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| 2 | |
| 3 |
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| 4 | #include <stdio.h>
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| 5 | #include <stdlib.h>
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| 6 | #include <signal.h>
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| 7 | #include <unistd.h>
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| 8 | #include <stdbool.h>
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| 9 | #include <string.h>
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| 10 |
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| 11 | #include <bpf/bpf.h>
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| 12 | #include <bpf/libbpf.h>
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| 13 | #include "bpf_util.h"
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| 14 |
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| 15 | #define SLOTS 100
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| 16 |
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| 17 | static void clear_stats(int fd)
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| 18 | {
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| 19 | unsigned int nr_cpus = bpf_num_possible_cpus();
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| 20 | __u64 values[nr_cpus];
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| 21 | __u32 key;
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| 22 |
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| 23 | memset(values, 0, sizeof(values));
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| 24 | for (key = 0; key < SLOTS; key++)
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| 25 | bpf_map_update_elem(fd, &key, values, BPF_ANY);
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| 26 | }
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| 27 |
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| 28 | const char *color[] = {
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| 29 | "\033[48;5;255m",
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| 30 | "\033[48;5;252m",
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| 31 | "\033[48;5;250m",
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| 32 | "\033[48;5;248m",
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| 33 | "\033[48;5;246m",
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| 34 | "\033[48;5;244m",
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| 35 | "\033[48;5;242m",
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| 36 | "\033[48;5;240m",
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| 37 | "\033[48;5;238m",
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| 38 | "\033[48;5;236m",
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| 39 | "\033[48;5;234m",
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| 40 | "\033[48;5;232m",
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| 41 | };
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| 42 | const int num_colors = ARRAY_SIZE(color);
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| 43 |
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| 44 | const char nocolor[] = "\033[00m";
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| 45 |
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| 46 | const char *sym[] = {
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| 47 | " ",
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| 48 | " ",
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| 49 | ".",
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| 50 | ".",
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| 51 | "*",
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| 52 | "*",
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| 53 | "o",
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| 54 | "o",
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| 55 | "O",
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| 56 | "O",
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| 57 | "#",
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| 58 | "#",
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| 59 | };
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| 60 |
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| 61 | bool full_range = false;
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| 62 | bool text_only = false;
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| 63 |
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| 64 | static void print_banner(void)
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| 65 | {
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| 66 | if (full_range)
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| 67 | printf("|1ns |10ns |100ns |1us |10us |100us"
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| 68 | " |1ms |10ms |100ms |1s |10s\n");
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| 69 | else
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| 70 | printf("|1us |10us |100us |1ms |10ms "
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| 71 | "|100ms |1s |10s\n");
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| 72 | }
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| 73 |
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| 74 | static void print_hist(int fd)
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| 75 | {
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| 76 | unsigned int nr_cpus = bpf_num_possible_cpus();
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| 77 | __u64 total_events = 0;
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| 78 | long values[nr_cpus];
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| 79 | __u64 max_cnt = 0;
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| 80 | __u64 cnt[SLOTS];
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| 81 | __u64 value;
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| 82 | __u32 key;
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| 83 | int i;
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| 84 |
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| 85 | for (key = 0; key < SLOTS; key++) {
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| 86 | bpf_map_lookup_elem(fd, &key, values);
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| 87 | value = 0;
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| 88 | for (i = 0; i < nr_cpus; i++)
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| 89 | value += values[i];
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| 90 | cnt[key] = value;
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| 91 | total_events += value;
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| 92 | if (value > max_cnt)
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| 93 | max_cnt = value;
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| 94 | }
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| 95 | clear_stats(fd);
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| 96 | for (key = full_range ? 0 : 29; key < SLOTS; key++) {
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| 97 | int c = num_colors * cnt[key] / (max_cnt + 1);
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| 98 |
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| 99 | if (text_only)
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| 100 | printf("%s", sym[c]);
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| 101 | else
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| 102 | printf("%s %s", color[c], nocolor);
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| 103 | }
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| 104 | printf(" # %lld\n", total_events);
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| 105 | }
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| 106 |
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| 107 | int main(int ac, char **argv)
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| 108 | {
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| 109 | struct bpf_link *links[2];
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| 110 | struct bpf_program *prog;
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| 111 | struct bpf_object *obj;
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| 112 | char filename[256];
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| 113 | int map_fd, i, j = 0;
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| 114 |
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| 115 | for (i = 1; i < ac; i++) {
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| 116 | if (strcmp(argv[i], "-a") == 0) {
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| 117 | full_range = true;
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| 118 | } else if (strcmp(argv[i], "-t") == 0) {
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| 119 | text_only = true;
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| 120 | } else if (strcmp(argv[i], "-h") == 0) {
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| 121 | printf("Usage:\n"
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| 122 | " -a display wider latency range\n"
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| 123 | " -t text only\n");
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| 124 | return 1;
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| 125 | }
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| 126 | }
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| 127 |
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| 128 | snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
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| 129 | obj = bpf_object__open_file(filename, NULL);
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| 130 | if (libbpf_get_error(obj)) {
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| 131 | fprintf(stderr, "ERROR: opening BPF object file failed\n");
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| 132 | return 0;
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| 133 | }
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| 134 |
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| 135 |
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| 136 | if (bpf_object__load(obj)) {
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| 137 | fprintf(stderr, "ERROR: loading BPF object file failed\n");
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| 138 | goto cleanup;
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| 139 | }
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| 140 |
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| 141 | map_fd = bpf_object__find_map_fd_by_name(obj, "lat_map");
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| 142 | if (map_fd < 0) {
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| 143 | fprintf(stderr, "ERROR: finding a map in obj file failed\n");
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| 144 | goto cleanup;
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| 145 | }
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| 146 |
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| 147 | bpf_object__for_each_program(prog, obj) {
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| 148 | links[j] = bpf_program__attach(prog);
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| 149 | if (libbpf_get_error(links[j])) {
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| 150 | fprintf(stderr, "ERROR: bpf_program__attach failed\n");
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| 151 | links[j] = NULL;
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| 152 | goto cleanup;
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| 153 | }
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| 154 | j++;
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| 155 | }
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| 156 |
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| 157 | printf(" heatmap of IO latency\n");
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| 158 | if (text_only)
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| 159 | printf(" %s", sym[num_colors - 1]);
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| 160 | else
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| 161 | printf(" %s %s", color[num_colors - 1], nocolor);
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| 162 | printf(" - many events with this latency\n");
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| 163 |
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| 164 | if (text_only)
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| 165 | printf(" %s", sym[0]);
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| 166 | else
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| 167 | printf(" %s %s", color[0], nocolor);
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| 168 | printf(" - few events\n");
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| 169 |
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| 170 | for (i = 0; ; i++) {
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| 171 | if (i % 20 == 0)
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| 172 | print_banner();
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| 173 | print_hist(map_fd);
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| 174 | sleep(2);
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| 175 | }
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| 176 |
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| 177 | cleanup:
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| 178 | for (j--; j >= 0; j--)
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| 179 | bpf_link__destroy(links[j]);
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| 180 |
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| 181 | bpf_object__close(obj);
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| 182 | return 0;
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| 183 | }
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