samples/bpf/tracex3_user.c

   1 /* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of version 2 of the GNU General Public
   5  * License as published by the Free Software Foundation.
   6  */
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <signal.h>
  10 #include <unistd.h>
  11 #include <stdbool.h>
  12 #include <string.h>
  13 #include <linux/bpf.h>
  14 #include "libbpf.h"
  15 #include "bpf_load.h"
  16
  17 #define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
  18
  19 #define SLOTS 100
  20
  21 static void clear_stats(int fd)
  22 {
  23         __u32 key;
  24         __u64 value = 0;
  25
  26         for (key = 0; key < SLOTS; key++)
  27                 bpf_update_elem(fd, &key, &value, BPF_ANY);
  28 }
  29
  30 const char *color[] = {
  31         "\033[48;5;255m",
  32         "\033[48;5;252m",
  33         "\033[48;5;250m",
  34         "\033[48;5;248m",
  35         "\033[48;5;246m",
  36         "\033[48;5;244m",
  37         "\033[48;5;242m",
  38         "\033[48;5;240m",
  39         "\033[48;5;238m",
  40         "\033[48;5;236m",
  41         "\033[48;5;234m",
  42         "\033[48;5;232m",
  43 };
  44 const int num_colors = ARRAY_SIZE(color);
  45
  46 const char nocolor[] = "\033[00m";
  47
  48 const char *sym[] = {
  49         " ",
  50         " ",
  51         ".",
  52         ".",
  53         "*",
  54         "*",
  55         "o",
  56         "o",
  57         "O",
  58         "O",
  59         "#",
  60         "#",
  61 };
  62
  63 bool full_range = false;
  64 bool text_only = false;
  65
  66 static void print_banner(void)
  67 {
  68         if (full_range)
  69                 printf("|1ns     |10ns     |100ns    |1us      |10us     |100us"
  70                        "    |1ms      |10ms     |100ms    |1s       |10s\n");
  71         else
  72                 printf("|1us      |10us     |100us    |1ms      |10ms     "
  73                        "|100ms    |1s       |10s\n");
  74 }
  75
  76 static void print_hist(int fd)
  77 {
  78         __u32 key;
  79         __u64 value;
  80         __u64 cnt[SLOTS];
  81         __u64 max_cnt = 0;
  82         __u64 total_events = 0;
  83
  84         for (key = 0; key < SLOTS; key++) {
  85                 value = 0;
  86                 bpf_lookup_elem(fd, &key, &value);
  87                 cnt[key] = value;
  88                 total_events += value;
  89                 if (value > max_cnt)
  90                         max_cnt = value;
  91         }
  92         clear_stats(fd);
  93         for (key = full_range ? 0 : 29; key < SLOTS; key++) {
  94                 int c = num_colors * cnt[key] / (max_cnt + 1);
  95
  96                 if (text_only)
  97                         printf("%s", sym[c]);
  98                 else
  99                         printf("%s %s", color[c], nocolor);
 100         }
 101         printf(" # %lld\n", total_events);
 102 }
 103
 104 int main(int ac, char **argv)
 105 {
 106         char filename[256];
 107         int i;
 108
 109         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 110
 111         if (load_bpf_file(filename)) {
 112                 printf("%s", bpf_log_buf);
 113                 return 1;
 114         }
 115
 116         for (i = 1; i < ac; i++) {
 117                 if (strcmp(argv[i], "-a") == 0) {
 118                         full_range = true;
 119                 } else if (strcmp(argv[i], "-t") == 0) {
 120                         text_only = true;
 121                 } else if (strcmp(argv[i], "-h") == 0) {
 122                         printf("Usage:\n"
 123                                "  -a display wider latency range\n"
 124                                "  -t text only\n");
 125                         return 1;
 126                 }
 127         }
 128
 129         printf("  heatmap of IO latency\n");
 130         if (text_only)
 131                 printf("  %s", sym[num_colors - 1]);
 132         else
 133                 printf("  %s %s", color[num_colors - 1], nocolor);
 134         printf(" - many events with this latency\n");
 135
 136         if (text_only)
 137                 printf("  %s", sym[0]);
 138         else
 139                 printf("  %s %s", color[0], nocolor);
 140         printf(" - few events\n");
 141
 142         for (i = 0; ; i++) {
 143                 if (i % 20 == 0)
 144                         print_banner();
 145                 print_hist(map_fd[1]);
 146                 sleep(2);
 147         }
 148
 149         return 0;
 150 }