1/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
  2 *
  3 * This program is free software; you can redistribute it and/or
  4 * modify it under the terms of version 2 of the GNU General Public
  5 * License as published by the Free Software Foundation.
  6 */
  7#include <stdio.h>
  8#include <stdlib.h>
  9#include <signal.h>
 10#include <unistd.h>
 11#include <stdbool.h>
 12#include <string.h>
 13#include <linux/bpf.h>
 14#include "libbpf.h"
 15#include "bpf_load.h"
 16
 17#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
 18
 19#define SLOTS 100
 20
 21static void clear_stats(int fd)
 22{
 23	unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
 24	__u64 values[nr_cpus];
 25	__u32 key;
 26
 27	memset(values, 0, sizeof(values));
 28	for (key = 0; key < SLOTS; key++)
 29		bpf_update_elem(fd, &key, values, BPF_ANY);
 30}
 31
 32const char *color[] = {
 33	"\033[48;5;255m",
 34	"\033[48;5;252m",
 35	"\033[48;5;250m",
 36	"\033[48;5;248m",
 37	"\033[48;5;246m",
 38	"\033[48;5;244m",
 39	"\033[48;5;242m",
 40	"\033[48;5;240m",
 41	"\033[48;5;238m",
 42	"\033[48;5;236m",
 43	"\033[48;5;234m",
 44	"\033[48;5;232m",
 45};
 46const int num_colors = ARRAY_SIZE(color);
 47
 48const char nocolor[] = "\033[00m";
 49
 50const char *sym[] = {
 51	" ",
 52	" ",
 53	".",
 54	".",
 55	"*",
 56	"*",
 57	"o",
 58	"o",
 59	"O",
 60	"O",
 61	"#",
 62	"#",
 63};
 64
 65bool full_range = false;
 66bool text_only = false;
 67
 68static void print_banner(void)
 69{
 70	if (full_range)
 71		printf("|1ns     |10ns     |100ns    |1us      |10us     |100us"
 72		       "    |1ms      |10ms     |100ms    |1s       |10s\n");
 73	else
 74		printf("|1us      |10us     |100us    |1ms      |10ms     "
 75		       "|100ms    |1s       |10s\n");
 76}
 77
 78static void print_hist(int fd)
 79{
 80	unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
 81	__u64 total_events = 0;
 82	long values[nr_cpus];
 83	__u64 max_cnt = 0;
 84	__u64 cnt[SLOTS];
 85	__u64 value;
 86	__u32 key;
 87	int i;
 88
 89	for (key = 0; key < SLOTS; key++) {
 90		bpf_lookup_elem(fd, &key, values);
 91		value = 0;
 92		for (i = 0; i < nr_cpus; i++)
 93			value += values[i];
 94		cnt[key] = value;
 95		total_events += value;
 96		if (value > max_cnt)
 97			max_cnt = value;
 98	}
 99	clear_stats(fd);
100	for (key = full_range ? 0 : 29; key < SLOTS; key++) {
101		int c = num_colors * cnt[key] / (max_cnt + 1);
102
103		if (text_only)
104			printf("%s", sym[c]);
105		else
106			printf("%s %s", color[c], nocolor);
107	}
108	printf(" # %lld\n", total_events);
109}
110
111int main(int ac, char **argv)
112{
113	char filename[256];
114	int i;
115
116	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
117
118	if (load_bpf_file(filename)) {
119		printf("%s", bpf_log_buf);
120		return 1;
121	}
122
123	for (i = 1; i < ac; i++) {
124		if (strcmp(argv[i], "-a") == 0) {
125			full_range = true;
126		} else if (strcmp(argv[i], "-t") == 0) {
127			text_only = true;
128		} else if (strcmp(argv[i], "-h") == 0) {
129			printf("Usage:\n"
130			       "  -a display wider latency range\n"
131			       "  -t text only\n");
132			return 1;
133		}
134	}
135
136	printf("  heatmap of IO latency\n");
137	if (text_only)
138		printf("  %s", sym[num_colors - 1]);
139	else
140		printf("  %s %s", color[num_colors - 1], nocolor);
141	printf(" - many events with this latency\n");
142
143	if (text_only)
144		printf("  %s", sym[0]);
145	else
146		printf("  %s %s", color[0], nocolor);
147	printf(" - few events\n");
148
149	for (i = 0; ; i++) {
150		if (i % 20 == 0)
151			print_banner();
152		print_hist(map_fd[1]);
153		sleep(2);
154	}
155
156	return 0;
157}