1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
  3 */
  4#include <stdio.h>
  5#include <stdlib.h>
  6#include <signal.h>
  7#include <unistd.h>
  8#include <stdbool.h>
  9#include <string.h>
 10#include <linux/bpf.h>
 11#include <sys/resource.h>
 12
 13#include <bpf/bpf.h>
 14#include "bpf_load.h"
 15#include "bpf_util.h"
 16
 17#define SLOTS 100
 18
 19static void clear_stats(int fd)
 20{
 21	unsigned int nr_cpus = bpf_num_possible_cpus();
 22	__u64 values[nr_cpus];
 23	__u32 key;
 24
 25	memset(values, 0, sizeof(values));
 26	for (key = 0; key < SLOTS; key++)
 27		bpf_map_update_elem(fd, &key, values, BPF_ANY);
 28}
 29
 30const char *color[] = {
 31	"\033[48;5;255m",
 32	"\033[48;5;252m",
 33	"\033[48;5;250m",
 34	"\033[48;5;248m",
 35	"\033[48;5;246m",
 36	"\033[48;5;244m",
 37	"\033[48;5;242m",
 38	"\033[48;5;240m",
 39	"\033[48;5;238m",
 40	"\033[48;5;236m",
 41	"\033[48;5;234m",
 42	"\033[48;5;232m",
 43};
 44const int num_colors = ARRAY_SIZE(color);
 45
 46const char nocolor[] = "\033[00m";
 47
 48const char *sym[] = {
 49	" ",
 50	" ",
 51	".",
 52	".",
 53	"*",
 54	"*",
 55	"o",
 56	"o",
 57	"O",
 58	"O",
 59	"#",
 60	"#",
 61};
 62
 63bool full_range = false;
 64bool text_only = false;
 65
 66static void print_banner(void)
 67{
 68	if (full_range)
 69		printf("|1ns     |10ns     |100ns    |1us      |10us     |100us"
 70		       "    |1ms      |10ms     |100ms    |1s       |10s\n");
 71	else
 72		printf("|1us      |10us     |100us    |1ms      |10ms     "
 73		       "|100ms    |1s       |10s\n");
 74}
 75
 76static void print_hist(int fd)
 77{
 78	unsigned int nr_cpus = bpf_num_possible_cpus();
 79	__u64 total_events = 0;
 80	long values[nr_cpus];
 81	__u64 max_cnt = 0;
 82	__u64 cnt[SLOTS];
 83	__u64 value;
 84	__u32 key;
 85	int i;
 86
 87	for (key = 0; key < SLOTS; key++) {
 88		bpf_map_lookup_elem(fd, &key, values);
 89		value = 0;
 90		for (i = 0; i < nr_cpus; i++)
 91			value += values[i];
 92		cnt[key] = value;
 93		total_events += value;
 94		if (value > max_cnt)
 95			max_cnt = value;
 96	}
 97	clear_stats(fd);
 98	for (key = full_range ? 0 : 29; key < SLOTS; key++) {
 99		int c = num_colors * cnt[key] / (max_cnt + 1);
100
101		if (text_only)
102			printf("%s", sym[c]);
103		else
104			printf("%s %s", color[c], nocolor);
105	}
106	printf(" # %lld\n", total_events);
107}
108
109int main(int ac, char **argv)
110{
111	struct rlimit r = {1024*1024, RLIM_INFINITY};
112	char filename[256];
113	int i;
114
115	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
116
117	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
118		perror("setrlimit(RLIMIT_MEMLOCK)");
119		return 1;
120	}
121
122	if (load_bpf_file(filename)) {
123		printf("%s", bpf_log_buf);
124		return 1;
125	}
126
127	for (i = 1; i < ac; i++) {
128		if (strcmp(argv[i], "-a") == 0) {
129			full_range = true;
130		} else if (strcmp(argv[i], "-t") == 0) {
131			text_only = true;
132		} else if (strcmp(argv[i], "-h") == 0) {
133			printf("Usage:\n"
134			       "  -a display wider latency range\n"
135			       "  -t text only\n");
136			return 1;
137		}
138	}
139
140	printf("  heatmap of IO latency\n");
141	if (text_only)
142		printf("  %s", sym[num_colors - 1]);
143	else
144		printf("  %s %s", color[num_colors - 1], nocolor);
145	printf(" - many events with this latency\n");
146
147	if (text_only)
148		printf("  %s", sym[0]);
149	else
150		printf("  %s %s", color[0], nocolor);
151	printf(" - few events\n");
152
153	for (i = 0; ; i++) {
154		if (i % 20 == 0)
155			print_banner();
156		print_hist(map_fd[1]);
157		sleep(2);
158	}
159
160	return 0;
161}