1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/unistd.h> 3 #include <linux/bpf.h> 4 5 #include <stdlib.h> 6 #include <stdio.h> 7 #include <unistd.h> 8 #include <string.h> 9 #include <errno.h> 10 #include <arpa/inet.h> 11 12 #include "libbpf.h" 13 #include "bpf_util.h" 14 15 #define MAX_INDEX 64 16 #define MAX_STARS 38 17 18 char bpf_log_buf[BPF_LOG_BUF_SIZE]; 19 20 static void stars(char *str, long val, long max, int width) 21 { 22 int i; 23 24 for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++) 25 str[i] = '*'; 26 if (val > max) 27 str[i - 1] = '+'; 28 str[i] = '\0'; 29 } 30 31 int main(int argc, char **argv) 32 { 33 unsigned int nr_cpus = bpf_num_possible_cpus(); 34 const char *map_filename = "/sys/fs/bpf/tc/globals/lwt_len_hist_map"; 35 uint64_t values[nr_cpus], sum, max_value = 0, data[MAX_INDEX] = {}; 36 uint64_t key = 0, next_key, max_key = 0; 37 char starstr[MAX_STARS]; 38 int i, map_fd; 39 40 map_fd = bpf_obj_get(map_filename); 41 if (map_fd < 0) { 42 fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n", 43 map_filename, strerror(errno), errno); 44 return -1; 45 } 46 47 while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) { 48 if (next_key >= MAX_INDEX) { 49 fprintf(stderr, "Key %lu out of bounds\n", next_key); 50 continue; 51 } 52 53 bpf_map_lookup_elem(map_fd, &next_key, values); 54 55 sum = 0; 56 for (i = 0; i < nr_cpus; i++) 57 sum += values[i]; 58 59 data[next_key] = sum; 60 if (sum && next_key > max_key) 61 max_key = next_key; 62 63 if (sum > max_value) 64 max_value = sum; 65 66 key = next_key; 67 } 68 69 for (i = 1; i <= max_key + 1; i++) { 70 stars(starstr, data[i - 1], max_value, MAX_STARS); 71 printf("%8ld -> %-8ld : %-8ld |%-*s|\n", 72 (1l << i) >> 1, (1l << i) - 1, data[i - 1], 73 MAX_STARS, starstr); 74 } 75 76 close(map_fd); 77 78 return 0; 79 } 80