root/samples/bpf/tracex3_user.c

DEFINITIONS

1. clear_stats
2. print_banner
3. print_hist
4. main

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
   3  */
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <signal.h>
   7 #include <unistd.h>
   8 #include <stdbool.h>
   9 #include <string.h>
  10 #include <linux/bpf.h>
  11 #include <sys/resource.h>
  12 
  13 #include <bpf/bpf.h>
  14 #include "bpf_load.h"
  15 #include "bpf_util.h"
  16 
  17 #define SLOTS 100
  18 
  19 static void clear_stats(int fd)
  20 {
  21         unsigned int nr_cpus = bpf_num_possible_cpus();
  22         __u64 values[nr_cpus];
  23         __u32 key;
  24 
  25         memset(values, 0, sizeof(values));
  26         for (key = 0; key < SLOTS; key++)
  27                 bpf_map_update_elem(fd, &key, values, BPF_ANY);
  28 }
  29 
  30 const char *color[] = {
  31         "\033[48;5;255m",
  32         "\033[48;5;252m",
  33         "\033[48;5;250m",
  34         "\033[48;5;248m",
  35         "\033[48;5;246m",
  36         "\033[48;5;244m",
  37         "\033[48;5;242m",
  38         "\033[48;5;240m",
  39         "\033[48;5;238m",
  40         "\033[48;5;236m",
  41         "\033[48;5;234m",
  42         "\033[48;5;232m",
  43 };
  44 const int num_colors = ARRAY_SIZE(color);
  45 
  46 const char nocolor[] = "\033[00m";
  47 
  48 const char *sym[] = {
  49         " ",
  50         " ",
  51         ".",
  52         ".",
  53         "*",
  54         "*",
  55         "o",
  56         "o",
  57         "O",
  58         "O",
  59         "#",
  60         "#",
  61 };
  62 
  63 bool full_range = false;
  64 bool text_only = false;
  65 
  66 static void print_banner(void)
  67 {
  68         if (full_range)
  69                 printf("|1ns     |10ns     |100ns    |1us      |10us     |100us"
  70                        "    |1ms      |10ms     |100ms    |1s       |10s\n");
  71         else
  72                 printf("|1us      |10us     |100us    |1ms      |10ms     "
  73                        "|100ms    |1s       |10s\n");
  74 }
  75 
  76 static void print_hist(int fd)
  77 {
  78         unsigned int nr_cpus = bpf_num_possible_cpus();
  79         __u64 total_events = 0;
  80         long values[nr_cpus];
  81         __u64 max_cnt = 0;
  82         __u64 cnt[SLOTS];
  83         __u64 value;
  84         __u32 key;
  85         int i;
  86 
  87         for (key = 0; key < SLOTS; key++) {
  88                 bpf_map_lookup_elem(fd, &key, values);
  89                 value = 0;
  90                 for (i = 0; i < nr_cpus; i++)
  91                         value += values[i];
  92                 cnt[key] = value;
  93                 total_events += value;
  94                 if (value > max_cnt)
  95                         max_cnt = value;
  96         }
  97         clear_stats(fd);
  98         for (key = full_range ? 0 : 29; key < SLOTS; key++) {
  99                 int c = num_colors * cnt[key] / (max_cnt + 1);
 100 
 101                 if (text_only)
 102                         printf("%s", sym[c]);
 103                 else
 104                         printf("%s %s", color[c], nocolor);
 105         }
 106         printf(" # %lld\n", total_events);
 107 }
 108 
 109 int main(int ac, char **argv)
 110 {
 111         struct rlimit r = {1024*1024, RLIM_INFINITY};
 112         char filename[256];
 113         int i;
 114 
 115         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 116 
 117         if (setrlimit(RLIMIT_MEMLOCK, &r)) {
 118                 perror("setrlimit(RLIMIT_MEMLOCK)");
 119                 return 1;
 120         }
 121 
 122         if (load_bpf_file(filename)) {
 123                 printf("%s", bpf_log_buf);
 124                 return 1;
 125         }
 126 
 127         for (i = 1; i < ac; i++) {
 128                 if (strcmp(argv[i], "-a") == 0) {
 129                         full_range = true;
 130                 } else if (strcmp(argv[i], "-t") == 0) {
 131                         text_only = true;
 132                 } else if (strcmp(argv[i], "-h") == 0) {
 133                         printf("Usage:\n"
 134                                "  -a display wider latency range\n"
 135                                "  -t text only\n");
 136                         return 1;
 137                 }
 138         }
 139 
 140         printf("  heatmap of IO latency\n");
 141         if (text_only)
 142                 printf("  %s", sym[num_colors - 1]);
 143         else
 144                 printf("  %s %s", color[num_colors - 1], nocolor);
 145         printf(" - many events with this latency\n");
 146 
 147         if (text_only)
 148                 printf("  %s", sym[0]);
 149         else
 150                 printf("  %s %s", color[0], nocolor);
 151         printf(" - few events\n");
 152 
 153         for (i = 0; ; i++) {
 154                 if (i % 20 == 0)
 155                         print_banner();
 156                 print_hist(map_fd[1]);
 157                 sleep(2);
 158         }
 159 
 160         return 0;
 161 }