comm_monitor.hh revision 11904 
1/*
2 * Copyright (c) 2012-2013, 2015 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 */
64class 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    BaseMasterPort& getMasterPort(const std::string& if_name,
88                                  PortID idx = InvalidPortID) override;
89
90    BaseSlavePort& getSlavePort(const std::string& if_name,
91                                PortID idx = InvalidPortID) override;
92
93  private:
94
95    /**
96     * Sender state class for the monitor so that we can annotate
97     * packets with a transmit time and receive time.
98     */
99    class CommMonitorSenderState : public Packet::SenderState
100    {
101
102      public:
103
104        /**
105         * Construct a new sender state and store the time so we can
106         * calculate round-trip latency.
107         *
108         * @param _transmitTime Time of packet transmission
109         */
110        CommMonitorSenderState(Tick _transmitTime)
111            : transmitTime(_transmitTime)
112        { }
113
114        /** Destructor */
115        ~CommMonitorSenderState() { }
116
117        /** Tick when request is transmitted */
118        Tick transmitTime;
119
120    };
121
122    /**
123     * This is the master port of the communication monitor. All recv
124     * functions call a function in CommMonitor, where the
125     * send function of the slave port is called. Besides this, these
126     * functions can also perform actions for capturing statistics.
127     */
128    class MonitorMasterPort : public MasterPort
129    {
130
131      public:
132
133        MonitorMasterPort(const std::string& _name, CommMonitor& _mon)
134            : MasterPort(_name, &_mon), mon(_mon)
135        { }
136
137      protected:
138
139        void recvFunctionalSnoop(PacketPtr pkt)
140        {
141            mon.recvFunctionalSnoop(pkt);
142        }
143
144        Tick recvAtomicSnoop(PacketPtr pkt)
145        {
146            return mon.recvAtomicSnoop(pkt);
147        }
148
149        bool recvTimingResp(PacketPtr pkt)
150        {
151            return mon.recvTimingResp(pkt);
152        }
153
154        void recvTimingSnoopReq(PacketPtr pkt)
155        {
156            mon.recvTimingSnoopReq(pkt);
157        }
158
159        void recvRangeChange()
160        {
161            mon.recvRangeChange();
162        }
163
164        bool isSnooping() const
165        {
166            return mon.isSnooping();
167        }
168
169        void recvReqRetry()
170        {
171            mon.recvReqRetry();
172        }
173
174        void recvRetrySnoopResp()
175        {
176            mon.recvRetrySnoopResp();
177        }
178
179      private:
180
181        CommMonitor& mon;
182
183    };
184
185    /** Instance of master port, facing the memory side */
186    MonitorMasterPort masterPort;
187
188    /**
189     * This is the slave port of the communication monitor. All recv
190     * functions call a function in CommMonitor, where the
191     * send function of the master port is called. Besides this, these
192     * functions can also perform actions for capturing statistics.
193     */
194    class MonitorSlavePort : public SlavePort
195    {
196
197      public:
198
199        MonitorSlavePort(const std::string& _name, CommMonitor& _mon)
200            : SlavePort(_name, &_mon), mon(_mon)
201        { }
202
203      protected:
204
205        void recvFunctional(PacketPtr pkt)
206        {
207            mon.recvFunctional(pkt);
208        }
209
210        Tick recvAtomic(PacketPtr pkt)
211        {
212            return mon.recvAtomic(pkt);
213        }
214
215        bool recvTimingReq(PacketPtr pkt)
216        {
217            return mon.recvTimingReq(pkt);
218        }
219
220        bool recvTimingSnoopResp(PacketPtr pkt)
221        {
222            return mon.recvTimingSnoopResp(pkt);
223        }
224
225        AddrRangeList getAddrRanges() const
226        {
227            return mon.getAddrRanges();
228        }
229
230        void recvRespRetry()
231        {
232            mon.recvRespRetry();
233        }
234
235      private:
236
237        CommMonitor& mon;
238
239    };
240
241    /** Instance of slave port, i.e. on the CPU side */
242    MonitorSlavePort slavePort;
243
244    void recvFunctional(PacketPtr pkt);
245
246    void recvFunctionalSnoop(PacketPtr pkt);
247
248    Tick recvAtomic(PacketPtr pkt);
249
250    Tick recvAtomicSnoop(PacketPtr pkt);
251
252    bool recvTimingReq(PacketPtr pkt);
253
254    bool recvTimingResp(PacketPtr pkt);
255
256    void recvTimingSnoopReq(PacketPtr pkt);
257
258    bool recvTimingSnoopResp(PacketPtr pkt);
259
260    void recvRetrySnoopResp();
261
262    AddrRangeList getAddrRanges() const;
263
264    bool isSnooping() const;
265
266    void recvReqRetry();
267
268    void recvRespRetry();
269
270    void recvRangeChange();
271
272    /** Stats declarations, all in a struct for convenience. */
273    struct MonitorStats
274    {
275
276        /** Disable flag for burst length histograms **/
277        bool disableBurstLengthHists;
278
279        /** Histogram of read burst lengths */
280        Stats::Histogram readBurstLengthHist;
281
282        /** Histogram of write burst lengths */
283        Stats::Histogram writeBurstLengthHist;
284
285        /** Disable flag for the bandwidth histograms */
286        bool disableBandwidthHists;
287
288        /**
289         * Histogram for read bandwidth per sample window. The
290         * internal counter is an unsigned int rather than a stat.
