1 #include <linux/unistd.h> 2 #include <linux/bpf.h> 3 4 #include <stdlib.h> 5 #include <stdio.h> 6 #include <unistd.h> 7 #include <string.h> 8 #include <errno.h> 9 #include <arpa/inet.h> 10 11 #include "libbpf.h" 12 #include "bpf_util.h" 13 14 #define MAX_INDEX 64 15 #define MAX_STARS 38 16 17 char bpf_log_buf[BPF_LOG_BUF_SIZE]; 18 19 static void stars(char *str, long val, long max, int width) 20 { 21 int i; 22 23 for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++) 24 str[i] = '*'; 25 if (val > max) 26 str[i - 1] = '+'; 27 str[i] = '\0'; 28 } 29 30 int main(int argc, char **argv) 31 { 32 unsigned int nr_cpus = bpf_num_possible_cpus(); 33 const char *map_filename = "/sys/fs/bpf/tc/globals/lwt_len_hist_map"; 34 uint64_t values[nr_cpus], sum, max_value = 0, data[MAX_INDEX] = {}; 35 uint64_t key = 0, next_key, max_key = 0; 36 char starstr[MAX_STARS]; 37 int i, map_fd; 38 39 map_fd = bpf_obj_get(map_filename); 40 if (map_fd < 0) { 41 fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n", 42 map_filename, strerror(errno), errno); 43 return -1; 44 } 45 46 while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) { 47 if (next_key >= MAX_INDEX) { 48 fprintf(stderr, "Key %lu out of bounds\n", next_key); 49 continue; 50 } 51 52 bpf_map_lookup_elem(map_fd, &next_key, values); 53 54 sum = 0; 55 for (i = 0; i < nr_cpus; i++) 56 sum += values[i]; 57 58 data[next_key] = sum; 59 if (sum && next_key > max_key) 60 max_key = next_key; 61 62 if (sum > max_value) 63 max_value = sum; 64 65 key = next_key; 66 } 67 68 for (i = 1; i <= max_key + 1; i++) { 69 stars(starstr, data[i - 1], max_value, MAX_STARS); 70 printf("%8ld -> %-8ld : %-8ld |%-*s|\n", 71 (1l << i) >> 1, (1l << i) - 1, data[i - 1], 72 MAX_STARS, starstr); 73 } 74 75 close(map_fd); 76 77 return 0; 78 } 79