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 * Authors: Andreas Sandberg
38 */
39
40#include "mem/probes/stack_dist.hh"
41
42#include "params/StackDistProbe.hh"
43#include "sim/system.hh"
44
45StackDistProbe::StackDistProbe(StackDistProbeParams *p)
46 : BaseMemProbe(p),
47 lineSize(p->line_size),
48 disableLinearHists(p->disable_linear_hists),
49 disableLogHists(p->disable_log_hists),
50 calc(p->verify)
51{
52 fatal_if(p->system->cacheLineSize() > p->line_size,
53 "The stack distance probe must use a cache line size that is "
54 "larger or equal to the system's cahce line size.");
55}
56
57void
58StackDistProbe::regStats()
59{
60 BaseMemProbe::regStats();
61
62 const StackDistProbeParams *p(
63 dynamic_cast<const StackDistProbeParams *>(params()));
64 assert(p);
65
66 using namespace Stats;
67
68 readLinearHist
69 .init(p->linear_hist_bins)
70 .name(name() + ".readLinearHist")
71 .desc("Reads linear distribution")
72 .flags(disableLinearHists ? nozero : pdf);
73
74 readLogHist
75 .init(p->log_hist_bins)
76 .name(name() + ".readLogHist")
77 .desc("Reads logarithmic distribution")
78 .flags(disableLogHists ? nozero : pdf);
79
80 writeLinearHist
81 .init(p->linear_hist_bins)
82 .name(name() + ".writeLinearHist")
83 .desc("Writes linear distribution")
84 .flags(disableLinearHists ? nozero : pdf);
85
86 writeLogHist
87 .init(p->log_hist_bins)
88 .name(name() + ".writeLogHist")
89 .desc("Writes logarithmic distribution")
90 .flags(disableLogHists ? nozero : pdf);
91
92 infiniteSD
93 .name(name() + ".infinity")
94 .desc("Number of requests with infinite stack distance")
95 .flags(nozero);
96}
97
98void
99StackDistProbe::handleRequest(const ProbePoints::PacketInfo &pkt_info)
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 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 readLinearHist.sample(sd);
120 else
121 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 readLogHist.sample(sd_lg2);
130 else
131 writeLogHist.sample(sd_lg2);
132 }
133}
134
135
136StackDistProbe *
137StackDistProbeParams::create()
138{
139 return new StackDistProbe(this);
140}