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25763b3c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
0fb1170e DW |
2 | /* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com |
3 | * Copyright (c) 2015 BMW Car IT GmbH | |
0fb1170e DW |
4 | */ |
5 | #include <stdio.h> | |
6 | #include <unistd.h> | |
7 | #include <stdlib.h> | |
8 | #include <signal.h> | |
3677d0a1 | 9 | #include <bpf/libbpf.h> |
2bf3e2ef | 10 | #include <bpf/bpf.h> |
0fb1170e DW |
11 | |
12 | #define MAX_ENTRIES 20 | |
13 | #define MAX_CPU 4 | |
14 | #define MAX_STARS 40 | |
15 | ||
16 | struct cpu_hist { | |
17 | long data[MAX_ENTRIES]; | |
18 | long max; | |
19 | }; | |
20 | ||
21 | static struct cpu_hist cpu_hist[MAX_CPU]; | |
22 | ||
23 | static void stars(char *str, long val, long max, int width) | |
24 | { | |
25 | int i; | |
26 | ||
27 | for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++) | |
28 | str[i] = '*'; | |
29 | if (val > max) | |
30 | str[i - 1] = '+'; | |
31 | str[i] = '\0'; | |
32 | } | |
33 | ||
34 | static void print_hist(void) | |
35 | { | |
36 | char starstr[MAX_STARS]; | |
37 | struct cpu_hist *hist; | |
38 | int i, j; | |
39 | ||
40 | /* clear screen */ | |
41 | printf("\033[2J"); | |
42 | ||
43 | for (j = 0; j < MAX_CPU; j++) { | |
44 | hist = &cpu_hist[j]; | |
45 | ||
46 | /* ignore CPUs without data (maybe offline?) */ | |
47 | if (hist->max == 0) | |
48 | continue; | |
49 | ||
50 | printf("CPU %d\n", j); | |
51 | printf(" latency : count distribution\n"); | |
52 | for (i = 1; i <= MAX_ENTRIES; i++) { | |
53 | stars(starstr, hist->data[i - 1], hist->max, MAX_STARS); | |
54 | printf("%8ld -> %-8ld : %-8ld |%-*s|\n", | |
55 | (1l << i) >> 1, (1l << i) - 1, | |
56 | hist->data[i - 1], MAX_STARS, starstr); | |
57 | } | |
58 | } | |
59 | } | |
60 | ||
61 | static void get_data(int fd) | |
62 | { | |
63 | long key, value; | |
64 | int c, i; | |
65 | ||
66 | for (i = 0; i < MAX_CPU; i++) | |
67 | cpu_hist[i].max = 0; | |
68 | ||
69 | for (c = 0; c < MAX_CPU; c++) { | |
70 | for (i = 0; i < MAX_ENTRIES; i++) { | |
71 | key = c * MAX_ENTRIES + i; | |
d40fc181 | 72 | bpf_map_lookup_elem(fd, &key, &value); |
0fb1170e DW |
73 | |
74 | cpu_hist[c].data[i] = value; | |
75 | if (value > cpu_hist[c].max) | |
76 | cpu_hist[c].max = value; | |
77 | } | |
78 | } | |
79 | } | |
80 | ||
81 | int main(int argc, char **argv) | |
82 | { | |
3677d0a1 DL |
83 | struct bpf_link *links[2]; |
84 | struct bpf_program *prog; | |
85 | struct bpf_object *obj; | |
0fb1170e | 86 | char filename[256]; |
3677d0a1 | 87 | int map_fd, i = 0; |
0fb1170e DW |
88 | |
89 | snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); | |
3677d0a1 DL |
90 | obj = bpf_object__open_file(filename, NULL); |
91 | if (libbpf_get_error(obj)) { | |
92 | fprintf(stderr, "ERROR: opening BPF object file failed\n"); | |
93 | return 0; | |
94 | } | |
95 | ||
96 | /* load BPF program */ | |
97 | if (bpf_object__load(obj)) { | |
98 | fprintf(stderr, "ERROR: loading BPF object file failed\n"); | |
99 | goto cleanup; | |
100 | } | |
0fb1170e | 101 | |
3677d0a1 DL |
102 | map_fd = bpf_object__find_map_fd_by_name(obj, "my_lat"); |
103 | if (map_fd < 0) { | |
104 | fprintf(stderr, "ERROR: finding a map in obj file failed\n"); | |
105 | goto cleanup; | |
106 | } | |
107 | ||
108 | bpf_object__for_each_program(prog, obj) { | |
109 | links[i] = bpf_program__attach(prog); | |
110 | if (libbpf_get_error(links[i])) { | |
111 | fprintf(stderr, "ERROR: bpf_program__attach failed\n"); | |
112 | links[i] = NULL; | |
113 | goto cleanup; | |
114 | } | |
115 | i++; | |
0fb1170e DW |
116 | } |
117 | ||
118 | while (1) { | |
3677d0a1 | 119 | get_data(map_fd); |
0fb1170e DW |
120 | print_hist(); |
121 | sleep(5); | |
122 | } | |
123 | ||
3677d0a1 DL |
124 | cleanup: |
125 | for (i--; i >= 0; i--) | |
126 | bpf_link__destroy(links[i]); | |
127 | ||
128 | bpf_object__close(obj); | |
0fb1170e DW |
129 | return 0; |
130 | } |