This source file includes following definitions.
- stars
- print_hist
- get_data
- main
1
2
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4
5 #include <stdio.h>
6 #include <unistd.h>
7 #include <stdlib.h>
8 #include <signal.h>
9 #include <linux/bpf.h>
10 #include <bpf/bpf.h>
11 #include "bpf_load.h"
12
13 #define MAX_ENTRIES 20
14 #define MAX_CPU 4
15 #define MAX_STARS 40
16
17 struct cpu_hist {
18 long data[MAX_ENTRIES];
19 long max;
20 };
21
22 static struct cpu_hist cpu_hist[MAX_CPU];
23
24 static void stars(char *str, long val, long max, int width)
25 {
26 int i;
27
28 for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
29 str[i] = '*';
30 if (val > max)
31 str[i - 1] = '+';
32 str[i] = '\0';
33 }
34
35 static void print_hist(void)
36 {
37 char starstr[MAX_STARS];
38 struct cpu_hist *hist;
39 int i, j;
40
41
42 printf("\033[2J");
43
44 for (j = 0; j < MAX_CPU; j++) {
45 hist = &cpu_hist[j];
46
47
48 if (hist->max == 0)
49 continue;
50
51 printf("CPU %d\n", j);
52 printf(" latency : count distribution\n");
53 for (i = 1; i <= MAX_ENTRIES; i++) {
54 stars(starstr, hist->data[i - 1], hist->max, MAX_STARS);
55 printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
56 (1l << i) >> 1, (1l << i) - 1,
57 hist->data[i - 1], MAX_STARS, starstr);
58 }
59 }
60 }
61
62 static void get_data(int fd)
63 {
64 long key, value;
65 int c, i;
66
67 for (i = 0; i < MAX_CPU; i++)
68 cpu_hist[i].max = 0;
69
70 for (c = 0; c < MAX_CPU; c++) {
71 for (i = 0; i < MAX_ENTRIES; i++) {
72 key = c * MAX_ENTRIES + i;
73 bpf_map_lookup_elem(fd, &key, &value);
74
75 cpu_hist[c].data[i] = value;
76 if (value > cpu_hist[c].max)
77 cpu_hist[c].max = value;
78 }
79 }
80 }
81
82 int main(int argc, char **argv)
83 {
84 char filename[256];
85
86 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
87
88 if (load_bpf_file(filename)) {
89 printf("%s", bpf_log_buf);
90 return 1;
91 }
92
93 while (1) {
94 get_data(map_fd[1]);
95 print_hist();
96 sleep(5);
97 }
98
99 return 0;
100 }