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 11 #include <bpf/bpf.h> 12 #include <bpf/libbpf.h> 13 #include "bpf_util.h" 14 15 #define SLOTS 100 16 17 static void clear_stats(int fd) 18 { 19 unsigned int nr_cpus = bpf_num_possible_cpus(); 20 __u64 values[nr_cpus]; 21 __u32 key; 22 23 memset(values, 0, sizeof(values)); 24 for (key = 0; key < SLOTS; key++) 25 bpf_map_update_elem(fd, &key, values, BPF_ANY); 26 } 27 28 const char *color[] = { 29 "\033[48;5;255m", 30 "\033[48;5;252m", 31 "\033[48;5;250m", 32 "\033[48;5;248m", 33 "\033[48;5;246m", 34 "\033[48;5;244m", 35 "\033[48;5;242m", 36 "\033[48;5;240m", 37 "\033[48;5;238m", 38 "\033[48;5;236m", 39 "\033[48;5;234m", 40 "\033[48;5;232m", 41 }; 42 const int num_colors = ARRAY_SIZE(color); 43 44 const char nocolor[] = "\033[00m"; 45 46 const char *sym[] = { 47 " ", 48 " ", 49 ".", 50 ".", 51 "*", 52 "*", 53 "o", 54 "o", 55 "O", 56 "O", 57 "#", 58 "#", 59 }; 60 61 bool full_range = false; 62 bool text_only = false; 63 64 static void print_banner(void) 65 { 66 if (full_range) 67 printf("|1ns |10ns |100ns |1us |10us |100us" 68 " |1ms |10ms |100ms |1s |10s\n"); 69 else 70 printf("|1us |10us |100us |1ms |10ms " 71 "|100ms |1s |10s\n"); 72 } 73 74 static void print_hist(int fd) 75 { 76 unsigned int nr_cpus = bpf_num_possible_cpus(); 77 __u64 total_events = 0; 78 long values[nr_cpus]; 79 __u64 max_cnt = 0; 80 __u64 cnt[SLOTS]; 81 __u64 value; 82 __u32 key; 83 int i; 84 85 for (key = 0; key < SLOTS; key++) { 86 bpf_map_lookup_elem(fd, &key, values); 87 value = 0; 88 for (i = 0; i < nr_cpus; i++) 89 value += values[i]; 90 cnt[key] = value; 91 total_events += value; 92 if (value > max_cnt) 93 max_cnt = value; 94 } 95 clear_stats(fd); 96 for (key = full_range ? 0 : 29; key < SLOTS; key++) { 97 int c = num_colors * cnt[key] / (max_cnt + 1); 98 99 if (text_only) 100 printf("%s", sym[c]); 101 else 102 printf("%s %s", color[c], nocolor); 103 } 104 printf(" # %lld\n", total_events); 105 } 106 107 int main(int ac, char **argv) 108 { 109 struct bpf_link *links[2]; 110 struct bpf_program *prog; 111 struct bpf_object *obj; 112 char filename[256]; 113 int map_fd, i, j = 0; 114 115 for (i = 1; i < ac; i++) { 116 if (strcmp(argv[i], "-a") == 0) { 117 full_range = true; 118 } else if (strcmp(argv[i], "-t") == 0) { 119 text_only = true; 120 } else if (strcmp(argv[i], "-h") == 0) { 121 printf("Usage:\n" 122 " -a display wider latency range\n" 123 " -t text only\n"); 124 return 1; 125 } 126 } 127 128 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 129 obj = bpf_object__open_file(filename, NULL); 130 if (libbpf_get_error(obj)) { 131 fprintf(stderr, "ERROR: opening BPF object file failed\n"); 132 return 0; 133 } 134 135 /* load BPF program */ 136 if (bpf_object__load(obj)) { 137 fprintf(stderr, "ERROR: loading BPF object file failed\n"); 138 goto cleanup; 139 } 140 141 map_fd = bpf_object__find_map_fd_by_name(obj, "lat_map"); 142 if (map_fd < 0) { 143 fprintf(stderr, "ERROR: finding a map in obj file failed\n"); 144 goto cleanup; 145 } 146 147 bpf_object__for_each_program(prog, obj) { 148 links[j] = bpf_program__attach(prog); 149 if (libbpf_get_error(links[j])) { 150 fprintf(stderr, "ERROR: bpf_program__attach failed\n"); 151 links[j] = NULL; 152 goto cleanup; 153 } 154 j++; 155 } 156 157 printf(" heatmap of IO latency\n"); 158 if (text_only) 159 printf(" %s", sym[num_colors - 1]); 160 else 161 printf(" %s %s", color[num_colors - 1], nocolor); 162 printf(" - many events with this latency\n"); 163 164 if (text_only) 165 printf(" %s", sym[0]); 166 else 167 printf(" %s %s", color[0], nocolor); 168 printf(" - few events\n"); 169 170 for (i = 0; ; i++) { 171 if (i % 20 == 0) 172 print_banner(); 173 print_hist(map_fd); 174 sleep(2); 175 } 176 177 cleanup: 178 for (j--; j >= 0; j--) 179 bpf_link__destroy(links[j]); 180 181 bpf_object__close(obj); 182 return 0; 183 } 184