Eric Lee / smarc-fsl-linux-kernel

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samples/bpf/lathist_user.c 1.99 KB
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0fb1170ee   Daniel Wagner   bpf: BPF based la... 
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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
  ", j);
  		printf("      latency        : count     distribution
  ");
  		for (i = 1; i <= MAX_ENTRIES; i++) {
  			stars(starstr, hist->data[i - 1], hist->max, MAX_STARS);
  			printf("%8ld -> %-8ld : %-8ld |%-*s|
  ",
  				(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;
d40fc181e   Joe Stringer   samples/bpf: Make... 
79
 
  			bpf_map_lookup_elem(fd, &key, &value);
0fb1170ee   Daniel Wagner   bpf: BPF based la... 
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  			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;
  }