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