1 #include <linux/unistd.h>
17 char bpf_log_buf[BPF_LOG_BUF_SIZE];
19 static void stars(char *str, long val, long max, int width)
23 for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
30 int main(int argc, char **argv)
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];
39 map_fd = bpf_obj_get(map_filename);
41 fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
42 map_filename, strerror(errno), errno);
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);
52 bpf_map_lookup_elem(map_fd, &next_key, values);
55 for (i = 0; i < nr_cpus; i++)
59 if (sum && next_key > max_key)
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],