1 /* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
2 * Copyright (c) 2015 BMW Car IT GmbH
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of version 2 of the GNU General Public
6 * License as published by the Free Software Foundation.
7 */
8 #include <stdio.h>
9 #include <unistd.h>
10 #include <stdlib.h>
11 #include <signal.h>
12 #include <linux/bpf.h>
13 #include <bpf/bpf.h>
14 #include "bpf_load.h"
15
16 #define MAX_ENTRIES 20
17 #define MAX_CPU 4
18 #define MAX_STARS 40
19
20 struct cpu_hist {
21 long data[MAX_ENTRIES];
22 long max;
23 };
24
25 static struct cpu_hist cpu_hist[MAX_CPU];
26
stars(char * str,long val,long max,int width)27 static void stars(char *str, long val, long max, int width)
28 {
29 int i;
30
31 for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
32 str[i] = '*';
33 if (val > max)
34 str[i - 1] = '+';
35 str[i] = '\0';
36 }
37
print_hist(void)38 static void print_hist(void)
39 {
40 char starstr[MAX_STARS];
41 struct cpu_hist *hist;
42 int i, j;
43
44 /* clear screen */
45 printf("\033[2J");
46
47 for (j = 0; j < MAX_CPU; j++) {
48 hist = &cpu_hist[j];
49
50 /* ignore CPUs without data (maybe offline?) */
51 if (hist->max == 0)
52 continue;
53
54 printf("CPU %d\n", j);
55 printf(" latency : count distribution\n");
56 for (i = 1; i <= MAX_ENTRIES; i++) {
57 stars(starstr, hist->data[i - 1], hist->max, MAX_STARS);
58 printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
59 (1l << i) >> 1, (1l << i) - 1,
60 hist->data[i - 1], MAX_STARS, starstr);
61 }
62 }
63 }
64
get_data(int fd)65 static void get_data(int fd)
66 {
67 long key, value;
68 int c, i;
69
70 for (i = 0; i < MAX_CPU; i++)
71 cpu_hist[i].max = 0;
72
73 for (c = 0; c < MAX_CPU; c++) {
74 for (i = 0; i < MAX_ENTRIES; i++) {
75 key = c * MAX_ENTRIES + i;
76 bpf_map_lookup_elem(fd, &key, &value);
77
78 cpu_hist[c].data[i] = value;
79 if (value > cpu_hist[c].max)
80 cpu_hist[c].max = value;
81 }
82 }
83 }
84
main(int argc,char ** argv)85 int main(int argc, char **argv)
86 {
87 char filename[256];
88
89 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
90
91 if (load_bpf_file(filename)) {
92 printf("%s", bpf_log_buf);
93 return 1;
94 }
95
96 while (1) {
97 get_data(map_fd[1]);
98 print_hist();
99 sleep(5);
100 }
101
102 return 0;
103 }
104
