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