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
  15 #include "libbpf.h"
  16 #include "bpf_load.h"
  17 #include "bpf_util.h"
  18
  19 #define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
  20
  21 #define SLOTS 100
  22
  23 static void clear_stats(int fd)
  24 {
  25         unsigned int nr_cpus = bpf_num_possible_cpus();
  26         __u64 values[nr_cpus];
  27         __u32 key;
  28
  29         memset(values, 0, sizeof(values));
  30         for (key = 0; key < SLOTS; key++)
  31                 bpf_map_update_elem(fd, &key, values, BPF_ANY);
  32 }
  33
  34 const char *color[] = {
  35         "\033[48;5;255m",
  36         "\033[48;5;252m",
  37         "\033[48;5;250m",
  38         "\033[48;5;248m",
  39         "\033[48;5;246m",
  40         "\033[48;5;244m",
  41         "\033[48;5;242m",
  42         "\033[48;5;240m",
  43         "\033[48;5;238m",
  44         "\033[48;5;236m",
  45         "\033[48;5;234m",
  46         "\033[48;5;232m",
  47 };
  48 const int num_colors = ARRAY_SIZE(color);
  49
  50 const char nocolor[] = "\033[00m";
  51
  52 const char *sym[] = {
  53         " ",
  54         " ",
  55         ".",
  56         ".",
  57         "*",
  58         "*",
  59         "o",
  60         "o",
  61         "O",
  62         "O",
  63         "#",
  64         "#",
  65 };
  66
  67 bool full_range = false;
  68 bool text_only = false;
  69
  70 static void print_banner(void)
  71 {
  72         if (full_range)
  73                 printf("|1ns     |10ns     |100ns    |1us      |10us     |100us"
  74                        "    |1ms      |10ms     |100ms    |1s       |10s\n");
  75         else
  76                 printf("|1us      |10us     |100us    |1ms      |10ms     "
  77                        "|100ms    |1s       |10s\n");
  78 }
  79
  80 static void print_hist(int fd)
  81 {
  82         unsigned int nr_cpus = bpf_num_possible_cpus();
  83         __u64 total_events = 0;
  84         long values[nr_cpus];
  85         __u64 max_cnt = 0;
  86         __u64 cnt[SLOTS];
  87         __u64 value;
  88         __u32 key;
  89         int i;
  90
  91         for (key = 0; key < SLOTS; key++) {
  92                 bpf_map_lookup_elem(fd, &key, values);
  93                 value = 0;
  94                 for (i = 0; i < nr_cpus; i++)
  95                         value += values[i];
  96                 cnt[key] = value;
  97                 total_events += value;
  98                 if (value > max_cnt)
  99                         max_cnt = value;
 100         }
 101         clear_stats(fd);
 102         for (key = full_range ? 0 : 29; key < SLOTS; key++) {
 103                 int c = num_colors * cnt[key] / (max_cnt + 1);
 104
 105                 if (text_only)
 106                         printf("%s", sym[c]);
 107                 else
 108                         printf("%s %s", color[c], nocolor);
 109         }
 110         printf(" # %lld\n", total_events);
 111 }
 112
 113 int main(int ac, char **argv)
 114 {
 115         char filename[256];
 116         int i;
 117
 118         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 119
 120         if (load_bpf_file(filename)) {
 121                 printf("%s", bpf_log_buf);
 122                 return 1;
 123         }
 124
 125         for (i = 1; i < ac; i++) {
 126                 if (strcmp(argv[i], "-a") == 0) {
 127                         full_range = true;
 128                 } else if (strcmp(argv[i], "-t") == 0) {
 129                         text_only = true;
 130                 } else if (strcmp(argv[i], "-h") == 0) {
 131                         printf("Usage:\n"
 132                                "  -a display wider latency range\n"
 133                                "  -t text only\n");
 134                         return 1;
 135                 }
 136         }
 137
 138         printf("  heatmap of IO latency\n");
 139         if (text_only)
 140                 printf("  %s", sym[num_colors - 1]);
 141         else
 142                 printf("  %s %s", color[num_colors - 1], nocolor);
 143         printf(" - many events with this latency\n");
 144
 145         if (text_only)
 146                 printf("  %s", sym[0]);
 147         else
 148                 printf("  %s %s", color[0], nocolor);
 149         printf(" - few events\n");
 150
 151         for (i = 0; ; i++) {
 152                 if (i % 20 == 0)
 153                         print_banner();
 154                 print_hist(map_fd[1]);
 155                 sleep(2);
 156         }
 157
 158         return 0;
 159 }