1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
  3 * Copyright (c) 2015 BMW Car IT GmbH
  4 */
  5#include <stdio.h>
  6#include <unistd.h>
  7#include <stdlib.h>
  8#include <signal.h>
  9#include <linux/bpf.h>
 10#include <bpf/bpf.h>
 11#include "bpf_load.h"
 12
 13#define MAX_ENTRIES	20
 14#define MAX_CPU		4
 15#define MAX_STARS	40
 16
 17struct cpu_hist {
 18	long data[MAX_ENTRIES];
 19	long max;
 20};
 21
 22static struct cpu_hist cpu_hist[MAX_CPU];
 23
 24static void stars(char *str, long val, long max, int width)
 25{
 26	int i;
 27
 28	for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
 29		str[i] = '*';
 30	if (val > max)
 31		str[i - 1] = '+';
 32	str[i] = '\0';
 33}
 34
 35static void print_hist(void)
 36{
 37	char starstr[MAX_STARS];
 38	struct cpu_hist *hist;
 39	int i, j;
 40
 41	/* clear screen */
 42	printf("\033[2J");
 43
 44	for (j = 0; j < MAX_CPU; j++) {
 45		hist = &cpu_hist[j];
 46
 47		/* ignore CPUs without data (maybe offline?) */
 48		if (hist->max == 0)
 49			continue;
 50
 51		printf("CPU %d\n", j);
 52		printf("      latency        : count     distribution\n");
 53		for (i = 1; i <= MAX_ENTRIES; i++) {
 54			stars(starstr, hist->data[i - 1], hist->max, MAX_STARS);
 55			printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
 56				(1l << i) >> 1, (1l << i) - 1,
 57				hist->data[i - 1], MAX_STARS, starstr);
 58		}
 59	}
 60}
 61
 62static void get_data(int fd)
 63{
 64	long key, value;
 65	int c, i;
 66
 67	for (i = 0; i < MAX_CPU; i++)
 68		cpu_hist[i].max = 0;
 69
 70	for (c = 0; c < MAX_CPU; c++) {
 71		for (i = 0; i < MAX_ENTRIES; i++) {
 72			key = c * MAX_ENTRIES + i;
 73			bpf_map_lookup_elem(fd, &key, &value);
 74
 75			cpu_hist[c].data[i] = value;
 76			if (value > cpu_hist[c].max)
 77				cpu_hist[c].max = value;
 78		}
 79	}
 80}
 81
 82int main(int argc, char **argv)
 83{
 84	char filename[256];
 85
 86	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 87
 88	if (load_bpf_file(filename)) {
 89		printf("%s", bpf_log_buf);
 90		return 1;
 91	}
 92
 93	while (1) {
 94		get_data(map_fd[1]);
 95		print_hist();
 96		sleep(5);
 97	}
 98
 99	return 0;
100}