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