#include <linux/unistd.h> #include <linux/bpf.h> #include <stdlib.h> #include <stdio.h> #include <unistd.h> #include <string.h> #include <errno.h> #include <arpa/inet.h> #include "libbpf.h" #include "bpf_util.h" #define MAX_INDEX 64 #define MAX_STARS 38 char bpf_log_buf[BPF_LOG_BUF_SIZE]; static void stars(char *str, long val, long max, int width) { int i; for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++) str[i] = '*'; if (val > max) str[i - 1] = '+'; str[i] = '\0'; } int main(int argc, char **argv) { unsigned int nr_cpus = bpf_num_possible_cpus(); const char *map_filename = "/sys/fs/bpf/tc/globals/lwt_len_hist_map"; uint64_t values[nr_cpus], sum, max_value = 0, data[MAX_INDEX] = {}; uint64_t key = 0, next_key, max_key = 0; char starstr[MAX_STARS]; int i, map_fd; map_fd = bpf_obj_get(map_filename); if (map_fd < 0) { fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n", map_filename, strerror(errno), errno); return -1; } while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) { if (next_key >= MAX_INDEX) { fprintf(stderr, "Key %lu out of bounds\n", next_key); continue; } bpf_map_lookup_elem(map_fd, &next_key, values); sum = 0; for (i = 0; i < nr_cpus; i++) sum += values[i]; data[next_key] = sum; if (sum && next_key > max_key) max_key = next_key; if (sum > max_value) max_value = sum; key = next_key; } for (i = 1; i <= max_key + 1; i++) { stars(starstr, data[i - 1], max_value, MAX_STARS); printf("%8ld -> %-8ld : %-8ld |%-*s|\n", (1l << i) >> 1, (1l << i) - 1, data[i - 1], MAX_STARS, starstr); } close(map_fd); return 0; }