lwt_len_hist_user.c 1.6 KB

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