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 <sys/resource.h> 11 12 #include <bpf/bpf.h> 13 #include <bpf/libbpf.h> 14 #include "bpf_util.h" 15 16 #define SLOTS 100 17 18 static void clear_stats(int fd) 19 { 20 unsigned int nr_cpus = bpf_num_possible_cpus(); 21 __u64 values[nr_cpus]; 22 __u32 key; 23 24 memset(values, 0, sizeof(values)); 25 for (key = 0; key < SLOTS; key++) 26 bpf_map_update_elem(fd, &key, values, BPF_ANY); 27 } 28 29 const char *color[] = { 30 "\033[48;5;255m", 31 "\033[48;5;252m", 32 "\033[48;5;250m", 33 "\033[48;5;248m", 34 "\033[48;5;246m", 35 "\033[48;5;244m", 36 "\033[48;5;242m", 37 "\033[48;5;240m", 38 "\033[48;5;238m", 39 "\033[48;5;236m", 40 "\033[48;5;234m", 41 "\033[48;5;232m", 42 }; 43 const int num_colors = ARRAY_SIZE(color); 44 45 const char nocolor[] = "\033[00m"; 46 47 const char *sym[] = { 48 " ", 49 " ", 50 ".", 51 ".", 52 "*", 53 "*", 54 "o", 55 "o", 56 "O", 57 "O", 58 "#", 59 "#", 60 }; 61 62 bool full_range = false; 63 bool text_only = false; 64 65 static void print_banner(void) 66 { 67 if (full_range) 68 printf("|1ns |10ns |100ns |1us |10us |100us" 69 " |1ms |10ms |100ms |1s |10s\n"); 70 else 71 printf("|1us |10us |100us |1ms |10ms " 72 "|100ms |1s |10s\n"); 73 } 74 75 static void print_hist(int fd) 76 { 77 unsigned int nr_cpus = bpf_num_possible_cpus(); 78 __u64 total_events = 0; 79 long values[nr_cpus]; 80 __u64 max_cnt = 0; 81 __u64 cnt[SLOTS]; 82 __u64 value; 83 __u32 key; 84 int i; 85 86 for (key = 0; key < SLOTS; key++) { 87 bpf_map_lookup_elem(fd, &key, values); 88 value = 0; 89 for (i = 0; i < nr_cpus; i++) 90 value += values[i]; 91 cnt[key] = value; 92 total_events += value; 93 if (value > max_cnt) 94 max_cnt = value; 95 } 96 clear_stats(fd); 97 for (key = full_range ? 0 : 29; key < SLOTS; key++) { 98 int c = num_colors * cnt[key] / (max_cnt + 1); 99 100 if (text_only) 101 printf("%s", sym[c]); 102 else 103 printf("%s %s", color[c], nocolor); 104 } 105 printf(" # %lld\n", total_events); 106 } 107 108 int main(int ac, char **argv) 109 { 110 struct bpf_link *links[2]; 111 struct bpf_program *prog; 112 struct bpf_object *obj; 113 char filename[256]; 114 int map_fd, i, j = 0; 115 116 for (i = 1; i < ac; i++) { 117 if (strcmp(argv[i], "-a") == 0) { 118 full_range = true; 119 } else if (strcmp(argv[i], "-t") == 0) { 120 text_only = true; 121 } else if (strcmp(argv[i], "-h") == 0) { 122 printf("Usage:\n" 123 " -a display wider latency range\n" 124 " -t text only\n"); 125 return 1; 126 } 127 } 128 129 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 130 obj = bpf_object__open_file(filename, NULL); 131 if (libbpf_get_error(obj)) { 132 fprintf(stderr, "ERROR: opening BPF object file failed\n"); 133 return 0; 134 } 135 136 /* load BPF program */ 137 if (bpf_object__load(obj)) { 138 fprintf(stderr, "ERROR: loading BPF object file failed\n"); 139 goto cleanup; 140 } 141 142 map_fd = bpf_object__find_map_fd_by_name(obj, "lat_map"); 143 if (map_fd < 0) { 144 fprintf(stderr, "ERROR: finding a map in obj file failed\n"); 145 goto cleanup; 146 } 147 148 bpf_object__for_each_program(prog, obj) { 149 links[j] = bpf_program__attach(prog); 150 if (libbpf_get_error(links[j])) { 151 fprintf(stderr, "ERROR: bpf_program__attach failed\n"); 152 links[j] = NULL; 153 goto cleanup; 154 } 155 j++; 156 } 157 158 printf(" heatmap of IO latency\n"); 159 if (text_only) 160 printf(" %s", sym[num_colors - 1]); 161 else 162 printf(" %s %s", color[num_colors - 1], nocolor); 163 printf(" - many events with this latency\n"); 164 165 if (text_only) 166 printf(" %s", sym[0]); 167 else 168 printf(" %s %s", color[0], nocolor); 169 printf(" - few events\n"); 170 171 for (i = 0; ; i++) { 172 if (i % 20 == 0) 173 print_banner(); 174 print_hist(map_fd); 175 sleep(2); 176 } 177 178 cleanup: 179 for (j--; j >= 0; j--) 180 bpf_link__destroy(links[j]); 181 182 bpf_object__close(obj); 183 return 0; 184 } 185