LXR linux/samples/bpf/tracex3

   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
  21static 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
  32const 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};
  46const int num_colors = ARRAY_SIZE(color);
  47
  48const char nocolor[] = "\033[00m";
  49
  50const char *sym[] = {
  51        " ",
  52        " ",
  53        ".",
  54        ".",
  55        "*",
  56        "*",
  57        "o",
  58        "o",
  59        "O",
  60        "O",
  61        "#",
  62        "#",
  63};
  64
  65bool full_range = false;
  66bool text_only = false;
  67
  68static 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
  78static 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
 111int 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}
 158