icache_main.cpp revision e806829c9a1f8e16170d70b8b8190322794b048c 
1#include <stdio.h>
2#include <sys/time.h>
3#include <getopt.h>
4
5#include <thread>
6#include <iostream>
7#include <iomanip>
8
9#include <sched.h>
10
11#include "Profiler.h"
12
13extern "C" void icache_test(long count, long step);
14
15static constexpr size_t MAX_CODE_SIZE = 128*1024;
16static constexpr size_t CACHE_LINE_SIZE = 64;
17static constexpr size_t MAX_ITERATIONS_COUNT = MAX_CODE_SIZE / CACHE_LINE_SIZE;
18static constexpr size_t REPETITIONS = 0x800000L;
19
20
21using namespace utils;
22
23static cpu_set_t g_cpu_set;
24
25static void printUsage(char* name) {
26    std::string exec_name(name);
27    std::string usage(
28            "ICACHE is a command-line tool for testing the L1 instruction cache performance.\n"
29            "(Make sure security.perf_harden is set to 0)\n\n"
30            "Usages:\n"
31            "    ICACHE [options]\n"
32            "\n"
33            "Options:\n"
34            "   --help, -h\n"
35            "       print this message\n\n"
36            "   --affinity=N, -a N\n"
37            "       Specify which CPU the test should run on.\n\n"
38    );
39    const std::string from("ICACHE");
40    for (size_t pos = usage.find(from); pos != std::string::npos; pos = usage.find(from, pos)) {
41         usage.replace(pos, from.length(), exec_name);
42    }
43    printf("%s", usage.c_str());
44}
45
46static int handleCommandLineArgments(int argc, char* argv[]) {
47    static constexpr const char* OPTSTR = "ha:";
48    static const struct option OPTIONS[] = {
49            { "help",                 no_argument, 0, 'h' },
50            { "affinity",       required_argument, 0, 'a' },
51            { 0, 0, 0, 0 }  // termination of the option list
52    };
53    int opt;
54    int option_index = 0;
55    while ((opt = getopt_long(argc, argv, OPTSTR, OPTIONS, &option_index)) >= 0) {
56        std::string arg(optarg ? optarg : "");
57        switch (opt) {
58            default:
59            case 'h':
60                printUsage(argv[0]);
61                exit(0);
62                break;
63            case 'a':
64                size_t cpu = std::stoi(arg);
65                if (cpu < std::thread::hardware_concurrency()) {
66                    CPU_SET(cpu, &g_cpu_set);
67                } else {
68                    std::cerr << "N must be < " << std::thread::hardware_concurrency() << std::endl;
69                    exit(0);
70                }
71                break;
72        }
73    }
74    return optind;
75}
76
77int main(int argc, char* argv[]) {
78    CPU_ZERO(&g_cpu_set);
79
80    [[maybe_unused]] int option_index = handleCommandLineArgments(argc, argv);
81    [[maybe_unused]] int num_args = argc - option_index;
82
83    if (CPU_COUNT(&g_cpu_set)) {
84        sched_setaffinity(gettid(), sizeof(g_cpu_set), &g_cpu_set);
85    }
86
87    Profiler& profiler = Profiler::get();
88    profiler.resetEvents(Profiler::EV_CPU_CYCLES | Profiler::EV_L1I_RATES);
89
90    if (!profiler.isValid()) {
91        fprintf(stderr, "performance counters not enabled. try \"setprop security.perf_harden 0\"\n");
92        exit(0);
93    }
94
95    size_t const stepInBytes = 1024;    // 1 KiB steps
96    size_t const step = stepInBytes / CACHE_LINE_SIZE;
97
98    std::cout << std::fixed << std::setprecision(2);
99
100    printf("[KiB]\t[cyc]\t[refs]\t[MPKI]\t[ns]\n");
101
102    Profiler::Counters counters;
103
104    for (size_t i=step ; i <= MAX_ITERATIONS_COUNT ; i += step) {
105        profiler.reset();
106
107        auto now = std::chrono::steady_clock::now();
108        profiler.start();
109        icache_test(REPETITIONS, i);
110        profiler.stop();
111        auto duration = std::chrono::steady_clock::now() - now;
112
113        profiler.readCounters(&counters);
114
115        std::cout << ((i*CACHE_LINE_SIZE)/1024) << "\t"
116            << counters.getCpuCycles()/double(REPETITIONS) << "\t"
117            << counters.getL1IReferences()/double(REPETITIONS) << "\t"
118            << counters.getMPKI(counters.getL1IMisses()) << "\t"
119            << duration.count()/double(REPETITIONS) << "\t"
120            << std::endl;
121    }
122
123    return 0;
124}
125