogram readAddrDist;
 379
 380         /**
 381          * Histogram of number of write accesses to addresses over
 382          * time.
 383          */
 384         Stats::SparseHistogram writeAddrDist;
 385
 386         /**
 387          * Create the monitor stats and initialise all the members
 388          * that are not statistics themselves, but used to control the
 389          * stats or track values during a sample period.
 390          */
 391         MonitorStats(const CommMonitorParams* params) :
 392             disableBurstLengthHists(params->disable_burst_length_hists),
 393             disableBandwidthHists(params->disable_bandwidth_hists),
 394             readBytes(0), writtenBytes(0),
 395             disableLatencyHists(params->disable_latency_hists),
 396             disableITTDists(params->disable_itt_dists),
 397             timeOfLastRead(0), timeOfLastWrite(0), timeOfLastReq(0),
 398             disableOutstandingHists(params->disable_outstanding_hists),
 399             outstandingReadReqs(0), outstandingWriteReqs(0),
 400             disableTransactionHists(params->disable_transaction_hists),
 401             readTrans(0), writeTrans(0),
 402             disableAddrDists(params->disable_addr_dists),
 403             readAddrMask(params->read_addr_mask),
 404             writeAddrMask(params->write_addr_mask)
 405         { }
 406
 407         void updateReqStats(const ProbePoints::PacketInfo& pkt, bool is_atomic,
 408                             bool expects_response);
 409         void updateRespStats(const ProbePoints::PacketInfo& pkt, Tick latency,
 410                              bool is_atomic);
 411     };
 412
 413     /** This function is called periodically at the end of each time bin */
 414     void samplePeriodic();
 415
 416     /** Periodic event called at the end of each simulation time bin */
 417     EventFunctionWrapper samplePeriodicEvent;
 418
 419     /**
 420      *@{
 421      * @name Configuration
 422      */
 423
 424     /** Length of simulation time bin*/
 425     const Tick samplePeriodTicks;
 426     /** Sample period in seconds */
 427     const double samplePeriod;
 428
 429     /** @} */
 430
 431     /** Instantiate stats */
 432     MonitorStats stats;
 433
 434   protected: // Probe points
 435     /**
 436      * @{
 437      * @name Memory system probe points
 438      */
 439
 440     /** Successfully forwarded request packet */
 441     ProbePoints::PacketUPtr ppPktReq;
 442
 443     /** Successfully forwarded response packet */
 444     ProbePoints::PacketUPtr ppPktResp;
 445
 446     /** @} */
 447 };
 448
 449 #endif //__MEM_COMM_MONITOR_HH__