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/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
* Copyright (c) 2015 BMW Car IT GmbH
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <linux/bpf.h>
#include "libbpf.h"
#include "bpf_load.h"
#define MAX_ENTRIES 20
#define MAX_CPU 4
#define MAX_STARS 40
struct cpu_hist {
long data[MAX_ENTRIES];
long max;
};
static struct cpu_hist cpu_hist[MAX_CPU];
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';
}
static void print_hist(void)
{
char starstr[MAX_STARS];
struct cpu_hist *hist;
int i, j;
/* clear screen */
printf("\033[2J");
for (j = 0; j < MAX_CPU; j++) {
hist = &cpu_hist[j];
/* ignore CPUs without data (maybe offline?) */
if (hist->max == 0)
continue;
printf("CPU %d\n", j);
printf(" latency : count distribution\n");
for (i = 1; i <= MAX_ENTRIES; i++) {
stars(starstr, hist->data[i - 1], hist->max, MAX_STARS);
printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
(1l << i) >> 1, (1l << i) - 1,
hist->data[i - 1], MAX_STARS, starstr);
}
}
}
static void get_data(int fd)
{
long key, value;
int c, i;
for (i = 0; i < MAX_CPU; i++)
cpu_hist[i].max = 0;
for (c = 0; c < MAX_CPU; c++) {
for (i = 0; i < MAX_ENTRIES; i++) {
key = c * MAX_ENTRIES + i;
bpf_lookup_elem(fd, &key, &value);
cpu_hist[c].data[i] = value;
if (value > cpu_hist[c].max)
cpu_hist[c].max = value;
}
}
}
int main(int argc, char **argv)
{
char filename[256];
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
}
while (1) {
get_data(map_fd[1]);
print_hist();
sleep(5);
}
return 0;
}
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