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 "libbpf.h" 17 #include "bpf_load.h" 18 #include "bpf_util.h" 19 20 #define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x))) 21 22 #define SLOTS 100 23 24 static void clear_stats(int fd) 25 { 26 unsigned int nr_cpus = bpf_num_possible_cpus(); 27 __u64 values[nr_cpus]; 28 __u32 key; 29 30 memset(values, 0, sizeof(values)); 31 for (key = 0; key < SLOTS; key++) 32 bpf_map_update_elem(fd, &key, values, BPF_ANY); 33 } 34 35 const char *color[] = { 36 "\033[48;5;255m", 37 "\033[48;5;252m", 38 "\033[48;5;250m", 39 "\033[48;5;248m", 40 "\033[48;5;246m", 41 "\033[48;5;244m", 42 "\033[48;5;242m", 43 "\033[48;5;240m", 44 "\033[48;5;238m", 45 "\033[48;5;236m", 46 "\033[48;5;234m", 47 "\033[48;5;232m", 48 }; 49 const int num_colors = ARRAY_SIZE(color); 50 51 const char nocolor[] = "\033[00m"; 52 53 const char *sym[] = { 54 " ", 55 " ", 56 ".", 57 ".", 58 "*", 59 "*", 60 "o", 61 "o", 62 "O", 63 "O", 64 "#", 65 "#", 66 }; 67 68 bool full_range = false; 69 bool text_only = false; 70 71 static void print_banner(void) 72 { 73 if (full_range) 74 printf("|1ns |10ns |100ns |1us |10us |100us" 75 " |1ms |10ms |100ms |1s |10s\n"); 76 else 77 printf("|1us |10us |100us |1ms |10ms " 78 "|100ms |1s |10s\n"); 79 } 80 81 static void print_hist(int fd) 82 { 83 unsigned int nr_cpus = bpf_num_possible_cpus(); 84 __u64 total_events = 0; 85 long values[nr_cpus]; 86 __u64 max_cnt = 0; 87 __u64 cnt[SLOTS]; 88 __u64 value; 89 __u32 key; 90 int i; 91 92 for (key = 0; key < SLOTS; key++) { 93 bpf_map_lookup_elem(fd, &key, values); 94 value = 0; 95 for (i = 0; i < nr_cpus; i++) 96 value += values[i]; 97 cnt[key] = value; 98 total_events += value; 99 if (value > max_cnt) 100 max_cnt = value; 101 } 102 clear_stats(fd); 103 for (key = full_range ? 0 : 29; key < SLOTS; key++) { 104 int c = num_colors * cnt[key] / (max_cnt + 1); 105 106 if (text_only) 107 printf("%s", sym[c]); 108 else 109 printf("%s %s", color[c], nocolor); 110 } 111 printf(" # %lld\n", total_events); 112 } 113 114 int main(int ac, char **argv) 115 { 116 struct rlimit r = {1024*1024, RLIM_INFINITY}; 117 char filename[256]; 118 int i; 119 120 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 121 122 if (setrlimit(RLIMIT_MEMLOCK, &r)) { 123 perror("setrlimit(RLIMIT_MEMLOCK)"); 124 return 1; 125 } 126 127 if (load_bpf_file(filename)) { 128 printf("%s", bpf_log_buf); 129 return 1; 130 } 131 132 for (i = 1; i < ac; i++) { 133 if (strcmp(argv[i], "-a") == 0) { 134 full_range = true; 135 } else if (strcmp(argv[i], "-t") == 0) { 136 text_only = true; 137 } else if (strcmp(argv[i], "-h") == 0) { 138 printf("Usage:\n" 139 " -a display wider latency range\n" 140 " -t text only\n"); 141 return 1; 142 } 143 } 144 145 printf(" heatmap of IO latency\n"); 146 if (text_only) 147 printf(" %s", sym[num_colors - 1]); 148 else 149 printf(" %s %s", color[num_colors - 1], nocolor); 150 printf(" - many events with this latency\n"); 151 152 if (text_only) 153 printf(" %s", sym[0]); 154 else 155 printf(" %s %s", color[0], nocolor); 156 printf(" - few events\n"); 157 158 for (i = 0; ; i++) { 159 if (i % 20 == 0) 160 print_banner(); 161 print_hist(map_fd[1]); 162 sleep(2); 163 } 164 165 return 0; 166 } 167