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 <sys/resource.h>
  15
  16 #include "libbpf.h"
  17 #include "bpf_load.h"
  18 #include "bpf_util.h"
  19
  20 #define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
  21
  22 #define SLOTS 100
  23
  24 static void clear_stats(int fd)
  25 {
  26         unsigned int nr_cpus = bpf_num_possible_cpus();
  27         __u64 values[nr_cpus];
  28         __u32 key;
  29
  30         memset(values, 0, sizeof(values));
  31         for (key = 0; key < SLOTS; key++)
  32                 bpf_map_update_elem(fd, &key, values, BPF_ANY);
  33 }
  34
  35 const char *color[] = {
  36         "\033[48;5;255m",
  37         "\033[48;5;252m",
  38         "\033[48;5;250m",
  39         "\033[48;5;248m",
  40         "\033[48;5;246m",
  41         "\033[48;5;244m",
  42         "\033[48;5;242m",
  43         "\033[48;5;240m",
  44         "\033[48;5;238m",
  45         "\033[48;5;236m",
  46         "\033[48;5;234m",
  47         "\033[48;5;232m",
  48 };
  49 const int num_colors = ARRAY_SIZE(color);
  50
  51 const char nocolor[] = "\033[00m";
  52
  53 const char *sym[] = {
  54         " ",
  55         " ",
  56         ".",
  57         ".",
  58         "*",
  59         "*",
  60         "o",
  61         "o",
  62         "O",
  63         "O",
  64         "#",
  65         "#",
  66 };
  67
  68 bool full_range = false;
  69 bool text_only = false;
  70
  71 static void print_banner(void)
  72 {
  73         if (full_range)
  74                 printf("|1ns     |10ns     |100ns    |1us      |10us     |100us"
  75                        "    |1ms      |10ms     |100ms    |1s       |10s\n");
  76         else
  77                 printf("|1us      |10us     |100us    |1ms      |10ms     "
  78                        "|100ms    |1s       |10s\n");
  79 }
  80
  81 static void print_hist(int fd)
  82 {
  83         unsigned int nr_cpus = bpf_num_possible_cpus();
  84         __u64 total_events = 0;
  85         long values[nr_cpus];
  86         __u64 max_cnt = 0;
  87         __u64 cnt[SLOTS];
  88         __u64 value;
  89         __u32 key;
  90         int i;
  91
  92         for (key = 0; key < SLOTS; key++) {
  93                 bpf_map_lookup_elem(fd, &key, values);
  94                 value = 0;
  95                 for (i = 0; i < nr_cpus; i++)
  96                         value += values[i];
  97                 cnt[key] = value;
  98                 total_events += value;
  99                 if (value > max_cnt)
 100                         max_cnt = value;
 101         }
 102         clear_stats(fd);
 103         for (key = full_range ? 0 : 29; key < SLOTS; key++) {
 104                 int c = num_colors * cnt[key] / (max_cnt + 1);
 105
 106                 if (text_only)
 107                         printf("%s", sym[c]);
 108                 else
 109                         printf("%s %s", color[c], nocolor);
 110         }
 111         printf(" # %lld\n", total_events);
 112 }
 113
 114 int main(int ac, char **argv)
 115 {
 116         struct rlimit r = {1024*1024, RLIM_INFINITY};
 117         char filename[256];
 118         int i;
 119
 120         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 121
 122         if (setrlimit(RLIMIT_MEMLOCK, &r)) {
 123                 perror("setrlimit(RLIMIT_MEMLOCK)");
 124                 return 1;
 125         }
 126
 127         if (load_bpf_file(filename)) {
 128                 printf("%s", bpf_log_buf);
 129                 return 1;
 130         }
 131
 132         for (i = 1; i < ac; i++) {
 133                 if (strcmp(argv[i], "-a") == 0) {
 134                         full_range = true;
 135                 } else if (strcmp(argv[i], "-t") == 0) {
 136                         text_only = true;
 137                 } else if (strcmp(argv[i], "-h") == 0) {
 138                         printf("Usage:\n"
 139                                "  -a display wider latency range\n"
 140                                "  -t text only\n");
 141                         return 1;
 142                 }
 143         }
 144
 145         printf("  heatmap of IO latency\n");
 146         if (text_only)
 147                 printf("  %s", sym[num_colors - 1]);
 148         else
 149                 printf("  %s %s", color[num_colors - 1], nocolor);
 150         printf(" - many events with this latency\n");
 151
 152         if (text_only)
 153                 printf("  %s", sym[0]);
 154         else
 155                 printf("  %s %s", color[0], nocolor);
 156         printf(" - few events\n");
 157
 158         for (i = 0; ; i++) {
 159                 if (i % 20 == 0)
 160                         print_banner();
 161                 print_hist(map_fd[1]);
 162                 sleep(2);
 163         }
 164
 165         return 0;
 166 }