291         */
292        unsigned int readBytes;
293        Stats::Histogram readBandwidthHist;
294        Stats::Formula averageReadBW;
295        Stats::Scalar totalReadBytes;
296
297        /**
298         * Histogram for write bandwidth per sample window. The
299         * internal counter is an unsigned int rather than a stat.
300         */
301        unsigned int writtenBytes;
302        Stats::Histogram writeBandwidthHist;
303        Stats::Formula averageWriteBW;
304        Stats::Scalar totalWrittenBytes;
305
306        /** Disable flag for latency histograms. */
307        bool disableLatencyHists;
308
309        /** Histogram of read request-to-response latencies */
310        Stats::Histogram readLatencyHist;
311
312        /** Histogram of write request-to-response latencies */
313        Stats::Histogram writeLatencyHist;
314
315        /** Disable flag for ITT distributions. */
316        bool disableITTDists;
317
318        /**
319         * Inter transaction time (ITT) distributions. There are
320         * histograms of the time between two read, write or arbitrary
321         * accesses. The time of a request is the tick at which the
322         * request is forwarded by the monitor.
323         */
324        Stats::Distribution ittReadRead;
325        Stats::Distribution ittWriteWrite;
326        Stats::Distribution ittReqReq;
327        Tick timeOfLastRead;
328        Tick timeOfLastWrite;
329        Tick timeOfLastReq;
330
331        /** Disable flag for outstanding histograms. */
332        bool disableOutstandingHists;
333
334        /**
335         * Histogram of outstanding read requests. Counter for
336         * outstanding read requests is an unsigned integer because
337         * it should not be reset when stats are reset.
338         */
339        Stats::Histogram outstandingReadsHist;
340        unsigned int outstandingReadReqs;
341
342        /**
343         * Histogram of outstanding write requests. Counter for
344         * outstanding write requests is an unsigned integer because
345         * it should not be reset when stats are reset.
346         */
347        Stats::Histogram outstandingWritesHist;
348        unsigned int outstandingWriteReqs;
349
350        /** Disable flag for transaction histograms. */
351        bool disableTransactionHists;
352
353        /** Histogram of number of read transactions per time bin */
354        Stats::Histogram readTransHist;
355        unsigned int readTrans;
356
357        /** Histogram of number of timing write transactions per time bin */
358        Stats::Histogram writeTransHist;
359        unsigned int writeTrans;
360
361        /** Disable flag for address distributions. */
362        bool disableAddrDists;
363
364        /** Address mask for sources of read accesses to be captured */
365        const Addr readAddrMask;
366
367        /** Address mask for sources of write accesses to be captured */
368        const Addr writeAddrMask;
369
370        /**
371         * Histogram of number of read accesses to addresses over
372         * time.
373         */
374        Stats::SparseHistogram readAddrDist;
375
376        /**
377         * Histogram of number of write accesses to addresses over
378         * time.
379         */
380        Stats::SparseHistogram writeAddrDist;
381
382        /**
383         * Create the monitor stats and initialise all the members
384         * that are not statistics themselves, but used to control the
385         * stats or track values during a sample period.
386         */
387        MonitorStats(const CommMonitorParams* params) :
388            disableBurstLengthHists(params->disable_burst_length_hists),
389            disableBandwidthHists(params->disable_bandwidth_hists),
390            readBytes(0), writtenBytes(0),
391            disableLatencyHists(params->disable_latency_hists),
392            disableITTDists(params->disable_itt_dists),
393            timeOfLastRead(0), timeOfLastWrite(0), timeOfLastReq(0),
394            disableOutstandingHists(params->disable_outstanding_hists),
395            outstandingReadReqs(0), outstandingWriteReqs(0),
396            disableTransactionHists(params->disable_transaction_hists),
397            readTrans(0), writeTrans(0),
398            disableAddrDists(params->disable_addr_dists),
399            readAddrMask(params->read_addr_mask),
400            writeAddrMask(params->write_addr_mask)
401        { }
402
403        void updateReqStats(const ProbePoints::PacketInfo& pkt, bool is_atomic,
404                            bool expects_response);
405        void updateRespStats(const ProbePoints::PacketInfo& pkt, Tick latency,
406                             bool is_atomic);
407    };
408
409    /** This function is called periodically at the end of each time bin */
410    void samplePeriodic();
411
412    /** Periodic event called at the end of each simulation time bin */
413    EventWrapper<CommMonitor, &CommMonitor::samplePeriodic> samplePeriodicEvent;
414
415    /**
416     *@{
417     * @name Configuration
418     */
419
420    /** Length of simulation time bin*/
421    const Tick samplePeriodTicks;
422    /** Sample period in seconds */
423    const double samplePeriod;
424
425    /** @} */
426
427    /** Instantiate stats */
428    MonitorStats stats;
429
430  protected: // Probe points
431    /**
432     * @{
433     * @name Memory system probe points
434     */
435
436    /** Successfully forwarded request packet */
437    ProbePoints::PacketUPtr ppPktReq;
438
439    /** Successfully forwarded response packet */
440    ProbePoints::PacketUPtr ppPktResp;
441
442    /** @} */
443};
444
445#endif //__MEM_COMM_MONITOR_HH__
446